Anybody know these?

[markeebee]

Apologies if this is old ground, but I did a quick search and couldn't find anything on the forum.  I''m thinking of building one of these into an amp.  Anybody used these?  Are they any good?

http://www.profusionplc.com/images/data%20sheets/ra-fx3c.pdf


http://www.nitrogen.myzen.co.uk/Korg/ACE16Vs.pdf

Also posted in Digital & DSP board to maximise my audience 

[Ripthorn]

I've never heard of either, but now that I have, I'm a little interested.  How much do these things cost?

[markeebee]

Looks like less than £20.

[petemoore]

  Yup, they're any good.
 Similar flavors can be found fairly easily, look for a manufactured unit sporting similar specs and features [24bit digi-multi-effects].
 That board is probably already in something that's 'out there'.
  http://www.zzounds.com/item--DGTRP500
  Hard to say how close these are without going down the lists and comparing features and specs but there's a 24-bit chomper...one thing I noticed is this unit shows 44.1khz sampling frequency.
 
 

[Brymus]

Where can you get one?
And where do you get a 4bit binary code rotary switch?
I wouldnt mind adding one of these to one of my amps they make it simple enough minus the swicth that controls it.

[anchovie]

I bought a RA-FX3C along with a RA-FX1V as an impulse purchase over a year ago but I haven't done anything with them yet. I got a couple of binary rotary switches from RS (that's the UK RS, not RatShack!). I'll build them up some day, when I stop mucking about with distortions!

Both the RA boards are based on the Alesis Wavefront chip that is mentioned in an ancient thread in the DSP section. The FX1V board needs gray code rather than normal binary if the patches are to cycle in the correct order, so when I finally get round to making use of it I'll be using a binary/gray conversion circuit that I found one time (it's out there somewhere in Google-land, uses a bunch of XOR gates). The FX1V also allows the use of external pots to control certain parameters for each effect.

The Wavefront chips aren't really flexible enough for use in stuff like the Digitech that Pete linked to, they're more a case of a bunch of presets that can be used as a value-added feature on practice amps. It's also the chip that's used in the Alesis Picoverb, though again that's a case of picking one preset at a time rather than chaining them together and saving parameters.

It's also worth noting that Profusion's postage costs are extortionate - they charged me £9 for putting a couple of tiny plastic containers into a jiffy bag!

[puretube]

Have you seen (OCT-)Frank`s trick to go around the encoder with the help of a rotary switch and a cmos-chippy?  

[edit] 74HC148 in this thread:

[SeanCostello]

The Wavefront chips aren't really flexible enough for use in stuff like the Digitech that Pete linked to, they're more a case of a bunch of presets that can be used as a value-added feature on practice amps. It's also the chip that's used in the Alesis Picoverb, though again that's a case of picking one preset at a time rather than chaining them together and saving parameters.

The Wavefront AL3201 is a pretty capable chip, for stompboxes. Behringer uses its clone of this chip, the V1000, in many of its pedals. Both of these chips, as well as the Spin Semi FV-1, have many similarities to the early Lexicon hardware boxes (224, 224XL, PCM70), but with some design optimizations and much higher precision multipliers. Paying a few $ for a chip that duplicates what cost $8500 back in 1979 is pretty cool!

The AL3201/V1000 have a smaller instruction set than the FV-1, and are particularly optimized for time delay effects (reverb, echo, chorus, flanger, pitch shifting). The FV-1 has some commands that make other effect types possible, like compressors, limiters, nonlinear processing, and dynamic filters. The FV-1 is designed to be directly integrated into an analog design with very little supporting circuitry, while the AL3201/V1000 require a microcontroller and AD/DA convertor to get your own presets in there. However, the AL3201/V1000 has the capability of having a larger set of controls than the 3 controls that are hardwired into the FV-1.

All of these chips are programmable, and can go far beyond the supplied presets. The FV-1 development chip was considerably cheaper than the AL3201 development kit last time I checked.

The Digitech processor mentioned above seems to be far more powerful than the AL3201 and FV-1, at least as far as raw DSP cycles. In addition, the presets supplied with the Digitech are undoubtedly world class, although I am a fan of the Alesis style reverb algorithms. However, if you want to roll your own DSP code, the Digitech won't let you go any further than altering parameters on existing algorithms, while you can really roll your own with the AL3201 and FV-1.

The modules from Cliff don't seem to have any provisions to program your own algorithms, unfortunately. All of the above applies to the DSPs in general, not these specific modules.

The ACE boards use a DSP that sounds familiar. Did some of the Boss pedals use the AK7712?

Sean Costello