Submarine Bass Preamp

[JonnyAngle]

http://www.aronnelson.com/gallery/main.php/v/Renegadrian/SUBMARINE+BASS+PREAMP.gif.html

I had a friend build me this vero board Submarine Bass preamp.  However, the output volume is extremely low.  Is there anything in this circuit that may contribute to the low output volume?  Thanks!

Edit-I contacted the designer and he never actually built the pedal

[mistahead]

Quite a bit could be happening there, does the tone pot impact on volume?

Hate to do it... but can you have a look at the debugging thread and crack an audio probe onto the circuit, if I'm reading the layout correctly I'm going to guess one of those Q's isn't biased correctly.

[Thecomedian]

Did you substitute any parts? are the transistors facing the right way/having the right inputs going to E/C/B?

[deadastronaut]

yep my bet is the FET isn't biased properly too.

''he never actually built it'' ....yep that happens quite a bit..

If your friend is into making you a pcb then i highly recommend this bass preamp.

i breadboarded it, tweaked it, built it and its a great preamp, really puts life into your bass. (i use 5 string btw)

files:
http://www.diystompboxes.com/smfforum/index.php?topic=101898.msg906821#msg906821

demo:
http://www.youtube.com/watch?v=2V-6-083Kfo&feature=c4-overview&list=UUGP0eO8ADt0H9FY5UcHTf8A

[JonnyAngle]

Thanks for your help all, I'll report back in a few weeks once it gets looked at.

[Renegadrian]

Late reply I know but yeah I stubled on this page by fate...
Seems someone else used my layout with success. We know FETs can be choosy on the voltage they get, so a trimmer in sub(marine)stitution of those 6.8k res would help, expecially on the upper fet.
Still I didn't build this one, as some other layouts in my gallery.

[j-pee]

wow, I'm so negatively impressed...
there is the onboard preamp, designed by the late Albert Krezuer...
someone makes a rip off of it...
redesigning some parts...

and publishes it with the parts bill, but without mentioning that it has never been built...

as for me right now, I want to make the Albert Kreuzer original design, as well as the slightly simplified version by Alex S, which works, which is verified.... and I definitely wanted to make the Aron Nelson version, too...
as  a matter of fact, I was just 2 minutes from turning on the soldering iron...
the parts I have ordered during the week, so they are here on my table....

I wanted to understand the redesigning concept...
but, alas, it is only a theoretic design...
OMG...

I'm so happy skipped this bad trip !!!!
a bad trip based on a GREAT original design -- Albert Kreuzer's...

huhh...


in any case, I suggest two links,

one:
Alex S's layout... (only slightly simplified, and for  areason)

and #2:
Albert Kreuzer's original design....

so #1:
http://guitar-fx-layouts.42897.x6.nabble.com/Albert-Kreuzer-onboard-FET-pre-Submarine-td11076.html#a47130

and #2:
https://web.archive.org/web/20100425064745/http://www.albertkreuzer.com/start.htm

PS:
I hope I saved someone a bad building attempt

[ElectricDruid]

...and welcome to you too, J-pee 

[Rob Strand]

late Albert Krezuer...

Hey that's sad news I didn't know that.

there is the onboard preamp, designed by the late Albert Krezuer...
someone makes a rip off of it...
redesigning some parts...
and publishes it with the parts bill, but without mentioning that it has never been built...

Welcome to the effects industry for the last 55 years or so.
BTW, Albert Krezuer's tone control comes out of the National Semiconductor Audio Handbook 1976.