Re: Repeater noise problem

[Kim Flint <kflint@loopers-delight.com>]

At 08:20 AM 9/10/2001, Tom Ritchford wrote:
>Our man Flint wrote (in part):
>
>>I was also looking at the audio routing diagrams in the back of the 
>>manual and saw the direct audio path through Repeater actually does 
>>appear to go through the digital convertors and through the DSP. Is that 
>>correct? The direct audio path isn't analog?
>
>If it WERE analog, there'd be no way to cure the "wet/dry balance issue"
>in software, wouldn't you think?

No, I wouldn't think that at all. It is very common these days to design 
audio products using digitally controlled analog parts. You can get 
software controlled analog switches, analog multiplexors, potentiometers, 
analog gain controls, matrix switches, simple mixers, filters, etc., and 
they are pretty cheap. A lot of digital audio codecs also come with an 
assortment of routing and mixing options that occur in the analog portion 
of the part and are under software control. So no I wouldn't at all be 
surprised if those options were available in Repeater and somebody just 
had 
to change a few register settings to enable them the way you want. Even in 
the echoplex we did that sort of thing, using high-quality audio VCA's 
under software control to switch audio in and out of the loop with fast 
crossfades. We also did level control of the loop output in analog, since 
it happens our D/A convertor had that function, and many of the analog 
control voltages are routed around with digitally controlled analog muxes.

Although, if somebody were designing a direct analog audio path in a 
looper, I would imagine they would naturally think to include a wet/dry 
mix 
control since you have to deal with mixing things anyway. Certainly if 
you've spent any amount of time with guitar players and hoped they would 
be 
your customers, the idea of an all digital direct path should cause you to 
shake in fear right down to your toes. They get worked up if you put an 
opamp in their direct signal path, let alone A/D and D/A convertors!

kim


______________________________________________________________________
Kim Flint                     | Looper's Delight
kflint@loopers-delight.com    | http://www.loopers-delight.com