Bass Guitar Headphone Amp?

[jman 31]

Hey, I'm new to these forums so please forgive me if this is not in the right place. I would like to build a headphone amp for my bass guitar and I have read tons of info on this subject. It has succeeded in making me extremely confused.

If anyone can point me to schematics and pictures for this project I would appreciate it greatly. I have looked over the cmoy options, but I don't quite understand how to convert it to work with the very low output of a bass pickup. Seems like every time I think I have found the best option, the next thirty posts go into all of the reasons why it's not.

Thanks in advance

Jeremy

[jman 31]

Never mind, I found one on headwize that I'm going to give a try. I will let you know how it goes. Ordering the parts today.

Jeremy

[Ted205]

do you have a link ?

[wxn]

Originally posted by jman 31
but I don't quite understand how to convert it to work with the very low output of a bass pickup.

The only thing required is high input impedance (250k-1M) which can be easily achieved by adding a buffer opamp if the circuit doesn't allow for such a modification.

And no, the output of a bass pickup is not low, I've measured peaks of 3V on mine! But any passive pickup has considerable output impedance (usually about 10k) and no current output. Less so with active basses.

So your headphone amps only job is to act as a current amplifier, well maybe with a little bit of gain

[kuldeepsingh]

Try the Cmoy or Mini3 headphone amplifiers (both on headwize)..
you can have higher gains by adjusting the feedback resistors. Both the amps deliver stunning performance as far as headphones are concerned.

[jman 31]

Originally posted by Ted205
do you have a link ?

Here it is: http://headwize.com/projects/showfil...guitar_prj.htm

[leadbelly]

IMHO, do NOT just build the typical headphone amps some have suggested on this thread . For best performance, you want a high impedance input like wxn pointed out. I would do a search on guitar headphone amps schematics, there are so many out there. I myself only use JFET opamps in guitar amp circuits for this reason.

[DigitalJunkie]

Yea,A high input impedance is an important note.
What about a little LM386N based amp,like the "headbanger" ?
http://www.minidisc.org/headbanger.html

[jman 31]

Originally posted by leadbelly
IMHO, do NOT just build the typical headphone amps some have suggested on this thread . For best performance, you want a high impedance input like wxn pointed out. I would do a search on guitar headphone amps schematics, there are so many out there. I myself only use JFET opamps in guitar amp circuits for this reason.

I guess that is really my problem. I haven't been able to find one that has some good instructions that I can follow step by step. I am perfectly capable of putting it together, but I don't have the technical knowledge to pick through all the posts and understand what everyone is saying and what each component is doing.

Can I use the same curcuit that I am looking at, but with a JFET op amp?

[leadbelly]

Originally posted by jman 31
Can I use the same curcuit that I am looking at, but with a JFET op amp?

That'll work in general, but you want to make sure that the component values don't degrade the high imput impedance that the FET opamp affords you. If you want details you can post the schematic here and I'll mark it up. If you want to learn how they are designed you can look at Rod Elliot's site sound.westhost.com and see how he designs guitar circuits. He uses FET opamps in his designs.