Fodera, Sadowsky, aguilar, and other bass preamps

bajaman · Post by **bajaman** » 09 Nov 2012, 03:54

I believe you darmstat

Just concerned for those folks who will try to build it from an incorrectly drawn schematic and then the inevitable " I built this tone control but it just makes this funny farting noise and has very low output.....etc. Can you tell me what i am doing wrong etc."

cheers
bajaman

darmstat · Post by **darmstat** » 09 Nov 2012, 03:57

Did you breadboard it or did just build on perf or stripboard?

Duckman · Post by **Duckman** » 09 Nov 2012, 04:07

Here is a PDF with my single sided trough hole PCB version.
73mm x 37mm. Admits on board pots (long leg)
Ground plane version and trace ground version included.
Hope it helps.

darmstat · Post by **darmstat** » 09 Nov 2012, 04:17

Bajaman...I hope i did not side track you from the Fender with the Benavente build and schematic. I breadboarded the Benavente just a few minutes again and did not get any unpleasant noises. No farting or low output.

bajaman · Post by **bajaman** » 09 Nov 2012, 05:21

yes darmstat

BUT YOU PROBABLY CONNECTED PIN 8 of the opamp to +9v and PIN 4 of the opamp to GROUND

My comment was that your schematic DOES NOT SHOW THESE CONNECTIONS

bajaman

bajaman · Post by **bajaman** » 09 Nov 2012, 05:23

thanks Duckman

You saved me the effort

nice looking layout too!

cheers
bajaman

Duckman · Post by **Duckman** » 09 Nov 2012, 14:17

Thanks, Baja! Just a try to give back a little to this endless fountain of info.
Any way, I'll always look for your personal experienced vision.

darmstat · Post by **darmstat** » 09 Nov 2012, 14:54

Here is the Benavente with the connection for 9 volt and ground....

bajaman · Post by **bajaman** » 10 Nov 2012, 09:04

Thanks to Duckman (and Sprint Layout v5.0), I have managed to shrink Duckman's through hole board layout for the Fender American Deluxe Jazz Bass Active preamp down to the same size as the SMD layout which I previously posted in this thread.
Here are some bitmap photoviews taken from Sprint Layout V5.0 ( I LOVE this PCB drawing program

).
The first bitmap image shows the silkscreen top layer with an X-Ray view of the bottom layer tracks.
The second image shows the bottom layer copper tracks with an X-Ray view of the silkscreen top layer.
Enjoy

bajaman

: Baja three band active bass preamp through hole 101112 small.bmp (672.71 KiB) Viewed 3360 times

: Baja three band active bass preamp through hole 101112 rear small.bmp (672.71 KiB) Viewed 3360 times

As a foot note

This preamp is designed for +18 volt operation - (My earlier SMD board post wrongly shows +9 volt

)
Although it will work on +9 volt, the CORRECT +18 VOLT SUPPLY will provide for a much greater headroom and freedom from clipping when the controls are maxed out

Cheers
bajaman

Duckman · Post by **Duckman** » 10 Nov 2012, 14:21

I knew it!
Great! Nice and neat!
What's the final size?

bajaman · Post by **bajaman** » 10 Nov 2012, 20:31

approximately 59mm x 28mm

( pretty much the same size as the original Fender SMD board )

Your layout saved me a lot of time Duckman

Thank you

cheers
bajaman

ps: your original pdf artwork is missing the ground connection traces to the input and output level potentiometer

Duckman · Post by **Duckman** » 10 Nov 2012, 21:16

Dammit!

Thanks for pointing it, Baja!
Now is corrected for those who like more spaced layouts

Seriously Baja, your work is great.

It would be nice if some moderator please delete the previous .pdf I posted, since include that big mistake.

bajaman · Post by **bajaman** » 10 Nov 2012, 22:35

Here is a 300 dpi paleted bitmap image for the Fender preamp

: Baja three band active bass preamp through hole 101112 copper.bmp (908.55 KiB) Viewed 3333 times

- unfortunately the forum does not allow me to upload gerber files, so I traced the photoviews posted earlier in CorelDraw and increased some of the trace widths to conserve etching solution

This is the largest dpi image that I can upload because the forum restricts files to under 1 Megabytes

Anyway - if you want to etch a board yourself , this may be helpful.
Thanks again to Duckman whose layout I have shrunken down for this Fender board sized layout

cheers
bajaman

Duckman · Post by **Duckman** » 11 Nov 2012, 02:02

Here's the darmstat's Benavente, re-drawn just to clarify

bajaman · Post by **bajaman** » 11 Nov 2012, 03:07

the benavente looks very much like the Fender circuit

BUT - where is the volume level control fitted ?

cheers
bajaman

bajaman · Post by **bajaman** » 11 Nov 2012, 03:12

I have a design for the two band passive ladder Sadowsky (fet version of the Fender Bassman 100 tube preamp

) preamp.
My version runs at about a 10th of the current - extremely low noise AND long battery life.
I have built it into two of my bass guitars and am very pleased with it's performance (but then I always have been a BIG fan of Leo Fender - a true genius).
Perhaps i should post it

bajaman

DrNomis · Post by **DrNomis** » 11 Nov 2012, 03:29

I reckon you should post it Bajaman, but it's really up to you.....

Are there any copyright issues with Fender?.....

Duckman · Post by **Duckman** » 11 Nov 2012, 16:26

bajaman wrote:where is the volume level control fitted ?

I just redrawn darmstat's work... don't kill the messenger!

bajaman wrote:Perhaps i should post it

Well... you're in the right thread

bajaman · Post by **bajaman** » 11 Nov 2012, 19:01

I just redrawn darmstat's work... don't kill the messenger!

Sorry, I should have addressed the question to darmstat

cheers
bajaman

roseblood11 · Post by **roseblood11** » 11 Nov 2012, 20:35

Nice layout bajaman, thx! I'll definitely give it a try in my wife's Ibanez SRX 700 NT.

3 hints...
-your black is dark grey
-if you save the file as GIF, it has 28.8kB
-if you want to post a gerber file, just change the file extension to .txt

regards, Immo