Hughes & Kettner Cream Machine - Noisy

[josegrad]

Hi,

I have this old H&K Cream Machine which is a bit noisy and hummy:
http://hughesandkettnermicroamps.wee...m-machine.html

The schematics are here:



I did replace the valves not long ago so they are quite new. But still it is quite noisy.

Any advices where to start with this, new caps maybe?

Thanks.

[vintagekiki]

I did replace the valves not long ago so they are quite new. But still it is quite noisy.

In principle, each HiGain (pre)amp generates more or less some noise.

Question
Is the replaced tube quite (as) new or new.
Replace V1 (CM1) with new low noise tube 12AX7 (7025)

Is there noise when VR1 (Gain) set to min. (far left)

[josegrad]

Thanks Vintagekiki.

Actually I did buy new tubes. With low gain it is not noisy, but setting gain and master above 7 makes it quite noisy.