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Questions about the Fatso
Old 2nd May 2003
Gear Maniac
khai's Avatar

Questions about the Fatso

Hi Dave and everyone here,

thanks for designing a brilliant product like the Distressor. Guess what, it was my first ever compressor! I wanted to get something i wouldn't want to sell after a few years of use, and since then I've always thought my choice was right.

Now I'm thinking of buying a Fatso! I read great reviews about it. But also some more skeptical commentries. For some reasons, a lot of people seem to think it's not so much a tape emulator, but more a distortion generator. Some even said " if you have a distressor, you won't need a Fatso". How's that?
Old 2nd May 2003
The Distressor's "daddy"
Dave Derr's Avatar

Fatso as tape emulator

To answer quickly - The Distressor and Fatso have some similarities but theres a lot of difference too, as anyone who owns both would tell you here.

As far as the accuracy of the tape emulation, its far from perfect but that being said, analog tape decks sound different from each other also, even the exact same models, sometimes.

The Distressor is a full featured and controllable compressor, with attack, decay controls as well as a wide selection of ratios. We threw in some wierd distortion generators and a few sidechain filters to help prevent pumping and to control some harsh sources more automatically.

The Fatso has four types of processing, three of which emulate analog tape, and the fourth being some fixed compressors.

1) Broadband saturation is the distortion generator part of the box
2) Tranny is a transformer set up internally to sound like the low frequency emphasis or low frequency harmonic generation that older tape decks produce, as well as some older transformer I/O devices
3) The Warmth circuitry is the most complex and softens the high end dynamically, saturatimg (kind of compressing) the pileup of high frequencies much like analog tape does. The transients and pileup of high frequencies on analog tape intereact with the bias (erase) frequency and start to self erase (or saturate) themselves, attenuating the high frequency content instantly. Engineers strove for years and years to get rid of this effect, including HX Pro which turned down the bias frequency in hopes that it wouldnt erase the real desired "pileup" of high frequencies in the audio. Well... guess what? It was really kind of a nice thing to have the pileup attenuated in lots of cases! This is what our warmth circuit does with a very fast wierd dynamic filter. It works pretty well... I just wish it wasnt hundreds of components inside the dang Fatso.
4) Lastly we threw in some fixed (but future programmable) compressors in the Fatso. Our website is under total renovation but if you check in a week or two, there will be a complete manual there along with some user comments and suggestions.

Anyone who owns a Fatso and a Distressor are welcome to chime in here, even if they really hate them! lol NO piece of gear is perfect and it doesnt do any designer much good if people dont give him negative feedback. The Fatso has all kinds of quirks in the control and interface circuitry but we tried to keep the actual audio path pretty dang spanking!

By the way - the Fatso almost wasnt put into production because of complexity... but thats another story. Thanks!
Old 2nd May 2003
Gear Maniac
khai's Avatar

Thanks Dave.

I don't think I've got anything bad to say about the Distressor.

Please, one more question about the Fatso, I've heard the warmth generator reacted depending on the amount of compression that was applied, if this is true, how can i get a lot of warmth from the Fatso but using the Distressor's compression instead? In other words, is it possible to get warmth without compression on the Fatso?

And please Dave, I've got another question about the Fatso (if you don't mind!). When you started to work on a tape emulation project, did you choose a particular tape deck to emulate or did you just work from the general idea you had about tape compression?
Old 2nd May 2003
Lives for gear
bassmac's Avatar

Hi Dave, I have both - EL7 & EL8. (like em' lots)

Can you tell me what Ratio, Attack and Release settings I would use on the EL8 to match the Tracking Comp setting on the EL7?


Old 2nd May 2003
The Distressor's "daddy"
Dave Derr's Avatar


The Tracking compressor is the ONE on the Fatso, isnt it? I spent some time comparing that to an 1176 in 8:1 ratio, I think it was. That being said, im just guessing but... maybe try the Distressor on 6:1 attack on 4 and release on 4 too? I bet that could be close but dont contact your lawyer if it isnt, ok?

Thanks for buying our wierd stuff!
Old 2nd May 2003
Lives for gear
bassmac's Avatar

Originally posted by Dave Derr
The Tracking compressor is the ONE on the Fatso, isnt it?
haha... yeah, you got it right.

I like the Fatso's Tracking Comp, but want to vary it a little, so knowing the starting point on the Distressor is helpful - Thanks.

Wierd stuff is cool!
Old 6th May 2003
The Distressor's "daddy"
Dave Derr's Avatar

(Quick answer: None Specifically)


I almost missed your post asking if there was a specific tape deck I tried to emulate. The answer is NO. However, I did buy a digital scope and had a couple Dat players that I recorded things onto for comparison. Then I put sine waves, square waves, and then music, both full program material, as well as snare samples, vocal samples, Bass tracks onto various tape decks. Some sources I just listened to, but most of the time, I would measure signals with my HP Analyzer, and would save waveforms onto my HP54600B digital scope (This started back in 97), and/or record onto my Dat player. There is also a wealth of documentation on tape deck frequency, phase, and transient response that I read up on.

The tape decks I looked at were an 3M M56 16 track 2 inch, a Studor A800, an A80, Otari M80, a Revox 2 track and even a Sony Cassette deck. I used Ampex 456 and 499 tape mostly. But I also remember 3m 996 was it and some BASF tape that escapes me right now. The general affect of all the tapes were very similar but the high end changed as experienced engineers know. Different bias settings could make huge differences as well as operating levels. Also, the Otari M80 had HX-PRO which attempts to counter the high frequency saturation of analog tape. Overall, I think the Studers had the best heads and most consistent performance, while the Otari's had some great electronics at a great price.

Honestly, its very scary watching 15KHZ sine waves come back off analog tape, all squigly and jumpy, changing amplitude from one part of the tape to the other! Its like ".. And I trust my music on that?" (laughing!). Even getting a good solid 1KHz was sometimes difficult on some tape. There would be fast amplitude modulation of a fraction of a dB continuously.

BUT, the nice thing was the analog tape added harmonics on the low frequencies, lost the sub freqs complettely, softened the high end when it piled up, and soft clipped in general, allowing more apparant loudness without peaking out. Its amazing the contortions engineers went to get a semi accurate signal back off tape. My 3M M56 machine had a pre distort circuit that would actually "anti-clip" what tape does. I think I generally kept that circuit clicked out when i recorded. It also had these giant output transformers that added 1% THD on low frequencies even without going to tape.

Whew - i think I am running out of "Posting Room". Good question Khai and sorry for the delay in answering.
Old 6th May 2003
Fatso out of calibration?

Hey Dave,

I'm new to this forum, but let me first say thanks for making some great tools that I couldn't live without. I cut most of my tracks into ProTools through my Distressor and Fatso, and it really helps smooth things out.

That said, I've had a minor gripe with my Fatso that I'm wondering if I've got a problem with my unit. When I use the Fatso in stereo, with both the Input and Output set the same, the Left channel seems to be about 0.3 db hotter than the Right. It's set now, so I never adjust the input gain, but it's frustrating that I have to do that. As it sits now, my left input is at about 3.7 and my right input is at 4.0. What would be ideal is to have a center detent, but I'd settle for both sides to match. It's been like this since the unit arrived 2 years ago.

Any thoughts?

- Kent
Old 6th May 2003
The Distressor's "daddy"
Dave Derr's Avatar

Sheesh, thats another POTENTIOMETER PROBLEM. .3 dB isnt bad compared to some potentiometer matches! If you knew how much time we spend on the pots. We changed pots recently to conductive plastic that match better, but are touchier when working with really hot levels. There is a trim pot inside that you mite be able to adjust to match but chances are, it will then not match at some other position on the knob.

Someday we may offer switched attenuators, which is what everyone goes to when you really need a great channel to channel match. Of course, those attenuators cost between $65 and $300 each! Yay, it sucketh verily! Keep your eyes out on our website for information and other solutions to the Pot match problem.

By the way, dual pots usually dont match very well either. We measured hundreds of dual pots and none of them matched within .5 dB over a wide range of adjustment. Beware of your monitor pots on your mixing consoles, because they are often dual pots and the image may shift a little at different listening levels! EveAnna, Hutch, George Massenburg and I have threatened to start our own potentiometer company, its so exasperating.
Old 6th May 2003
Gear Maniac
khai's Avatar

Thanx again Dave,

that's exactly the sort of information I was after.

My last question will be about the "Tranny". Why did you include this feature in the Fatso?


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