Gretsch Amps

Executive Hum

1

I know this has been talked about before, but I can't seem to find it. My Executive hums pretty bad just sitting there with the volume all the way off, it bugged me so much I actually sold it but told the guy he could bring it back.... which he did when he compared it to his buddies that was dead silent. Seems like its a crap shot if they hum or not. This one i guess was owned by Tavo a couple owners before me, if he didn't fix it maybe they are not fixable?????? Mine also makes some popping when the tremolo foot switch is pressed, but I could care less about that. But being I play mine 99.999% at low bedroom levels the hum sucks. I tried moving/switching tubes but that did do much of anything. Its strange it hums with the volume all the way and if you turn it up the volume doesn't increase. Any help would be appreciated. And sorry if there is already post about this.

2

It was mostly the reverb with mine.

3

With mine you can barely tell it's turned on. The room has to be dead quiet to hear anything at all and then it isn't a hum per se just an ever so slight noise a shade above turned off.

I'd recommend calling Victoria amps and speaking with their designer - sorry forgot his name. I'm sure he'll have the solution. Please let us know when you've solved the problem.

4

I need new glasses. At first glance I was sure this topic read Execute him.

5

I need new glasses. At first glance I was sure this topic read Execute him.

– Deed Eddy

Well there is that, given the atmosphere south of our border these days!

6

Mark Baier is his name.

Rockndawg, there is definitely something seriously wrong with your amp. My Executive is very quiet (that is, until I step on the tremolo). But, no hum like you describe.

I think that it is good advice to call Mark at Victoria Amplifiers but there isn't really much that he can do to help you with your situation unless you ship it to him. Best to get it into the hands of a local or regional highly qualified amp tech, and preferably one with experience in working on Fender-type amps since the Executive shares some traits with the Fender amps.

7

Might wanna check with Tavo, see if he had any problems with the amp. Ric12string is right....it's basically a Princeton Reverb with a different PI. The reverb circuit is almost identical. If Tavo had no problems, I'd look at the weakest link which would be a tube. A bad tube can cause hum. If you get as far as looking inside, check out the blue wire coming off the reverb transformer. It's very sensitive to stray fields. I've had to reorient that wire to quiet down a PR.

8

Footawitch pop is "normal" on these amps. Excessive hum is not. I'd get it serviced

9

Thanks i thought a lot of them hummed, i don't mind the pop. I will see if i can find an amp expert near me.

Tavo, if you see this did it hum when you had it?

Thanks everyone ed

10

Has the hum been there all the time, or is this new? People have different tolerances for the noise too. I've been on a rampage recently swapping in preamp tubes with lower gain in order to tame hot amps, and reduce the noise floor. You could try that, but costs some money to get the tubes for some trial and error... unless you have some other amps to swap with.

11

Footawitch pop is "normal" on these amps. Excessive hum is not. I'd get it serviced

– redrocker

Funny guy. It probably isn't "normal", but certainly not infrequent.

12

They're good for pop music.

13

My Execulux (same chasis 12" speaker) only hums when the reverb circuit is on, and then only when a guitar is plugged in. Hum gets louder when volume or reverb are turned up. Checked grounds, shielded wire on footswitch was fine, swapped out some tubes, cleaned contacts on RCA plugs. Still a mystery to me.

14

A tube driven spring reverb circuit is super lossy. The classic Fender reverb circuit pushes the signal thru the springs using a 12AT7 wired in parallel. They all pretty much use the same reverb transformer, with the blue wire connecting the two plates of the 12AT7 together. This loop of wire has been the source of noise for me more than once. Either shortening, re-routing or in some cases replacing the loop with shielded wire has always solved my reverb noise problems. The Executive uses the same layout.

15

I had my Executive for a couple of years -- NO hum that I could detect. I did have the footswitch pop -- was not a problems for me since I rarely used the tremolo.

I agree with others' suggestions to get it service by a reputable tech who knows Fender amps.

16

A tube driven spring reverb circuit is super lossy. The classic Fender reverb circuit pushes the signal thru the springs using a 12AT7 wired in parallel. They all pretty much use the same reverb transformer, with the blue wire connecting the two plates of the 12AT7 together. This loop of wire has been the source of noise for me more than once. Either shortening, re-routing or in some cases replacing the loop with shielded wire has always solved my reverb noise problems. The Executive uses the same layout.

– Powdog

What is the likely source of this problem, Powdog:

When the reverb is switched on, and you step on the tremolo switch, you get a very loud pop. I think that it also pops when you switch it off, but I can say that with 100% confidence.

If the reverb is switched off, and the tremolo is switched on, there is no similar popping.

17

I bought one recently and when the footswitch is disconnected the hum goes away but you can't use the tremolo, only the reverb. But with less hum.

18

I think BZ has already developed a fix for this. Requires some re-wiring though. I think there is also a push button sequence you can follow that alleviates the pop. Might sharpen your tap dancing skills.

19

So, looking closer at the schematic the Exec is more like a Deluxe Reverb than a Princeton (duh!).

It looks like the footswitch activates the reverb by lifting a ground while it activates the tremolo by making a ground, all thru the same jack. Reverb circuits are notorious antennae, so I think with the reverb on you're hearing the ground connection being made on the trem. By removing the footswitch you're also removing the means for the trem to complete the circuit. That's why it doesn't work without the footswitch.

20

Its not the reverb or preamp tubes, you can actually pull all the preamp tubes out and it still hums. I also tried disconnecting the reverb tank and switch. I will take it in and have it looked at. I also have some newer power amp tubes coming in the mail. Anybody no what voltage the bias should be set at??

21

The symptom that you're talking about almost always has one of just a few causes, listed in order of difficulty in diagnosing/repair: mismatched power tubes (or unbalanced phase inverter tube), improper bias, a bad ground (cold solder joint that may look and feel OK, often on the reverb return), or bad filter caps.

22

If you've already tried different power tubes and switched around the various pre-amp tubes, you can't really address the other potential problems without a soldering iron and a multimeter. I would say that you could reflow the grounds without a multimeter, but you'd need one to be sure that the filter caps are discharged before messing around inside the amp. It's fairly safe to do a "chopstick test," though - open the chassis while the amp is on taking care not to touch any wires, and just tap on every component with a wooden chopstick or similar non-conductive object. You may not be able to fix it, but you can get an idea of where the problem is. That may make your bill lower if you need to take it to a tech.

23

I had an Executive for awhile. Hummed very loudly. I remember multiple people chiming in before that's a well known problem with the model.

24

My Executive doesn't hum and so I am pretty surprised by this resounding complaint. Did anyone report the problem within the warranty to Gretsch and, if so, what was done about it?

25

My Executive doesn't hum

Apparently there's something wrong with yours, Rickity.


You know if you tune to an open Bb (maybe with 4ths and 5ths stacked above it) and play one-chord songs, 60 Hz will provide an excellent drone for the therapeutic meditative trance music we'll all be needing in the future.


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