Gibson Maestro G-1 Rhythm 'N Sound doesn't work  [SOLVED]

Forum dedicated to helping people debug and troubleshoot non-functional pedals or builds. Please use an clear and informative title, indicating circuit and basic problem. Don't forget to mark the issue as fixed if this is the case.
Post Reply
User avatar
pmkipp
Breadboard Brother
Information
Posts: 75
Joined: 05 Oct 2014, 02:11
Has thanked: 17 times
Been thanked: 4 times

Post by pmkipp »

This is a 1967 "pedal" in its own little suitcase. Someone sent this to me for the cost of shipping. It is in mint cosmetic condition, but does not work. If I plug it in and crank all the output controls to maximum and crank my guitar and amp all the way up I can hear the effects very faintly on all settings. So where do I begin to look for the problem, or what could cause this kind of problem? I cannot find a schematic for this, which is not surprising. Should I look into replacing all the electrolytic caps given the age and probable lack of use for many years? I am attaching a picture. It kinda looks like Grandma's parlor organ from the 60's. Thanks for any guidance.
Attachments
G-1.jpg
Pete's Pedals
St Louis, MO

User avatar
modman
a d m i n
Information
Posts: 4890
Joined: 19 Jun 2007, 16:57
Has thanked: 4394 times
Been thanked: 2131 times

Post by modman »

You didn't really search for the schematic, now did you? took me like 1 minute
http://tonefiend.com/guitar/welcome-to-the-museum/
Attachments
maestro-g2-rhythm-sound-fuzz-schematic-diagram.pdf
Maestro G2 Rhythm Sound Fuzz schematic
(540.81 KiB) Downloaded 247 times
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

User avatar
pmkipp
Breadboard Brother
Information
Posts: 75
Joined: 05 Oct 2014, 02:11
Has thanked: 17 times
Been thanked: 4 times

Post by pmkipp »

I promise I did! Now, any advice about where to begin looking?
Pete's Pedals
St Louis, MO

User avatar
idy
Breadboard Brother
Information
Posts: 126
Joined: 14 Dec 2011, 04:41
Completed builds: FFs, Octavias, TBMKIIIs, Buzzarounds/alikes, Axis Fuzz', CS Overdriver, BMPs, Black '65s, MOSFETODs, WiiO, RAH, Klons, AC30, DLS, TSs and many variants, Small Clones, UniVibes, E. Mistress, Mutron Env Filter, Ross/Dynacomps,, EA Trems, TremLunes, Katana Boosters, BYOC Tri Boosters, other boosters and buffers, PT2399 delays, SKRM based delays, Belton Brick Reverbs, 3band parametric EQ,
Location: Idyllwild, CA
Has thanked: 27 times
Been thanked: 31 times

Post by idy »

Audio probe audio probe audio probe.

User avatar
DrNomis
Old Solderhand
Information
Posts: 6807
Joined: 16 Jul 2009, 04:56
my favorite amplifier: Self-Built Valve Amp Head :)
Completed builds: Dallas Arbiter Fuzz Face,Tone Bender Professional Mk 3,Tone Bender 3-Knob,Baja BK Butler Tube Driver,Baja Real Tube Overdrive,Roger Mayer Octavia,EH Soul Preacher,Tech 21 XXL Distortion,MFOS Weird Sound Generator.
Location: Darwin,Northern Territory Australia
Has thanked: 98 times
Been thanked: 278 times

Post by DrNomis »

pmkipp wrote:I promise I did! Now, any advice about where to begin looking?

Build yourself an audio probe then, using a copy of the schematic, trace back from the outputs with the Audio probe till you get a good signal, next make a note of where you got the good signal and then trace back along the path towards the output till you loose the signal again, between those two points on the signal path will be whatever is causing a loss of signal...... :thumbsup
Genius is not all about 99% perspiration, and 1% inspiration - sometimes the solution is staring you right in the face.-Frequencycentral.

User avatar
tube-exorcist
Resistor Ronker
Information
Posts: 445
Joined: 05 Jul 2007, 20:09
Has thanked: 173 times
Been thanked: 67 times

Post by tube-exorcist »

pmkipp wrote:I promise I did! Now, any advice about where to begin looking?
At best NOT at the schematic.

You have a G-1 and the schematic is for a G-2 - which is a completely different unit.
"I've noticed there's an inverse relationship between cost of gear and talent. If you need the most expensive gear to get decent tones, then you suck as a player."

User avatar
pmkipp
Breadboard Brother
Information
Posts: 75
Joined: 05 Oct 2014, 02:11
Has thanked: 17 times
Been thanked: 4 times

Post by pmkipp »

I guess the G-1 schematic is more difficult to locate. I will do my best to follow the circuit from the input. It is a pretty packed house inside, as you might imagine. Great old classic components. It will be fun to poke around.

Thanks.
Pete's Pedals
St Louis, MO

User avatar
pmkipp
Breadboard Brother
Information
Posts: 75
Joined: 05 Oct 2014, 02:11
Has thanked: 17 times
Been thanked: 4 times

Post by pmkipp »

Finally, with some help, figured this out. It was a combo of a bad can multi-cap, and the input transistor. Now this works great, though it remains an extremely odd "pedal." Best effect is by far the octave fuzz. The percussion sounds are best if pushed into the background as they add a little edge to each note. :applause:
Pete's Pedals
St Louis, MO

User avatar
pinkjimiphoton
Transistor Tuner
Information
Posts: 1242
Joined: 12 Sep 2010, 19:03
my favorite amplifier: my own, a redesigned princeton
Completed builds: so fucking many goddamn pedals it would make your ass hurt just looking at 'em all!!!!!
there's videos that totally suck of about 90 of 'em here:
http://youtube.com/666pinkster
gimme a like: http://facebook.com/pinkjimiphotonrocks
Location: new world order land (formerly la-la land)
Has thanked: 358 times
Been thanked: 479 times
Contact:

Post by pinkjimiphoton »

"When the power of love overcomes the love of power the world will know peace."
Slava Ukraini!

Post Reply