GoodSoundClub - Romy the Cat's Audio Site

04-29-2019

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anthony
Posts 338
Joined on 08-18-2014

Post #:	26
Post ID:	25397
Reply to:	25396

So playful

I cannot find the Gorenstein version of Gogol Suite in Australia but it is available on Discogs and Amazon overseas for extortion prices. Streamed it from Youtube, not Gorenstien, but someone else, and it really made me smile. Listened to another version on Tidal, but not as playful a performance. I do like it.

ABC Classic FM is pretty good. I have it on the radio in my ute all the time and have picked up some gems over the years. Mind you it is the only classical music station on our airwaves, at least where I live, so I have nothing to compare.

As a general rule my digital sound quality list is as follows, from worst SQ to best: Internet streaming via Youtube >> Internet streaming via Tidal >> playback from local computer files via XXHE, whether they are downloaded from Tidal or ripped from CD.

To my way of thinking apart from Youtube MP3's, the difference in sound between internet streaming from Tidal and playback of those very same downloaded files is computer hardware, and how it is managed. XXHE does this management brilliantly.

Mastering to me is a whole other thing. I am getting back into vinyl because it gives me access to different mastering. So much of the music that I listen to is compressed rubbish but I still manage to adore it no matter how much I wish the compressor stayed out of the production.

Yes, I certainly do practice delta listening, at least from time to time. It is useful in particular circumstances where I am trying to figure out if I should sell my dac for another one (haha) but unless one has an eye for the "whole picture" delta listening can be detrimental. A good example of this is the Killerdac that I mentioned earlier in this thread. It is so, so good at what the owners listened to that I was envious, but when it tried to play my kind of music it fell in a pile...it was not even good. The dac had been infinitely tuned and tweaked selecting this tiny length of "god" wire here, this particular $$$ capacitor there, this particular resistor there et cetera and perhaps the tweaker only listened to the same narrow music selection (I don't know if this is true, it is just a guess) the dac was a fail with complex music. Anything that does not sound good on the Killerdac is said by the group to be poorly mastered or compressed. Well, I don't know. Maybe they are right. The implication of that thinking is that when playback attains a "certain level" you can only stand to play be best recordings? I don't buy it. And I don't want that. Well I do want to get to that "certain level" but in doing so I do not want the poorer quality recordings to sound more like festering turds than they do on a lesser playback, because I like a lot of poorly produced music. If they sound ordinary that is fine, but not worse, surely.

So, apart from the delta listening, I also practice long-term listening where I let things sit and not think about them. I get to play whatever music my mood determines for a week or a month. Sometimes there are certain things about a change that I enjoy at first but it has some detrimental side-effect that I did not notice at first. Digital is like that, at least to me. Mood is such an influence on my musical enjoyment: I hear things differently if stressed or happy or introspective or busy or if I expect something to help or am ambivalent about a change. Long-term listening evens out those mood peaks and troughs and lets me figure out what it is that satisfies me.

Romy the Cat wrote:
Does it make the component B “better”? Not necessary and it take some time to understand it within yourself. You need to work with yourself, your undersetting of the work, learning about the performer and circumstances of the play, the recording techniques, listen many other interpretations, listen your own objectives and interests…. then the answer of “interpretation properness” will come to you. A component that “helps” you and that create less ambiguity of your own confusions should be recognized as better. A component that will push you for more polar or radical interpretations should be recognized as better but it has to be viewed in context of other this as well. A component that pushes you listening preferences away from bad music or weak interpretations should be recognized as better.

I am on-board with this style of thinking, but am not "there" yet. Here is an example of "learning the performer and circumstances of play" and "interpretation properness" and "more polar or radical interpretations". I have had a musical crush on Beth Gibbons since I was young and she was the lead for trip-hop duo Portishead. Her solo album is still played regularly. For this work she learned to sing the Polish lyrics to Gorecki 3 and absolutely nailed it I think. Certainly not a traditional interpretation or performance but she is the queen of mourning and loss and does it as only she can. I love it...you may disagree.

Here is the Tidal link...for a better quality version.

...or the second act on Youtube

https://youtu.be/zrYxBNziy24

04-30-2019

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anthony
Posts 338
Joined on 08-18-2014

Post #:	28
Post ID:	25399
Reply to:	25398

I finally measured the dac output

...and it is a neat 1.5VRMS with zero attenuation. So with my -6dB it puts out 0.75VRMS, so not quite as bad as I thought. I will have to do some listening to try and determine whether -6dB is needed or if I can get away with less attenuation (zero would be ideal).

Last night I did the maths on the LCR phono that I intend to build and it should have 0.9V output with a balanced SUT or 1.8V output with a singled ended SUT, which equates to 73db-79dB total gain. Again, I wish there was more output but it is what it is. The balanced input is roughly the same as my attenuated dac.

Also, I've contacted Guy Hammel about a Placette line amplifier so I will see were that goes. I do not want another box so it is going to have to fit into the current linestage box if I decide to go that way. This afternoon I will order a bit more stuff to finish my diy SS pre with gain and try to get it finished as quickly as I can so that I can measure just how much voltage input I need for the DSETs in my room.

05-10-2019

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anthony
Posts 338
Joined on 08-18-2014

Post #:	30
Post ID:	25404
Reply to:	25399

The Placette has died

Well, probably not up in smoke, but it is just not functional any more. I was away for a few days and came back to my room to find the Placette refusing to change volume or select a source input, so something is amiss. Perhaps something has been amiss for some time which may explain why I have not found it as transparent as Romy and others.

There is no time at the moment to look under the hood for the fault. I've been listening to my dac directly connected to the DSET and it is so nice...but not loud. The amps are getting the full 1.5V output but it is not loud enough, of course.

On another point, I have been reading a little about pre-amplification and current output and output impedance. Up to this point I had not realised that the ability of a preamp to drive capacitive loads has almost nothing to do with low output impedance, but is all to do about current output. A beast such as the DSET with 6 x triodes and a few inductors and capacitors at the input is likely to be a mighty capacitive load. This needs to be measured. If one stage cannot sink enough current into the next (i.e. the current clips) higher frequencies will roll off. The limiting factors are input capacitance of the DSET, desired frequency response, preamp voltage output and desired headroom.

DSET Input Capacitance: to be measured
Desired Frequency response: The RAAL ribbons are good to 50kHz or so I think, so I choose that
Preamp voltage output: 4VRMS to drive DSET to clipping
Desired Headroom: x10 (20dB)

So, I have to measure the input capacitance of my DSET and then do some math to figure out how much current my preamp needs to produce in order to satisfy the load.

05-11-2019

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Romy the Cat

Boston, MA
Posts 10,156
Joined on 05-28-2004

Post #:	31
Post ID:	25405
Reply to:	25404

Not necessarily...

anthony wrote:
Well, probably not up in smoke, but it is just not functional any more. I was away for a few days and came back to my room to find the Placette refusing to change volume or select a source input, so something is amiss. Perhaps something has been amiss for some time which may explain why I have not found it as transparent as Romy and others.

Ok, your Placette did not die. This is “normal” for Placette, I wish it did not have it but it does. The way how Placette is made it need to be plug in all time. If you unplug the Placette for prolog period of time then it need a few days to be powered to have the remote control functionality start operating again, the manual controls still should be working, if you have them. So, let it run for a day or two and your Placette’s control will be back. Another very important thing. The Placette is powered by main 120V power that drive output stage and by flimsy computer-grade low voltage adapter, connected separately. Why Placette was made this way is beyond me but it is what it is. The voltage adapter should be not in operation after the volume was changed so, it should not be a factor in quality. However, over the years I have seen that the low voltage adapter get weaker and impact the remote control functionality. Also, the type of the low voltage adapter I used did have very profound impact to sound, which absolutely makes no sense. I had 4 or 5 of them over the year and the difference was very noticeable. Again there is no explanation for it but it is what it is. Ask Guy to send you a new power adapter, it costs like $20-$30, and you might find that it worth it.

anthony wrote:
On another point, I have been reading a little about pre-amplification and current output and output impedance. Up to this point I had not realised that the ability of a preamp to drive capacitive loads has almost nothing to do with low output impedance, but is all to do about current output. A beast such as the DSET with 6 x triodes and a few inductors and capacitors at the input is likely to be a mighty capacitive load. This needs to be measured. If one stage cannot sink enough current into the next (i.e. the current clips) higher frequencies will roll off. The limiting factors are input capacitance of the DSET, desired frequency response, preamp voltage output and desired headroom.

Yes, it is factor but it is also not. There are very few topologies that can give out a very low, let say sub 10R output. Mostly we are taking about SS DC coupled topologies… It happened that in the realm of a few oHms output any devise will drive a capacitive load.

PS: I need to say that the subject of you post “The Placette has died” make me to cringe. I imagine if my Placette dies then why the hell I would be doing!? In my experience it is VERY hard to find sub 10R pream with proper sound and if my Placette died it would be a disaster for my system

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

05-13-2019

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anthony
Posts 338
Joined on 08-18-2014

Post #:	32
Post ID:	25412
Reply to:	25405

The damn wall wart

Romy the Cat wrote:
However, over the years I have seen that the low voltage adapter get weaker and impact the remote control functionality. Also, the type of the low voltage adapter I used did have very profound impact to sound, which absolutely makes no sense. I had 4 or 5 of them over the year and the difference was very noticeable. Again there is no explanation for it but it is what it is. Ask Guy to send you a new power adapter, it costs like $20-$30, and you might find that it worth it.

Interesting. Yes, the remote has been suffering from reduced functionality but the batteries still measured 1.5V each so I put them back in. The wall wart getting weaker might be the problem. Since it has arrived, I've run the Placette from a step down transformer feeding it about 120V instead of the normal 240V in Aus. To achieve this both the power cord and the wall wart for the Placette are plugged into the variac, which I had forgotten about until I turned it off the other day. The wall wart power is used only to change the relays and should be plugged into a different, general household, power circuit to the power cord for the linestage circuits, and of course I have never done this because I have only one variac to step down to 120V. The long-term intention was always to change-out the transformers and wall wart to suit 240V mains so I can plug things directly into the wall, but it has never happened.

I must say that with the Placette turned off the Phasure dac direct driving the DSET has never sounded so good. Perhaps my Placette transperancy issue is caused by the wall wart injecting noise into my audio mains circuit when it should be injecting it into a different circuit. Perhaps it is the variac causing the issue, or even the Placette itself as I originally thought.

First thing to do is make good on converting that wall wart to 240V so it can be plugged into a different circuit. Output according to the label is 5V 1A, and I have some linear power supplies already made for a different (abandoned) project that will handle that easily. So when I get some time I will re-purpose one of them and experiment further with the Placette.

Romy, thanks for your input here, I had put looking at it in the "let's do that later" basket which probably means quite some time down the track. I would be interested to hear roughly how the different power supplies have changed the sound, and if you plug the wall wart into a separate non-audio circuit or if it goes into your PP3000.

05-13-2019

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Romy the Cat

Boston, MA
Posts 10,156
Joined on 05-28-2004

Post #:	33
Post ID:	25415
Reply to:	25412

My experience might be limited but....

Come on, Anthony, you need to “clean your room” as Peterson say before you move forward. Variac is notoriously bad for sound, at least 3 types that I tried were horrible. I do not see why Placette cannot run from 220V, confirm it with Guy. Both line stage circuits AND the adopter that powers the switches circuit MUST be plug into good quality of power source. The adopter that powers the switches in my view much be replaced each 3-4 years and they get weaker for some reasons. Each time I updated my adopter I got better sound, do not ask me why as they should be affecting sound at all. Be advised that I still at suspicion of what you do as I personally do not feel that your DAC can stress Placette into being not transparent. I owned some nice gear and I NEVER was able to recognize Placette as being less transparent element in chain. I do not insist that I am right and I understand that I should not never say never but from what I have done personally I feel that Placette is quite unique in term of bypassing performance.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-03-2020

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anthony
Posts 338
Joined on 08-18-2014

Post #:	35
Post ID:	25901
Reply to:	25420

DHT Preamp update

So, it has been a while. I have DSET/Macondo in stereo now although there is still some work to do to finish it and tune it to the room. As discussed earlier in this thread I need a preamp with gain and the Placette is just not cutting it for me (no gain). There are three sources for which gain is needed: 2 x phono stages; and dac.

Over the weekend I prototyped a 10Y/801a/VT25/VT62 preamplifier just on a lump of MDF. It uses one of Ale Bartolas Hybrid Mu-Follower boards, a regulated B+ power supply and a locally designed CCS for the DHT filaments and Slagle Autoformers at the output for volume control. The build was relatively simple and trouble free, and when finished it had something like 0.003mVDC on the outputs but a little (3mVAC) AC pickup up through the autoformers (they will require better separation or shielding). Plugged into the DSETs the preamp is silent...no noise.

Output impedance is about 30R before the autoformer, gain is x8, but the autoformer reduces the output impedance logarithmically with attenuation so in normal or even loud use case is going to be 1R or below. 20mA plate current.

Listening to it tonight for the first time I am really hopeful that this is a good solution. Still the honeymoon period but it seems to have hit quite close to the design brief in terms of loudness and sound quality when driving the DSETs. No signs of lag or loss of detail or softening of the sound or overt warmth. I have three SS gainstages here that also get the volume, and this DHT preamp seems to be everything my favourite is and more, at least on the phonostage I listened to tonight.
All dressed up.jpg

08-05-2020

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Romy the Cat

Boston, MA
Posts 10,156
Joined on 05-28-2004

Post #:	36
Post ID:	25902
Reply to:	25901

Very interesting, how does it Sound?

Hm you are true in the “terra incognita” territory as far as I concern. The preamps are mystery to me. All my attempts to make any decently sounding preamp or even buffer failed. To me Placette was truly God sent and if I got burned that I am looking with fear what will I do.

The idea to make a tube-based preamp is noble one and 10Y is a very good tube. The 30R before the autoformer is good and if you are able to drive it lover with autoformer them it is wonderful, even I am not so comfortable with the ideas of autoformers. The changing preamp output impedance is very bad for the Milquades as each preamp output impedance will change the setting of the input filters. However, if your impedance slides under a few Ohms then it might have no auditable impact at all. You can calculate how your moving output impedance impacts your amp filters. I do not care about the fact that it moves a few Hz up or down. I am care about phase. If you time aligned two channels and move volume of your preamp, then will the changing the preamp output impedance result the channels juts out of alignment? They certainly will BUT the it is possible since the impedance number are so low the timing error will be very much within the margin of errors of your time alignment.

I do not have the answer if the changing of the Rout would be prohibitive in this situation. What I would like you to consider is that in 10 years you will find your DPoLS and then you might realize that your playback can maintain the DPoLS only with let sat 30% of your volume and then the phase micro-shifts kick the system out of DPoLS. I do not mean to “scare” you, juts present you an architectural concept.

Romy the Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-05-2020

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Paul S
San Diego, California, USA
Posts 2,657
Joined on 10-12-2006

Post #:	37
Post ID:	25903
Reply to:	25902

Active vs. Passive Placette?

Anthony, congrats on your amazing progress! I know how hard it is to carve out time for this stuff! I see you are looking for gain from your pre-amp, which makes me wonder if you have been using the passive Placette, as opposed to the active unit, which I understood has +6 dB, not to mention a VERY low, locked output impedance. What I am getting from Romy is that a constant, very low output impedance from the pre-amp is as critical for driving your Milqs properly as the input voltage. Not to steer you toward greater expense, but it would be a shame to put out all the time and effort building a pre-amp only to wind up with a reactive situation, where your channels' crossovers are in constant flux. With all the complexity of the greater circuit here, it would be nice to start with pre-amp output locked down. But perhaps you've already considered this fully with the design you're working on?

Best regards,
Paul S

08-05-2020

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anthony
Posts 338
Joined on 08-18-2014

Post #:	38
Post ID:	25905
Reply to:	25902

Nice

Romy the Cat wrote:
Hm you are true in the “terra incognita” territory as far as I concern. The preamps are mystery to me. All my attempts to make any decently sounding preamp or even buffer failed. To me Placette was truly God sent and if I got burned that I am looking with fear what will I do.

Early days of course, but at the moment the 10y preamp sounds nice. I do like it. There may be ways to wring more performance from it and I am mulling over several alternative options for loading the tube. No doubt those DHT's do enable something nice with the sound, that hint of extra dynamics not really heard elsewhere.

Romy the Cat wrote:
The idea to make a tube-based preamp is noble one and 10Y is a very good tube. The 30R before the autoformer is good and if you are able to drive it lover with autoformer them it is wonderful, even I am not so comfortable with the ideas of autoformers. The changing preamp output impedance is very bad for the Milquades as each preamp output impedance will change the setting of the input filters. However, if your impedance slides under a few Ohms then it might have no auditable impact at all. You can calculate how your moving output impedance impacts your amp filters. I do not care about the fact that it moves a few Hz up or down. I am care about phase. If you time aligned two channels and move volume of your preamp, then will the changing the preamp output impedance result the channels juts out of alignment? They certainly will BUT the it is possible since the impedance number are so low the timing error will be very much within the margin of errors of your time alignment.

I do not have the answer if the changing of the Rout would be prohibitive in this situation. What I would like you to consider is that in 10 years you will find your DPoLS and then you might realize that your playback can maintain the DPoLS only with let sat 30% of your volume and then the phase micro-shifts kick the system out of DPoLS. I do not mean to “scare” you, juts present you an architectural concept.

Romy the Cat

I am not sure how phase changes depending on the activated winding of the autoformer, unless you are saying that the preamp Zout will possibly change the DSET filter phase somehow?

Below is an old DSET input impedance measurement. I bumped the 10kHz Channel F filter aircaps upon reassembly and did not bother to reset them (better to get the amp into the room) so above 10kHz may not be indicative. The green phase and yellow impedance lines deviate near each of the crossover frequencies but phase is pretty much well controlled until the highest octave or two, near the bad filter. This measurement needs re-doing.

DSET Input Impedance 2V Pink Noise FFTsmaller.jpg

DSET Input Impedance 2V Pink Noise FFTsmaller.jpg

With the autoformer at the output of the preamp, impedance will vary from 30R to 1R in my normal listening volume range. Of course I can swap it to the preamplifier input and have 30R full-time regardless of attenuation.

08-05-2020

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anthony
Posts 338
Joined on 08-18-2014

Post #:	39
Post ID:	25906
Reply to:	25903

Active for sure

Paul S wrote:
Anthony, congrats on your amazing progress! I know how hard it is to carve out time for this stuff! I see you are looking for gain from your pre-amp, which makes me wonder if you have been using the passive Placette, as opposed to the active unit, which I understood has +6 dB, not to mention a VERY low, locked output impedance. What I am getting from Romy is that a constant, very low output impedance from the pre-amp is as critical for driving your Milqs properly as the input voltage. Not to steer you toward greater expense, but it would be a shame to put out all the time and effort building a pre-amp only to wind up with a reactive situation, where your channels' crossovers are in constant flux. With all the complexity of the greater circuit here, it would be nice to start with pre-amp output locked down. But perhaps you've already considered this fully with the design you're working on?

Best regards,
Paul S

Hi Paul,

Yes, I definitely have the Active Placette linestage, but it is unity gain only. I have talked to Guy about sending it over to him to add a bit of gain but have not progressed on that front. Freight over the Pacific and back will be significant, especially these days, and I am not 100% convinced it is the best option for me. It may be the best option in the end but I would like to try to sort out my own preamp incarnation to see what I can achieve. There are several features that I would like to build into my diy pre that are not available on the Placette: HT bypass, switch between SS and DHT gain/line stages, networking options etc. It will be the hub of my system.

Anthony

08-07-2020

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Romy the Cat

Boston, MA
Posts 10,156
Joined on 05-28-2004

Post #:	40
Post ID:	25907
Reply to:	25905

Of cause but I do not know if it maters.

*** … unless you are saying that the preamp Zout will possibly change the DSET filter phase somehow?

Yep, this is exactly what I am saying. Look the impedance of your preamp is factored in the source impedance of your channel’s filter. The argument you can make is that your channel is approximately 5kR each and your Zout is let say 20R. it very much might be negligible, but it might be not. You might see if the frequency crossover point change if you short the amp inputs vs load it with let say 50R. It might not have any practical meaning but on theoretical level the crossover point will certainly move, so will be the phase shift. What I would do is to listen a recording with very complex multi-layers imaging and see if the imaging will “curve” with the change of the preamp volume.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-07-2020

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anthony
Posts 338
Joined on 08-18-2014

Post #:	41
Post ID:	25908
Reply to:	25907

Listening to the 10y

Last night and this morning I have been comparing my favourite SS preamp with gain and the breadboarded 10y. I've been using my dac with its low 1.125Vrms voltage output as the source because I know what it is capable of and know its (lack of) sound well. Early on in my Macondo/Melquiades journey I measured listening SPLs and was surprised how much louder things were with the loudspeakers that sidestep sounding compressed. This listening had peaks circa 105dBa with crescendos sitting a consistent 100dBa+ at the listening chair. This is 10dB louder than with previous speakers. Calms were still registering 70dBa.

The 10y plays in another league. Imaging and layering were almost like comparing a finger painting to a Monet. Both were good, but the 10y brings such clarity to Macondo, separation between notes, guitar strings almost rendered individually with their own attack/ sustain/ decay. Sound was neither darker nor brighter, just more clear, revealing, rich.

Plus there is loads of gain. Even at those listening levels with my quietest source attenuation was 10dB. This equates to a Zout of 12r. At the lower end of my listening windowwith 20dB attenuation Zout is about 1r. I should measure this to confirm, but both those numbers are lower than the Placette.

Speaking of the Placette, I will have to pull it out of the cupboard to compare it to the 10y with matched volumes. I also have another SS pre just arrived with has been measurebated into existence with measured spec's difficult to confirm with the best measuring equipment getting about.

Also, I plan to reconfigure things a little and put YO186 into the preamp. It will be interesting to hear.

08-08-2020

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rowuk

Germany
Posts 454
Joined on 07-05-2012

Post #:	42
Post ID:	25909
Reply to:	25908

Congratulations on your next step!

I am always a bit hesitant to buy into "listening descriptions". I am a musician and am confronted every day with Sound bias - attraction to what we are accustomed to, expectations being confirmed. We are creatures of habit and modifying old habits is a very big deal.
As long as what we are comparing are in a similar league, we need weeks if not months to really sort out what is happening. Certainly there is no measureable parameter for "neutral color". There has to be a reason for the 10Y being in another league. The rest of your equipment is too good for that to happen - unless the 10Y is adding something special.
I am very happy that the breadboarded preamp is fulfilling your dreams. Your project has been in a state of "wanting to get done" for a long time. I can imagine the joy of being this far. Gain cannot be underestimated. With a very high quality source material, I find a need for a "plausible" playback volume. If we can't quite get there, we know that we are missing something.
I will be following this closely to see how it unfolds. Have a great weekend!

Whenever I feel blue, I start breathing again.

08-08-2020

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Romy the Cat

Boston, MA
Posts 10,156
Joined on 05-28-2004

Post #:	43
Post ID:	25910
Reply to:	25908

My view of the situation.

Anthony, I am afraid I do not agree with your assessment of the situation. Let look at what is going on together.

The 10Y preamp is not another league but juts a proper architectural solution for your system configuration. You have a power amp with very complex input, and you need a very current-able preamp to push it through. Most of the preamps are either not powerful enough or juts sonically not good. I have the same power amp and I very much know how it sound what I dive it from frond end. Note that I have more or less powerful front-ends that can push some current, not at the level of a good preamp of cause. When I use to do it, I used between the front-ends and Milq my T-bridge attenuators that maintain constant load impedance but variable output impedance. I do not like how my playback sound with it because with each volume setting it sound very different. Also, it sounds different from source to source. A good preamp stabilizes all of it and a good preamp should make it to sound better, pretty much along the lines that you describe. So, I feel your reaction is just a presents of a good preamp vs driving you playback directly from front ends. At least it is my version of interpreting what you say.

Now, about your 10Y preamp specifically. I am not familiar with the sound of that configuration + you have the autoformer in play. However, I know that all elements at the top of their class performance sound identical: what we note are not the benefits of an element of the chain but the discrepancies the element creates. Your 10Y preamp might be a good and transparent component that rectify the disability of you front end to drive Milq. This is very easy to test. Take an ordinary conventional loudspeaker with an ordinary conventional power amp and drive it from your frond end and from 10Y. You will not see the “another league” situation. The 10Y will be most likely much better but it would be in different way than what you described in case 10Y drives Milq.

I would be very interesting to see your 10Y vs Placette evaluation at the same volume level (this is very critical). I am still a bit skeptical that you have properly functioning Placette as your description of it performance is very much different with what I experience. In my view an active Placette (the older version) operates very much atop of what is possible with preamps. If 10Y is a good pream then it should be very close to what Placette does. It should be different but very close and should not be “another league”. I might be wrong of cause…

About the YO186 in the 10Y preamp. Most likely you will have better and softer bass, in my language “softer bass” is a positive thing. I do not think that YO186 will be able to beat 10Y. It would be very interesting battle but do not forget that 10Y and YO186 have own character of how they react to operation points, power supplies, type of bias and zillion other things. Good lack to spend next year of your life to investigate all of it, I mean nothing negative, I just mean that it all takes time to discover methodologically honestly.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-09-2020

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anthony
Posts 338
Joined on 08-18-2014

Post #:	44
Post ID:	25911
Reply to:	25909

Me too...

rowuk wrote:
I am always a bit hesitant to buy into "listening descriptions". I am a musician and am confronted every day with Sound bias - attraction to what we are accustomed to, expectations being confirmed. We are creatures of habit and modifying old habits is a very big deal.

Me too. I have attempted to "reset" my expectations in regards to this preamp several times now. Truth is that I was not expecting it to be so successful so early.

Today has been a day away from audio on the farm. Two hours drive each way and a whole day chasing cattle has been invaluable time to think about the situation. I have been trying to think of ways in which the sound was deficient yesterday with the 10y in play. You see I had some friends visit yesterday afternoon, and my family were away last night so we spent a lot of time listening to music and talking about it and catching up with a few beers and single malts. It was a wonderful night and the sound was magnificent.

The breadboarded amp is not perfectly laid out, some of the wire loops near the tube are too large, power transformers could be a little too close together, nothing is shielded, the B+ power supply is not my ideal choice being regulated but was selected because it was very easy to adjust the output voltage and has very low noise and output impedance, I've not experimented with any capacitors, haven't even matched the 10y pair in use. There are probably a number of other things wrong with the setup. You see, this was the first step...sounding to see if something good could come of the venture...but it has already achieved more than I expected.

One of the things that I wonder is whether I would be so enthused about it in a different system than DSET\Macondo? Kind of a moot point really, because that is the sole purpose of this preamp with special considerations to make it especially suitable, but really, would it work so well elsewhere? At one stage we wanted some music from Tidal and streamed it on another lesser dac, it was quite disappointing, so I think the situation may be less the 10y adding some kind of special sauce but simply the 10y competently driving the DSET and allowing my best dac to shine.

Romy the Cat wrote:
The 10Y preamp is not another league but juts a proper architectural solution for your system configuration.

^^^ this. After yesterday and last night I am more likely to concur. The 10y might add a little special sauce, but in this situation it may not prove to be much at all, and if it does then it is working for me at the moment.

My understanding of the Bartola hybrid mu-follower boards is that the DHT does the amplification, a SS mu-follower provides an almost ideal anode load, and that the output is pseudo push-pull from the mu-out of the SS mu-follower with output impedance set by the chip in the said follower. The mu-follower has quite a high PSRR and I am currently using what sounds like quite a competent B+ regulated supply with a lower output impedance than is likely to be possible with tube rectifiers or non-regulated supplies. The system sounds like it has boundless energy when required and good resolution all the way from the lowest bass notes up past the midrange.

At the moment it all sounds so 'right'...no obvious deficiencies or inadequacies...and that may be because I am still in the honeymoon period and have been caught a little by surprise at how much more enjoyable the music has suddenly become. Time is required to properly understand what I am hearing and apart from trying a few more simple things as discussed earlier in the thread, am considering boxing up the preamp and perhaps returning to it once Macondo is complete and tuned into the room, and once I am able to digest where and how I would like things to improve.

Romy the Cat wrote:

About the YO186 in the 10Y preamp. Most likely you will have better and softer bass, in my language “softer bass” is a positive thing. I do not think that YO186 will be able to beat 10Y. It would be very interesting battle but do not forget that 10Y and YO186 have own character of how they react to operation points, power supplies, type of bias and zillion other things. Good lack to spend next year of your life to investigate all of it, I mean nothing negative, I just mean that it all takes time to discover methodologically honestly.

Bass is deliciously soft at the moment with the 10Y, particularly at night when the power is better. Still though, the YO186 will be an interesting test.

08-10-2020

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anthony
Posts 338
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Post #:	45
Post ID:	25912
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Transparency

anthony wrote:
I also have another SS pre just arrived with has been measurebated into existence with measured spec's difficult to confirm with the best measuring equipment getting about.

I've been listening to the new buffer with imd/thd/snr/blah blah blah all claimed to be state of the art. Huge PSRR and CMRR, gain up to 20dB, super low output impedance, able to source 50mA or thereabouts, and able to drive quite a capacitive and low input impedance load (300r claimed). The buffer has been configured for 12dB gain and plugged directly between my favourite dac and the DSET's...no analog volume control nor input selector in use.

It sounds nice...better than the previous SS preamp I have been using. Imaging is clearer, sound is neither lighter nor darker and the buffer is more enjoyable to listen with than the previous SS pre. More clarity, more definition. Volume matched with the 10y though, even with its input selector and analogue volume control vs a cleaner signal path with the buffer, the DHT is more moist, more three dimensional with its imaging, more flesh on things such as vocals, strings and noticeably the left hand of the piano. More emotive. The valves still seem to draw a more detailed, higher resolution picture but the gap is no longer an order of magnitude as it was before with the previous SS pre.

Perhaps, with a lesser source or lesser speakers, some people may prefer the buffer to the DHT pre because it does paint a less detailed picture, maybe a smoother picture in some circumstances with less capable loudspeakers, but Macondo is able to deliver the clarity and detail at significant listening volumes and with the buffer I feel as though I am missing out on a little bit of something the 10y is able to provide. Based on the excellent measurements and drive capabilities of the buffer, you could make the assumption that either the 10y is better at driving DSET or it would appear that the 10y is adding something not entirely inaudible, which is not unexpected. If it is adding something, it is not adding much but it is engaging and I like it right now.

To date, I've only listened with my favourite dac. The Phasure NOS1a/10y partnership is something I am enjoying. Perhaps at a later date I will not be loving the DHT pre with some other source/s and it would be nice to include something like this buffer into the preamp and be able to switch between SS and DHT gain stages. Something to think about.

08-11-2020

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Romy the Cat

Boston, MA
Posts 10,156
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An important note

Anthony, I do not know what you new buffer is. A few notes. The difference between sub 10R and 300R of output impedance is significant for the load you have (Milq) between your new buffer and your 10Y preamp. The type of the description you provided, however, is not something he I feel might be attributed to impedance difference.

Now the important note. Beside the acknowledgment of the sonic differences (which is semi-important) you might look at the overall musical capacity. When you get a grip of the overall musical capacity then the cataloging and recognizing the sonic differences begin to have slightly different twist for you as you have a context under which the sonic differences are observed. The “imaging is clearer”. What is it mean? I do not mean to be cynical at all. It is a legitimate question. How much imaging clarity we need and how much other problems we will tolerate to have “imaging clearer”? We certainly do not have “imaging” during our live events. Just think about it. I know, it is an annoying part of me and my wife goes crazy whan she tells me that she loves me and I ask her “what does it mean?”

Ok, let me give you a tip in this direction. I would make a statement that many people would not understand but trust me, I know what I am taking about. Imaging is super important byproduct of playback as it is a very objectively depicts timing of everything. The ultimate objective in playback is however is not to get best imaging but take it to next step: to make system to present music with no imaging at all. According to my experience it happens only in DPoLS configuration. The DPoLS playback also has imaging but it has absolutely nothing to do with imagine that a playback has outside of DPoLS. Saying that, do I feel that we need to have “imaging clearer” outside of DPoLS? Yes, we do. We, however, always should ask ourselves what does it mean in connect of a larger picture.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-11-2020

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anthony
Posts 338
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Post #:	47
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Clarification

Romy the Cat wrote:
Anthony, I do not know what you new buffer is. A few notes. The difference between sub 10R and 300R of output impedance is significant for the load you have (Milq) between your new buffer and your 10Y preamp. The type of the description you provided, however, is not something he I feel might be attributed to impedance difference.

Nice pick Romy. The output impedance of the buffer is < 0.1R. One of the chips it uses is spec'd for 600r loads and it will drive 300r satidfactorily...apparently.

Romy the Cat wrote:
Now the important note. Beside the acknowledgment of the sonic differences (which is semi-important) you might look at the overall musical capacity. When you get a grip of the overall musical capacity then the cataloging and recognizing the sonic differences begin to have slightly different twist for you as you have a context under which the sonic differences are observed. The “imaging is clearer”. What is it mean? I do not mean to be cynical at all. It is a legitimate question. How much imaging clarity we need and how much other problems we will tolerate to have “imaging clearer”? We certainly do not have “imaging” during our live events. Just think about it. I know, it is an annoying part of me and my wife goes crazy whan she tells me that she loves me and I ask her “what does it mean?”

When listening to the various preamps/buffers thus far there has been a direct correlation between 'clarity' of the image and how realistic I perceive the sounds on the individual instruments to be. When in the sweet spot, Macondo throws a spectacular soundstage with images locked in place. A piano that is a little to the left of centre seems to be more coherently "put together" in the soundstage when the sounds that it is making seem more "real". It is not something that I recall noticing with other speakers. A pair of good 2-way standmounts can image wonderfully when setup correctly, but they do not image in the same way that Macondo seems to be imaging. With the point source speakers the image is there and you can move around the room and it does not really fall apart or move but with Macondo in nearfield you move far from the sweet spot and the soundstage collapses. However, the show that Macondo gives you from that sweet spot surpasses anything that I have ever experienced elsewhere, and the more "right" instruments sound the clearer they seem to image within that soundstage.

I think the 'clarity' is related to how well DSET is responding to the preamplifier. The reason I say that is that I have brought the Placette Active Linestage back into the room.

First, I rewired the Placettes dual-primary power transformers for 230v operation rather than the default 115v. Guy advised just to run a step down transformer and I had been using a variac, but now there are no compromises. Secondly, I made up a 5v linear power supply that runs the relays and volume control to replace the failed supply. Then I brought it into the room and matched the volume between it and the 10y using sine waves from a number of frequencies...I'm sure I have a pink noise file somewhere for this but it has disappeared. The 10y has 18dB of gain on paper and to match the Placette it is being run at -19dB, so pretty close.

More volume would be nice, but it is what it is. Previous experience suggests that the Placette gets better with time, so other than the initial listen immediately after matching the volumes, I will continue to listen to the Placette for a day or two to reorient myself with the sound and then compare it formally to the 10y.

Romy the Cat wrote:
Ok, let me give you a tip in this direction. I would make a statement that many people would not understand but trust me, I know what I am taking about. Imaging is super important byproduct of playback as it is a very objectively depicts timing of everything. The ultimate objective in playback is however is not to get best imaging but take it to next step: to make system to present music with no imaging at all. According to my experience it happens only in DPoLS configuration. The DPoLS playback also has imaging but it has absolutely nothing to do with imagine that a playback has outside of DPoLS. Saying that, do I feel that we need to have “imaging clearer” outside of DPoLS? Yes, we do. We, however, always should ask ourselves what does it mean in connect of a larger picture.

DPoLS sounds like such work. Yet to be experienced.

08-13-2020

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anthony
Posts 338
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Post #:	48
Post ID:	25916
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Polarity?

anthony wrote:

I have brought the Placette Active Linestage back into the room.

This comparison is proving more difficult than anticipated. Inconsistent results between subject tracks have given me some doubt on just what I have been hearing so I have had to go back to first principles in an attempt to explain it.

Often, the 10y sounds flat out better than the Placette: more resolution, better transients, more energy. However, with some other tracks the difference is not so noticeable and there is really very little separating the two preamps. It has not happened yet where the Placette is clearly preferred, but the two are occasionally quite difficult to differentiate.

Thinking about why this may be happening this morning led me to think about absolute polarity. As far as I am aware the 10y inverts phase and the Placette is non-inverting (not 100% sure). Could the preference for the 10y be coming down to using more recordings where absolute polarity should be reversed? I don't know and never before has absolute polarity been a concern of mine...but perhaps it should be.

The buffer that I previously tested was also very good and although it is able to be set to inverting or non-inverting output it had been set to non-inverting. To get more volume in-room I had also been experimenting with using this buffer to add 12dB of gain before the Placette. So at lunch I set the buffer to invert the output so it is the same polarity as the 10y preamp and have gone back to some of the recordings where the 10y was ahead.

This is a fairer fight now! Regardless of how it turns out, there will be some way to set the buffer up to be able to switch absolute polarity on the fly possibly even using the remote.

08-14-2020

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Romy the Cat

Boston, MA
Posts 10,156
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You are getting somewhere...

This is very interesting, Anthony. I do think that absolute polarity has own role to play. Also, do check the DC that might be sent out of your preamps, certainly with Placette and with your 10Y before the transformer. Chas it with disconnected Milq and positive bios will kill any DC offset from preamp. You might also try to measure the AC voltage on your Milq’s input with and without connected preamp.

Another a very valid thing to try is to see of the same difference with the same recordings happens with different DACs, preamps the you will take care of the absolute phase. You see, different DACs topology have different post DAC filters and they send different amount and different type of UHF into the upstream chain. Your 10Y is UHF limited and in a way acts as low pass filter, which is not necessarily a bad thing. Placette is wide open monster in UHF, in fact it might run a video signal with is very good for it but not necessarily good for music. I in a past observe a phenomenon that Placette was very much picky to what I used in DAC output filters. I have some CDs that if I play them with Bidat vs. Lavry Gold DACs they sound like very much different recordings and the difference is VERY different than a typical delta between Bidat vs. Lavry. If do the same experiment with a different preamp then the difference will be between the DACs but in completely different way. In most of the cases TLO-Lavry Gold with Placette has too much “resolution” and too ferocious dynamics that is superbly impressive to thrill audiophiles but not so musical and I tend do not use this combination.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

08-16-2020

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anthony
Posts 338
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Post #:	50
Post ID:	25918
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DHT's tested

Have put all my DHT's on the curve tracer to see if pairs can be matched for preamp duties.

My stash of 10y/VT25/801a/VT62 are generally all very new or NOS specs with mu and plate resistance varying a little, but generally close to nominal specifications. The VT25's in particular were very even and I have put a pair of them in the breadboarded preamp with pretty much identical specs at the operating point. The VT62's all had higher plate resistances and lower plate current than the VT25's.

The YO186 were all over the shop...which you could guess by the margins offered in the spec sheet I suppose. The glass bottle shape and size varies with the year. Dates range from 1938 to 1956. A pair of April 1956 YO186 test almost identically and likewise a pair of 1938/1956 that I am running in the DSETs. Mu varied from 3.1 to 4.1, which is quite substantial, the low mu sourcing loads of current, up to 65mA where the spec sheet says 38ma, and the high mu source about 24mA at that same point. In between the mu3.7 tubes have the correct current and plate resistance. So, two closely matched pairs that sit right on the specification sheet parameters (one pair in the DSET's, one pair to try in the preamp), a pair of low mu/high current which I am not sure are particularly useful, and two pair of high mu/low current which may also be good in the preamp...they may actually be preferable there.

The CX371a pair tested 85% and NOS, which is nice. One 45 ST was more or less dead after the abuse it suffered breathing life into two DSET amplifiers while its mate tests perfectly. The four UX245 globes that tested NOS on a TV7 and AVo MK3 show up as about 70% emmission in the eTracer. Shame...they are really beautiful tubes.

After all that, I have identified three matched pairs of YO186 to trial in the preamp and gained a better understanding of the voltage gain they are able to offer. The low current sourcing pairs are more or less the same gain as a 45 but with a lower plate resistance, not that the plate resistance matters when using a mu-follower but it does if using an output transfomer. Both the 45 and YO186 are therefore borderline candidates for the preamp because they offer 12dB of gain which would barely be enough with the mu-follower, and they are unsuitable in my situation for use with an output transformer because gain would be lost.

I will try them with a hybrid mu-follower though.