Hi All,
I just built a "Dumble-style" Deluxe Reverb. Mostly AB763 w/ 'verb channel turned into a switchable OD channel. Still has 'verb and 6G6-style trem. Everything is working, mostly. A couple quirks.
1) Normal volume (also known as clean channel volume) won't go all the way to zero. All the way down some guitar signal still coming thru AND a loud "hissss" is present. Much louder than normal. Amp gets very loud very quickly. At 10 o'clock volume comes on all at once and sounds 1/2way up. Clean tone at this point, but starts overdriving the amp very soon after. 1/2 way up on the knob is full volume and overdriving like crazy. Other pots, including O/D controls seem to work normally. I thought about bad grounds, but other pots are fine. Changed 1M volume pot, no change in sound. Ideas?
2) 6G6-style trem works well but does not go all the way to zero. Speed and Depth all the way down, still seeing the bias go up and down. Just a few milliamps +/-, not audible, but still worrysome.
3) Power tranny running hot. Has eaten a couple fuses, but not right away like a burnt tranny. May have something to do with my relay power supply, tapped off the 6.3v.
I didn't use a brass ground plate. Instead I ran a "ground buss", connecting all the pot grounds with a wire, grounded to a screw in the chassis, near the input jacks. Also connected all the circuit board grounds and grounded them at this "preamp ground" spot. Preamp filters are also grounded here. All power grounds are grounded to a PT mounting screw. No 60Hz hum issues. Amp is built an a DR chassis from Mojo. I may need to change some grounding, but not sure what to change as so much is working correctly.
Suggestions? Ideas? Thanx!!!
I just built a "Dumble-style" Deluxe Reverb. Mostly AB763 w/ 'verb channel turned into a switchable OD channel. Still has 'verb and 6G6-style trem. Everything is working, mostly. A couple quirks.
1) Normal volume (also known as clean channel volume) won't go all the way to zero. All the way down some guitar signal still coming thru AND a loud "hissss" is present. Much louder than normal. Amp gets very loud very quickly. At 10 o'clock volume comes on all at once and sounds 1/2way up. Clean tone at this point, but starts overdriving the amp very soon after. 1/2 way up on the knob is full volume and overdriving like crazy. Other pots, including O/D controls seem to work normally. I thought about bad grounds, but other pots are fine. Changed 1M volume pot, no change in sound. Ideas?
2) 6G6-style trem works well but does not go all the way to zero. Speed and Depth all the way down, still seeing the bias go up and down. Just a few milliamps +/-, not audible, but still worrysome.
3) Power tranny running hot. Has eaten a couple fuses, but not right away like a burnt tranny. May have something to do with my relay power supply, tapped off the 6.3v.
I didn't use a brass ground plate. Instead I ran a "ground buss", connecting all the pot grounds with a wire, grounded to a screw in the chassis, near the input jacks. Also connected all the circuit board grounds and grounded them at this "preamp ground" spot. Preamp filters are also grounded here. All power grounds are grounded to a PT mounting screw. No 60Hz hum issues. Amp is built an a DR chassis from Mojo. I may need to change some grounding, but not sure what to change as so much is working correctly.
Suggestions? Ideas? Thanx!!!
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