EL-7 FATSO design?

Does anyone know of a clone design for the Empirical Labs Fatso, or maybe something else that does what it does? I love these things, but $2500 is too big a chunck of change for me at this point, yet I'll be in the digital medium world for quite awhile (until I can afford my own MTR-90!), at which point I could buy a fatso as well. I know all the collective brilliance on here has to have some ideas!

This subject has come up a few times, and some of the board experts had a few ideas to try. The simple one was just to get some decent 1:1 input iron to put in front of the converters. Not quite tape saturation, but some good color, perhaps.

There's also this circuit I found some time ago:

http://www.261.gr/limiters.html

If you scroll down to Figure 8 at the above link, they describe a diode-based soft clipper that supposedly introduces a tape-saturation effect. It uses a mix of silicon and germanium diodes.

I also found this little snippet of description on the Presonus site, for their Eureka channel strip:

The saturation circuit works by adjusting the drain current on the FET amplifier, and is intended to simulate the effects of tape saturation and tube "warmth."

Possibly enough there to play around with.

One other idea I had was to cannabalize a open-reel tape deck to record your signal to, then take the out from the playback head immediately to your computer. This would introduce latency, but as long as the latency is the same for each track, you can compensate for it. The disadvantages would be, one, potentially ruining a perfectly good tape deck, and two, a limit on the number of tracks you could process at a time, since you'd want to use a cheaper deck for this.

There are lots of ideas out there.

EDIT: I just realized this is my first post in the Drawing Board. Go me!! :wink:

I found the thread!!!

http://www.groupdiy.com/index.php?topic=3720

Steffen had some cool stuff he did with pre-emphasis and de-emphasis plus the above-mentioned diode clipper. From what I remember, it sounded pretty good, too.

Any news, Steffen?

Cheers! :thumb: :guinness:

There's also this circuit I found some time ago:

http://www.261.gr/limiters.html

Click to expand...

That looks to be a copy of an article about headphone limiters from http://www.headwize.com/

There is further information on clippers on my web site, especially the article about Warp controls:

http://www.muzique.com/lab/warp.htm

regards, Jack

Thanks, Jack! I seem to remember you being rather into the other threads. :wink:

I'm still curious about the "cannanalize an old open-reel deck" approach I outlined above...

[quote author="Consul"]I found the thread!!!

http://www.groupdiy.com/index.php?topic=3720

Steffen had some cool stuff he did with pre-emphasis and de-emphasis plus the above-mentioned diode clipper. From what I remember, it sounded pretty good, too.

Any news, Steffen?

Cheers! :thumb: :guinness:[/quote]

not much @ the moment.... but I´m after it...I need a box like this....

steff

anyone know where one could find a schematic for the FATSO? Or, for that matter, a good source in general for gear schematics? Let me know, or tell me to shut up if it's not appropriate to ask.

The FATSO design is most likely proprietary. The manufacturer will not be so ready to provide anyone with a schematic. That being said, it is possible it's out there somewhere.

Basically, what we can do is to try engineering our own solution to the same problem. As you can see, that's pretty much already been done.