New Digital reverb ICs

[David Root]

As an alternative to ready-made high end SS reverbs (eg Andy Fuchs' Verbrator, which is by all accounts a remarkable piece w/ verb and a tube driven loop, but is $379), I would like to build in a reverb IC however I need to learn a lot before I can do that.

Anyone using these? I know that Hermida use an older chip, and that the Belton "block" also use an older chip and these are not universally admired.

There is a brand new chip, actually two, from Cirrus Logic, CS4811 and deluxe version CS4812 targeted to sell in the $10-$15 range. I am not sure these have even started shipping yet, but I figure going with the newest technology is probably a good idea.

Any input appreciated especially how to make the chip actually function as a reverb in an amp., both physically and electrically.

[FYL]

The CS4811 & CS4812 are obsolete. They were launched in 2000 and withdrawn in 2003.

The Belton brick sounds really nice when properly used and is IMO the easiest and best silicon solution available today.

[glasman]

There are a lot of altenatives out there.

My first digital reverb used the TDK ACE-8. Easy to implement and I thought it sounded much better than the Princeton Technologies chip that is in the Belton units.

Spin semi also makes a nice unit, but a little harder to implement. There is a LOT of information available.

A couple of things to remember.

1. Most of these unit require padding. Most have a max input level of 1 to 1.5v.
2. You will need to have at least 20 dB of recovery gain. Best got from an opamp.
3. Probably need a 3.3v or 5V bus to run the unit and separate analog and digital ground.

Gary

[David Root]

Well I guess that clip off their website I picked up on must have been old. No wonder when I went back in to the home page and looked up Products, neither of those were listed!

Gary, the Spin Semi IC, is that the FV-1? I downloaded the application sheets on it and woooooo I need to go back to school!

The Belton units have all the heavy lifting done for you, right? Maybe I should use one of those.

[Deric]

This might help..

http://www.oct-distribution.com/datashe ... C8-XXX.pdf

http://www.oct-distribution.com/datashe ... C8-R01.pdf

[David Root]

Thanx deric, I am going to have to take a good look at these.

[odourboy]

I've been playing with the SPIN FV-1 chip. It's pretty cool, but you're going to want to sharpen your DSP algorithm/programming skills if you're going to use it to it's potential. Significant learning curve. Are you an EE David?

http://www.spinsemi.com/

[glasman]

The belton is easier, but not in the same leagure as the spin unit.

If you only want reverb, the belton would be easier. But I like to offer a bit more for the end user and the spin gets me there (as well as others).

Gary

[David Root]

Sorry, no, not an EE. I have learned the tube stuff but not modern SS. Looks like a big learning curve!

Would that book on the Spin Semi website by Keith Barr be a good introduction? It looks like it would.

[greenbottle]

David
If you have not already been there, try Tonepad.com. They have a Digital Reverb project using the FV-1 chip. They can supply ready to solder boards relatively cheaply.
Generalguitargadgets.com also have Digital Reverb progects. Look under
section labeled Modulation, etc

Small Bear Electronics may hve some of the more obscure parts.

I am having trouble with dyslexic fingers.

Good luck

Alan

[David Root]

Thanx greenbottle, those sites look good. I can get the board from Tonepad but where do I get the FV1 IC?

[Structo]

Small Bear has the FV-1 chip for $17

http://www.smallbearelec.com/Detail.bok?no=695

[David Root]

Thanx Tom. I thought they had it but I couldn't find it last time I looked.

So that's $17 board and $17 chip plus the other parts on the BOM plus the clock crystal. I read the notes from those who had built it and several of them built their own 3.3V supply too. So probably $50 before shipping costs. That's OK.

[Deric]

The Tonepad board had some errors in it. They may be fixed now. Just FYI.

[FYL]

The Tonepad board had some errors in it. They may be fixed now. Just FYI.

The layo seems quite crude and far from optimized - ugly routing, very poor decoupling, approximative grounding, needless straps, etc.

BTW the FV-1 chip comes as a surface mount SOIC 28, with legs .016" wide spaced by .050". It's OK if you're familiar with SMD's and can use the right tools but *not* for most builders.