Fosgate Signature Phono V1 Preamplifier

I own the same Fosgate V1 as you, a couple years back I bought the 6X4 SER Rectifier Tube. It seemed to make the sound smoother, less edgy. I liked it enough that I bought another for a backup.
 
That said I have made many tube changes of the other six tubes since and I have not tried listening with the stock 6X4 with my current tube setup.

Gary

Thanks Gary, I am leaning towards the SER but still open to suggestions from owners of the Fosgate V1. I might try the SER and one other. How did it handle the bass. Also did any of the other tube changes make a difference? I read that only the V3 position 12AX7 will.

I have found my Fosgate to react to any and all changes, this would include duplex outlet, power cord, interconnect, and also changing the fuse to the Synergistic Research Black fuse made a noticeable difference. I am currently considering trying the Orange fuse.

Also I have found that every tube change makes a difference, V3 may very well show the largest difference but I hear a difference with every tube changed. Currently the only stock tube I am using is V1, but if I put on a different cartridge that would most likely require some tube change.

I can't address your question about the SER and bass as that would require changing back to the stock Rectifier tube, just give it a try and see how you like it.

I have owned this for a long time and think it can sound fantastic, with a great sound stage. My only complaint is its not having enough gain for most MC cartridges. 

Gary