Fosgate Signature Phono Preamp

Hi, just got a used Fosgate Signature Phono V1 that is a little noisy and I am suspecting the tubes. Any suggestions if this is likely? Also, what brand were the stock tubes? The current tubes are: 

V2,V1: 2x Jolinda 12AT7 WA USA

V3: 1x 6DJ8 Unison Research 

V4: 1x Svetlana 12AX7

V5,V6: 2x Mullard 12AT7/ECC81 Russia

V7: 1x 6x4 USA

I would be grateful for any help. Thanks. Frank

Wow!

Nearly 10 year old thread. I was reminded I dropped in, back in 2018.

Are you referring to tube rush?  Don't  expect dead silence at cranked levels, or have your ear pressed against the speaker, you're going to be disappointed.

My Foz is quiet. till around 12:00 o'clock(MC setting) Past that, once the music kicks in, it's forgotten, and not a deal breaker. I don't listen at concert levels, so at moderate
levels, very quiet, especially the MM setting.

I have a V2, allegedly with improvements to make it quieter. The cheesy blue LED under the tubes were replaced with orange LED's also. I disconnected that front blue LED, which I found too 1980's  looking!

ALL tube units have some degree of hiss. The Foz has active gain, so it's a little noisier than the current popular units which are aided by transistor and step up circuitry.

From the listening position, it should be acceptably quiet at moderate levels.
If you have a spare 12ax7,at7 and 6DJ8 you could swap to see if it makes any difference. I doubt it's a tube. Sometimes just reseating them can eliminate a pesky noise.

Per the manual, V3 is the money tube(12ax7 or at7) for sonic tweaking.It's subtle and naturally subjective. To my ears, the Foz is more similar than different than the current players. I've had a few current,popular tube units side by side with the Foz. They are definitely quieter at high volume .

If you find it too noisey, a Manley Chinook or Herron is in your future.

Hi Frank, I also own the Fosgate Signature V1 that I bought new. I don't know if you have the owners manual but the tube complement you referenced in your unit is way off.

The original tube complement would consist of, V1 and V2 being 6DJ8, then V3 and V4 being 12AX7, and V5 and V6 being 12AT7.

I am not a tube expert but if you have 12AT7 tubes in V1 and V2 that is probably where most of the noise is originating. I would suggest contacting Musical Surroundings and try to acquire at least one of the originally supplied 6DJ8 tubes. The original supplied V1 6DJ8 is very quite, I use it in the V1 position then in V2 I've substituted  a Tungsram E88CC (compatible with 6DJ8 and 6922). 

Next you need to remove the 6DJ8 from the V3 position (you could use it in V1 or V2) and replace with 12AX7 or you can substitute a 12AT7 but you will have less gain with that tube. 

The Fosgate is fun to tube roll and you can alter its sound a lot, I have been at it for years and think (maybe) I've found my preferred arrangement. 

Gary 

Thanks, Gary. This has been extremely helpful! :) I suspect the previous owner removed his more expensive tubes and just threw a bunch of “left over” tubes on the unit. I will try your suggestions and see if this may result in improvements. 

One more question, Gary. What brand is your original 6DJ8 tube in case I can find a matched pair?