Clarifier Pre-Amp Craig Anderton

[Michiel93]

Hello everyone,

I recently started trying to build the "Clarifier" onboard pre-amp, so that i could just plug in my headphones without using an external amp.
Another reason for not using an external amp is because is don't have one yet.
To test if my pre-amp is working i use Audacity, the problem is that it does work when i plug it in on my computer but doesn't work when i just plug in my headphones..



This the back view of the layout, I added a DPDT switch so i could switch between clean sound and the pre-amp.
"A" is connected to the pickup switch. the clean signal and the pre amp'd signal are both connected to the same output jack pin ( not sure if that is a problem )

Any ideas what the problem could be ?

Some photos :
http://imageshack.com/a/img540/1610/P4XtAD.jpg
http://imageshack.com/a/img661/2936/qc3rpN.jpg
http://imageshack.com/a/img661/3971/HEbMuz.jpg
http://imageshack.com/a/img540/614/JSJCOc.jpg

[loudthud]

The layout looks like a bunch of components connected at random. Got a schematic? I'm not even sure what kind of IC you are using. You've got the wire marked "-" connected to pins 4 and 5 of the IC. The wire marked "+" should go to pin 7 or 8 of the IC depending on what type it is. The center terminal of the pot doesn't seem to go anywhere. One end of R1 doesn't seem to go anywhere. None of this makes any sense.

[g1]

A pre-amp may not be sufficient to drive headphones. It is not the same as a headphone amp. Is this one supposed to be able to drive headphones?

[loudthud]

Maybe the chip is an LM386. I didn't consider that as a possibility.

[Michiel93]

Thanks for the quick replies

The layout looks like a bunch of components connected at random. Got a schematic? I'm not even sure what kind of IC you are using. You've got the wire marked "-" connected to pins 4 and 5 of the IC. The wire marked "+" should go to pin 7 or 8 of the IC depending on what type it is. The center terminal of the pot doesn't seem to go anywhere. One end of R1 doesn't seem to go anywhere. None of this makes any sense.

Forgot to attach the schematic, sorry for that. about the layout, i forgot to draw the lines from the end of R1 to pin 3 ( The IC is mirrored, because it is a backview ), The - wire i attached to pin 4 ( blue lines are jumpers ). The IC i'm using is a TL071. The center terminal of the pot is going to the output jack.
Hope this makes it a bit clearer, i'm still a rookie ( obviously )

A pre-amp may not be sufficient to drive headphones. It is not the same as a headphone amp. Is this one supposed to be able to drive headphones?

That could be a possibility, it is not designed specifically for headphones. How can you tell if it is or isn't sufficient ?

Schematics below :

[J M Fahey]

Well, I borrowed a pair of glasses from

and could see it's a TL071 Op Amp.

Supposing it works, it is a signal preamp and will feed a Guitar Amp, a PC Audio card, etc. flawlessly, but will not drive headphones.

Please post the schematic, but anyway I suggest Michiel build this instead:
DirtBox 'Smokey' Amp | DirtBox

Not inside the guitar but a beer can, altoids tin, cigar box, etc.

May use any "found" speaker , including those 2" plastic or paper cone inside PC speakers (in fact he can use the enclosure) and of course, also drive headphones if wired to a proper jack.

EDIT: in general I like Craig Anderton designs very much, they are good although quite dated, but this particular one makes me puke.

Sorry but it's the best word I could find.

He's trying to meet 2 absolutely opposite goals in a terrible way, failing in both.

[Michiel93]

Thanks for the tip, i will try that one instead!
Good to know that this one is not as good as i thought.

I have a speaker that was originally used for an guitar amplifier, can use that one ?