Fosgate Signature Phono Preamp

I have this Fosgate Phono pre-amp and would like to offer up some comments. Over the years, several high gain solid state phono pre-amps have passed thru my system. Most were very quiet, but two in particular (shall remain name-less) had a noticeably higher noise floor than the all tube Fosgate. For a high gain phono pre-amp that takes 7 tubes, its remarkably quiet out of the box. IME, I can assuredly state that the rating of 60db is quite conservative.

Speaking of tubes, this pre-amp is a tube rollers dream. As one would expect given its design, the unit responds to each and every tube swap. Very easy to tailor the sound to one's personal preference. Additionally, you are rewarded with an even lower level of noise.( Don't get me wrong, its sounds good with the stock tubes as well.) I have little to no tolerance for noisy phono stages and its a non-issue for me with the Fosgate. My speakers are 90db efficient, and will easily reveal any annoying tube "noise". And yes, I also own a solid state phono stage that is virtually silent to make the comparison. I run my phono stages thru a modified Cary SLP-2002 tube line stage that itself is dead silent.

For those that are serious tube phono stage aficionados , with a large NOS library. I'd say this unit is a must audition.

Here is the tube compliment I've settled on after an evening of experimentation. I'm pretty content right now with the way it sounds with these tubes.

V1- 1966.......Amperex Holland 6DJ8 Bugle Boy
(other various vintage 6DJ8 BB also great)
v2- 1965.......Amperex Holland 6922
(other various 6922's also great)
V3- 1960's.....Telefunken 12AX7 Smooth Plate
V4- 1960's.....Raytheon 5751 Black Plate or Grey Plate
V5- 1960's.....Tungsol 12AT7 Grey Plate
V6- 1960's.....Tungsol 12AT7 Grey Plate

I have not experimented yet with the 6X4 power supply Rectifier tube, but plan on doing so in the near future.

Sonic attributes, I'll address regardless of tube compliment. To me, this unit sounds exactly like the circuit its built upon. Have you ever heard the clarity of a DC powered phono stage but wished it had a little more oomph? That's what you get with the Fosgate. A very clear, deep, wide open space that lets an unforced, natural musical flow come through. The signal path tubes are powered by DC fed from large storage capacitors. The power supply is fed AC and high voltage rectification is achieved by a 6X4 rectifier tube. That's where you get the extra little oomph, that's missing in other DC powered stages I've heard.

Rolling tubes, you can really enhance dynamic contrasts, bass punch, extend bandwidth and get the sound field well off the speaker cabinets. With the stock tubes, the unit leans toward a warmer and more relaxed presentation.

Being that this is an all tube unit, don't expect "stump" puller type bass response. So if your speakers are in need of some extra help in the bass, the Fosgate won't add that to the signal- it's a rather neutral and accurate piece. (However, the supplied 6X4 JAN Philips rectifier tube is well known to be softer in the bass. A NOS Tungsol or Raytheon 6X4 will definitely deliver more bass power) Ahh, but if you want to hear a drum kit sound realistic- this unit will give you that in a way that solid state can't touch. It's also quite capable of resolving low level detail, you may hear sounds and vocals previously unnoticed.

Now using a NOS Sylvania BP 6X4 Rectifier and swapped one of the Tungsol 12AT7's for a BP Brimar 12AT7. Dynamics, bandwidth and bass slam beyond belief. Also, unit is now broken in.

Lula,

That is one of the very reasons I bought this tube preamp. The circuit uses 1/2 of the triode in positions V1-V6 for the left channel and the other half for the right. Matched pairs are not required! All you need is a single tube that has reasonably equal output from each triode per position.

I'm currently listening to a blend of Holland, W. German, USA and UK NOS tube sound and loving the results!!