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Author Topic: An universal guitar preamp  (Read 27008 times)

danV

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An universal guitar preamp
« on: October 18, 2008, 05:08:21 PM »
Hi all!

Enter Infinity, a guitar preamp offering great sound versatility, from clean to heavy distortion. It can be used for DI applications (in conjuction with the PA and a monitor), and for recording. A short presentation can be downloaded here.



 :) Samples
A Youtube video of first prototype, and containing some samples (direct recording to the PC soundcard): Here!
Other samples:
- Here! for a Vox style.
- Here! for Pink Floyd's Comfortably Numb (delay was added through Audacity).
- Here! for "Two minutes to 2h in the morning" (since I recorded it at 2AM), Iron Maiden style.
- Here! for a Plexi style.
- Here! for "Thunderstruck", AC/DC style
- Here! for "Sharp Dressed Man", ZZ Top style.

 :) Files
The latest schematics of Infinity (V1.1) are here!
And the parts layout:
The .pdf format is here!

 :) Building pictorial

Here is a .zip file with all the photos ( size 4,73Mo).

The prototypes:


The final version:


Enjoy!  :)
« Last Edit: March 24, 2009, 08:16:53 PM by danV »

danV

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Re: An universal guitar preamp
« Reply #1 on: November 24, 2008, 05:31:12 PM »
400 views and no comment  :-[

Anyway, here are 2 pics of the new prototype:



A layout will be ready soon ...

 :tu:

syndromet

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Re: An universal guitar preamp
« Reply #2 on: November 26, 2008, 02:50:32 AM »
Looks and sounds great! Too many knobs for my liking, but it looks great.

Robin755

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Re: An universal guitar preamp
« Reply #3 on: November 27, 2008, 03:39:15 PM »
Very nice work dude!

danV

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Re: An universal guitar preamp
« Reply #4 on: November 28, 2008, 04:39:43 PM »
Thanks!

I've finished the layout, and my PCBs will be probably made in 1-2 weeks.

About the number of pots, I would have liked to reduce it to 7 (without the bass control in the pre-equalizer), however fuzz tones and fine-tuning in the sound (especially for the samples of Scorpions and Dire Straits songs) would not be available anymore.

Streel

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Re: An universal guitar preamp
« Reply #5 on: January 04, 2009, 01:13:47 PM »
This preamp sounded great,wow I like this. Excellent controls and design. Very nice! Definitely on my project list to build. And very good video too, very good job.

STDog

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Re: An universal guitar preamp
« Reply #6 on: January 04, 2009, 07:30:58 PM »
Nice. A lot of sounds from that thing.

What would the parts to reproduce it run? (not counting the PCB or chassis).

Problem with so many variable is getting it to sound like something. I could turn nobs all day and never find the sound I'm looking for.
I've tried it with some other amps. Someone that know what they are doing comes over and in 2 minutes has the right sound for a given style/song. Then a few tweaks and it's sounding like a whole different amp.

More knobs and I'm even less likely to get anywhere.  :'(

zyggurat

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Re: An universal guitar preamp
« Reply #7 on: January 27, 2009, 08:11:02 PM »
Awesome! That´s what I´ve been looking for ! It´s really UNIVERSAL  8| I´ve got only one question  - what opamps have you used ???

danV

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Re: An universal guitar preamp
« Reply #8 on: February 04, 2009, 02:32:15 AM »
Thanks for the replies, and sorry for answering a bit late ...

anyway, the opamps are 2 TL074 and a TL072. You can use other ones, such as the TL06x or the TL08x.

I recorded a few other samples, sorry for the uninspired / bad playing:
- Here for a Voxxy style.
- Here for the 2ns solo of Comfortably Numb (delay was added through Audacity).

I also did a new version of the schematics, since there were 2 mistakes in the component values:Here

Now I'm working on a tutorial, and I hope to receive my PCBs soon. I have also decided to make a full opamp version, in order to avoid the biasing and selecting of the JFETs, and enable more PSU flexibility, mostly for switching in multi-channel configurations.

spraguetr

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Re: An universal guitar preamp
« Reply #9 on: March 15, 2009, 04:28:02 PM »
This looks pretty interesting and I like the combination of sounds so far.

I have a 13 Y.O. son - plays better than me ?;>) with a Roland Cube 15.  I have an old Marshall Lead 12/5005.  I'm thinking of doing some DIY amps to give both of us an upgrade on our equipment and keep us in a budget.  This looks like a good front end for a power amp built around an LM3886 sitting on a 2 x 12 case (or 2).

Great work - and thanks!

rogeryu

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Re: An universal guitar preamp
« Reply #10 on: March 18, 2009, 09:22:03 AM »
Hi all!

It's been a long time since I posted here ::). Anyway, I worked a bit and came up with this ... a Universal Guitar Preamp!  :tu:

It is based on a BSIAB II distortion stompbox, with a redesigned output filter section. I added (simple) pre- and post-equalizers for some extreme sound flexibility. The post-equalizer has also a tunable cabinet simulator included. The preamplifier can be used for recording, or for DI applications.

Here's a video with photos, and, more importantly, some samples.
http://de.youtube.com/watch?v=BRB0erDUqHU

Schematics are here:
http://www.techniguitare.com/projets/ChaosPreamp/Preampli-Schems-En.pdf

Enjoy!  :)

Hey Sebastian a.k.a DSV  8|, remember me rogeryu  :) Nice to see you also hear in this forum.... Great work pal...

spraguetr

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Re: An universal guitar preamp
« Reply #11 on: March 20, 2009, 11:20:08 AM »
Thanks for the replies, and sorry for answering a bit late ...

anyway, the opamps are 2 TL074 and a TL072. You can use other ones, such as the TL06x or the TL08x.

I recorded a few other samples, sorry for the uninspired / bad playing:
- Here for a Voxxy style.
- Here for the 2ns solo of Comfortably Numb (delay was added through Audacity).

I also did a new version of the schematics, since there were 2 mistakes in the component values:Here

Now I'm working on a tutorial, and I hope to receive my PCBs soon. I have also decided to make a full opamp version, in order to avoid the biasing and selecting of the JFETs, and enable more PSU flexibility, mostly for switching in multi-channel configurations.

I have a question for you - I noticed your schematic and the one BSIAB2 are identical near the 5th JFET (2N5457) trimpot.  I also noted that your board artwork has the center wiper tied to +9V leg of the pot instead of the leg going to the JFET.  Probably not much difference, but did it have an impact on the JFET bias voltage? 

danV

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Re: An universal guitar preamp
« Reply #12 on: March 21, 2009, 04:13:14 AM »
I completely forgot to update this thread  ::)

Hi rogeryu. Name's Daniele!  ;)

Hi spraguetr! The old schems have got 2 little errors: a capacitor in the output filters, and the source resistor of the 5th jfet. I'll update the 1st post with all the new info!

danV

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Re: An universal guitar preamp
« Reply #13 on: March 24, 2009, 08:15:05 PM »
1st post is now updated with the .pdf version of the layout.  :)

rogeryu

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Re: An universal guitar preamp
« Reply #14 on: March 25, 2009, 06:15:21 AM »
I completely forgot to update this thread  ::)

Hi rogeryu. Name's Daniele!  ;)

Hi spraguetr! The old schems have got 2 little errors: a capacitor in the output filters, and the source resistor of the 5th jfet. I'll update the 1st post with all the new info!

ugh! :loco Sorry Daniele, i thought somebody else. Anyway I'm also with Diystompboxes and I read your thread same here. Great job buddy  :tu: