Tube type results

[toskrlec]

Noticed one interesting thing that is not directly connected with VVR. When I was put some old cheep SOVTEK AX7 WA tubes, and haven't scratchiness on pots when using VVR so didn't need upgrade preamp section, but I was order few new Tung-Sol higher quality, tested tubes from tubedepot, and put it in my amp. Whit them I get lot of noise, and interesting, very loud scratchiness when using volume pot on guitar and amp. So what You thing, it is connected whit tube gain factor, or some other tube parameter.

I was try put few SOVTEK AX7 LPS, on second position but it hums like crazy, I never see any amp so sensitive on tube type.

[selloutrr]

these amps are best suited for low noise tubes.

you may want to check lead dressing with the new tubes in and see if you can get the noise floor down.

[WhopperPlate]

Tungsol, while sounding decent at times, have issues in general.

[KellyBass]

Is the scratchiness there with the VVR set at minimum?...or does the scratchiness seem more apparant when the VVR is cranked?

[Structo]

It could be that the new tubes just had the correct gain for the designation and the other tubes were weak to worn out.
Just guessing here of course.

A few strategically placed caps should cure the scratchiness.

[toskrlec]

I will go with capacitors in preamp stage, as sugest Dana, to eliminate issues. Is anyone try 5751 on V1 position ? It is lower gain, but how affect the tone ?

[Big Jim]

I run a Sylvania NOS 5751 in V1 most of the time....The one I have has very low noise. Smoothed out the preamp section just right in my build. 5751 produces about 70% as much gain as 12ax7. Luckily wrecks have a little gain to spare...and treble...and mids....and sustain....and feedback...
Forgive me, I really enjoyed my Express yesterday.
Jim