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Discussion Starter · #1 ·
Just picked up a Deluxe Reverb clone built from a Mojo kit (AB763). The amp has a few quirks, but for $600 I was willing to look past them in the hopes they were easily fixed.

The main issue is the volume control. There's no audible signal until you turn the volume pots to 3.

The other issues relate to the Reverb. The Reverb control doesn't actually provide much "control" ( cuts in around 2 on the dial then after 3 it's full on surf) and theee are random Reverb "splashes" in the background when playing

I have some basic knowledge on how how tube amps work but that's about as far as my amp skills go, lol! Hoping someone can lend some insight to these issues
 

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Make sure no pots lugs touching metal housings, refresh solder points, some don't look nice. All should be nice and shiny, shouldn't show layers of solder or look grey.Wiring looks OK. Could be an issue with bad ground connection. Cheers
 

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....did the builder put star washers between pots and chassis ?
Would this potentially reduce the "efficiency" of the ground?
I'm trying to learn more about electronics and troubleshooting. This is purely from an "academic" perspective as I won't be working on any amps.

Thanks for taking the time to respond/explain.
 

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Discussion Starter · #11 ·
Personally, I don't like using back of the pot for ground connection, did the builder put star washers between pots and chassis ?
When you say "using back the pot for ground" are you referring to soldering the third lug of each volume pot directly to the back of the pot, as this builder did? Seems to be what the schematic calls for. Also, I don't think Star washers were used - looks like regular washers
 

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Would this potentially reduce the "efficiency" of the ground?
I'm trying to learn more about electronics and troubleshooting. This is purely from an "academic" perspective as I won't be working on any amps.

Thanks for taking the time to respond/explain.
Front threaded part of casing is made out of zinc most of the time, it's oxidated straight from the factory - cast metal. Star - toothed washer bites into the metal both ways, chassis and the pot's casing and assure good ground connection.
 

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When you say "using back the pot for ground" are you referring to soldering the third lug of each volume pot directly to the back of the pot, as this builder did? Seems to be what the schematic calls for. Also, I don't think Star washers were used - looks like regular washers
Yes, that's what I meant, star - toothed washer is recommended to make proper ground connection, especially if ground lug of the pot was soldered directly to the pot's casing.
 

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Star - toothed washer bites into the metal both ways, chassis and the pot's casing and assure good ground connection.
Interesting. Thanks!

I was wondering if the "teeth" on the star-toothed washer would reduce the area of surface contact and subsequently reduce the ability to provide for a good ground.
Totally wrong...again...typical for me...LOL
 
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