Moog Music Forum

Here are the resistances I'm getting between the power rails and ground: +15V = 70.3 Ohms -15V = 64.5 Ohms +8.5V = 337 Ohms -6.5V = 878 Ohms +10.6V = 540 Ohms The rails can be accessed on the power supply just behind the output molex connector. The +15V is the brown wire at the top and they go down ...

I did some minor work inside the keyboard, and when I turned it back on it blew a 500mA fuse and the synth went dead, and want to make sure there are no shorts before powering it back up. As far as I know, the 15V rail will get power when I turn it back on.

With the power off, I am getting a 70-ohm resistance between the +15V power rail on the card riser (the lower bar that the cards screw into) and ground. Does anyone know if this is normal or is this indicative of a partial short?

The lead synth on this track is all Moog Slim Phatty. The beginning features a single sawtooth oscillator, then a second one comes in for a more chorusy sound.

soundcloud.com/jonathan-eli-goodman/soldier-on

MC wrote:Is the top octave oscillator for the square wave emitting a signal?

I haven't found the correct test points yet. This manual is spinning my head around. I've been focusing on the TL board..

I've got a first generation Polymoog 203a, serial # 1979, with no square wave output. The sawtooth oscillator is functioning, however. The square waveform was working intermittently, but has now dropped out altogether. I've reseated the wire connectors, but the problem persists. I have the service m...

SOB II is probably my favorite of the two - a lot more use of reverb for a sense of space. Got SOB I and II on vinyl, along with The Well-Tempered Synthesizer - the only way to listen! As far as I know, Wendy is very rigorous when it comes to keeping her music off the free d/l sites like Youtube, Pa...

I have a Slim Phatty that was purchased new in early 2012, currently running firmware version 3.1 668/31. The Moog website has a downloadable version listed as "Phatty Firmware v3.12 - Slim Phatty" that was added on 6/20/2011. Should I be downloading this, or is my existing version the lat...

A very interesting read indeed... especially as I am about to begin a Quadra restoration of my own!!! Mine has many issues- only the lead section works and is the arpeggiator is stuck on, couple of keys don't work, and a couple of the membrane switches don't work. For this reason I am considering j...

The cap in question is in the top left corner of the pic. Assuming the blue smudge down the side is the dot, or modifier, doesn't make sense, at least according to this chart: http://www.marvac.com/fun/tantalum_capacitor_codes.aspx http://i1198.photobucket.com/albums/aa441/Jonathan4011/IMAG0171_zps8...

I managed to remove and clean the touch sensor mechanism, and am measuring 0 - 300kOhms across it, so it appears to be working. Now looking at the Keyboard Electronics Board, I'm thinking the area toward the bottom right corner may be where the problem is. There is a funky multi-colored tantalum cap...

Is there any trick to getting the aftertouch to work better? I'm only getting it to change the pitch by about 1/2 of a semitone. I've already tried adjusting R1 on the touch sensor board, and am not sure where to go from here.

Regarding knobs or sliders, it's wise to keep them at the zero position before storing any electronics. I was told this by Dave Sesnak at Wine Country years ago when my Prophet's pots were being buggy. If you leave the wiper inside a potentiometer in any position along its sweep path for an extended...

I'm a fan of cardboard for storage, as I feel it absorbs moisture and allows air flow quite well. I usually use a cardboard box and surround the electronic unit with packing paper, and throw in an aforementioned silica gel pack or two. And, most importantly: location, location, location! Never in a ...

Congrats on the Opus 3 - it's one of my favorite stringers, if for the brass section alone. With regards to PCB cleaning, I am currently working on an ARP Quadra with some sticky sliders. All of them work, but they are gummy and sluggish, almost oily to the touch. I am too under-equipped to perform ...