My chandler/tube driver don't work :-(

[SpiderBass]

Hello  

I build the Tube driver somes month ago. It work correctly at the beginning, great sound and lot of distorsion. But after 5-6 hours the effect don't work at well... no sound or just a hiss when gain or volume set to the max. Another problem is the time of power on before i can use correctly this effect ( 3 minutes... )

I begining to try the problem with testing lots of components, i replaced the main caps and IC for testing correctly the effect. After i use a signal tracer to find the fault. At pin 3 of the main IC the signal is correct. At the output of the 4558, the signal is lost  :?

I use a power supply AC 12v - 500mA but when i would test the supply in the board, it seems strange... I find -21.3v for V-, and 6.7v for V+. The problem is JRC4558 don't support more that 18v  :roll: .

Before R19 i check 17.8v and after 6.7.

I find the schematic at generalguitargadgets.com ( very nice website    )

The schematic :
http://www.generalguitargadgets.com/v2/diagrams/tube_driver_sc.gif


Do you think i haven't use the good 4558 ( i find other manufacturer can accept maximum voltage of 22 v ) or the power supply is not correct  :?

Many thanks you for answers and sorry for my poor english  :lol:  

[george]

have you tried a different valve (tube) - sounds like there's something wrong with the heater filaments in the one you are using, it shouldn't take 3 minutes to warm up ...

the power supply sounds about right, I think an opamp can take up to +/- 15V power supply ie a difference of 30V on the V+ and V- pins

[SpiderBass]

I use a Mesa Boogie 12AX7A valve, but i try with other tubes for test. The heater filaments are supply with 12AC supply, but the valve is very hot  :shock:

But when i try to test if the opamp work correctly, i use a signal tracer and find signal at input but not output, it's why i'm not sure that V+ and V- are correct. But if the maximum difference is 30v it seems correct  

I change the valve and opamp last week and see  

Thanks  :wink:

[Rodgre]

I have a similar problem with a REAL Tube Driver (not a DIY one) and I loved the tone so much through my AC 30 that I was ready to mount the sucker on my pedalboard until I started getting these symptoms. I think (it's been a while since I used it because of this) that it would work for a half hour or so and then start to just turn into hiss.

I never tried to fix it other than to replace the tube and it still did it.

Roger