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  »  New  Where are our good phonostages?..  Omnigon Tubes...  Analog Playback Forum     61  435011  05-31-2004
  »  New  Another interesting corrector: Likhnitsky's RX correcto..  Again, the capacitors...  Analog Playback Forum     6  44774  02-10-2005
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  »  New  Van den Hul 's Grail..  Van den Hul 's Grail...  Analog Playback Forum     0  13638  09-30-2010
  »  New  The tales of two phonostages: Allnic and 834PT...  The tales of two phonostages: Allnic and 834PT....  Analog Playback Forum     0  14426  12-21-2011
11-11-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 51
Post ID: 12239
Reply to: 12238
What we use vs. what we CONCEPTUALLY prefer.
fiogf49gjkf0d

 perrew wrote:
Romy,

I might be confused with the passive and active, but from my understanding you prefer your active 834PT to the passive RC network and passive LCR networks. You also prefer the passive LCR to the passive RC. So 834PT>LCR>RC.

If I got it right a RL network will be similar to a LCR from needing a capacitor for the ground and then additional capacitor for the amplifier stage unless the amplifier stage is direct coupled or you can use a Transformer in between, which need to be matched.

If the biggest advantage from the LCR network is the RIAA curve is not altered from change in tubes is not such big advatage any longer why then choose the increasing complexity of the LCR over the simpler RC?

P

Perrew,

We need to keep a perspective on what we are talking about. There is a different about what we prefer and what we use. What I prefer is RL filtration and in context of RIAA it gets converted into LCR filter. Theoretically it is possible to avoid the final cap at the bottom as well and use only pure inductance filtertration:

http://www.RomyTheCat.com/TreeItem.aspx?PostID=644

…but the pure inductive RX ides has own issuers.  That is what I “prefer” but it is not necessary what I use. We trade opinions about conceptual advantages but we do not justify that that what we use. I do use a phonostage with feedback, I like it very much and am not going to change it to LCR. (I have then LCR phonostage as well). My feedback phonostage is a different type feedback, the one that use native tube’s Miller capacitance to write the curve. Still, I have no experience to evaluate METHODOLOGICALLY PROPERLY the advantages of my type of RIAA vs. LCR RIAA.  To compare two completed phonostages does not signify a lot about the advantages/disadvantages of a given RIAA filtration method.  So, my position is my feeling that LCR might be adventitious and it is what I “prefer” as better RIAA filter. Still, I use my feedback RC, so what, who said that what I USE must be what I prefer?

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
11-12-2009 Post does not mapped to Knowledge Tree
twogoodears


Italy
Posts 116
Joined on 03-26-2008

Post #: 52
Post ID: 12244
Reply to: 12237
EC8020/437A/3A-167M -price-tag vs. performance vs availability
fiogf49gjkf0d
 Romy the Cat wrote:
I never had a lot of trouble with high transconductance tubes. I use the EC8020 a lot.

Stefano, you might look into this EC8020. I never seen it but just looked into the datasheet and it looks very interesting tube and it might be better candidate to your phonocorrector’s fist stage then the WE 437A. I generally, under other equal conditions, prefer Telefunken/Siemens tubes to any other tubes. My second choose would be the older British tube and only then I would look into all of those RAC/WE/Raytheon. Of cause it is a gross generalization but … I am comfortable with this generalization.

 Thomas Mayer wrote:
This is true for RC RIAAs, not for LCR RIAAs. This is one of the big advantages of the LCR technique. The network has a constant 600 Ohms input impedance, if it's terminated by the proper 600 Ohm value. Variation in the driving tubes rp does only affect the loss in the network, but the loss is always the same over the frequency band. So the RIAA curve will not chabge when the tube detoriates or when tubes are changed.

That is not necessarily true. I think any passive RIAA would not be a subject of curve variation with tube aging. Moreover, I would take this argument even further. Even if we have a feedback RIAA, where the gain of the open loop is in the task of direct shaping the RIAA curve, than I feel that aging of the tube and minor change of their gain is not truly a practical issue. There are a lot of people out there who go totally crazy with writing the accuracy of the RIAA curve with .05dB precession. I feel that it is absolutely not necessary. If you want RIAA precession then have your corrector to run multiple curves as 50% of records out there are NOT RIAA pre-equalized. It is not to mention that there was a huge deviation in the RIAA equalizers during the cutting of the records. From what I see the .25dB-.5dB accuracy is plenty for normal record playing. The MC R loading, MM C loading, VTAs, the cartridges themselves give much higher discrepancies then .25dB. so, if you look how the small tubes change gain with time then in most cases it is not significant to affect RIAA too mach. Unless your LP is the only source you use and unless you run your phonostage a few hours each day I would not feel that the tubes aging might be a factor in RIAA running away.

The Cat


Thanks, Roman...

when I began my perusal for LCR phono-stage, the Telefunkens' were my first choice... the relative scarcity of these tubes as N.O.S. possibly shopping at the most serious tubes merchants (Tubeworld, Billington, EIFL and few others) made me to carefully think about the relationship between availability/cost/performance.

Actually a N.O.S. EC-8020 "diamond" is worth EUR 500+ ea., an STC 3A/167M is fetching EUR 750+ ea. (I own one N.O.S. sampler with original carton box, bought by chance for cheap, years ago) and WE 437A is at "only" EUR 350+ ea.... the only tube to be still commercially available is the Western Electric's, at USD 750 ea. (EUR 501,88)... 

Tube market is quite strange: considering that a Telefunken VF-14 with original carton-box for Neumann U-47 classic microphones reached USD 1.000/1.200 ea. price-tags the WE 437As appears like true bargains;-)!

The choice, at the above prices, was - sort of - mandatory: had to go for N.O.S. samplers, not using Ebay, preferably, due to safeness reasons, and so I did.

Now, I would probably go for WE416B or C or WE417 or Telefunken EC810F, not because I'm disatisfied with my actual LCR/WE437A, but because the cost involved in tuning or simply obtaining the correct balance between right and left channels in such a design, proved to be quite expensive... always less than any medical surgery, anyway;-)

Herr Mayer and myself agreed and - all considered - that's what I ended with... a nicely sounding LCR phono stage, much better than my previous vintage preamp.

  
 


"Use your ears as your eyes" - Gertrude Stein

Stefano
11-12-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 53
Post ID: 12245
Reply to: 12244
It is also important to know where to stop.
fiogf49gjkf0d

 twogoodears wrote:
Actually a N.O.S. EC-8020 "diamond" is worth EUR 500+ ea., an STC 3A7167M is fetching EUR 750+ ea. (I own one N.O.S. sampler with original carton box, bought by chance for cheap, years ago) and WE 437A is at "only" EUR 350+ ea.... the only tube to be still commercially available is the Western Electric's, at USD 750 ea. (EUR 501,88)... 

You got to be kidding? If the prices are in this scale then I would have problems. Perhaps not becose it is too expensive but become there is absolutely no assurance that the given bought tube will be able to work in your phonostage according it noise characteristic. I would agree that probably it worth to buy them ONCE to trey what they are all about but if I have a devise that I would really upon then I prefer to have a few spare tube. I would say for phonostage that I might settle you would need to have at least 3 pairs of tested replacement tubes for me to feel comfortable. The most ridiculously expensive tube I ever paid it was a pair of new RE604. I tested what the hype was all about and went for another tube. Now, if I did select the RE604 to stay in my amps then considering the power tube go south faster I would probably need to get 3-5 tested pairs of them to feel comfortable. It has nothing to do with rational or sanity, it is how my sick mind works. According to Zodiac I am a Cancer and like any crabs we Cancers always build the stash of possessions, otherwise we do not feel comfortable…. So, to have 3 workable pair of WE437A I would need 8-10 pairs of “random” WE437A. That sounds bitey… from another hard if  your Thomas claims that  EC-8020 is very stable then you would need just 3 pairs of them…

 twogoodears wrote:
Tube market is quite strange: considering that a Telefunken VF-14 with original carton-box for Neumann U-47 classic microphones reached USD 1.000/1.200 ea. price-tags the WE 437A's appears like true bargains;-)!

And you know that 90% of this cost is not from the people who NEED them and know what to do with them but from the people, who hear the hype, buy them to learn what the hype all about. I think it would be a good idea to large dealers of NOS tubes to have trial stock of tubes.  I would not mind for instance instead of buying all those tubes that I have bought for my Milq MF channel to pay let say $500 for a weekend and to have an assortment of different tube send to me to try. Perhaps it would be a good business for somebody…

 twogoodears wrote:
Now, I would probably go for WE416B or C or WE417 or Telefunken EC810F, not because I'm disatisfied with my actual LCR/WE437A, but because the cost involved in tuning and maintaining to specs, or simply obtaining the correct balance between right and left channels in such a design proved to be quite expensive... always less than any medical surgery, anyway;-)

BTW, the WE417A that I used have a habit to change gain very fast and very erratically, so if you match then NOW it does not mean that it would be matched in 3 weeks or in 3 month. I presume that WE437A will behave the same.

 twogoodears wrote:
Herr Mayer and myself agreed and - all considered - that's what I ended with... a nicely sounding LCR phono stage, much better than my previous vintage preamp. 

I do not know what previous vintage preamp you used, whatever vintage preamps/phonocorrectors I have seen they all where crap. In what you do you need to have a very perspective about what you are trying to accomplish. Mr. Mayer and anyone else on the technical side who might assist you with building of your phonostage are endlessly blind in what they do. They build just a phonostage as an absentminded instrument and it is up to you to make this inattentive tool to serve your purpose. You do not really need a phonostage but you are trying to construct a special sound. The knowledge that your technical associates have in design audio might not be in direct relation with your sonic objective. The DIYers would go over zillion topologies, tube and options without respect to Sound. It shall be your job to discriminate result, to navigate what they do in the direction where it shall go and eventually to say to yourself: “stop, here is where I have got what I would like to have.”

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
11-12-2009 Post does not mapped to Knowledge Tree
twogoodears


Italy
Posts 116
Joined on 03-26-2008

Post #: 54
Post ID: 12247
Reply to: 12245
Wisdom!
fiogf49gjkf0d
Very wise, Roman... I - myself and my wallet - both must agree about your feelings and opinions... I've been into tube collecting since early '80s and what I guessed was dear (ITL 50.000 (about EUR 25) for an AD1 or "Luftwaffe" RE604 is now a TRUE bargain... same for smooth plate, diamond Telefunken's ECC83, Arcturus 45, Cunningham's CX-350, etc.

The problem is: using this "lamps" or simply stocking'em in a closet... now a vault;-)?

With instruments is the same: a Stradivarious needs to be played... in a vault it's an expensive bunch of glued wood!

The "sound" obtained from gears and "when to stop" are two beloved topics of mine, indeed... I'll add also "by chance" to this... some people - myself, by chance - love "searching" per se.

Any find has a very tasty weight and pleasure involved, also negatives... like after a car crash you can find your soul-mate;-)

Death will stop me, I know for sure... my wallet says "stop" or "go"... my ears love novelty and recognize difference in sound qualities and I'm (still) pleased in accomplish this quest.

I'm not a prey for tech-heads... sure I'm a victim of Music... but, IMO, it's like being killed with honey!

Seriously, as I'm also Cancer-born, and I guess "I know" your feeling: I own 2 quartets - i.e. 4 matched pairs of WE 437A... I agree they'll possibly change sound character, but they'll possibly survive to me...

In the meantime, I enjoy the toys I had built for me, tamed, fine-tuned bent to my tastes and knowledge.... same I do with my guitars and my luthier (under my direct direction...) strings, set-up, tunings... and I play my music. 

Sincerely: thanks for your time and wisdom...

P.S. - the vintage preamp was a Marantz 7C...  classic looking crap, made by another Cancer-born: Saul Marantz.
;-)      


"Use your ears as your eyes" - Gertrude Stein

Stefano
11-13-2009 Post does not mapped to Knowledge Tree
twogoodears


Italy
Posts 116
Joined on 03-26-2008

Post #: 55
Post ID: 12253
Reply to: 12247
Western Electric prices fluctuations and availability...
fiogf49gjkf0d
Something strange - but maybe understandable - happens in WE's price list and catalog... have a look... the WE 417A is USD 550 a piece, WE 437A USD 750, but in Web-Order form it's 450, while it's confirmed 417's price-tag, still at USD 550 (both are in stock).

http://www.westernelectric.com/pricing.asp

... an error?

... as a comparison, Tubeworld Inc. sells N.O.S.matched pairs of WE 417A at price-tags between USD 295 and USD 395, depending on production batch.

WE 437A, always at Tubeworld Inc., are sold-out;-) 


"Use your ears as your eyes" - Gertrude Stein

Stefano
11-13-2009 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 56
Post ID: 12258
Reply to: 12253
The BS about the “matched pairs” of NOS.
fiogf49gjkf0d
I do not know here to start. I absolutely assertively insist that under normal circumstances it is absolutely imposable to buy matched pairs of NOS tubes, particularly the high Mu tubes. When sellers advertised the “matched pairs” I just discard the claim and if they insist that their tubes as matched then I just abandon the deal and walk away. It is possible match tubes but it would happen ONLY if the seller has personal relationship with you, a large pool of the tubes,  time to do it, knowledge and erumpent to do it (a regular tube tester will NOT do it) and has a very specific knowledge HOW your tube is used in your circuit.  Even that will not be an assurance for proper matching for shitty (from noise perspective) high Mu triodes.  They all age differently and matching according to the plate impedance, cathode emission, noise, gain at the given curst NOT might not be how those tubes will behaves in 3 month. It is not to mention that the tunes like 417A will have different noise contingent upon where they are located and what kind sockets are used. They are very finicky. This is one of the reasons why I am a bit afraid of high gain triodes WE style.

You see, when the tube become to do the oscillation things then this it is not good but this “not good” might manifest itself in a very different ways. It is good when the tube burns your tweeter. Yes I do consider it good as you know that the tube is oscillating.  The bigger problems happens when the tube is oscillating and you knave no knowledge about it. You are not keeping a fast scope all time on you phonostage and you might not know that the 417A went berserk.  In many cases the fact of oscillation is not directly auditable but has impact to many other auditable properties. So, I would like the tube to have the oscillation or not but would like it do not develop it after it was chosen to work in my phonostage. I remember what when I used Lamm LP2 with two stages of 417A I each month had a center image of a leading instrument moved to right of left side. In my case it was not oscillation/noise but gain change but I know the people who had the same spontaneous oscillations with LP2 and 417A. I found it very unreliable and frankly speaking annoying. I do not hear the Lamm LP2 user even complain about it - ether they have not problem or they do not understand what they hear. I vote for the last one….

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
11-13-2009 Post does not mapped to Knowledge Tree
perrew
Posts 30
Joined on 10-06-2009

Post #: 57
Post ID: 12259
Reply to: 12258
Preferrence and Stability
fiogf49gjkf0d
"So, my position is my feeling that LCR might be adventitious and it is what I “prefer” as better RIAA filter. Still, I use my feedback RC, so what, who said that what I USE must be what I prefer?"
Romy that is Very refreshing view!

Im not convinced the transformer RL network would be preferable to the RC so for now I will stick with simple RC and try to find the more stable tubes.
01-04-2010 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,540
Joined on 05-28-2004

Post #: 58
Post ID: 12623
Reply to: 4732
Inductive RIAA link
fiogf49gjkf0d

BTW, the hoodlums who are interested about Inductive RIAA might fins this link useful:

http://digilander.libero.it/paeng/inductive_riaa.htm

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
Page 3 of 3 (58 items) Select Pages:  « 1 2 3
   Target    Threads for related reading   Most recent post in related threads   Forum  Replies   Views   Started 
  »  New  Where are our good phonostages?..  Omnigon Tubes...  Analog Playback Forum     61  435011  05-31-2004
  »  New  Another interesting corrector: Likhnitsky's RX correcto..  Again, the capacitors...  Analog Playback Forum     6  44774  02-10-2005
  »  New  Allnic Verito MC Phono Cartridge..  One more example...  Analog Playback Forum     3  31649  10-19-2009
  »  New  An interesting Russian pnonocorrector...  Uber-tweeky phono topologies deconstructed...  Analog Playback Forum     9  56224  03-01-2010
  »  New  Van den Hul 's Grail..  Van den Hul 's Grail...  Analog Playback Forum     0  13638  09-30-2010
  »  New  The tales of two phonostages: Allnic and 834PT...  The tales of two phonostages: Allnic and 834PT....  Analog Playback Forum     0  14426  12-21-2011
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