Hey
My friend bought a bass and I'm building him an amp. I have the enclosure, the power amp and everything else complete, I just need a pre-amp to convert the signal from the pickup to line level. I've heard that people use mic inputs to record, which got me thinking: can I use a mic preamp for the bass? It's a simple op-amp based design with a 4558 that I pulled out of a dead DVD player with a karaoke function. His bass already has tone controls on it. The signal would run bass-mic pre-power amp's line input-12" RFT driver. We're not looking for spectacular performance, just a practice amp for until he can afford something decent.
Thanks!
My friend bought a bass and I'm building him an amp. I have the enclosure, the power amp and everything else complete, I just need a pre-amp to convert the signal from the pickup to line level. I've heard that people use mic inputs to record, which got me thinking: can I use a mic preamp for the bass? It's a simple op-amp based design with a 4558 that I pulled out of a dead DVD player with a karaoke function. His bass already has tone controls on it. The signal would run bass-mic pre-power amp's line input-12" RFT driver. We're not looking for spectacular performance, just a practice amp for until he can afford something decent.
Thanks!
If the bass has an EQ, then it's an active bass. Signal levels coming from a typical active bass (and some passives for that matter) usually are close to, or even exceed, line level. Active basses also have low output impedance. And perhaps a volume control as well? So although it is possible to connect a bass to a mic pre, it not necessary for reasons given . Chances are the bass will overdrive the mic pre anyway.
His is a passive. As far as I know, and I'm no expert, passive basses have tone controlls, too. It's a cheap Harley-Benton I think, I cant remember the model number from the top of my head, but I don't remember it having a built in pre. I can ask for the model number and maybe someone here can then tell me if it need the mic pre or if I can plug it in straight?
Ok, well tone controlS (plural) are usually only present on active basses. If there's only a single tone pot (treble roll-off), than you're right, it's probably passive.
As far as signal levels are concerned. I own a passive bass with 1.5 time the output of one of my active basses, so that's not the issue, but output impedance can be troublesome. Lots of poweramps only have an input impedance of 5k to 10k. Connecting a passive bass (high output impedance), will limit the amount of signal transfer. A mic pre can work, but input sensitivity is probably way too high with clipping as a result. A lot of passive basses do include a volume control as well, so dialing it back quite a bit might be necessary.
As far as signal levels are concerned. I own a passive bass with 1.5 time the output of one of my active basses, so that's not the issue, but output impedance can be troublesome. Lots of poweramps only have an input impedance of 5k to 10k. Connecting a passive bass (high output impedance), will limit the amount of signal transfer. A mic pre can work, but input sensitivity is probably way too high with clipping as a result. A lot of passive basses do include a volume control as well, so dialing it back quite a bit might be necessary.
This is his bass: Harley Benton PB-Shorty LH BK Std. Series - Thomann UK
Now what do I need to make it play?
Thanks!
Now what do I need to make it play?
Thanks!
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