Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: rafe on October 02, 2023, 03:52:36 pm
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Reverb very faint and can hear tremolo clicking and speed of click changes. Both turn on and off with the footswitch. If I rattle the reverb tank it responds normal LOUD. I removed the tubes and substituted tubes. The 2200 resistor on V3 is out of spec. so I suspect it. This was working fine. It was sitting for a while and hadn't been used for about a year. Yesterday I replaced the bias cap and cut out the 2000pf's on the power tubes . ++update++ as I was typing this I heard sputtering from the other room. I went in and the amp was crackling and some hissing ...but the reverb was working. I'll have to take out the chassis again and see what I can find....Might could use suggestions if any one has had similar issues ...I'm going to check voltages. Question: I believe I can just remove those 2000picos with out re-grounding those pins correct?
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I believe you'd have to replace the caps with resistors or different value capacitors if you were going to remove them. Otherwise your grid would have a direct reference to ground.
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Just snip the leads on the 2200pF caps. Do nothing else.
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If the amp was working previously, and you have a bias resistor in the reverb that's out of spec, and the reverb is your main issue, maybe you could replace that resistor to get the reverb circuit working again. I have doubts that changing the power arrangement would assist in helping your reverb, but I may be wrong.
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Thanks Steve , I was pretty sure that was the case, I went back to the post from Willabe, can't believe it's been 4 years, and He said just snip them out .... Just wanted to be 100% sure I still have to install 1ohms , but have to order them. It was playing fine after I put in the new bias cap and cut the 2000's out. I put it all togrther and brought it in the house and it sounded great.....just no reverb ....Now it has to go back out to the shed and come apart again. It's pretty heavy. ....That 2200 was pretty high. I'll start with that....all the others tested good.. It's odd to me that neither signal was coming through Trem or Rev but now the reverb works, but the amp is crackling and hissing like a camp fire. Here is a quote from you from the same thread Sept.2019 "Reverb and tremolo issues are seldom related." I'll be working on it!
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++*SOLVED*++Hidden in plain sight . Removed first two tubes and replaced the second. Before I did do that I discovered that if I turned off tthe reverb ....It was Crisp clean and sounded great. Turn on the reverb It was great for a while then would develop a low howl but not always ....if I tapped the 2nd tube when low howl it would either stop or go to feedback...sometimes pop and hiss too ...But only with reverb on...for now it's great going to get some new tubes on that end ....didn't have to carry it out to the shed ...~~UPDATE~~ The 52 GA40 les paul is pretty good , I may (or may not) hook up a footswitch to get the tremolo working ...It's in the shed now on a cradle ....but next is the 53 GA-50T ......wish me luck on that one ....it's busy in there.....But it sure does have a great (CLEAR readable) schematic