Insane Gain Pre amp advice wanted

[Travis]

I'm looking for some books or web sites that can point me in the right direction for tone like the peavey 5150, XXX, or Mesa Triple Rec, ENGL Powerball, or even beyond this. I want to build a very insane preamp. All feedback welcomed!!!

[lastwinj]

none specifically address this. Build some different preamp topologies. you will get an idea of what to do. good luck!!

germ

[Jana]

As someone who has done much experimenting in this area, here are some tips: it's not really about insane amounts of gain, if you try to go this route it will soon become uncontrollable. The key is multiple gain stages that don't necessarily give a huge boost in gain but instead serve to shape the signal. Clip the signal on one side of the wave form ever so slightly in one stage, clip the other side a tiny bit in the next, repeat and rinse. If you try to go all out with gain, after about the second stage it is nothing but mangled square wave with no tone, no character of the guitar left, etc.

[doctord02]

I'd spend some time over at AX84.com and look at the lead preamp projects or search for Brian S's Super-eXtreme amp...

http://ax84.com/bbs/index.php?area=33

Lots of discussions about multiple gain stages, voicing, etc...

[benoit]

Isn't the SLO 100 basically the daddy of the triple recto and 5150, as well as THE DIY high gain amp? Seems like sloclone forum would be a good resource.

[CaseyJones]

SLOclone is pretty much a ghost town.

Here on Amp Garage the links actually work, a fair amount of us are available to answer questions, etc. It's like everyone was beamed up by aliens around April 2006 over there.

On mega high gain: Mega high gain take mega amp building skills. It's easy to cascade stages and end up with something horrible as mentioned above.

It's possible to get mega distortion from two gain stages. When it comes to additional stages less is usually better. Add only as many stages as necessary, beyond that signal degradation shows its ugly head. It gets ugly really quick. In all honesty I like having at least one amp that puts out almost pure white noise, it's fun to have something in really bad taste for joke value if nothing else. Odlly enough finesse takes... finesse.

[Jana]

Mega high gain take mega amp building skills.

+1 on this!

[lastwinj]

Mega high gain take mega amp building skills.

+1 on this!

double +1

[John_P_WI]

A lot of guys have had good success with the "Rocca" mods. Look over on Metro Amp for more info.

As said before, your lead dress, decoupling, grounding scheme etc must be impeccable. High gain is all about building up gain slowly, proper attenuation between stages, keeping grid blocking distortion under control, the use of one or several large Rk's (10k or larger), tone shaping etc. Remember, all noise is amplified too. I have had success building high gain preamps using DC heaters too, along with the aforementioned. A good scope and signal generator will help "tune" each gain stage too.

You could aslo think about subtracting a gain stage or two with relays for rhythm work unless you only plan on using the amp for lead work.

Good luck,

John

[jimipage]

this looks like it would be worth trying:

http://schematicheaven.com/newamps/bogner_ecstacy.pdf

and, yes, I'm thinking about building one, too

[Travis]

this looks like it would be worth trying:

http://schematicheaven.com/newamps/bogner_ecstacy.pdf

and, yes, I'm thinking about building one, too

on the bogner ecstacy: could you use this pre amp circuit for a lower power amp, something like 30 watts?

[Travis]

Nothing

[Travis]

Im working on a cabnet for 2 12" speakers, 30w celestions most likely. I want to keep the power amp down to about 30 watts however. I did like the 5150 combo(60watts) tone and volume but I want to keep the volume down from that one. I like the Bogner so I might build the preamp for it and use a much lower 30 watt power circuit. Any thoughts on this?

[jimipage]

shoot, you could probably couple the Bogner pre to the power/output section of a Deluxe Reverb and have a great sounding combo with 2x12's. (At least, that's what I'm contemplating, though I am leaning towards doing a 2x10 combo wth Eminence's) It would certainly be loud enough for most small and medium sized gigs.

[John_P_WI]

Remember when you mate a high gain preamp with the output you want to maintain the bottom end thump of the power amp otherwise it can sound like a mosquito, unless that is what you want.

IMHO, the best sounding high gain out there is the Splawn Nitro. Check it out. It uses a huge output section.

You can easily get high gain with 4 gain stages driving the eq off of the plate, not wasting half a tube with the cathode follower....

Good luck,
John