Micro Moog Story...

  • Thread starter Thread starter sweetbeats
  • Start date Start date
sweetbeats

sweetbeats

Reel deep thoughts...
Well, bit of a departure here for me but it's not going to be an extensive "Story...", but one close to my heart...and it's not an analog recorder/reproducer or mixer or the like...but it IS analog. :D

I love my brother. He's my only sibling. He's about two and a half years older than me...just a really great guy and has a lot to do with the things I'm interested in and the things with which I have some knack. Lots of memories doing music things growing up...playing with the SOS echo on the family Sony TC-630...

Here we are many a year ago, me sitting at the drums and he at his Micro Moog analog synthesizer. Funny thing is I couldn't really play either of them. He was the drummer and the keyboardist. But I'd pinch-hit where I could. :)

image.webp


I was over at his place this last weekend and saw the Moog in his closet. He hasn't used it in years and says one of the filters isn't working...and it's really noisy. But he can't bring himself to do anything but hang on to it. I said "let me take it with me and have a look...clean it up...maybe recap it. So this "Story" is for him. Don't know if I'll be able to rectify its maladies and I'm not an analog synth guy, but at the very least it'll get a good cleaning.

image.webp
 
Very nice!
That thing looks like it would sound really fat, being a Moog and all.
Cool old school photo too. Ha! Mini-beats! Love that blue sparkle kit. Looks similar to the one I have.
This is gonna be an interesting refurb.
 
Couldn't help but read the post in the Wonder Years narrative voice.
Looking forward to hearing how you get on with this. :)

I refurbed an old MG-1 not too long ago. All the sliders gum up because the 'protective' foam layer deteriorates.
Obviously this unit has no sliders, but hopefully it'll be a straight forward job for you.
 
I always wondered what 30 years of dust looked like. Now I know! :D

Cheers! :)
 
Yah I'm curious to open it up.

J.harv I've still got that kit! Is awaiting the day when I can get them re-wrapped, and finish truing up and reshaping the bearing edges.

My green maple kit I built is 10-12-14-20...that blue sparkle vintage Pearl President kit is 13-16-22, and with the shell type (pre Remo Acousticon type construction...thin, impervious to environment, consistent in density) and some new bearing edges they will be huge.
 
Wonderful! The Micromoog does indeed sound great (my friend has one) and I can't wait to see you pull it apart.
 
I am sure that I can see mushrooms starting to grow out the top?

I love old keyboards, good luck with it.

Alan.
 
Awesome! I've been restoring my 30-year-old Moog Opus 3. It's quite a different animal from the Micro Moog. I bought quite a few original replacement parts from eBay seller chipforbrains. I personally had good experience with him, but he hasn't been active for a while. You might want to send him a message through ebay if you need some parts. He would probably be a good contact anyway.

eBay Feedback Profile for chipforbrains
 
Cory, I'd like to join Tim in recommending another potential helping hand in the form of a guy with whom I briefly had dealings with and who gets the highest thumbs up from many people, someone who beautifully restores old synthesizers, analogue effects and electric pianos. He in fact reminds me of you, the care he brings to his projects. His name is Maciek and he's in Poland but speaks fluent English. His direct email address is info@analogia.pl and website analogia.pl

I'm not sure if and to what extent he would help but you may want to send him the link to this thread.. ;)

BTW, cool vintage photo indeed, very much Wonder Years. Where's Winnie Cooper tho? :D
 
Tim and Daniel, thanks so much for those potential resources. They may very well be helpful since there is a bunged up rotary switch. I'm not too hopeful of actually finding one, and I may very well be able to make this one work, but it would be nice to just have a good part to put in there.

IMG_2683.webp


Hey, look! Micromoog guts!

IMG_2672.webp

IMG_2673.webp

IMG_2675.webp

IMG_2677.webp

IMG_2678.webp

IMG_2679.webp

IMG_2680.webp


Shiny MOD wheel!

IMG_2681.webp


Keyboard all cleaned back together and keys straightened...and the power supply is cleaned up and reinstalled with new filter caps (increased the value on those as well). The power supply is at the back right...you can see the two shiny tops of the new filter caps. I thought about upgrading the regulators as well but gonna leave those for now. I have also recapped most of the main PCB, but have to wait on parts to replace the last of them...serviced all the pots and switches, reseated the socketed ICs...soon it will be time to put it all back together and see what we've got.

IMG_2688.webp
 
Don't you just love the days when they used to make gear that you could actually take apart and fix.

Alan.
 
Oh yeah. I've got a bunch of stuff from my Dad right now to eBay and a Mackie 1202 VLZ Pro mixer is among the lot...granted I've got it all apart to deep clean it, but the components on the motherboard in there? Forget it. Tiny surface mount ICs, tiny pots...its a joke. Pretty sure there's no difference between that mixer and the ones that look the same from Behringer, Alesis, Phonic, etc. Looked and Looked for a 797 Audio logo on the guts and can't be found but I'm pretty sure Mackie paid extra to omit that...
 
So I finished recapping the moog, which is no great feat since there are only 8 electrolytic caps on the whole thing...find them...I dare ya...it's like "Where's Waldo"...

image.webp

image.webp


And furthermore I put that funky switch back in and fixed it together like it appears they were from the factory...with blobs if epoxy...this worked...

image.webp


And then put it all back together hoping for the best...

image.webp

image.webp

image.webp

image.webp

image.webp


Unfortunately, it's still not really passing audio...faint at best. So my brother and I opened it back up again and out came the scope. We went for the output amp first...checked some of the old carbon comp resistors and sure enough they were well outside of spec so we replaced them...didn't fix the problem but at least we've eliminated other potential issues. In the process of testing and probing around we were able to get signal with a work-around, which honed our suspicions in on a "transconductance" opamp in the output stage...an LM3080. Gonna have to order a replacement for that. Checked a transistor related to the output amp, as well as some small-value caps...everything there checks good, but the results of a test from the troubleshooting section of the service manual again pointed to that LM3080. Just to be sure it wasn't the output amp, we replaced that...didn't fix the problem...didn't think it would, but it was easy to do and with the stock 1458 out of there and replaced by a humble TL072 I have to say it was the most dramatically noticeable opamp upgrade I've ever done. The output has a noticeably lower noise floor, and much greater clarity.

So it's *working*, just something isn't right with the output amp. We await parts. Oh and there is *still* trouble with the "sample and hold" feature. This means nothing to me but my brother knows what it is. It's never worked. I'd love to get that working for him. First we'll get it passing audio without any workarounds. :)

Here we are hard at work hahah...geek crap everywhere. :D

image.webp


And here's a short little sound sample...I couldn't resist...this thing sounds so cool...the flange effect is added in my brother's DAW. I'm just randomly shifting the frequency knob so that's why it's kind of all over the place...

http://torridheatstudios.com/audio/moog/micromoog_test_2014-06-08.aac
 
Last edited:
There's a guy out in Oregon City that has done a lot of work on my Quadra. He's semi-retired, PM me and I can get you his contact info. He was an ARP certified tech, so I'm guessing he could help out here as well. Also there is this guy in England: I got a MPU for a Quadra from him a while back.Synth Repair Services

You sir, are a steely eyed missile man!

Ditto on the gear you can actually work on.... If I knew then what I know now there is a bunch of stuff I never would have got rid of....
 
I love my micromoog. I recently had a problem with a failed op amp that held the entire synth up and passed no audio. Found it with some freeze spray. Apparently they're notorious for op amp failures, broken pitch ribbons and those rotary knobs. Glad to see you fixed the knob with epoxy... I did the same thing hoping for the best and it worked also. I think the micromoog has a great sound especially for a single oscillator synth.

How are the key bushings on yours? Clackety clack or smooth? Make sure to Deoxit the buss bar and j wires.
 
You must log in or register to reply here.
Back
Top