Baja Music Man guitar and bass onboard preamps  [documentation]

Original effect designs complete with schematics, layouts and instructions. Freely contributed by members or found in printed or online publications. Cannot be used for commercial purposes without consent of the respective owners of the copyright.
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oldschoolbassplayer
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Post by oldschoolbassplayer »

Jarno wrote: 27 Sep 2021, 14:14 Start with the resistors, then capacitors, semiconductors (IC's, transistors) last.
But in general, lower/smaller components before bigger ones.
I almost want to build my own tube amp now! :D

I'm looking forward to this it should be fun.

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oldschoolbassplayer
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Post by oldschoolbassplayer »

Jarno,

Did you know that solder has a shelf life? I have a 1-lb Kester .8mm (.031") 60/40 rosin core paper-weight manufactured Jul 07 17.

I guess I will not be buying any more 1-lb spools of solder, but before I go ahead and order less, I wondered if you had any solder thoughts or advice?

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Jarno
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my favorite amplifier: Something nice
Completed builds: Alembic-like state-variable and sallen-key filter preamps
Lovepedal Eternity
Phase 100
Brown source
Fuzz Face
Flipster
Alembic F2B (tube preamp)
Opamp and FET buffers
Loads of speakercabinets and ampracks
Busy building a modular synth (ssm2044 vcfs, preamps, ADSR's, VCO's, VCA's)
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So many things! :D
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Post by Jarno »

Does it still work properly? If it does, don't worry about it.

As to my preference, I use Stannol solderwire, with lead, not sure if that's easy to get where you are. There are several variants I think I've used HS and HF, both have no-clean flux, and I do not clean my boards.
"It crackles....., but that's ok"

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deltafred
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Post by deltafred »

oldschoolbassplayer wrote: 28 Sep 2021, 22:57 Did you know that solder has a shelf life?
That's odd because I have a roll that I started sometime in the 80's and it hasn't gone off yet. :lol:
Politics is the art of so plucking the goose as to obtain the most feathers with the least squawking. - R.G. 2011
Jeez, she's an ugly bastard, she makes my socks hurt. I hope it's no ones missus here. - Ice-9 2012

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oldschoolbassplayer
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Post by oldschoolbassplayer »

I'm wondering how lead and tin go bad sitting is a closet? Probably the rosin core is what deteriorates but geez when I was a kid seems like a spool of solder lasted 10-years or you lost it...

What do you clean your boards with? Do you prep your boards in any particular way?

Are you an electronics guy that plays the bass or a bass player that knows electronics?

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Jarno
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Posts: 261
Joined: 12 Nov 2008, 10:18
my favorite amplifier: Something nice
Completed builds: Alembic-like state-variable and sallen-key filter preamps
Lovepedal Eternity
Phase 100
Brown source
Fuzz Face
Flipster
Alembic F2B (tube preamp)
Opamp and FET buffers
Loads of speakercabinets and ampracks
Busy building a modular synth (ssm2044 vcfs, preamps, ADSR's, VCO's, VCA's)
Tables
Bookshelves
Basses
So many things! :D
Location: Rosmalen, NL
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Post by Jarno »

As mentioned in my post I do not clean, also no special preparation unless I etched boards myself, and they have been in a drawer for a while (very fine steel wool).

I myself am a mechanical engineer, with affiliation with electronics. The hobby has helped my career as well, I now lead a group of development engineers who do both mechanics and electronics (and software, really need to know more about that area) development.
Apart from that, a bassplayer, and I have built a rather big modular synth. :D
Last edited by Jarno on 30 Sep 2021, 16:45, edited 2 times in total.
"It crackles....., but that's ok"

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deltafred
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Post by deltafred »

I've seen acid cored solder corrode over time but never rosin.

If needed (if they don't tin properly) I clean the solder pads with with a typist's eraser (a pencil shaped eraser where the "rubber" is loaded with fine sand). As we don't have typists anymore I guess that typist's erasures are no longer produced.

"Are you an electronics guy that plays the bass or a bass player that knows electronics?"

Good question, make your own mind up.

Back in the 60's I started messing with electronics when I was about 12 y.o. and started playing bass at 16. I worked in an electronics design lab in the early 70's then moved from design to commissioning and fault finding where I stayed until they moved the electronics design and production to another site. Software was in it's infancy and I retrained as a software engineer, finally ending up in software quality control where I was when I retired.

As far as bass playing goes I have been a weekend warrior since 1967 with occasional short breaks when life got in the way. I turned down a few opportunities to go pro because I had a family and a good career (with a pension at the end of it). I currently play in 3 bands and sub for a 4th.
Politics is the art of so plucking the goose as to obtain the most feathers with the least squawking. - R.G. 2011
Jeez, she's an ugly bastard, she makes my socks hurt. I hope it's no ones missus here. - Ice-9 2012

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oldschoolbassplayer
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Post by oldschoolbassplayer »

Thanks guys - its good to know I am not getting advice from a couple of "internet experts" :lol:

I am grateful for all your help.

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oldschoolbassplayer
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Post by oldschoolbassplayer »

Any suggestions for a reasonably priced digital multi-meter that isn't junk?

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Jarno
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Posts: 261
Joined: 12 Nov 2008, 10:18
my favorite amplifier: Something nice
Completed builds: Alembic-like state-variable and sallen-key filter preamps
Lovepedal Eternity
Phase 100
Brown source
Fuzz Face
Flipster
Alembic F2B (tube preamp)
Opamp and FET buffers
Loads of speakercabinets and ampracks
Busy building a modular synth (ssm2044 vcfs, preamps, ADSR's, VCO's, VCA's)
Tables
Bookshelves
Basses
So many things! :D
Location: Rosmalen, NL
Has thanked: 6 times
Been thanked: 46 times

Post by Jarno »

Even the cheap ones are OK, still have one I bought from the dutch version of Home Depot a decade ago. Also have one from china which is OK (has capacitance and inductance measurements), I have a bench multimeter from Fluke which has seen better days (but it is more than 50 years old, and a dumpster find), and a analogue Hioki from the 80's which has no features, but always works (reading the dial is a bit of a puzzle).
"It crackles....., but that's ok"

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flavio-san
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Post by flavio-san »

Hi stompboxers, I've built the 2 band EQ preamp suggested by the great Bajaman (thank you Sir)

please find below my results

https://postimg.cc/ppqG3hq8

with pots:

https://postimg.cc/HrnZmYhN

FFT with EQ closed

https://postimg.cc/zHNKG7XB

FFT with Bass full open

https://postimg.cc/5QmvYz6m

FFT with bass and treble full open

https://postimg.cc/7brWzy5C

FFT with flat response (bass closed and treble somewhere near 3/4 open)

https://postimg.cc/dDRSmSC5

I will try this one on a P-J bass that I'm not using since the tone is not of my taste anymore (getting old maybe)

F

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JudgeMingus
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Completed builds: JH-1 renovation with mods for crisper tone
Tuner/Mute box with loop reverser (for Gilmour 'seagulls' wah effect)
Si Fuzz Face clone
Rat clone
Tonepad Rebote 2.5 echo
Phase 90 clone
MXR noise gate clone
Runoffgroove Professor Tweed
Distortion+ clone
OD250 clone
Fuzz Central Liquid Drive
MXR DynaComp clone
Orange Squeezer clone
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Skreddy Lunar Module clone
Dual-output buffers (derived from AMZ Super Buffer)
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Post by JudgeMingus »

To revive discussion of the 'typist' erasers mentioned above - they are still available:
I found some on http://www.erasersticks.com/block-erasers.html
and one at https://www.aroundtheoffice.com/Richard ... ER-4421-BN

I haven't tried the ones I linked, but I suspect any old fashioned ink eraser would be abrasive enough to polish off superficial oxidation from copper traces.

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