Baja Music Man guitar and bass onboard preamps

chicago_mike · Post by **chicago_mike** » 28 Apr 2009, 14:12

Go outboard. You can use preamp for other instruments.

Jarno · Post by **Jarno** » 29 Apr 2009, 14:02

Well, a battery cavity is not very hard to do with a drill and a chisel

And upgrading a OLP is something I want to do as well, it's just that the string spacing on the 5 is narrower than on a original, sadly. Not sure what the spacing is on the new low end stingray 5s.

chicago_mike · Post by **chicago_mike** » 29 Apr 2009, 14:11

It might be what my squier 5 is. Its wide but not 3/4 like my lakland.

Actually, this preamp is going to g into my squier jazz, as well as new pups too.

I think the new import stingray is the same, it looks like it at least.

Hauge · Post by **Hauge** » 31 Aug 2009, 12:18

chicago_mike wrote: Quick Q: If I use seperate volume controls for my pups, do I still need to output volume control or can that be a trimpot?

I would like to know about this as well. I'm thinking about building one of these for my Jazz Bass. Can I still use the original volume controls in front of the preamp?

Martin

Jarno · Post by **Jarno** » 04 Sep 2009, 20:25

Volumes or volume and blend before the preamp works fine, I would add either a trimpot at the end or a adjustable gain to the preamp. But I'm not sure you can do the adjustable gain thing with this preamp as the tonecontrols are also in the feedback loop (I think, I am not quite sure anymore what this schematic looks like, it's been a while).

gryphix · Post by **gryphix** » 13 Sep 2009, 00:43

I was looking over your schematic/layout for the stingray preamp and there is a small discrepancy between the two. In the schematic, there are four 1u capacitors and one 10u capacitor. However, in the layout, there are three 1u capacitors and two 10u capacitors. Can you please tell me which one is correct?

bajaman · Post by **bajaman** » 13 Sep 2009, 01:55

Hi Gryphix
There should be 4x 1uf capacitors - the 10uf connected to the volume pot on the layout drawing is wrong; it should be 1uf - the schematic is correct - sorry.
Cheers
bajaman

flood · Post by **flood** » 26 Sep 2009, 05:09

thanks steve thanks steve thanks steve thanks steve thanks steve thanks steve

i finally got my cheapass chinese 6-string working and sounding even halfway decent, not distorting when i dig in hard... it'S no stingray, but it'S all i have at the moment. i need to swap out the pots and even though there is very little noise to speak of, i'm going to shield the insides to squeeze the last dB from the SNR. it would have been impossible for me to procure a decent preamp in bombay, and my DIY attempts were mostly fail... until now! three cheers for baja!

bajaman · Post by **bajaman** » 26 Sep 2009, 07:18

Thanks flood

always happy to help folks with DIY
cheers
bajaman

chicago_mike · Post by **chicago_mike** » 27 Sep 2009, 02:45

I still have to finish wiring my jazz bass witht this circuit..

wasted_bassist · Post by **wasted_bassist** » 06 Oct 2009, 06:59

This looks like a perfect addition to my old no-name P-basses. I've got 2 of them so I can do some experimenting. Push-pull pot for active-passive switching? I think that's a big heck yes. I'll get back to you with the results.

Tuiman · Post by **Tuiman** » 18 Oct 2009, 17:53

I love it! but I have 3 problems.

1. How to turn off it when I remove lead jack? Because I can not found stereo jack look like mono jack on my bass.

2. How to increases gain? I thing it have output like passive output. I want to get more output.

3. I thing Saber preamp, it's worng wiring between Resistor(220K) and capacitor(1uF). Schematic and PCB are not match.

Thank you.

ps. Sorry for my languge isn't well.

Jarno · Post by **Jarno** » 19 Oct 2009, 07:21

To turn it off you'll need a stereo jack connector, or a separate switch (which you'll forget to turn off, at least I would). If you have a stero jack connector, connect the battery ground to the "ring" contact, and the rest of the preamp and all other grounds to the ground contact (signal goes to the "tip" contact, of course).
The one I built had plenty of gain, certainly more than a passive bass, you might want to check your build.

Good luck!

Post by **MarcoMike** » 09 Jan 2010, 14:06

thank you Baja!!!
I just made it and works great (I made it on perf, so it took me quite long to debug, as usual... it seems I have some kind of conductive flux in my solder)

and besides suggesting this project to everyone... I also suggest buying OLP MM basses to upgrade. the body seems a bit too light, but the neck is great! AND the pickup is a 2x2.7k ohm!!! which sounds like the perfect clone of the original MM pickup!
the day is starting great!

Post by **azrael** » 12 Jan 2010, 23:53

Whoa, this might eb cool. My friend just got a Stingray, and I'm not sure if I like the sound. i was beginning to think it was always distorted!

I'm going to try it on my OLP Stingray first, and then we'll see.

Post by **azrael** » 13 Jan 2010, 00:07

Wait, I found this on eBay:
https://cgi.ebay.com/ws/eBayISAPI.dll?V ... 0390578219

Looks like the same layout to me....

Duckman · Post by **Duckman** » 18 Jan 2010, 23:33

Hi, guys! Need help with this one:

How to correctly rise the input impedance to deal with a piezo pickup?

Tkx!

Jarno · Post by **Jarno** » 19 Jan 2010, 09:59

Well, you could raise the input resistor from 1M to 10M, but that brings along extra noise. I think the best way would be to use a dedicated FET inputstage.

Duckman · Post by **Duckman** » 19 Jan 2010, 21:49

Thanks for the answer, Jarno!

Ok, I agree. After a little more reading, seems to be a good option.

I´ll try this simple input buffer I found in Jack Orman's site.
Just connecting output and input will be ok?
I'm not sure if both circuits must share the 1uF and if R5 must be eliminated, sorry... I'm guessing... not enough knowledge

Tanks for any help!!

: from Jack Orman's AMZ; buff3.gif (1.66 KiB) Viewed 3472 times

Jarno · Post by **Jarno** » 20 Jan 2010, 10:00

That'll work fine I suppose (although I'm by no means an expert), I think there is a schematic somewhere with a slightly different biasing scheme called "noiseless bias" but this will be fine as well, I would keep everything in place (C2 and R5) and just put one circuit in front of the other. Make R5 a trimpot, and take the output of of it's middle pin so you can tweak a bit should the first stage overload the musicman preamp input.

Baja Music Man guitar and bass onboard preamps [documentation]