Deluxe Reverb: slight distortion at low volume

[Jonny toetags]

Thanks for all the help guys...I pulled the chassis yesterday and cleaned/reseated all the connections.
She's back to normal now.

[Chuck H]

Ever since amps started using effects loops with switching jacks I've "repaired" a lot of amps by cleaning contacts. Todays amps use even more of that sort of thing. Including ribbon cable connections.

[The Dude]

Ever since amps started using effects loops with switching jacks I've "repaired" a lot of amps by cleaning contacts. Todays amps use even more of that sort of thing. Including ribbon cable connections.

+1. In my rigs, I just put a small jumper send to return if I'm not using the loop. I also carry a couple small jumpers for house rigs, just in case. I've learned over the years not to depend on switching jacks.

[Jonny toetags]

Ever since amps started using effects loops with switching jacks I've "repaired" a lot of amps by cleaning contacts. Todays amps use even more of that sort of thing. Including ribbon cable connections.

Well I spoke too soon.
I played the amp for about 30 min then put it on standby for about 30 min.
When I turned it back on, the problem was back: low gritty signal passing with the vol at 0, going away at 2.
This time it was only on the channel I was using at the time.
What could be causing this?

[Chuck H]

Keep cleaning. De Ox the tube sockets. Spray (or daub) a little on the pins of a preamp tube and plug it into the sockets. Rock the tube slightly in a rotating motion. Do this with each socket.

If that doesn't do it I have another guess...

It's possible that you're filter capacitors for that stage is stabilizing a little with the repeated voltage of testing. But it may not ever be good enough to filter correctly. It may still need replacement.

[Jonny toetags]

Keep cleaning. De Ox the tube sockets. Spray (or daub) a little on the pins of a preamp tube and plug it into the sockets. Rock the tube slightly in a rotating motion. Do this with each socket.

If that doesn't do it I have another guess...

It's possible that you're filter capacitors for that stage is stabilizing a little with the repeated voltage of testing. But it may not ever be good enough to filter correctly. It may still need replacement.

ALright...I'll pull the chassis and clean everything again.

Do you think I should change all my filter caps as a precaution?
The amp is only a few years old and has probably less than 40 hrs on it.

[Chuck H]

The amp is only a few years old and has probably less than 40 hrs on it.

This could be precisely the trouble. It usually takes longer for electrolytic caps to "dry out" but an unused amp does exacerbate the problem and some Fender models had this problem of caps that didn't last.

Are the tube sockets not accessible without chassis removal on these amps???

Clean all non soldered, metal contacts that you haven't already. If you already properly cleaned the contacts only accessible with the chassis out you shouldn't need to do it again.

If cleaning doesn't help, try paralleling a good filter cap with the preamp filter in the amp. If that helps, replace the filter caps. Do the bias supply caps and the small electrolytics in the preamp too just so you know that all the electrolytics will be of good quality.

[g1]

An iffy solder joint is also possible. Maybe at one of the connections you wiggled. The heat after it's on awhile may be affecting it. If it has board mounted tube sockets, check the solder on them.

[Jonny toetags]

This could be precisely the trouble. It usually takes longer for electrolytic caps to "dry out" but an unused amp does exacerbate the problem and some Fender models had this problem of caps that didn't last.

Are the tube sockets not accessible without chassis removal on these amps???

Clean all non soldered, metal contacts that you haven't already. If you already properly cleaned the contacts only accessible with the chassis out you shouldn't need to do it again.

If cleaning doesn't help, try paralleling a good filter cap with the preamp filter in the amp. If that helps, replace the filter caps. Do the bias supply caps and the small electrolytics in the preamp too just so you know that all the electrolytics will be of good quality.

I have access to the tubes without removing the chassis. The first thing I did was clean the sockets and try different tubes, but I will clean them again.

I don't have any electrolytics in stock so I will have to order some.
I was thinking of getting some Spragues, but they only have 20uF's. Would it make a difference if I use those instead of the stock 22's?
I can get some FT's in 22uF values (Ive used that brand in a few 5E3 builds I've done)

[Jonny toetags]

An iffy solder joint is also possible. Maybe at one of the connections you wiggled. The heat after it's on awhile may be affecting it. If it has board mounted tube sockets, check the solder on them.

I'll look at the joints.
The tube sockets are all chassis mounted (nothing on the board)

[Jonny toetags]

This is what I have in there

[Chuck H]

The "stock" value for the originals is 16uf. The reissue likely uses the larger value because a few uf's makes almost no difference in the sound and 22uf is a more standard value, and therefor cheaper. 20uf is fine.

Having cleaned the sockets I don't think you need to do it again.

I wouldn't use the Atom caps. They're way too expensive for what they are. IMHO you'd be best off to use Nichicon or Panasonic capacitors and retrofit the radial leads. I've been using the Nichicon PW series. Better performance, no problems and less than half the price. When I used Atom's they didn't perform as well. I even had trouble with filter cap problems in new builds occasionally.



Do check continuity on and around

[Chuck H]

I've only been privy to the Fender capacitor problem by paying attention around here. I've never dealt with it myself. But I have replaced a butt load of IC (Illinois) electrolytics that had gone bad prematurely. They may make some higher quality products too. I don't know. But those gray ones sure look like the caps I've seen go bad early in several amps.

[pecorporation]

I've seen a couple of these units with the EXTERNAL speaker jack not completely latching when in its normally closed position, usually due to insufficient tension on the latching switch, yes, even on the new ones. This adds a little resistance value to the output load and sometimes is affected by even the slightest vibration or low volume. Even saw cold solder on those same jacks that caused the same subtle distortion effect.

Thought it might be worth a mention...

[g1]

I thought that ext.spkr. jack issue was for some of the HR and Blues series amps?
I don't think the 65 Deluxe reissue uses series spkr jacks, the schematic I have shows parallel jack like the original Deluxe.