Homebrew digital delay

[Threefish]

Colleagues, mentors, good people,
Altronics sells a digital delay kit using the M65830P chip that I'm thinking of having a tinker with, see if I can build a workable delay pedal. In the form they sell it, it's for using with surround sound or PA systems, for introducing a short delay to one channel. There is no "wet" and "dry" to it, just the "wet".  I'd use the kit as the "wet" signal path, and build a "dry" circuit around it. It would have a buffer at the input (maybe with some slight attenuation, unless the signal being split attenuates it enough to not distort the delay circuit) then the wet/dry split, and a summing amplifier at the end with a bit of gain, as I'm expecting some overall volume drop. I'd probably use a dual opamp for the buffer/summing duty. I'm trying to work out the summing amp setup, as I'm guessing just adding the signals would cause some loss if they're in phase. I'm looking at other delay circuits to see how it's done. In particular, it doesn't look that far removed from the PT2399 delay.
This circuit as it is runs at a fixed delay, which I'm not that concerned about. I think more than anything I'd like to have a fiddle with this particular kit – I've been eyeing it off for a while, and I'm interested to see what I can get out of it, more than trying to create a delay with a lot of features (or any features at all maybe....). If I can get some sort of "good" sound/effect out of it, I'll be happy. Delay time is 20ms, which I understand will get me more of a chorus or "thickening" (?) effect than a delay ()
Here's the kit : http://www.altronics.com.au/index.asp?area=item&id=K5595
And here's a project that is pretty much identical to the kit, though again just the "wet" part of what would be required for a pedal, from Rod Elliot's great website: (cheers Rod – I've learnt a lot from your stuff) : http://sound.westhost.com/project26.htm
(as you can see from the Altronics page, the project was published in Silicon Chip in Feb 1996 – I haven't got a copy of it handy Thnkto post)
Has anyone done anything like this before, in particular with this chip? Ideas of the summing amp setup? If anyone can point me to a audio sample of what 20ms delay sounds like?

Thanks 

[Threefish]

...Well I suppose 20ms makes it more like a stereo simulator or chorus, doesn't it? 
Though chorus needs modulation of the delay time, as I understand it.
I think I'll just build the kit and have a fiddle, see what I can get out of it, with buffers front and back.
If anyone has any suggestions or comments please speak up. I haven't much idea where I'm headed with this.

[sfx1999]

From what I've heard, the PT80 is killer.

Anyway, digital delays are relatively simple. It should be possible to build one entirely out of logic blocks, a DAC, and an ADC. In fact, it could be made even simpler with a microcontroller, if you know how to use them.

[Threefish]

sfx1999, thanks for your input. I'm not quite that advanced with that sort of thing though. Part of the reason for the attraction of that kit - part of it sorted for me, the rest I'd have to figure out (and learn a little), even if only the analogue part.

So it's a pity the kit isn't actually available anymore. 

Went to Altronics today to pick one up, and they're out of stock, and the kit's been discontinued. The M65830P chip on it's own has been discontinued too. I suggested politely to the staff that the kit be taken off the website. I was bloody disappointed. My first disappointment with Altronics though. They're pretty good.
Oh well. Out of all this, I've learnt a bit about delay circuits generally.
I'll be in contact with Futurlec soon for a PT2399 chip and the other bits for a PT80 or Rebote.