Author Topic: Gibson G101 Questions  (Read 2384 times)

Offline 58Mike

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Gibson G101 Questions
« on: July 19, 2016, 07:23:06 PM »
I bought a Gibson G101 organ earlier today.   Sounds great, but a couple things don't work, namely the "Percuss P" switch, the "Reverb" switch, and the "Repeat" knob.

First, I'm wondering what these each do.   Is "Percuss P" the same as the "Percuss" switch in the bass section?   In other words, is it basically an ADSR envelope set to recreate more of a piano profile (or some other decaying instrument)?

I have no clue what "Repeat" might do, but I assume "Reverb" is an actual reverb, spring or otherwise?

Thanks to Alan Lenhoff's great website, as well as the excellent Combo-Organ Heaven website, I know that the problem with the Perc and Repeat is likely a burned out neon bulb.   Is this an easy repair, or is it something I should leave to a pro?   I've soldered my share of cables, and I know a resistor from a transistor, but I get pretty nervous if things get too deep.

If it is indeed something I could tackle myself, where the heck is it?   In the picture below, I'm assuming it's that thing that looks sort of like a fuse-holder, just above and between the black Perc switch (the furthest rocker switch to the right) and the Repeat knob (or rather, the post of the Repeat knob.)   Is that correct?   Any tips on how to access it would be very much appreciated.

One other question - This thing sounds great to me.   But I'm wondering if replacing capacitors is something I should consider?   I'm not making a museum piece, mind you, and it's already very quiet.    But is replacing caps something that people typically do?   I have a Farfisa Combo Compact and a Vox Continental (I bought this G101 to complete the set) and they were both in much rougher shape, so we *had* to replace a bunch of caps (and transistors, and even a few resistors.    But I wonder if replacing caps in an instrument that already sounds good would make it sound even better.

« Last Edit: July 19, 2016, 07:25:06 PM by 58Mike »

Offline Alan Lenhoff

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Re: Gibson G101 Questions
« Reply #1 on: July 19, 2016, 09:10:58 PM »
I'll answer the easy question first:  There is no reverb in a G101.  Really.

If you read the owner's manual (free download here: http://www.combo-organ.com/Schematics/index.htm), it says that the reverb switch is there only to activate the reverb unit on a Gibson/Maestro amp of the same era.  If you don't have that amp (I know I've never seen one) the reverb switch does nothing. Odd, huh?

The owner's manual also describes the percussion and repeat features. (On the same page, you can also download the service manual, with a full set of schematics.)

On the bulb:  The spares and repairs page on Combo-organ.com includes an explanation of how to swap the bulb, including a link to a very good explanation that includes a photo that shows where the bulb is.  After you've read that, you can make an informed judgment on whether this is something you'd be comfortable doing yourself.

Assuming that this is for hobby/home use, I would not replace caps unless/until something fails.  The electrolytic caps in the power supply are far beyond their expected lifetime, but mine are still going strong. If you plan to use this on stage or in a studio where a sudden failure would be a real problem, you could buy some "insurance" by re-building the power supply if its components are original.

Enjoy your Gibson.  (I haven't played mine in a while. Thanks for the reminder!)

Alan



1974 Rhodes Mark I Stage 73
1972 Rhodes Silver Sparkletop Piano Bass
1978 Hohner Clavinet D6
1968 Hohner Pianet N II
1966 Wurlitzer 140B
1967 Gibson G101 combo organ
1965 UK Vox Continental
1954 Hammond B2; Leslie 21H; Leslie 31H
1977 Fender Twin Reverb
Vox AC30CC2X amp
(SEE THE COLLECTION: https://vintagerockkeyboards.com/ )

Offline Alan Lenhoff

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Re: Gibson G101 Questions
« Reply #2 on: July 19, 2016, 09:34:29 PM »
>>I have a Farfisa Combo Compact and a Vox Continental (I bought this G101 to complete the set)>>

To "complete the set?"  Haha...

As many of us can attest, if you have the space and the money, there is always another great instrument to buy.  (If you don't want to be tempted, maybe you shouldn't hang out around this group. We're bad influences.) ;-)

Just recently, I bought a second Vox Continental. I didn't need it. But it was like being at an animal shelter.  That little orphaned Italian organ just looked up to me with its sad puppy-like eyes -- and the next thing I knew, I was reaching for my wallet. 

Alan
1974 Rhodes Mark I Stage 73
1972 Rhodes Silver Sparkletop Piano Bass
1978 Hohner Clavinet D6
1968 Hohner Pianet N II
1966 Wurlitzer 140B
1967 Gibson G101 combo organ
1965 UK Vox Continental
1954 Hammond B2; Leslie 21H; Leslie 31H
1977 Fender Twin Reverb
Vox AC30CC2X amp
(SEE THE COLLECTION: https://vintagerockkeyboards.com/ )

Offline 58Mike

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Re: Gibson G101 Questions
« Reply #3 on: July 19, 2016, 10:42:52 PM »
Thanks Alan!   Funny, I knew about the combo-organ.com site, and even saw where I could download the schematics, but I somehow missed the owner's manual.   I love the first line: "Gibson's got the sound of today . . . the sound of action!"

The manual answers all my questions about what the switches do, so thank you!    Funny about the reverb.   I couldn't find reverb springs or a tank anywhere, so I figured someone must have pilfered it.

I'm tempted to give it a shot replacing the bulb myself, but we'll see.  ;-)   It won't be soon, though, because I don't see myself using the Percussive setting or Repeat knob much.

No worries about you guys being bad influences.    I was already corrupted long ago.   Luckily for me, though, I bought most of my collection not long after the DX7 came out, back when people were dumping old keyboards for peanuts.    Believe it or not, my Clavinet cost me ninety bucks.

Right now, I'm looking for a Pianet N and a Cembalet.   Might cost a teensy bit more than $90, though . . .
« Last Edit: July 19, 2016, 10:45:10 PM by 58Mike »

Offline pianotuner steveo

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Re: Gibson G101 Questions
« Reply #4 on: July 20, 2016, 09:08:54 AM »
Mike,

I agree with Alan, do not replace any parts until it is necessary. I too have a G101, and I am very lucky in the respect that I know for a fact that I am only the second owner. I have known the original owner for a long time, and it was in storage most of its life. It was his high school graduation present!
Mine is set up, but I don't use it often. Sometimes I just like to look at it!

I keep mine unplugged when not used to prevent power surges.
Congrats on your purchase.

Steveo
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 200A EP
1980 Wurlitzer 270 Butterfly Grand
2000 Yamaha acoustic piano
2004 Hammond XK3
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
....and a few guitars...

Offline K-man

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Re: Gibson G101 Questions
« Reply #5 on: July 20, 2016, 09:21:51 AM »
Thanks Alan!   Funny, I knew about the combo-organ.com site, and even saw where I could download the schematics, but I somehow missed the owner's manual.   I love the first line: "Gibson's got the sound of today . . . the sound of action!"

The manual answers all my questions about what the switches do, so thank you!    Funny about the reverb.   I couldn't find reverb springs or a tank anywhere, so I figured someone must have pilfered it.

I'm tempted to give it a shot replacing the bulb myself, but we'll see.  ;-)   It won't be soon, though, because I don't see myself using the Percussive setting or Repeat knob much.

No worries about you guys being bad influences.    I was already corrupted long ago.   Luckily for me, though, I bought most of my collection not long after the DX7 came out, back when people were dumping old keyboards for peanuts.    Believe it or not, my Clavinet cost me ninety bucks.

Right now, I'm looking for a Pianet N and a Cembalet.   Might cost a teensy bit more than $90, though . . .
I buy non working cembalet without legs in last year with ship 135$ :)
1973 Rhodes 73 stage
Hammond x-2 + Elka leslie
2014 Kurzweil MPS 20

Offline 58Mike

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Re: Gibson G101 Questions
« Reply #6 on: July 20, 2016, 11:01:04 AM »
Mike,

I agree with Alan, do not replace any parts until it is necessary. I too have a G101, and I am very lucky in the respect that I know for a fact that I am only the second owner. I have known the original owner for a long time, and it was in storage most of its life. It was his high school graduation present!
Mine is set up, but I don't use it often. Sometimes I just like to look at it!

I keep mine unplugged when not used to prevent power surges.
Congrats on your purchase.

Steveo
You guys have talked me out of recapping.   It wasn't something I wanted to do, mind you, but I thought I'd ask.   I plan to sample it, so I wanted to make sure I'm not missing something.   It sounds great to me as is, so I'll leave it.

I probably won't actually use mine much, either, but I hear you about it being nice to just look at.   Especially next to the red Farfisa, which, truth be told, I only bought because I liked how it looks.    I'm so shallow . . .
« Last Edit: July 20, 2016, 11:08:06 AM by 58Mike »

Offline 58Mike

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Re: Gibson G101 Questions
« Reply #7 on: July 20, 2016, 11:03:14 AM »
I buy non working cembalet without legs in last year with ship 135$ :)
You're killing me here!   Tell you what, I'll give you double that.  ;-)

Offline 58Mike

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Re: Gibson G101 Questions
« Reply #8 on: July 20, 2016, 11:04:42 AM »
Okay, triple.   ;)
« Last Edit: July 20, 2016, 11:09:32 AM by 58Mike »

Offline K-man

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Re: Gibson G101 Questions
« Reply #9 on: July 20, 2016, 11:47:59 AM »
I send You restoring pic for free :)
1973 Rhodes 73 stage
Hammond x-2 + Elka leslie
2014 Kurzweil MPS 20