Nice little llink to St.LouisMusic schems

[Mark Hammer]

http://www.stlouismusic.com/downloads/division_logos/Schematics/

Someone posted this earlier today on Ampage.  very generous selection/collectionof both Crate and Ampeg schems from their current/recent product line.

One of the things I was surprised to see as often as I did was an interesting and commonly used feedback circuit in all of Crate's solid-state amps (generally using either the TDA2030, 2040, or 2050, or else some of the high-power NatSem chips like the 3886) involving an envelope follower tied to an optoisolator at the the input of the power stage.  I gather this is some sort of limiter.  Interesting circuit.  I'm going to give it the twice over on the busride home tonight.

These guys porobably use as many VTL5C7's optoisolators as they use 10k resistors!  That part was absolutely everywhere; in some cases several to a product.  I guess what this means is that if you are desparate for an LED/LDR package, and there is an authorized Crate service bench near you, they may just have one in stock.

[ahermida]

Thanks for the link.  Have you seen the schematics for Crate's new V series? V1512 or whatever?  The smallest amp (I think its 15W) is all tubes...the other 2 models have DSP effects etc.  I'm mostly interested in the 15W one.  I played one at a store and it had a very nice sound.

Alf

[Marcos - Munky]

Thanks for the link. Hey Mark, what schems uses the 3886 IC? I didn't have time to look at all the schems.

[Mark Hammer]

The DX212C uses one, and a few others do too, though most of the solid state amps above 40-50W seem to use discrete transistor amps..

[Marcos - Munky]

Thanks, Mark.

[R.G.]

One lesson I had reinforced by Stephan's AC30 sim is that you *can* make a solid state amp sound like a tube amp - you just have to feed it a signal that can't be distinguished from a tube amp output.

Look for more 3886's and tube simulator circuits. They're going to happen.