Fender Princeton 112 Distortion Build Report... with Sounds

[Triffid]

All right, a while ago some of you helped me with a schematic for the distortion channel in my Fender Princeton 112.  It's just my practice amp, but I liked the distortion and wanted it in my setup.  

Here is the link to the old thread
http://www.diystompboxes.com/sboxforum/viewtopic.php?t=18602&start=0&postdays=0&postorder=asc&highlight=princeton+112

First of all... thanks to all of you who helped me with this.   I finally got around to building it and I think it sounds pretty good.  My first impression was an "american rock" type of feel... but that's just me.   I left off the last tone stage so I just have the gain, contour, and volume knobs.  

Here is a sound clip.  The gain is maxed and I start the contour out at 0, then increase it to half, then full. Please keep in mind that this was recorded with my computer mic sitting next to my amp .  Let me know what you think...

http://www.castagno.org/112plus.mp3

Some build notes...
1.  I first tried it without the contour stage and it didn't sound all that great to me.
2.  The 680 cap in the contour stage REALLY makes a difference.. I tried lowering and raising the value and it producing surprisingly different tones.
3.  I am using 1n4148 clipping diodes.  I have 2 ge diodes but one of them broke in half while I was bending the leads... pretty fragile.

Thanks again everyone

[petemoore]

Got the Metal Compression Grind thing happening I hear !!!

[Prive]

Cool!!!!! great job, have you any photo?
Is a pedal now or still in process? lots of gain!!!
The sample quality is really good to my ears.
What do you use for power stage?

Saludos, Marcelo.

[Triffid]

The pics aren't too interesting yet as it is still just on a bread board .  I am thinking about putting a pot at the input similar to the bias pot of the boutique fuzz faces as I get the same problem with my wah as a with my fuzzface.  Impedance problems I guess.  

Thanks

[Triffid]

Anyone know any other pedals that produce this type of sound?

Thanks... I'm just looking for something to compare it to.

[Joep]

Sounds really nice!

You can try a buffer in front of this circuit. Just copy the front end of a Tubescreamer or something.

What pot's did you used? Linear or log?

Good luck,

Joep

[smoguzbenjamin]

Wow!!!! That sounds absolutely great!! Can you post a schematic, I'm having a hard time figuring the entire amp schemmo out... :oops:

[Triffid]

Thanks guys,

I used linear pots for the gain and contour, audio for the volume of course.

I'll take a look at the tube screamer input buffer, thanks  Is this to try to help with the wah problem?

Ya, the final schematic was a little tough to find in the last thread, here it is.  I left of the last tone control stage for now, but I'll try it soon.  Honestly, I left it off because I ran out of breadboard room
http://www.castagno.org/112plus_mod.png

Thanks again... I'll post any updates I have

[smoguzbenjamin]

Cool, thanks!

[Joep]

A buffer will definately fix the problem with you wah.

If you look at the Tubescreamer schem. Build everything up to the 1uF, instead of the 1uF connect you circuit.

Hope this helps,

Joep

[Triffid]

Do you think that the transistor has to be 2SC1815 or will others work... maybe BS170?

Thanks again

[Triffid]

About the gain pot... It does seem like the upper range of the gain sounds best, I wonder if the curcuit calls for a reverse log pot?  Can anyone tell by the schematic which one would make sense?  

Thanks

[Joep]

the BS170 is a mosfet and requires another circuit. But you can use 2N3904, 2N5088, BC547 etc....

[Triffid]

Thanks again man... i'll try it tonight and post the sounds

[spongebob]

Nice page about buffers:
http://www.muzique.com/lab/buffers.htm

[Joep]

Thanks! I was looking for that.....

[Triffid]

Do you think it would be a good idea to use a TL074 instead of TL072 and use the extra opamps as input and output buffers?  I think Mike Burgundy recommended this in the first thread.  

What would an output buffer help with?

Thanks

[smoguzbenjamin]

It would settle impedance problems. And it will be a help driving long cables.

[Triffid]

Ok, I tried the input buffer from the tube screamer with a few modifications...

1. I used a 2n3904 tranny instead
2. I didn't have a 510K resistor handy so I used 470K, hope thats ok

I just could not get the thing to sound very good.  At first it sounded really tinny and cut way to many lows  so I upped the input cap to 0.1uf... still too trebley... upped to 22uf... STILL too trebley, although much better.. I went all the way up to 100uf and couldn't get the sound back to where it was before I added the input buffer.  I this normal?  Should I try a different tranny? different buffer?

Thanks for you help

[Triffid]

On an up note... the input buffer did fix my wah problems  it just altered the sound too much.