Tube Amp Archive

Hi Ryan , I don't know if it's you amp , maybe.
I have to check on youtube!!

Seems to me more like a gain or something similar.

Anyway thanks for explanation.

About the pots of the Ultraphonix amp, I can see some clone with an add.potentiometer fitted in the second jack . What doest it make that pot?

Thanks

bad solder joint!

Thanks
R.

thanks , but the led works

Hi, I have a problem with my effect pedal Roger Mayer Vodoo Vibe.
The effects work , but the red led stay off when engage on.
any suggestion about the issue is well appreciated

Thanks
R

checked, mine has 311k value

Thanks Ryan and Ian

Hi, can I use 500K for bass pot in the #183?
I can see 300k, but is not a standard value.

Thanks

Hi , I have an Hartke HA4000 on my workbench and I have to set the bias, on the schematic there are no info about the correct setting.
Someone can help me?

Thanks
R.

Hi Phil, make some test with DMM in continuity mode on some shorting tubes, but the test don't work!.. When the tube is pulled into the amp , the fuse blowing, so your suggestion is not ok for me.

Someone have an idea for a little circuit for check tubes!
Thanks
R.

Hi Phil, Thanks, but I thought the tube under test must be in power on condition!!?!! Like old tube tester!

Hi all, There is a simple circuit to use for testing short pins of the tubes?

I have a multi tap transformer and maybe I could build a shorting tester.

my PT secondary:
0 - 130V @ 45mA
0 - 60V @ 30mA
14 - 0 - 14V
0 - 9V 45mA

Thanks
R.

ok.... , the 250K pot is a rev-log type like 3M3 pot?

R.

Yes, I tried your last scheme with 12ax7!

Hi , I tried to wired your scheme today, but don't work , compared to 6g9 vibrato , seems to me the negative voltage on depth pot is missing.( in the schematic lug is on ground!)
Neg voltage is required or not?