Tube Factor Problem

[duffrey]

Hey All
I have a Hughes and Kettner Tube Factor overdrive pedal, which I absolutely love.  Sadly though when I am playing through it, the volume will gradually decrease almost to nothing.  If I try switching modes it doesn't matter, If I shut it off, obviously the volume comes back up and then sometimes if I'm lucky I'll be able to switch it back on again and it'll be fine.  This only happens every so often, which makes it very unreliable.  I can play a gig and it'll be fine.  Then 2 weeks later it'll do it to me.  
Any ideas?  I asked the people at hughes and kettner and they said that it was probably the tube socket.  Doesn't sound like that to me, but I'm no electronic genius!
I have also replaced the 12ax7 that was in there just to see if the tube was the problem, which it wasn't.  So now the original tube is back in.  

Any ideas would be greatly appriciated.  

Jeff

[Lonestarjohnny]

I'm not sure of how the Tube Factor does it's switching, I have the H&K Tubeman, The switch on mine was acting up in sorta the same way, it would loose contact sometime's and sometime's it would not come on at all, so I cleaned the switch with electrical cleaner  that had a silicon base lubricant in it and that cured mine, it works everytime now, could be your problem also, but it could be a cold solder joint or somethin overheating on the board, but I would try the simple thing's first, clean the input/output jack's and switch first.
JD

[Paul Marossy]

Check out the "Low power loss of volume" section at the Tube Amp Debug part of http://www.geofex.com/

It sounds like the circuit may have a defective component somewhere, a bad resistor or a bad cap.

[Peter Snowberg]

Since it fades out, I'm wondering if the fillament is loosing power? If the filament is being fed by a regulator, check the temp of that regulator. It might be going into thermal shutdown when it shouldn't. Just an idea.

If you can see the tube, make sure its still glowing when the volume fades out.

Best of luck!
-Peter

[ErikMiller]

Funny, Peter, the first thing that popped into my head was "filament power."

But would that be a gradual fade? My guess is that it might, because the tube would stay hot for a while from the plate current.

[fluxus]

hello, if could be useful I made a web page for the Tube Factor, hope that helps!
http://www.sonicurbs.com/tubefactor/index.htm

[dmk]

i have the exact same problem with mine, so i just stopped using it and use a modded sd-1 now.
its not as good, but its reliable.
the internal step-up tranny died on my twice already though and those things are a bastard to get hold of in the uk.
ended up having to get them from a company in germany.
thats said, it really is an amazing pedal, THE best crunch ever. i was never a massive fan of the 2nd channel, mainly because when the gain was set above noon the first channel would be louder than the second gainier channel. it really needed channel volumes along with the master. and 2 gains. 
let me know if you get to the source if the problem, i'd really like to get mine going again.
dmk

[dmk]

any progress in getting to the bottom of your problem?

[moosapotamus]

Wow, a two year old thread. Whatever, anyway...

Funny, Peter, the first thing that popped into my head was "filament power."

But would that be a gradual fade? My guess is that it might, because the tube would stay hot for a while from the plate current.

Yeah, I think so, too.
I recently built a power supply for an alembic f2-b clone and had the exact sam problem, initially. After about a minute or two the output signal slowly faded to nothing and the LM317 regulator on my filament got screaming hot. After it cooled down I hooked up my voltmeter, fired it back up, and watched the voltage drift down to nothing along with the output signal.

My regulator was actually fine. But, I solved the problem by using a much beefier heatsink on it.

~ Charlie

[dmk]

i didnt even look at the dates 
cheers for the info