PV2

[Doctubes]

I have 4 Preamps PV2 and 2 of them are noisy . Samething wrong in anode resistor of output tubes , I guess . I couldn't download schematic . Is the a PCB layout available ? Thanks for help .

[admin]

Welcome to CJO, great to have you with us.

I think we do have the PV2 schematic in our database so I would recommend starting there to see if you can identify a bad component. You can download the schematics here: https://www.conradjohnsonowners.com/vie ... f=17&t=128

Did you consider other potential causes such as ground loops? I only ask as you don't provide us with too much information and there can be other causes of noise.

[Doctubes]

Thanks ! Sorry for my mistake . I have Premier Two Preamps . Unfortunately , this schematic is a little bit blurred and I can't read resistor number and value . Noise is more like cracking . This problem happens frequently when Anode resistors are defective . I'll trace the signal and keep you informed of results .

[AnotherJohnson]

More often than not, a noisy preamp needs retubing.

[roberto]

Hola Doctubes,

Before changing the anode resistors, change their solder at the solder joints. The solder with time, makes faulty contacts and become noisy. Usually that's the problem. Also, noises, 90% comes from noisy tubes. I agreed with AJ on this.

If you can't read the value, Conrad Johnson always use a 1% metal resistor tolerance value.

Happy listening!