Deluxe Reverb Reissue Crackle/hum/buz

[Mega_Matt]

Hi! First time posting on one of these things. I’m having issues with my Deluxe Reverb Reissue and I was hoping someone could help me with figuring it out. Thanks in advance for anyone offering advice.

I have some crackling when playing through it on both channels regardless of volume the amp is set at. The harder I strum the more it crackles. There is also a present hum/buz now. Turning the reverb knob up increases the hum/buz by quite a bit. None of the other knobs affect the noise. This amp has the Fritz mod btw, Which brings reverb over to the normal channel.



I’ve tried swapping out all the 12ax7 tubes one by one with a known good one from my 5e3 amp. This did not change anything.




I swapped out the 6V6’s and GZ34 tubes from my Princeton Reverb Mojotone clone. This did not change anything either.




I pulled V3 12at7 and this did not fix the issue. I then put that tube in place of the 12at7 in V6 and that did not solve the issue either.




So I feel like tubes are likely not the issue.




I tried unplugging the reverb tank and that did not fix the issue either.




I opened the amp to look at the board and noticed that the black heater wire on V5 had broke and it was hanging onto the tube socket by a thread. So I stripped that back and soldered it back. This did not fix the issue.




Another thing I noticed as on the V6 tube socket was that there was a strand of wire coming from pin 7 and it was touching pin 8. I was curious if it was soldered there and it wasn’t. I was able to push it away with the lead on my multimeter. This did not fix the issue either.




I’ve tried 3 different speakers and 3 different power sources, including a power source that is filtered through my Furman PST-8 power conditioner. None of these fixed anything.

Again, thank you to anyone who takes the time to give me advice or suggestions on what to check next.

[g1]

Did you install the mod? Was the amp ever ok after the mod was installed (no crackle or hum) ?
Both problems started at the same time?

[Mega_Matt]

Hi. Yes I installed the mod myself about 5-6 years ago and the amp has run great ever since. I tried reversing the mod last night and it didn’t change the situation.

And yes, both problems started at the same time. I noticed the crackle first through headphones while I was recording. Then I went to listen to the amp by itself and noticed the hum as well, so I assume they started at the same time.

[Chuck H]

When recording "using headphones" rather than "the amp by itself" what are you using for a load?

[Delta362]

Do you have a signal tracer? If not, you can rather easily and cheaply build one to help find where the noise begins.
http://musicfromouterspace.com/analo...naltracer.html

Perhaps the crackle is coming from one of the plate resistors from the first stage?

Edit: For the signal tracer capacitor, you'll want to use a much higher rated capacitor than 50V, so something like a 0.01uF 630V cap would be a much safer bet to use in tube amps.

[Chuck H]

A couple of thing right off... I've read here that some early years of that model used plate resistors in the preamp that weren't up to the job and could develop crackling noises such as you describe. If this IS an early model that would also put it's age in a range where it might be time to replace the power supply filter capacitors. If these aren't performing it might account for the hum and buzz. And FWIW it's not uncommon for whatever the usual background noise in the amp is to increase when the reverb is turned up. The reverb circuit accomplishes huge amplification in just a couple of stages so the noise floor for that circuit tends to be poor. If your amp is making more noise for some reason then turning up the reverb will only exacerbate this. In other words, there may be nothing "wrong" with your reverb circuit. It's just that the reverb circuit has a better chance of amplifying what IS wrong. So...

Without much else to go on and if the amp is an older one you may just need new plate load resistors in the preamp and new filter capacitors.

[galaxiex]

Does the amp have send / return jacks?

[Mega_Matt]

Chuck H I use an iso box with a 1x12 cab in it with a miked Weber 12F150 8 ohm speaker. The speaker is plugged into the internal speaker jack of the Deluxe. My headphones are plugged into my interface. When I noticed the noise in my headphones I shut off the amp, hooked up the internal speaker to the Deluxe to confirm the noise was coming from the amp.

That makes sense about the reverb amplifying the noise. I bought this amp new in 2014 so it’s not super old, but maybe old enough?

[Mega_Matt]

Delta362 I do not have a signal tracer. That looks easy to make though. I’ll look into that.

[Mega_Matt]

galaxiex I assume you mean for an FX loop or something like that? The amp does not have those.

[Chuck H]

Chuck H I use an iso box with a 1x12 cab in it with a miked Weber 12F150 8 ohm speaker. The speaker is plugged into the internal speaker jack of the Deluxe. My headphones are plugged into my interface. When I noticed the noise in my headphones I shut off the amp, hooked up the internal speaker to the Deluxe to confirm the noise was coming from the amp.

That makes sense about the reverb amplifying the noise. I bought this amp new in 2014 so it’s not super old, but maybe old enough?

Well that wouldn't be a particularly early model then. That doesn't mean it can't be the plate resistors and/or power supply filters but it seems less likely now.

What is your level of electronics experience? Do you have experience taking measurements in a live amp and know the safety protocols?

[Mega_Matt]

Chuck H I’vd built a couple guitar amps and a headphone amp, which required live voltage testing. I had a discharging tool for testing the amp dead, but I can’t find it. Could make a new one. I work in the electric field, so my hands are on live electricity every day. I’ve been using class “0” 1000 volt rubber gloves when I’ve been troubleshooting the Deluxe.

[Mega_Matt]

Chuck H I tried pulling out the tube for the phase inverter and it didn’t fix the issue. Does that rule out the plate load resistors in the preamp?

[Chuck H]

Chuck H I tried pulling out the tube for the phase inverter and it didn’t fix the issue. Does that rule out the plate load resistors in the preamp?

Okay,..

I have some crackling when playing through it on both channels regardless of volume the amp is set at. The harder I strum the more it crackles.

I have to guess that this crackle, as described, is not what you're saying was NOT alleviated? Since pulling the PI tube would make it impossible to hear anything from the preamp.?. So...

There is also a present hum/buz now. Turning the reverb knob up increases the hum/buz by quite a bit. None of the other knobs affect the noise.

Are you saying that the hum and buzz remains when you pull the PI tube then? AND, Since the reverb recovery circuit is behind the PI tube in the signal chain I'm still wondering what wasn't alleviated.

[Mega_Matt]

Chuck H Sorry, so the hum/buz was not fixed when I pulled the pi tube. No crackle with the pi tube removed because I couldn’t play out of it.