Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  
previous: Rob Prosper Christian:I hear the hum al... -- 8/26/1997 11:13 AM View Thread

Re: Deluxe Memory Man Troubleshoot

8/26/1997 4:00 PM
Mark Hammer
Re: Deluxe Memory Man Troubleshoot
If memory serves, the DMM is a companded device. If it is companded, most likely there is a Signetics NE570 or 571 in there. People often complain about thunks, ticks, and assorted other transient gremlins when using dynamic control devices like noise gates, limiters, duckers, etc. The cure often involves adjusting the timing aspects of the device so that it isn't asked to respond faster than is practical given what it has to do. Perhaps the compander on the DMM is responding too fast to transients; i.e., the attack time is set too fast, and the "untamed" transient demands more headroom of the MN3005 than it can deliver. This is, as always, mere speculation on my part, but it's worth a shot.  
The attack/decay characteristics of the NE570/571 are set by a capacitor between pin 1 and ground (pin 16 on the second gain cell on the chip). Higher values yield longer attack and decay times (i.e., more sluggish response, which may be what you want). Since there are two channels that need to be matched for mirror image compression/expansion, whatever you do to one channel, you need to do to the other. Since the values likely to be used for the desired timing range are likely electrolytic, be sure you are attentive to capacitor polarity.

Rob Prosper Mark:Did you see my message... -- 9/1/1997 8:28 PM