PUNCH - 1W amplifier

[tca]

Im using 470nf on the coupling cap after the jfet.  Is this still too much maybe?
Edit: so that's 470nf with dc power

Well, my version with DC power has a 1u cap and works great with my strat! I guess the speaker and the speaker cab plays an important role here and the guitar too. Didn't you say that you tested it with some big guitar speakers (Fender Twin speakers?). How that sounded in terms of freq response?

[chromesphere]

Yeah I mentioned this a while ago but it must gotten overlooked.  Doesnt matter wat set up I use even headphones the tone is dull and needs treble boost. Ill try incresing that cap after the buffer thanks tca!

[chromesphere]

I increased the coupling cap from 470nf to 1uf.  There wasn't much difference unfortunately.  The freq response still sounds kind of dull.  I think what I might be after is a treble boost.  With my 7 band eq pedal infront of it, slowly rolling up the last 4 bands, the output sounds much nicer to my ears.  I think this is just how the tda7052a sounds.  I think it just sounds like your guitar signal. Im just used to boosting treble on my amps!
Paul

[tca]

I increased the coupling cap from 470nf to 1uf. 

You should decrease it to cut some bass, not the other way around 

[chromesphere]

lol ok whoops anyway it doesn't matter.  I think im just saying it sounds 'dull' because its your un-altered guitar signal.  No amp EQ / treble boosted.
Paul

[tca]

The "dullness" occurs due to various factors, to name a few:

- the frequency response of these chips is flat
- with an output of .5W the distortion is about 1%
- the distortion is given by hard clipping, only odd harmonics
- it is not build to be overdriven by a a large input signal
- ...

my idea when making this amp *was* to use pedals before it to shape the signal to your taste. Simply put: a clean and transparent amplifier with a small number parts.

Cheers.

[chromesphere]

Oh don't get me wrong tca, its an amazing amp!  The amp isn't the shortcoming.  My understanding of how the amp should sound is the problem.  I'm so used to amps with the treble boosted that the punch amp without treble all of a sudden sounds 'dull'.  Not the amps fault.  My understanding is the problem.

I'm off to try it with a rangemaster now
Paul

[tca]

My understanding of how the amp should sound is the problem. 

I get you! Sometimes we just expect to much of simple things, just because they are simple.

[therealfindo]

Finished mine this morning - well the chasis (I'm going to put in a cab with two 5" bookshelf speakers I've got lying around) and it sounds pretty decent through m 10" Jensen C10Q
Only problem is that it's got a buzz when I use a powerplug, which goes away when I use a battery.. there's probably a fix to that, right?

[chromesphere]

Mines been super quiet!  Did you add the 100uf from + to ground?
EDIT: Oh yeah, but my power supply is pretty clean to start off with though.

[therealfindo]

Mines been super quiet!  Did you add the 100uf from + to ground?
EDIT: Oh yeah, but my power supply is pretty clean to start off with though.

Ah, I don't think I did.. will have a look. Though, like you, when I use it with my Power Plant Jr it's quiet as well, so probably the cheap Thomann powerplug doing the dirty.

[garcho]

It's simple to make a tiny PSU filter baby board, then never worry about the supply.

[therealfindo]

It's simple to make a tiny PSU filter baby board, then never worry about the supply.

Good point!! I take it that it would simply involve the 100uF cap from + to ground..?

[chromesphere]

Something like this will help: http://www.beavisaudio.com/Projects/Huminator/

[therealfindo]

Something like this will help: http://www.beavisaudio.com/Projects/Huminator/

Thanks!

[nomorebetts]

I finished my Punch!

I ended up with a Punch, Electra distortion and Rebote delay all housed right inside the speaker housing!

I'm very happy with it except I have some switch popping issues which I will live with as I have zero motivation to get back inside there and pull everything out

Thanks for the great project TCA!

More details and pictures in this thread:
http://www.diystompboxes.com/smfforum/index.php?topic=105106.0

 

Cheers!

[chromesphere]

Awesome David, that's cool!  What do you think of the sound quality / volume?
Paul

[nomorebetts]

Awesome David, that's cool!  What do you think of the sound quality / volume?
Paul

Thanks!  The sound quality is surprisingly good and it can get quite loud - much louder than conversation levels.  My wife can clearly hear me playing from the other end of the house. 
The cabinet plays a big part, it sounded tinny and crap when the speaker was outside of its box.

[chromesphere]

Brilliant hah?  If you have a guitar amp with a detachable speaker, plug it into that 

[tca]

I finished my Punch!

Nice work!

Cheers.