The Source noise source

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sinewave1kHz
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Joined: Thu Apr 20, 2017 8:15 am

The Source noise source

Post by sinewave1kHz » Thu Apr 20, 2017 8:37 am

Dear moog users,
this is my first post here. Sorry if my question is too simple, but I am wondering is it expected that the noise source on analog synthesizer sounds "looped"? On my Moog the Source, I can hear the "cut" every (approximately) 0.7 seconds when listening to the noise only.
Thank you for the answer!
The Source, Etherwave Plus, MF-104Z

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thealien666
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Re: The Source noise source

Post by thealien666 » Thu Apr 27, 2017 1:56 am

Hello and welcome.

The white noise on the Moog The Source is digital, not analog. It is generated by a badly designed chip (well known to have issues with audible short loop) the infamous MM5837 (used in many synthesizer of the eighties such as Prophet 5, Oberheim OB-x, early Korg Mono/Poly, the Moog MG-1, The Source, and a few others).
Moog Minimoog D (1975)
DSI OB6
DSI Prophet REV2
Oberheim Matrix-6
Ensoniq SQ-80
Korg DW8000
Behringer DeepMind 12
Alesis Ion

sinewave1kHz
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Joined: Thu Apr 20, 2017 8:15 am

Re: The Source noise source

Post by sinewave1kHz » Thu Apr 27, 2017 8:29 am

Thank you thealien666 for the detailed explanation! Although I love the sound of The Source, it's digital side is weak and sometimes useless, apart from 16 memory slots. For example, I found out that the arpeggio has a very bad latency (around 27 ms), when synced via SYNC IN.
The Source, Etherwave Plus, MF-104Z

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MC
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Re: The Source noise source

Post by MC » Thu Apr 27, 2017 4:50 pm

Factory service bulletin for Memorymoog but also applies to Source

http://www.interlogic.jpn.org/memorymoog/842-1.jpg
Gear list: '04 Saturn Ion, John Deere X300 tractor, ganged set of seven reel mowers for 3 acres of lawn, herd of sheep for backup lawn mowers, two tiger cats for mouse population control Oh you meant MUSIC gear Oops I hit the 255 character limi

torinkrell
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Re: The Source noise source

Post by torinkrell » Sun Apr 30, 2017 3:53 am

Sinewave1kHz welcome to the forum! I have recently added an early version Moog The Source to my studio and it exhibits exactly the same cyclic "rhythm" in its noise source - which is most noticeable in the lower noise frequencies. My 1973 Minimoog and the new Minimoog reissues in contrast have a very smooth, nonrhythmic, (and analog) noise source. Does anyone here have service notes specific to The Source on reducing this issue? Thanks thealien666 and MC as always for your info!
Akai AX-80
Korg Polysix
Roland Juno 60
Moog The Source
Yamaha e1010 BBD
Moog Parametric EQ
Sequential Prophet Pro~One
Altec AS-1600 audio oscillator (1947)
Moog Music Minimoog Model D (1973)

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thealien666
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Re: The Source noise source

Post by thealien666 » Sun Apr 30, 2017 1:14 pm

torinkrell wrote:Sinewave1kHz welcome to the forum! I have recently added an early version Moog The Source to my studio and it exhibits exactly the same cyclic "rhythm" in its noise source - which is most noticeable in the lower noise frequencies. My 1973 Minimoog and the new Minimoog reissues in contrast have a very smooth, nonrhythmic, (and analog) noise source. Does anyone here have service notes specific to The Source on reducing this issue? Thanks thealien666 and MC as always for your info!
Read MC's reply just above yours... It includes a PDF of a service bulletin (for the Memorymoog but also applies to The Source) which shows how to replace the MM5837 by the much improved MM5437, with minimal modifications because they're not pin for pin compatible unfortunately.

Thanks MC !
Moog Minimoog D (1975)
DSI OB6
DSI Prophet REV2
Oberheim Matrix-6
Ensoniq SQ-80
Korg DW8000
Behringer DeepMind 12
Alesis Ion

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