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-   -   Gibson Maestro FuzzTone stopped working after 50 years (https://www.gearslutz.com/board/geekslutz-forum/1292711-gibson-maestro-fuzztone-stopped-working-after-50-years.html)

BothHands 28th December 2019 06:35 PM

Gibson Maestro Fuzz-Tone stopped working after 50 years
 
6 Attachment(s)
Any ideas on how to get my Gibson Maestro Fuzz-Tone working again?

When I was about ten my Mom found a classified ad in the Washington Post newspaper for a used guitar amp and "fuzz box." We had little money but she always encouraged my brothers and me to follow our passion(s). So she drove me to the next county and paid a "suburban teenager" $50 or maybe $75 for the Sears Silvertone tube amplifier, tremolo footswitch and Gibson Maestro Fuzz-Tone pedal featured in the images below.

While raising a family I had to set music aside for a few decades, so all three items have been in storage for a long time. I "rediscovered" them recently and was very excited to try them out. Called my Mom to thank her, too.

1. The amp works like it always has.
2. The tremolo footswitch makes a loud crunch/clunk when switching tremolo in and out.
3. The Gibson Maestro Fuzz-Tone is not working. Ugh. When I depress the footswitch to take the Fuzz-Tone OUT, the guitar plays through the amp as it should. When I switch the Fuzz-Tone IN via footswitch there's NO SOUND at the amp.

I cleaned the battery terminals and swapped various AA batteries in and out. No dice. Any guidance/advice on how to get this heirloom working again would be much appreciated.

Tom

See pics below.

Bushman 29th December 2019 03:04 AM

Hmmm.... is it out of warranty?

I have had no luck in restoring very old dead gear. I don’t have the knowledge or patience required.
Good luck!

mbrebes 29th December 2019 11:12 PM

If I remember correctly, it was not an AA battery but a special 9 or 10 volt battery that went in the unit. Did you keep the original battery before you started sticking in AA's?

BothHands 30th December 2019 12:20 AM

Quote:

Originally Posted by mbrebes (Post 14412496)
If I remember correctly, it was not an AA battery but a special 9 or 10 volt battery that went in the unit. Did you keep the original battery before you started sticking in AA's?

Sparked by your comment I found a couple of articles online:

This one at VintageGuitar.com contains some interesting backgound information.

And this one at Wikipedia says (near the end) that the FZ-1A (mine) was a 1965 redesign of the original FZ-1. My FZ-1A used a single 1.5v battery, which is what an AA battery is.

Thanks for your input.

I'm currently in Utah, near Salt Lake City. I'll be moving to Fort Wayne, Indiana mid-January. If someone in either location can repair this pedal (expert repairs only) please weigh in. :heh:

BothHands 30th December 2019 12:52 AM

Here's a GREAT article on the FZ-1A Fuzz-Tone.

It provides schematics and explanations of the three signal stages.

Man, if only I knew how to DO this kind of work...

If YOU know how, please get in touch.

Thanks

samwinston123 30th December 2019 02:02 AM

Hey that's amazing that you still have this stuff. The pedal is worth a couple hundred bucks if you get it working. As you've discovered the circuit is quite simple, so troubleshooting would be pretty easy. Most likely it's either a dead transistor or a bad coupling cap. If you want to dive into it all you really need is a basic multimeter with a diode check function. I can walk you through some troubleshooting steps if you'd like.

BothHands 30th December 2019 03:10 AM

Quote:

Originally Posted by samwinston123 (Post 14412749)
Hey that's amazing that you still have this stuff. The pedal is worth a couple hundred bucks if you get it working. As you've discovered the circuit is quite simple, so troubleshooting would be pretty easy. Most likely it's either a dead transistor or a bad coupling cap. If you want to dive into it all you really need is a basic multimeter with a diode check function. I can walk you through some troubleshooting steps if you'd like.

Thanks a LOT, Sam, and yeah, it's amazing to me, too. :heh: I'm not a packrat, but I get sentimentally attached to things like this, and just keep 'em. i'm old enough now to realize that everything deteriorates when enough years pass. Electrical and electronic components included. Kinda bites.

Let me get back to you tomorrow, Monday. I'd much appreciate your advice and oversight on troubleshooting. I have a very basic multimeter, but it just might have a diode check function. I'll look into it and reappear here tomorrow.

GREAT!
Tom

mbrebes 30th December 2019 06:51 AM

I do repairs on these, but I am in Los Angeles.

BothHands 31st December 2019 05:17 AM

Quote:

Originally Posted by mbrebes (Post 14413066)
I do repairs on these, but I am in Los Angeles.

Thanks. It looks like I might be able to repair it MYSELF (yikes) with the help of Sam Winston who posted above.

Fingers crossed.

BothHands 31st December 2019 05:22 AM

Quote:

Originally Posted by samwinston123 (Post 14412749)
If you want to dive into it all you really need is a basic multimeter with a diode check function. I can walk you through some troubleshooting steps if you'd like.

Sam==

My multimeter does have a Diode Check function. I watched a YouTube video today and now understand (maybe) that the RED test lead belongs on the ANODE side of the diode, and the BLACK test lead belongs on the CATHODE side.

That's all I know. Should I pull the AA battery, or leave it in, or leave it in and turn on volume pot?

Thanks

davet 31st December 2019 04:55 PM

Way Cool!
 
Fuzz Tone was the first stomp box I owned. Pretty sure it was the only stomp box
available at the time. I remember the owners manual saying it could be used to replicate horns. Replicate horns! Are you kidding we wanted to play "Satisfaction"!!

I think they were around $50.00 at the time. That was a lot of money for a kid in a high school band.

Anyway, hope you get it working. kfhkh

Jim Williams 31st December 2019 05:46 PM

Check power with the DVM. Then trace audio from the input jack to the first transistor, got signal? Move to the next transistor. NOS germanium transistors are available from Mouser.

VertigoRecording 31st December 2019 10:19 PM

The circuit uses a couple of electrolytic capacitors that are probably dead. Check them if you are able or just replace them. Dead caps are usually the culprit.

samwinston123 31st December 2019 10:39 PM

1 Attachment(s)
Quote:

Originally Posted by BothHands (Post 14415048)
Sam==

My multimeter does have a Diode Check function. I watched a YouTube video today and now understand (maybe) that the RED test lead belongs on the ANODE side of the diode, and the BLACK test lead belongs on the CATHODE side.

That's all I know. Should I pull the AA battery, or leave it in, or leave it in and turn on volume pot?

Thanks

Take the battery out for the moment. First step is to test the transistors. They're the three metal cans. They have three pins coming out of the bottom. I attached a diagram as seen from the bottom. A transistor is essentially two diodes stuck together (see the diagram) and you can test whether it's bad with the diode function on the meter. Put the black lead on pin 2, then try pins 1 and 3 with the red lead. You should get something around 0.3 V (300mV). If there's a problem you'll either get an open circuit (OL, inf) or a short (0V). Try reversing the meter leads (red on 2) and check again. If the transistor is good then you'll probably get an open circuit - since the transistors aren't isolated it's difficult to tell how your meter will interact with the resistors around them. If you get a short circuit then there's definitely something wrong.

If the transistors all check out then I would test the two coupling caps next (two black cylinders with yellow ends). Use the resistance/ohm measurement on the meter. Try the leads on either side. You should get multiple kilo ohms. If it's close to zero then the cap is probably bad.

That's a start. I can give you some further steps if that doesn't get you anywhere.

VertigoRecording 1st January 2020 01:15 AM

Electroytic capacitors rarely short, they mostly just lose capacitance until they read a few pf. That will not read as a short, rather it will read open, just like a functioning capacitor, so without a cap meter, you cannot tell much on small value capacitors. You can sometimes watch them charge up and discharge on the ohms scale of your multimeter if they are not too small a value.