Preamp Deal of the Century

Frankiealverti. Houston...We have a problem!!!! Are you certain the tubes are 7029's. I have never heard of a 7029 designation. Perhaps you are confusing it with the 7027 or the 7027a. If it is a 7027.... Yup, the 7027 is electrically similiar to a 6L6 and should be fine in the supratek. That said: Am I missing something here? No offence but I would be "highly suspect" and immediately ask myself why anyone one would go through the exercise of relabelling tubes,and for what reason other than financial gain. Flat out Fraudulant if you ask me! The original old stock 7027 is a rare breed indeed and I have only come across this tube once or twice in over 30 years. A local musician brought in an old Ampeg guitar amp that employed the 7027 tube. I could not find replacements for them and had to retrofit his amp to operate with the 6L6's. Rumour has it, that the 7027 is the King of Tone and the cats meow in the this old Ampeg. The gentleman I am referring to is an incrediblly talented blues player and quite a famous recording artist. His comments were....What the f_ck did you do to my amp man! Well sir... " I put some [old stock] 6L6g's in it man as I couldn't find the 7027's anywhere" I could only imagine that the guitar amp crowd would probably trade in their back up guitar for a pair of these! Frank...I don't doubt the original old 7027 sounded better in the Heathkit W5's but I would be willing to wager that they are probably new stock chinese or russian metal base 6L6's with the labels washed off. Why take the chance in your Supratek anyway? Regarding the preamp making noises when your using the phono stage. Have you tested the rectifier? I would hazard to guess that your Mullard GZ-37 is either very weak or has grossly imbalanced halfs.This artifact you describe is really not that uncommon particularly in the supratek with phono stages. Yes, I believe the GZ34/5ar4 would be the safer choice. By the way: WOWZA and well done man!... You have one fabulous rig there sir and a very fine ear. To this very day I am still kicking myself for selling off my Radford ST-25. Over the years....I have had my share of highly regarded amplifiers paired with the Quad 57's and I can honestly say I have never heard a better amplifier than the STA-25/quad combo. Outfitted with the Genelex kt77 is pure magic with a capitol M. Now add the mighty supratek into the mix....sigh. Can only imagine!!!!

Hello ecclectique,
I am so fascinated by your kindness, experience and knowledge that I have waited until this hour (02.14 over here) for your reply. THANKS!
YES, you are right, I meant the 7027A. My RCAs and Westinghouses did a great job in my Heathkits. I also have a pair of new Sovtek 5881s. They do sound much inferior to the metal base 7027A's in the Syrah, but maybe it is just because they still are brand new. Anyway, I will try my burnt-in RCA 7027A's in the Syrah (I hope Mick isn't reading this ;-))
The tube seller is the most reputed and most expensive in Germany, thank god the previous owner paid him for these tubes, not me. If you would like to know who he is, just out of curiosity, you can email me privately and I will gladly give you his site address. This practice of wiping the branding off is very old, he has been doing it for many years. He then writes his name and the tube type in different colours depending on the quality of the tube according to his measuring, testing, matching etc.
A huge thanks for the rectifier tip, a Hytron GZ-34 is on its way here and hope it will reach me before Xmas. I know I need the metal base GZ-34, but before I spend what is big money for me for the metal base Mullard or Philips, I thought I should try the Hytron, see if the problem vanishes. No, I did not and cannot measure the Mullard GZ-37, I really hope that the rectifier tube is the problem.
Thanks for your kind words on my system, your systems are truly extraordinary (I have heard the TW once in a show twelve or more years ago, WOW!). My Quads have PK (absolutely great guy) treble panels, new EHT blocks and protection clamps. New PK bass panels maybe next fall. The Radford STA-25 MkIII is a really good match, indeed. Before the Syrah I used a (Bruce Moore designed) Precision Fidelity C-7a sp (with step-up trannies for MC inside). Not at all bad, not at all, but the Syrah is in a different league. Now if the problem could go before Xmas so that I can enjoy my LPs for more than a few minutes!
Many thanks and regards, ecclectique!
Best,
frankiealverti

It has been my experience that the regulators affect the sound much more than any of the 6SN7's. Yes, the WE 350B's are very expensive, but worth it, IMHO. The Genelex KT66's aren't even close to the WE's in my system. Since I have the 350B's, I haven't tried the 6F6's.

As far as the 6SN7's go, I have tried them all. The EH 6SN7's kicked out the Kenrad blackglass and Tungsol roundplates. Still have the Kenrads and the Tungsols, but they are sitting in a box. The EH's are just as good as the 'Rads and Tungsols and better than everything else.

It is my opinion that in most any other application the Kenrads and Tungsols would probably best the EH's, but I simply believe the 6SN7's contribute very little to the sound in the Supratek as compared to the regulators and the rectifier. Having rolled them all, I wish I had saved a bunch of monney on NOS 6SN7's and bought the EH's in the first place. Taking the money I wasted on NOS 6SN7's, I could have bought 3 pairs of WE350B's which do greatly affect the sound of MY Supratek.

Not trying to argue with Ecclectique, just offering a different experience.

Fiddler, thanks for your perspective. It is very much appreciated. You have tried so many tubes on your Supratek. My Syrah has a pair of matched GE side getter 6SN7s. I may buy the EH for a spare and try them in January. Best,
frankiealverti

Hello ecclectique, big disappointment. The GZ-34 did not solve the problem. On the contrary, with it in place of the Mullard GZ-37 the funny sounds began just a couple of minutes after begin of vinyl play... The GZ-34 is a Valvo with Mullard codes, not a Hytron. The seller wrote it measures good on his Funke tube tester. Any idea what else it could be? Thanks.
Regards,
frankiealverti