Anyone tried this tube-emulation circuit?

[valdiorn]

I was looking through muzique.com and found this circuit called "Tubetype Distortion" ( see: http://www.muzique.com/schem/projects.htm )

Its a petented circuit (US Patent 5,032,596) so I looked up the patent online, it looks like a really cool idea. Has anyone tried building this, or have any more information about it? I want to try it myself but it's time for exams at school so I don't have a lot of free time right now.

[anchovie]

That's the circuit used in the Ampeg solid-state amps from the late 80s - they ran the op-amps on a +15v/-15v supply (Crate bought out Ampeg, which is why the AMZ site mentions Crate amps). There were the SS-150 and SS-140c and they've got quite a reputation in death metal circles as the distortion on the lead channel was pretty huge - it had two of those stages cascaded. I'm not sure how much "tube emulation" played a part in that particular use though, it was more to do with the pre-filtering before the clipping stages and an active tone stack that combines a strong low-end boost with a brutal mid-scoop.

http://www.youtube.com/watch?v=9C2WkFxxuR0

I believe Crate are using the same lead channel as the Ampegs in their current Flexwave heads.

[valdiorn]

Hey, you're right. I checked my Ampeg HV140c schematics and I can clearly see two of these stages in both channels

[panterica]

Yes! This is the circuit I was talking about in my last post about zener diodes. I tried building it, but gave up too quick (I was a frustrated noob). Now I realize my power supply was wrong. I'll have to pull out those zener diodes and try again.

[sean k]

Channel A ampeg VH140c