Peavey Classic 30 scratching , popping sound

[Stewen]

Hallo ! Have been working several days with this amp now . It worked when I started but the owner wanted it to be more open and cleansounding . I fixed that with some common mods and quality

components . But this disturbing spikes have come instead . All tubes are new and tested and replaced again with known good tubes . All filtercaps are new F&Tīs . When I lift B+ , feeding V1A and

V2A everything is quite and fine ...... I have connected my oscill. to anode nr1 , V1A and there are some spikes at the same moment as it appears from the external speaker . I have lifted C3 couplingcap

and also R 38 , B+ feeding the reverbarea ....... but no luck . Also been tapping with a chopstick all over the three boards ...... no luck . All voltages at the tubes seems OK .... normal . The hinges

between the boards are controlled very carefully so also all soldering points . Thanks for some help . ...... Stewen

[g1]

Please post the original schematic and the schematic showing all your modifications.

[martin manning]

When I lift B+ , feeding V1A and V2A everything is quite and fine ...... I have connected my oscill. to anode nr1 , V1A and there are some spikes at the same moment as it appears from the external speaker . I have lifted C3 coupling cap

Have you tried replacing the V1A and V2A anode resistors? Looked for bad solder joints around V1A and V2A?