Search found 110 matches

by analogmonster
Wed Jan 21, 2015 3:28 am
Forum: Moog Music General Topics Forum
Topic: adding vibrato to bank of 921b's
Replies: 4
Views: 480

Re: adding vibrato to bank of 921b's

Thanks for this....I imagine this could be causing the tuning anomaly. So.......I'm using the Dot .Com VCO with a low sine wave output as vibrato signal control ...how would I determine if it has DC content ( volt meter? ) No, I wouldn't rely on a voltmeter because AC measuring is often caibrated t...
by analogmonster
Tue Jan 20, 2015 4:31 am
Forum: Moog Music General Topics Forum
Topic: adding vibrato to bank of 921b's
Replies: 4
Views: 480

Re: adding vibrato to bank of 921b's

Does your sine wave contain a DC offset? If so this changes the tuning. The sine wave must be symmetrical to zero if used for vibrato.
by analogmonster
Fri Jan 16, 2015 5:13 am
Forum: Moog Music General Topics Forum
Topic: s trig
Replies: 7
Views: 690

Re: s trig

By the way your 950 project looks pretty good, I too was considering a keyboard project but not with midi features. In fact it was an old Crumar keyboard using contact springs. Its on the project list. Thank you Your question was interesting. I made some more tests with my 950 clone and there is a ...
by analogmonster
Thu Jan 15, 2015 5:17 am
Forum: Moog Music General Topics Forum
Topic: s trig
Replies: 7
Views: 690

Re: s trig

Yes ..all my 911's work fine. ( I think !) What I'm trying to find out is does the 950 keyboard controller have any " pull up" voltage associated with the S trig output. Not a pull up, but a pull down to -12V. Q6 (NPN) of the 950 Interface works as current sink to ground if a positive vol...
by analogmonster
Thu Dec 18, 2014 7:31 am
Forum: Moog Music General Topics Forum
Topic: DIY 901b oscillator question...
Replies: 1
Views: 465

Re: DIY 901b oscillator question...

Well, I cloned the 901B with actual BC5xx transistor types. I didn't care about the "select" directive as the newer types surely have higher betas as the originals. If you use original transistor types it could be more interesting. But Q6 is a suspect concerning another issue - the small s...
by analogmonster
Thu Dec 18, 2014 7:03 am
Forum: Moog Music General Topics Forum
Topic: Wendy Carlos "Coincidence Switch" Module
Replies: 4
Views: 725

Re: Wendy Carlos "Coincidence Switch" Module

Did this module have a 9<xx> - number? I can imagine two forms of automated sound or patch modification: one is the well known sequential switch, which does a rerouting of signals, and the other type is a programmable or predefined CV source which is connected to dedicated modules / modulation input...
by analogmonster
Fri Aug 29, 2014 7:17 am
Forum: Moog Music General Topics Forum
Topic: Moog Model D + Solina String Ensemble MK I
Replies: 3
Views: 691

Re: Moog Model D + Solina String Ensemble MK I

Hi, probably you have to convert the gate of the Solina to a Moog compatible S-Trig. Schemos can be found everywhere on the web, assuming that the Solina provides a standard voltage gate out.
by analogmonster
Wed Aug 06, 2014 5:26 am
Forum: Moog Music General Topics Forum
Topic: CL-1 Diode
Replies: 5
Views: 1924

Re: CL-1 Diode

Ah, ok, that helps. Thank you all for the replies.
by analogmonster
Tue Aug 05, 2014 7:31 am
Forum: Moog Music General Topics Forum
Topic: CL-1 Diode
Replies: 5
Views: 1924

CL-1 Diode

Hi,

in some Moog modular circuits a Diode called "CL-1" occurs, e. g. in the Input Bias adjustment of the 902. Does anybody have some information / specs / data sheets of this component?

Thanks
by analogmonster
Mon Jul 21, 2014 9:54 am
Forum: Moog Music General Topics Forum
Topic: 904b setup info ?
Replies: 2
Views: 683

Re: 904b setup info ?

You can find some rough points concerning setup / calibration of my 904B clone on my web page where I describe the issues I considered as useful. But no precise calibration infos, sorry. See here:

http://www.analog-monster.de/mmt904b_en.html
by analogmonster
Thu Apr 03, 2014 10:56 am
Forum: Moog Music General Topics Forum
Topic: Moog Prodigy OSC2 not working
Replies: 1
Views: 438

Re: Moog Prodigy OSC2 not working

The CA3046 is only a part of the waveform creation, I think you have to check whether there is any waveform creation at all within osc 2. If so, you should check the signal routing to U10, if not you might start with the saw core to check.
by analogmonster
Sun Feb 16, 2014 6:23 am
Forum: Moog Music General Topics Forum
Topic: Testing 904a...
Replies: 13
Views: 2096

Re: Testing 904a...

Thanks Anmon......thats a great tip ! I tried/experimented several value resistors at R10 and at the moment a 1.8k is in there and yes, it certainly has made the filter sit up. That extra 800r at R10 has now created self oscillation and enhanced resonance considerably. Maybe there were some high va...
by analogmonster
Sat Feb 15, 2014 7:45 am
Forum: Moog Music General Topics Forum
Topic: Testing 904a...
Replies: 13
Views: 2096

Re: Testing 904a...

Just did a listening test with 8 Moog 904a modules together [borrowed from everyone In town]- and all the 1960s-era ones did not self-oscillate (actually pre-72, the R A Moog versions). What's funny, is that some of them had already been modified, with a jumper resistor to increase the gain in that...
by analogmonster
Tue Feb 11, 2014 3:31 am
Forum: Moog Music General Topics Forum
Topic: A question about power supply
Replies: 2
Views: 930

Re: A question about power supply

Without knowing the MFB-522 or having googled around: I assume there are regulators in the device. If an external unstable supply of 12V DC is sufficient the internal operating supply voltage might be at 9V DC stable, but the external voltage must be higher of course. 15V should be ok also as the de...
by analogmonster
Thu Feb 06, 2014 3:47 am
Forum: Moog Music General Topics Forum
Topic: Testing 904a...
Replies: 13
Views: 2096

Re: Testing 904a...

At this point the service manual is not precise enough. There are 3 possibilities of measuring voltages at resistors: 1.) Measuring resistor input vs. ground. In this case these points are the collectors of Q19 and Q20. In my clone I measured a value of 0.6 volts at both resistors. 2.) Measuring res...