Fender 68 Custom Deluxe Reverb

[royb3988]

Hello...

I have a 68 Custom Deluxe Reverb I bought 7 months ago and a '66 Super Reverb I bought in 1966. When both amps are turned on (or individually), ALL controls turned all the way down and nothing plugged in...I get noise...scratches, pops, sort of like gently stepping on a bag of potato chips and faint distant thunder and the noises are as if the Reverb is on...but it isn't. The noise isn't LOUD but it's there and often is absent for minutes at a time. This anomaly does not occur with my '67 DUAL Showman...it has no Reverb. Playing through the amps covers all the noise.
Could the AC current in my house be affecting only the amps with Reverb or is it likely both amps have problems? I have checked all tubes and they are fine.

Thanks,

RB3988

 

[strat a various]

Hello...

I have a 68 Custom Deluxe Reverb I bought 7 months ago and a '66 Super Reverb I bought in 1966. When both amps are turned on (or individually), ALL controls turned all the way down and nothing plugged in...I get noise...scratches, pops, sort of like gently stepping on a bag of potato chips and faint distant thunder and the noises are as if the Reverb is on...but it isn't. The noise isn't LOUD but it's there and often is absent for minutes at a time. This anomaly does not occur with my '67 DUAL Showman...it has no Reverb. Playing through the amps covers all the noise.
Could the AC current in my house be affecting only the amps with Reverb or is it likely both amps have problems? I have checked all tubes and they are fine.

Thanks,

RB3988

If it's both amps, I'd suspect the internet modem, the house wiring, the neighborhood transformer, etc. Did you try unplugging the reverb tank? Maybe it's an antenna? My apt has a noisy branch circuit where the wi fi is plugged in, only affects certain amps.

 

[tele_pathic]

So when I had an amp that had reverb, I used to get these "ghost" noises all the time. After days and weeks of experimenting and analysis (seriously), I finally figured out that it was ME stepping around the room. The room where the amps live is carpeted. And the amps are even on a stand, not sitting directly on the carpeted floor. YET, whenever I stepped I heard the noises: whenever I was extremely still, no noise. I mean, even tapping my foot would shake the reverb tank. It was crazy and frustrating to figure out.

 

[Blue Bill]

I've had this on several Fender tube amps, including a 68CDR. It usually comes down to one of the pre-amp tubes, the 12Au7, 12At7,or 12Ax7 ones. It's always a challenge to find the culprit tube, as you pointed out, it is intermittent. Sometimes, giving the amp a whack on the side will quiet it down for a while (I don't recommend hitting your amp, but it sometimes works for me). Another tactic is to give the tubes a circular wiggle, to ensure a clean and secure seat in the socket.

 

[john_t]

I just bought a used 68 DRRI and have the same issue. I'm ignoring it for now, but if there is an obvious solution I'd love to hear about it. I read on other threads about flipping the reverb tank around and turning down all knobs of the unused channel, etc. but maybe there is a more permanent solution.

 

[john_t]

So when I had an amp that had reverb, I used to get these "ghost" noises all the time. After days and weeks of experimenting and analysis (seriously), I finally figured out that it was ME stepping around the room. The room where the amps live is carpeted. And the amps are even on a stand, not sitting directly on the carpeted floor. YET, whenever I stepped I heard the noises: whenever I was extremely still, no noise. I mean, even tapping my foot would shake the reverb tank. It was crazy and frustrating to figure out.

This is interesting since my room is also carpeted. I'm going to have to look into that when I'm home.

 

[strat a various]

I've had this on several Fender tube amps, including a 68CDR. It usually comes down to one of the pre-amp tubes, the 12Au7, 12At7,or 12Ax7 ones. It's always a challenge to find the culprit tube, as you pointed out, it is intermittent. Sometimes, giving the amp a whack on the side will quiet it down for a while (I don't recommend hitting your amp, but it sometimes works for me). Another tactic is to give the tubes a circular wiggle, to ensure a clean and secure seat in the socket.

I don't think I'd wiggle them ... might crack the glass ... maybe pull them straight out and re-seat them once or twice. I get this same noise with an old Peavey SS amp ... but only on one branch circuit.

 

[clintj]

The 68 Series amps run less negative feedback, so the noise floor is going to be a bit higher than, say a 65 Reissue or a vintage amp. I'd still try to pinpoint it by swapping tubes and so forth to minimize it, though.

Sent from my Pixel 2 using Tapatalk

 

[Blue Bill]

I don't think I'd wiggle them ... might crack the glass ... maybe pull them straight out and re-seat them once or twice. I get this same noise with an old Peavey SS amp ... but only on one branch circuit.

I tend to be a bit crash-bang with amps; I grew up watching the Fonz fix the jukebox with a fist bump.

I do think a gentle circular motion, like stirring a tiny tea cup, may scrape corrosion off the pins and sockets, and improve the connection.

 

[strat a various]

I tend to be a bit crash-bang with amps; I grew up watching the Fonz fix the jukebox with



I tend to be a bit crash-bang with amps; I grew up watching the Fonz fix the jukebox with a fist bump.

I do think a gentle circular motion, like stirring a tiny tea cup, may scrape corrosion off the pins and sockets, and improve the connection.

Tube sellers love you.

 

[Blue Bill]

Tube sellers love you.

For real? I've been doing this for decades, I've never detected a single problem caused by this. I expect tube sellers hate me; I've bought maybe 4-5 tubes in the last 30 years. I have a SFDR, which I've had since 1982, It was my main amp from '82 - '99, plus I've played it every week for the last 6-7 years, a few thousand hours of use. It still has most of the tubes I put in it 35 years ago. I've only changed one tube in my 68CDR, which also has thousands of hours and miles, on it. (Sorry if this sounds rant-y)

Maybe MuchXS or other amp pro can check in on this.

 

[strat a various]

For real? I've been doing this for decades, I've never detected a single problem caused by this. Maybe MuchXS or other amp pro can check in on this.

Maybe. What happened to MuchXS?

 

[Blue Bill]

Maybe. What happened to MuchXS?

He's still too busy. He does make an appearance here now and then.

 

[dan40]

Removing tubes with a gentle rocking motion is how I have always done it also. I also use a slight swirling motion when installing them.

The OP mentioned that all tubes checked good...how did you you test the tubes? By swapping in known good tubes or by using a tube tester?

 

[royb3988]

Removing tubes with a gentle rocking motion is how I have always done it also. I also use a slight swirling motion when installing them.

The OP mentioned that all tubes checked good...how did you you test the tubes? By swapping in known good tubes or by using a tube tester?

Yes and yes. First I used my tester...old Sencore TC 136, all tested good (100%) or more. Then I substituted each for a known good tube but I don't have any 6V6 tubes. So, I went to the dealer and had him listen...he said it sounded like a tube to him so we retested all tubes including the 6V6's...all tested good on a really slick tester by Orange. I then put the tubes back in and he suggested using a different 12AT7 in each of the 12AT7 slot...still noise. As I was in a state of frustration, I put my tubes back in...made a mistake and had the 5AR4 in a 6V6 slot...yikes...fuse blew. I didn't realize the mistake until I got home and took each tube out again and paid attention while reinstalling them.........NO NOISE. I had the amp on for an hour and a half, played through it...it's a truly marvelous tone, but no noise.
I just turned it on again and 4 minutes in...the noise has returned but nowhere as loud. I think everyone's response is spot on...it's likely a tube and my next venture is removing each tube, using some DeOx on pins and doing the old push in, pull out etc to see if it is a bad contact somewhere. If I do the "stirring like a cup of tea" movement, there is one particular tube that snaps, crackles and pops...I hope its not a bad solder joint on that socket but I'll report back.
We're getting close.

 

[royb3988]

Well...I cleaned one particular 12AT7 with DeOx, did the insert-remove a couple of times and no noise last night at all. This morning...noise, not as loud and it disappears after about 4 minutes. The amp, at this moment is silent! Next step is to remove and clean ALL tubes and hope that gets the job done.

RB3988

 

[royb3988]

Well...I cleaned one particular 12AT7 with DeOxiT, did the insert-remove a couple of times and no noise last night at all. This morning...noise, not as loud and it disappears after about 4 minutes. The amp, at this moment is silent! Next step is to remove and clean ALL tubes and hope that gets the job done.

RB3988

 

[RLee77]

I’d unplug/plug in the reverb tank connectors, both ends, several times to remove any oxidation as well.

 

[royb3988]

Thanks RLee77...even with the reverb cables disconnected the noise was present...after the stuff I did yesterday the noise is significantly less noticeable...I may go back and re-test each tube letting them heat up for several minutes before I deem them good.

RoyB3988

 

[royb3988]

The dealer told me I can exchange if I want to bring it in...I'll likely order a 68 Vibrolux Reverb and try it out when it gets in before I leave the store.