Replace preamp stage in a cheap practice amp?

[jallenbass]

What I have is a Behringer BX108 Thunderbird that I picked up off of CL for $20. I replaced the OEM speaker with an Eminence and that made some improvement in the sound. I wouldn't mind putting a little more money into upgrading the preamp stage if that would also improve the sound. Warmer would be nice. As is, it's fine for small rehearsals and even small venue gigs. Any suggestions?

[bongomania]

The amount of time and money it would cost you to successfully replace the preamp stage would exceed the cost of just buying a better amp.

[Marton]

Does the thing have an effect loop ? If so, just get an preamp and plug into the effects return. I do it all the time with the Peavey TNT we have at school, because the preamp sounds so bad.

[seanm]

How about putting a preamp pedal in front to warm up the sound? Knowing Behringer the amp will probably use surface mount components and be very difficult to mod. Have you opened it up yet?

[jallenbass]

It has a Tape In and Out and a headphone jack. That's all. Would any of those work?

Bongo - I agree that a better amp could probably be had but this is a non-essential item for me and more of a "let's see how much improvement I can make for not too much money" project for me. More for fun.

[jallenbass]

Originally Posted by seanm

How about putting a preamp pedal in front to warm up the sound? Knowing Behringer the amp will probably use surface mount components and be very difficult to mod. Have you opened it up yet?

I've look at the guts but I don't know what I'm looking at. Ideally, I'd like too not have any extra pieces to plug in but I'm open to that.

What I'm hoping for, and this might be futile, is for an electronics expert to say "Oh, just replace the Op Amps (whatever those are) and you'll hear an improvement". Or something like that.

[RickenBoogie]

Not knowing a thing about electronics, or the topology of an amp, you want to work on one? THAT makes no sense at all, and what Bongo said is still true.

[greenboy]

I love the way so may people have projects they want others to figure out for them but haven't even bothered to do the elementary groundwork. Hey it's your project - school up or give up!

[jallenbass]

Allow me to clarify - If there is something that can easily be done then I'm all for it. Of course the circuit could be re-designed but that's not of interest to me and I would just leave it as is.

[Rick Auricchio]

All anyone can reasonably do is use a pedal or replace the entire amp.

[BassmanPaul]

Originally Posted by jallenbass

What I have is a Behringer BX108 Thunderbird that I picked up off of CL for $20. I replaced the OEM speaker with an Eminence and that made some improvement in the sound. I wouldn't mind putting a little more money into upgrading the preamp stage

Why???

It's a cheap Behringer amp! You paid $20 for it and it's not even worth that.

Don't waste your time and any more money - PLEASE!

[jallenbass]

It's a cheap amp that sounds reasonably good and serves me well.

Don't worry. I'm using my money and no one elses.

[bongomania]

It's cool--but honestly you would not get any appreciable benefit by swapping any components on the circuitboard, and it wouldn't be easy anyway, with the SMD components they used.

[Growly Lytes]

It doesnt make sense doing this.
As the guys have told you why would you waste time & money on a cheap crappy thing like that.
When you can get much better if you look around without wasting time & extra cash.
You dont like the sound use the FX loops & get a good preamp.Then your getting the sound of the preamp you use & not the preamp in the amp.
Put a pedal preamp infront of it , this will help to give the amp balls.

[jallenbass]

Originally Posted by bongomania

It's cool--but honestly you would not get any appreciable benefit by swapping any components on the circuitboard, and it wouldn't be easy anyway, with the SMD components they used.

Good. That's the kind of information that I was looking for.