Fodera, Sadowsky, aguilar, and other bass preamps

Stompboxes circuits published in magazines, books or on DIY electronics websites.
Brink
Degoop Doctor
Posts: 307
Joined: 11 Jul 2009, 21:22
Location: NY
Has thanked: 2 times
Been thanked: 18 times

Post by Brink »

Someone has come forward and offered to trace the Sadowsky preamp/DI. I just mailed the pedal off a few minutes ago.

User avatar
Silent Fly
Resistor Ronker
Posts: 425
Joined: 27 Feb 2008, 23:40
Has thanked: 24 times
Been thanked: 32 times

Post by Silent Fly »

Brink wrote:Someone has come forward and offered to trace the Sadowsky preamp/DI. I just mailed the pedal off a few minutes ago.
Excellent! Thanks :thumbsup
"Remember - all I am offering is the truth, nothing more". Morpheus

quaternotetriplet
Resistor Ronker
Posts: 377
Joined: 19 Nov 2008, 14:37
Has thanked: 10 times
Been thanked: 4 times

Post by quaternotetriplet »

Nice.

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

I would love a pcb layout gif to make one of these. :D
Skyline FX 2013

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

how would I take the green out to make this apcb printable file?

I am thinking of making my own class d bass amp and using something like this as the pre.
Skyline FX 2013

User avatar
lietuvis
Breadboard Brother
Posts: 101
Joined: 27 Sep 2008, 10:01
Location: Coalville,UK
Has thanked: 80 times
Been thanked: 57 times

Post by lietuvis »

chicago_mike wrote:how would I take the green out to make this apcb printable file?

I am thinking of making my own class d bass amp and using something like this as the pre.
Hi if you are talking about this one I've posted as a ampeg and swr hibrid bass preamp there is diptrace pcb file.if you have any questions pm me or email me litvanas at googlemail.com
Attachments
PREAMP.dip.zip
(8.16 KiB) Downloaded 564 times

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

:hug:
Skyline FX 2013

quaternotetriplet
Resistor Ronker
Posts: 377
Joined: 19 Nov 2008, 14:37
Has thanked: 10 times
Been thanked: 4 times

Post by quaternotetriplet »

:shock:

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

yes were all tree huggin lovie dovie hippies here... :P
Skyline FX 2013

quaternotetriplet
Resistor Ronker
Posts: 377
Joined: 19 Nov 2008, 14:37
Has thanked: 10 times
Been thanked: 4 times

Post by quaternotetriplet »

:hug: yeah can i join. LOL :applause:

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

sure....

umm.... how do I turn youre schematic/layout into a printable layout? I tried the program but eaglecad even gets me, so .... :oops:

IM super interested in building this. :)
Skyline FX 2013

User avatar
lietuvis
Breadboard Brother
Posts: 101
Joined: 27 Sep 2008, 10:01
Location: Coalville,UK
Has thanked: 80 times
Been thanked: 57 times

Post by lietuvis »

chicago_mike wrote:sure....

umm.... how do I turn youre schematic/layout into a printable layout? I tried the program but eaglecad even gets me, so .... :oops:

IM super interested in building this. :)

well you have to use diptrace software which is free to use to certain level and can be downloaded from here http://www.diptrace.com/.when it comes to printing you have to tick boxes or untick what layers you want to print for example silk screen is off then only traces will be printed.hapy building and dont forget to tell the results.it's based on Ampeg B2R +SVT-6 PRO EQ section and I took SWR workingmans 15 very front end with aural enchancer instead B2R ultramid.it easy can be modified to have efx send return option or built as only semiparametric EQ with Ampegs or SWR parameters by changing resistor+cap+pot values.

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

I saw the export option, but didnt see any format I could really use, well photoshop did recognize one thankfully. :)
Skyline FX 2013

User avatar
chicago_mike
Tube Twister
Posts: 1757
Joined: 03 Jul 2008, 05:38
Has thanked: 23 times
Been thanked: 290 times

Post by chicago_mike »

Nevermind...just made a pdf... :roll:

played around with diptrace..its interesting, but I already goof with eagle and my brain doesnt need more confusion. :cry:
Skyline FX 2013

User avatar
gena_p1
Breadboard Brother
Posts: 84
Joined: 25 Apr 2009, 22:47
Location: Russia
Has thanked: 23 times
Been thanked: 11 times

Post by gena_p1 »

Brink wrote:...
I've got a Sadowsky Bass Preamp/DI sitting around, in a unmodded and nonworking condition. The board is SMD and ungooped. Tracing this is beyond my abilities, but if someone else wants to do it I'll mail it to them.
...
Values are unreadable, so here is nothing to trace (and compare to cube 60 bass)

User avatar
lietuvis
Breadboard Brother
Posts: 101
Joined: 27 Sep 2008, 10:01
Location: Coalville,UK
Has thanked: 80 times
Been thanked: 57 times

Post by lietuvis »

Hi, got chance to trace Fender Precision Deluxe Lyte MIJ onboard preamp.files are in DIPTRACE software format.the PCB is doublesided :( but schematic is pretty simple so it can be done on single layer board.
Attachments
fender.jpg
P1020616.jpg
P1020611.jpg
fender 3band eq in diptrace.zip
(8.78 KiB) Downloaded 163 times
F PRE PCB.jpg
F PRE SCH.jpg

User avatar
Silent Fly
Resistor Ronker
Posts: 425
Joined: 27 Feb 2008, 23:40
Has thanked: 24 times
Been thanked: 32 times

Post by Silent Fly »

lietuvis wrote:Hi, got chance to trace Fender Precision Deluxe Lyte MIJ onboard preamp.files are in DIPTRACE software format.the PCB is doublesided :( but schematic is pretty simple so it can be done on single layer board.
Thanks!
"Remember - all I am offering is the truth, nothing more". Morpheus

quaternotetriplet
Resistor Ronker
Posts: 377
Joined: 19 Nov 2008, 14:37
Has thanked: 10 times
Been thanked: 4 times

Post by quaternotetriplet »

that was nice preamp..

User avatar
lietuvis
Breadboard Brother
Posts: 101
Joined: 27 Sep 2008, 10:01
Location: Coalville,UK
Has thanked: 80 times
Been thanked: 57 times

Post by lietuvis »

Here is another interesting bass preamp (has minor errors) with variable low pass filter and switchable Q found on other forum.
Attachments
Real Basses Are Passive And Have Four Strings - p65.jpg
Real Basses Are Passive And Have Four Strings - p64.jpg

jay42
Posts: 33
Joined: 06 Aug 2010, 01:36
Been thanked: 2 times

Post by jay42 »

I don't have permission to share the Sadowsky preamp schematic, however, I can describe it to the point that you can develop your own. First off, it's a Blackface preamp done with JFets. The tone stack is scaled appropriately...which is to say, the 100K slope resistor becomes a 10K slope resistor and the capacitors go up by a factor of 10. For a built-in, you've got a 500K audio pot for volume up front instead of after the tonestack. 2x 2N5457 You could add a mid-range pot in lieu of the fixed resistor, which is 750 ohms instead the 960 you would expect. I've been told that the Aguilar two-knob built-in is the same circuit, but I can't confirm it.

I sort of think it's ironic that some bassists will say, "I'm all modern here with active electonics and all. I need a flat pre-amp." They're really just playing through a Fender.

Post Reply