problem with Deluxe Reverb kit

[broumen]

My dad and I built a deluxe reverb kit ( this one: http://www.tubeampdoctor.com/de/shop_Am ... p_Kit_3406 ).

Normal channels works perfectly fine, but there's a problem with the vibrato ones. When volume is set higher than 7, the sound breaks up in a strange way. There's no easy way to explain it so I attached an audio file. All the connections have been measured and are correct. It doesn't matter if the reverb tank is connected and the vibrato/reverb foot switch doesn't affect this problem in any way either.

Is there something any of you could say based on the sound fragment? Where should we look for the problem?

[M Fowler]

That is the sound of a missed solder joint or poor solder joint.

[pdf64]

From the clip, it may just be regular farting out power amp clipping, resulting from high settings of the volume and bass controls.

Is there a similar amp you can compare it to, side by side?

Depending on the particular tapers used in the volume and tone controls, it may be expected for the amp to be overdriving at a volume setting of 7.

There's a mountain of bass available from the tone stack, and at high volumes, something has to give.

The key is to turn the bass down as the volume is turned up.

It's more apparent on the reverb channel than the normal channel because the former has more gain than the latter, due to the V4b wet/dry mixer recovery stage.