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  »  New  To Milq builders: corrections, simplification, modifica..  Talking about amp…....  Melquiades Amplifier  Forum     16  73256  05-17-2007
  »  New  6 Channel Version of Super Melquiades..  The first Milq screw up....  Melquiades Amplifier  Forum     131  861894  08-08-2007
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  »  New  Full range Melquiades implementation..  Solved...  Melquiades Amplifier  Forum     81  220963  02-23-2011
  »  New  Building Melquiades: questions and answers...  PeaceMAT XS™...  Melquiades Amplifier  Forum     96  303276  10-09-2007
07-28-2006 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,537
Joined on 05-28-2004

Post #: 26
Post ID: 2700
Reply to: 2642
Re: New Melquiades: A new run...
Eventually I fed the new Melqs with another pair of power transformers for output stage. I ended to run the 6C33C very-very moderately at 180V and 200mA or at 36W. I think it is little bit low and I could add 3-6W but I prefer to keep it for a time being. My previous version with 250V on plate had strange bandwidth. This lower voltage version it looks like more interesting. I get from it a moderate power but I have enough for 100dB of sensitively. I feed it at 2.4V and at full power it gave up 28.5V at 1khz. Here are some pictures:

1000Hz

20.000Hz

40.000Hz

100Hz

20Hz

15Hz




"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
07-28-2006 Post does not mapped to Knowledge Tree
hagtech


Hawaii
Posts 117
Joined on 02-13-2006

Post #: 27
Post ID: 2701
Reply to: 2700
Re: Scoped out
What does the input waveform look like?  I see a lot of 2nd order distortion in the output.  Also, can you show at 1W output?  And when you say 28.5V, is that rms or peak?  The scale must be uncalibrated as I can't figure out the volts/div.  If this is 2V/div then you get 5W output?  I assume you are using 8 ohm resistive load.

jh
07-28-2006 Post does not mapped to Knowledge Tree
AnonymousUser
Posts 19
Joined on 11-27-2004

Post #: 28
Post ID: 2702
Reply to: 2701
Re: Square Wave
Hi Romy,

For my benefit can you show the trace when it amplifies a 10K square wave?

rgs

Guy
07-28-2006 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,537
Joined on 05-28-2004

Post #: 29
Post ID: 2703
Reply to: 2701
Re: Scoped in, scoped out

OK, the first think first. The second and the their images from the tope that were marked 2000Hz and 40000Hz are in fact 20.000Hz and 40.000Hz. I just lost a zero when I typed it. I have corrected the labels

Jim, it is a good question about the input waveform? I have no idea now and I will post it later on tonight. I have quite rudimentary and not very well performing generator and perhaps it does not have a proper output (thought I doubt). From a different perspective, why should we not see a lot of 2nd order distortions in output? It is SET, it should be this way. Perhaps later on I will run my distortion analyzer against the Melq …

Regarding the power. 28.5V RMS is was into 12R, as I usually do. I measured it precisely at calibrated scale just once to have an idea about the power. When I was looking at the frequency response I uncalibrated the scare juts to starch the wave exactly across the 10 dividers on the screen and then, running the frequencies up and down, I used only time/div to view the valve. I know, that you might consider this way of viewing is quite barbaric and I might agree with you but I did not care when it hit 3dB and I was not concern about the absolute numbers of the response. To me it is more important to get a FEELING of dynamic of this process. I usually set the max outs voltage on generator before the wave get clipped at 1000Hz and then moving up I observe how dynamic  with whish amplitude goes down after 20Khz; and moving down, I observe HOW the wave get distorted under 30Hz. I had THAT feeling from my first excremental Melq and I was a little disappointed that this new Melq with 60W plate dissipation measure and sound so different and so poor. This current version with the lower plate dissipation (similar to the original Melq was) behaves and sounds and very similarly to the original Melq, although the original had very slightly more, 42W on plate.

Guy, yes, I post the 10K square wave tonight,,,

Rgs,
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
07-28-2006 Post does not mapped to Knowledge Tree
hagtech


Hawaii
Posts 117
Joined on 02-13-2006

Post #: 30
Post ID: 2704
Reply to: 2703
Re: Sined or sinned
 romy wrote:
I have quite rudimentary and not very well performing generator


That's what I thought.  I see a point at the tips of the sinewave, a dead giveaway to a ICL8038 style waveform generator.  I wanted to see the input because much of the distortion could be caused by it.

There is nothing wrong with seeing the 2nd order distortion - in fact it appears to be quite small for such a high power level.  It's just nice to be able to see it.  I understand how you like to FEEL the amplifier as you sweep the frequency.  I do the same thing.  You watch the distortions and glitches and look for patterns and trends.  It is easy to spot irregularities that cannot be seen in a static snapshot.  Try also to do the same thing with a triangle or sawtooth input. 

Guy suggests the square wave.  I'm absolutely anal about transient response.  I spend more time on step response and nice looking square waves than anything.  It gives you a very good understanding of phase and temporal relationship with the amplitude.  Now if we can only get more loudspeaker designers to do this.

Oh, I just thought of something.  The phase (polarity) switch needs to be ahead of the Melq.  And here's my theory:  The 2nd order distortion is polarity sensitive.  It must match the input polarity so that it adds properly.  Otherwise it subtracts.  Vocals are nonlinear and mimic a heavy 2nd order distortion.  If you amplify it with a nonlinearity of the wrong polarity then you partially cancel, or worse, turn it into 3rd order.  Think of it this way.  The transfer function of a PP amplifier is an "S".  For an SE amp it is a "J".  If you add two SE amps in series you either get a stronger "J" or it turns into an "S", depending on polarity.  I think it is important to match absolute polarity in this fashion.  Sound in a gas is similar to SE (1/P function).  A kick drum transient that pushes air (compress) before it pulls (rarefaction) will sound wrong if played backwards.  I think it also makes a difference if you add 2nd order distortion in the wrong way.  Sound in a gas has a curved function, so does your SE amp.  My theory is that it is better to have them sum rather than cancel.

jh
07-28-2006 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,537
Joined on 05-28-2004

Post #: 31
Post ID: 2705
Reply to: 2704
More data about the new Melq and some about the Super Melq

Well, Jim, it is time to say “Oops!” I told to myself do not make any posts early morning unit I eat a bagel but this mooring I disobeyed the rule. Anyhow, I do not know how I come up with 28.5V RMS. Defiantly it was peak-to-peak on the scope and I remember that I intended to get a correct calibrated number, so I did but, or I think I did…. but it hardly looks like anything mindful. The amp should be in 12W region, slight less then the original was. I juts feed it with 2.4V into 12R and my “true RMS meter” Fluke 87 said that it is 9.22V. Also, here is the feed directly from my generator that you asked.

Below are the square waves:

1000Hz

20.000Hz

100Hz

Here is I fed one channel from scope directly and another from amplifier. The wave that came form amplifier is located higher in all 3 pictures.

1000Hz

20.000Hz

BTW, boys, juts for fun… The Super Melquiades LF channels were made more powerful and it runs 6C33C at higher plate dissipation with a transformer with a single secondary, gaped for a double operating current with much more inductance and core mass.  The LF channels was tested and “tuned” (enough current + enough voltage”) as 4.2V at input, which is quite a difference with 2.4V of the current fill-range Melq. Still, I was trying to run it at 4,8V that makes it far beyond 20W. Well, take a look what it does… , if you feel that the Super Milq LF does not mesure insulting then I would assure you that it sound much more interesting then it measures….  I believe those who heard it would not disagree…

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
07-30-2006 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,537
Joined on 05-28-2004

Post #: 32
Post ID: 2706
Reply to: 2502
Building Melquiades Ending...

Best amplifier is the one that you just built…

Yes, it is a common unfortunate law of Audio but the people who know me personally know that try do not behave according to this behavioral pattern. So, this weekend I decided to do try the new Melquiades on the crap that I have been using for a few weeks but quick-make form Macondo a suitable mono speaker suitable for this SET. It took literally 1/4 hour to make the speaker. A pair of 5.5R woofer towers connected in series with 65Hz low pass first order driven from one of the new Melquiades monoblocks.   The Macondo upper bass horn driven full-range juts for sake simplicity. The S3 channel from Macondo with unavoidable 3UuF and the Macondo’s tweeter atop. The horns are driven by the second Melquiades monoblock, full range with EVS attenuator in front to EQ the sensitively gap with the LF chants. The both Melqs eventually fed with new tubes and driven the 180V, 200mA.

What is that marvelous sound; it was exactly the Melq that I remember. It is not exactly even because the speaker is simplified but it is the very-very the same sound as Melq is need to do. It has stunning resolution and transparency but it never go further into hyper-resolution and artificial effects. It has fantastic speed and transient characteristic but at the same time it perfectly maintains something that I call “acoustic-like harmonic structure” and capable to produce very fluent and soft sound. I have written about it  and many other things during my “Melquiades discovery phase”….

Anyhow, I juts listened on this my temporary playback a very complicated peace and mine the very favorite performance of Rafael Kubelik leading Berlin with Dvorak's Ninth Symphony. It is scare how good it is and how good the new Melqs handled it with … almost smile.

Good! I am very glad now with the result.


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
01-11-2007 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,537
Joined on 05-28-2004

Post #: 33
Post ID: 3477
Reply to: 2706
The Super Melquiades' “New” cooling fan.

I was replacing transformers in the Super Milq HF channels and while I was doing it I decided to perform a minor maintenance on the amp.  One of the amp’s fans developed a “flat” in it bearing and created a very minor “step”. I order a replacement fan, also this time I decided to mount it differently. I ordered the very same fan that I used before, the most silent that I was able to fine 2 years ago.

To my surprise the very same fan tuned out to look very different: the same price, the same box packaging, the same model of course only slightly differently looking blades. It was SilenX 120x120x25 12V fan with 1100RPM at 11dBA. So, I put the new fan next to the old fan on my table and tune them on. The new one is twice more silent! Hm… how little I need to be happy!

Also I abandoned to mount the fan with screws and fan rubber gaskets. This time I just dumped on the amp’s wall the black silicon that I used everywhere (mentioned above) and glued the fan to the amp via 3/8” of the silicon. The result of the new fan and new mounting is fantastic. When the fan is on, at full 12V (never happen) then my stethoscope pick absolutely no events on the Milq’s chassis. Very-very cool!

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
02-08-2007 Post does not mapped to Knowledge Tree
loudcloud
Posts 1
Joined on 02-08-2007

Post #: 34
Post ID: 3693
Reply to: 2648
Voltage Meters
Hello,  where did you source the voltage meter?
02-08-2007 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,537
Joined on 05-28-2004

Post #: 35
Post ID: 3694
Reply to: 3693
Melquiades' Meters...

Hello, loudcloud,

The Milq’s meters are by Hoyt (link). You might look at

http://www.hoytmeter.com

and from theer your might customize it in any direction wish. They are not dirt-cheap but I fine them reasonable for what they do. Here is the picture of the same meters in the Super Melquiades.

The Hoyt folks kind of screwed me up initially but eventually it turned out to be OK and I generally happy with them.

Rgs,
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
07-11-2007 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,537
Joined on 05-28-2004

Post #: 36
Post ID: 4731
Reply to: 2514
The new transformers for Super Melquiades.

It, looks like the problem with the steel chassis picking up stay magnetic fields from my Super Milq’s power supply is about to be gone. With the introduction of the 3 extra single-stage channels I needed more current for 6.3V filaments and slightly other voltages for B+…. I was thinking to make it in half-ass, using my current magnetic, but then, since it will me my last amp, I decided to go for the set of the new transformers. Sure, opening the Pandora Box I opened it wide open and eventually I went for a new set of custom toroids for everything, including the potted chokes and so on… Since they will be hanging outside of the chassis in L-brackets (like the bunny ears) it will be no more with-chassis talking….

Two: 12,6V – 10A, center tap, 6.3V – 10A center tap

Two: 440V – 350mA, no center tap, 440V – 150mA, center tap

Two: 220V – 3A, no center tap, taped primary with 240V out

Six: 10H 400mA

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
09-22-2007 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,537
Joined on 05-28-2004

Post #: 37
Post ID: 5354
Reply to: 2706
Well, the Melquiades going to graveyard...

 Romy the Cat wrote:
.....it is scare how good it is and how good the new Melqs handled it with … almost smile.
Since almost 3 years ago I was introduced to Milq it went a long way. There was two full-rage Milq ever built by me – one was the initial - I do not have it anymore and the one that I made for myself last year. That last one was very tough staffed, fully choke-regulated amp with somehow limited 200mA OPT’s gap. The presses of building that amp is well illustrated within this thread.

Over the last 2-3 years the full-range Milq begin to loose it’s importance as it paved the way for a Super Milq DSET. The full-rage Milq was sitting in my room, sitting, sitting and sitting, driving the Injection Channels, driving some other thing and eventually, since the new 6-chennal Super Milq has a built-in full-range channel I decided to decommission the pair of my full-range Milq monoblocks. I dumped the Milqs to my car and drove it to my storage… So long, the Melquiades.

It was certainly not an “emotional” moments but I had “special feeling” as the Melquiades had became my past. I still feel that I was not completely “done” with it as I would like to hear the full-range Milq with 350mA transformer, driving the 6C33C at 55W. I’m not willing to do it myself, partially because I do not have good speakers with which I would be able to listen such a full-range amp and partially becose I have no need in that.

The last question that was cursing in my mind when I was driving the Milq to the graveyard was how much in the sound of my today 6-chennal Super Milq I recognize the sound of the original Melquiades. I would like to be able to tell you/myself that very well researched and investigated sound of the original Milq is essentially the same as the sound of the new Super Milq. However, it would not be a right observation. The 6-chennal Super Milq has different sound. The 3-chennal Super Milq has slightly different sound and the 6-chennal Super Milq has even more differences. The character of the sound is similar in a way but there are many other things that make both sounds not exactly comparable.

So, the Milq went to sleep with fishes. It is kind of sad and happy event… One door open another door close…The life is going on. Bye-bye the Melquiades. You were a good ride…

Rgs, 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
08-29-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,537
Joined on 05-28-2004

Post #: 38
Post ID: 11584
Reply to: 5354
Touching the full-range Melquiades
fiogf49gjkf0d
A local guy asked me that since my low-powe,  full-range Milq is sitting in my storage and I do not use it then he would like to try it: he has 1110dB sensitive speakers and SET and PP amps. I figure out that if I give the Milqs to him now then I will be moving less crap from my storage in my new place as he will return Milqs back to new place.  Anyhow, I brought the Milq back home to inspect how much rats in my storage eat them. I kind of forgot how my full-range Milq looks like during the time passed and I tell you I have a renew love to those amps. I do not take about sound – it is not the subject for me anymore – I have discovered all about the Sound years back. In addition I have a full-range Milq built in my current 6-ch Milq configuration. What I meant that caring the full-range Melquiades last week I was stricken how pleasant the amp in its physical materialization.

The proportion of size, weigh, the distribution of weigh, my knowledge how much was stiffed into this amp and how rationally internally everything is located, grounded and wired made me very happy that this amp was made by basically such a deranged “designer” and “builder” as I am. Particularly the idea to have an empty steal shell that has no mounting holes for internal hardware was very-very cool idea. The large parts of the amp are not bolted to the chassis but glued with heavy-duty silicon and it gives to the amps a VERY special feeling. It is very interesting to tap the amp chassis or to drop it to floor from a few fee millimeters of heights – Milq responds with very interesting physical sound – it is like a sound of not completely cooked egg, has sort of own inertia in there – very cool feeling.
Anyhow, I had so much pleasure to touch the amp that I decided to celebrate the delight with a picture: here is goes…
 

Milq_Full_Range_Close.jpg

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
08-29-2009 Post does not mapped to Knowledge Tree
hagtech


Hawaii
Posts 117
Joined on 02-13-2006

Post #: 39
Post ID: 11585
Reply to: 11584
Beautiful Amp
fiogf49gjkf0d
I agree, I like the idea of glue or resin to attach components to a chassis.  It adds a nice layer of damping material.  I used to to this with step-up trannys for mounting in a box.  Works great with the Cinemag or similar style cans.

jh
11-19-2017 Post does not mapped to Knowledge Tree
S.yorke
Posts 2
Joined on 11-15-2017

Post #: 40
Post ID: 24567
Reply to: 2618
Operating point of Melq SET for Single full range speaker
Dear Romy,What would be your suggestion on the operating point and OPT impendance if I were to drive a single driver Back loaded horn speaker with over 102db/W? Knowing that you have mentioned a range of operating points in the forum, I still not too sure what would best for my setup. Thanks in advanced.  
BR 
11-19-2017 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,144
Joined on 10-12-2006

Post #: 41
Post ID: 24568
Reply to: 24567
This ought to liven things up!
Thanks, BR.  This time of year is usually pretty dead.



Best regards,
Paul S
11-20-2017 Post does not mapped to Knowledge Tree
S.yorke
Posts 2
Joined on 11-15-2017

Post #: 42
Post ID: 24569
Reply to: 24568
Not so active nowadays
Thanks for the heads up. Just that there are so many versions being built with different operating points over the decade. Not  sure if 200V/240mA , 650:8 ohm sounded right for my case?
11-20-2017 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,537
Joined on 05-28-2004

Post #: 43
Post ID: 24570
Reply to: 24569
50% help...
 S.yorke wrote:
Dear Romy,What would be your suggestion on the operating point and OPT impendance if I were to drive a single driver Back loaded horn speaker with over 102db/W? Knowing that you have mentioned a range of operating points in the forum, I still not too sure what would best for my setup. Thanks in advanced.  

S.yorke,
 
The operation point is simple to recommend, the OPT impedance is more complicated subject. The 6C33C is kind of current-loving type of tube. I run it at a little below 200V and as much current as I need.  With bass channel when I need as much power as I can get I use 275mA-190mA that made it sub 60W plate dissipation. Usually 55W on plate is max that I tend to drive the tube, not that you cannot go high if you need. Be advised that higher plate dissipation lower the plate output impedance, so you might factor it in. With all other things equal and regardless the specific demands of a given speaker I feel that the best is to drive 6C33C (if you use both filaments) with 47-53W. Note that specific configuration of current vs voltage is not too critical and might be easily offset by OPT ratio. You can use anything between 160V and 220V, and the current accordingly, that all will be fine.
   
The OPT impedance is a very complex question, not so “complex” but rather the answer is very much deepens from the acoustic system you use, your loading objectives, type of the sound you need, your operation point, the way how you integrate you speaker into the room, your personal, preferences, type and design of OPT you use and many other factors. I personally use a fully heated 6C33C logins it from 400R to 1400R and this is a huge margin. So I will stay away from any specific loading reconditions, not he last fact is that I do not know those “yellow drivers” and what they need to sound appropriate.


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
11-21-2017 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,144
Joined on 10-12-2006

Post #: 44
Post ID: 24571
Reply to: 24570
Variable Resistors
BR, I have never used Romy's amp design, but I have used 6C33C SETs with Lowthers.  I do not use my Lowthers FR, for reasons that are fully explicated throughout this site, so I don't worry about LF from those drivers.  IMO, their best is MF up to treble.  In fact, IMO, their overall performance is decidedly compromised by feeding them LF signal.  In any case, use variable resistors and test terminals to set operating points, and this will give you a chance to tune to taste.  In general terms, the Lowther does not need to be "clamped down" by the amp, and I got the best results with higher output impedance/lower plate dissipation than I might have used.  Likewise, much discussion here on OPT options via multi-tapped OPT.


Best regards,
Paul S
Page 2 of 2 (44 items) Select Pages:  « 1 2
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  To Milq builders: corrections, simplification, modifica..  Talking about amp…....  Melquiades Amplifier  Forum     16  73256  05-17-2007
  »  New  6 Channel Version of Super Melquiades..  The first Milq screw up....  Melquiades Amplifier  Forum     131  861894  08-08-2007
  »  New  Has anyone built the DIY Melquiades amp??..  You did not reply what music you are listening….....  Melquiades Amplifier  Forum     2  24069  08-24-2007
  »  New  Melquiades For Dummies™ - step by step...  Risk...  Melquiades Amplifier  Forum     24  129126  08-29-2007
  »  New  The short "6C33C Survival Guide"...  Ac filament.....  Melquiades Amplifier  Forum     20  247975  12-18-2007
  »  New  Full range Melquiades implementation..  Solved...  Melquiades Amplifier  Forum     81  220963  02-23-2011
  »  New  Building Melquiades: questions and answers...  PeaceMAT XS™...  Melquiades Amplifier  Forum     96  303276  10-09-2007
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