[sdiy] Re: [AH] If I'd consider making a PCB for a flanger ...

[Buck Buchanan]

At 06:52 PM 7/16/2007 +0100, Tom Wiltshire wrote:

>On 16 Jul 2007, at 16:28, Buck Buchanan wrote:
>
>>
>>But I can tell you first-hand that the Visual Sound reproduced
>>3207s can be clocked much faster than 200KHz.  The clock edges have
>>to be in good shape.
>
>How high can they go, Buck?
>
>I'm interested 'cos I've got a few 3207's and 3102 clock chips sat in
>a tube on top of my 'scope. If you know already, you'll save me an
>experiment.


I don't think I'd try and talk you out of an experiment since there's 
nothing like *knowing* for yourself.

But I've run mine up to 750KHz.  That's with the 3102 as a driver of just 
one 3207  with short clock leads and rise/fall times in the 30 - 50nS 
range.  I believe it ran further out even but 700KHz was the limit of what 
I was interesting in.

Now, when I say *run*, I mean that it passed a signal, seemed to be 
delaying the signal the correct amount of time per clock frequency, didn't 
notice any overt bad behavior, sounded "ok", etc.  Anything more scientific 
than that I have not done.  How much actual original signal is still 
present at that clock frequency I'm not totally sure.  The 3102 overlaps 
the clocks by about 200nS or so but I'm not sure of the effect of this or 
how important it is.

The 4013 didn't come close to driving it and since I was happy with the 
3102 anyway, that's where I stopped.