Doepfer

Hi M.

> Well, I tried every signal source I have, A-110, various LFO's, A-
121 and
> A-123, and ran them through an oscilloscope and a frequency counter 
but the
> frequencies stay roughly the same.
> I don't get it. My A-114 seems to work fine when used "as a ring 
modulator",
> but seemingly it won't do anything to the signal if I feed it the 
same
> inputs. I've tried the trick on a Putney and that worked.
> Maybe there's two different versions with different electrical 
behavior?

I'm baffled too. I think we must be overlooking something or 
misinterpreting readings. The circuit is relatively simple due to the 
fact that the 1496 chip takes care of the hard part - multiplying the 
2 signals together - so there are few external components. If it 
works for different signals, I see little reason why it shouldn't 
work for the same signal on both inputs (it would have to be a very 
subtle failure mode for it not to do so!). (Clutching at straws a 
bit...) are your 180 multiples wired as an '8-way' (all sockets 
connected together), or 2 '4-ways'? (there is a solder bridge in the 
middle of the 2 sets of sockets on the pcb, which can be removed - 
all mine are) - I'm wondering whether the signal isn't actually 
reaching one of the inputs. However, if it didn't you shouldn't get 
much out of the 114 at all (anything times zero is zero!), rather 
than, say, just the single input passing through. Very rough 
measurements from one section of my 114: with X in from 110 sine out, 
so +/- 5V approx, nothing connected to Y, sine o/p is approx +/- 
25mV, same frequency; with nothing on X, but signal to Y, o/p is a 
little bigger, +/- 0.25V and double frequency, but grounding the X 
input reduces this to approx +/- 50mV and restores it to same freq as 
input (there is always likely to be coupling between the 2 inputs of 
such a circuit). You could perhaps try this yourself for comparison, 
because another possibility is that your 114 isn't adjusted properly: 
without further tests I'm not sure what impact this would have on 
normal 'ring mod' operation, but I suspect such a check could 
highlight if the circuit is adjusted properly or not. I have 
a 'pseudo' 1496 lashed up on some breadboard at the moment - if I get 
the chance I'll take it out of adjustmeent and see what happens...

Tim

P.S. I've temporarily lost daily use of email/the internet (changing 
jobs!), so until I buy a PC of my own, I will be relying on visits to 
my local 'internet cafe', which will generally only happen at 
weekends, therefore there may be big gaps between my responses!