MOTM

> 
> I have a circuit here that uses a flip-flop, two 555 timers, and a
> couple of NOR gates.  It will preserve pulse width, if and only if
> the pulse widths are less than the delay time and the period 
between
> pulses is more than the delay time.
> 
> I do not think it is possible to exceed those limitations without
> building anything less complicated than a "real" digital delay.
> That's out of my league.  I can only cobble discrete CMOS together.
> I don't monkey around with microprocessors.
> 
> I also do not think it is possible to do it with only one timer, 
and
> you would need a current source since it's impossible to match (and
> in most cases buy) a dual pot.  Imho, a modular approach with
> separate timers, logic gates, edge detectors, etc. is much more
> flexible.

The circuit design I had worked out didn't use a current mirror or 
dual pot, it compared the voltage level of a charging cap (actually 
two of them) to a level set by a combination of input voltage and 
pot setting.  The first cap started charging on the gate leading 
edge, the second on the gate trailing edge.  

> 
> Yes, you could use the tempo clock to drive shift registers to 
delay
> gates, but only by a number of clock steps.  Which I don't think is
> all that useful.
> 
> This leads to an important question, what the uses for a gate
> delay??  If it is to delay things less than one beat, such as 
setting
> back a snare or delaying  the onset of an envelope or LFO, then the
> analogue solution will work.
> 
> 
> Imho, if you are going to do that, you might as well make a digital
> delay that can process control voltages as well as gates.  Let's 
say
> an 8-bit delay instead of a 1-bit delay.  The sampling rate 
wouldn't
> have to be that high for CV.  This way you could delay all the
> information required to play a note (not just the gate) and could 
use
> delay effects to modulate that CV.   A DC-coupled digital delay 
would
> be very useful.  I think I saw a mock-up for an MOTM module like 
that
> a long time ago.

I think a 1 bit delay line is in fact the way to go.  I haven't 
decided yet whether to have multiple clock ranges or a long delay 
line with the selection of the tap on a log scale.  I would agree 
that an 8 bit or perhaps 10 or 12 bit delay line clocked at roughly 
1Khz would be a good idea for delaying control voltages.  In fact I 
think there should be a whole family of time delay based modules.  
Perhaps the legendary 200 series?

> 
> >BTW, great Jerusalem rendition.
> 
> Definitely :)  Imho, I thought the drumming was no Palmer, but I
> thought the singing was better than Lake.   Did you know Blake 
wrote
> the lyrics??

I did not know who wrote the lyrics.  The singer I used is in fact 
an incredibly talented vocalist.  He has some operatic training and 
was warming up by switching between singing Merle Haggard and 
something from Wagner (thats the german classical composer, not 
Porter.)   If I recall there is a Monty Python episode where they 
sing Jerusalem while standing in a tub of water.