lm386 (not 383) as a preamp?

[dmartn149]

I am re-posting this question because I got the subject wrong the first time.

This isn't really a "stompbox " question, it's an amp question, but I bet lots of you know the answer. Anyway, I am new to building my own devices, and the first thing I built without a kit or pcb was an lm386 amp. It doesn't give enough clean headroom, so I was thinking I would build a tda2003  amp. (there is a kit on ebay for $5.00)  My question is, can I use the lm386 as a preamp?
Thanks!

[John Lyons]

Yep. Smashdrive, Lovepedal Purple Plexi and many others are pre amps based on the 386.

[phector2004]

wait... smashdrive is a preamp??

i'm planning on building a smashdrive (unless you'd suggest a better high-gain pedal!)

i can still use it as a pedal directly into my amp, right?

[Electron Tornado]

The 386 chip is an audio amp, so yes, it can be used in amp (Noisey Cricket) and pre-amp applications. It can also be used in a pedal. If you're going to build a pedal with the 386, take a look at the datasheet for the chip as well as some other pedals that use it.

[darron]

the lm386 is the amp used in the ruby. you can get low volume practice amp levels out of it only. i was over-driving a 0.25W speaker with one, so maybe something a tiny bit bigger like 5watt?

wait... smashdrive is a preamp??

i'm planning on building a smashdrive (unless you'd suggest a better high-gain pedal!)

i can still use it as a pedal directly into my amp, right?

(going OT... i can suggest the BSIAB2 [aka BSIABII] or its big brother the dr boogie as an excellent high [HIGH!] gain pedal for amp-like preamp modelling to run into an amp.)

[raulgrell]

IMO, the Krank Distortus Maximus is an improvement on the smash drive (also based on the LM386), whether it was intentional or not... It's basically the smash drive with a different tone stack and a booster in front of it. I recommend trying different boosters, as each gives the pedal a different kind of character.

IIRC, a forum member made a version of it called the "burning crunch" which makes use of some smart mods that make it sound a bit better... There was also a pedal that used two LM386 stages in series which sounded pretty damn good... been experimenting with the idea, toneshaping between/before stages and it's a surprisingly useful design concept.

I've seen the LM386 used a clean booster too... the little breakup it had was actually quite pleasing to the ear...

[phector2004]

thanks for the ideas...

i feel a bit guilty hijacking this thread

sorry!

[dedguy]

The Krank uses a lm386-3, which if I'm not mistaken has more gain than a regular lm386.

[dmartn149]

i feel a bit guilty hijacking this thread

Don't feel guilty. I 'm glad to find out that the lm386 has so many applications. Here is the amp kit that I ordered.
http://cgi.ebay.com/Audio-Power-Amplifier-20W-2x-TDA2003-Assembling-kit_W0QQitemZ230446223553QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item35a7aa50c1
Can't beat the price.
Thanks for all the input.

[raulgrell]

The Krank uses a lm386-3, which if I'm not mistaken has more gain than a regular lm386.

I think the suffix is related to optimum/maximum supply voltage actually... whether that has an effect on gain, I'm not sure...

[dedguy]

Okay so maybe gain was the wrong term.  The -1 with a 6v power supply has a output of 325 mW on average, whereas the -3 has a output of 700 mW with a 9v power supply. I hope that clears up any confusion.

[raulgrell]

Okay so maybe gain was the wrong term.  The -1 with a 6v power supply has a output of 325 mW on average, whereas the -3 has a output of 700 mW with a 9v power supply. I hope that clears up any confusion.

Boom! That's what it was =)