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karul wrote:rcustoms, can you measure the capacitors and the resistance of the coils?

hi mr Karul i dont have cap tester but this is the coil resistance

another shot.

5.7k and 6.1k, am I right ? - huh, that's quite big difference, and that's almost 2k more then the value mentioned at
http://www.electrosmash.com/emg81


And those values are for 81 or 85?

I can see 2 black and green and a yellow wires per coil. Can you draw a diagram ? Are those black wires connected with the green and yellow ?

And what's your plan to reduce microphonics ?

the "black wires" are just shadows of the green and yellow wires - lol

bajaman wrote: the "black wires" are just shadows of the green and yellow wires - lol

jajajaja just shadows.
i try to do a layuot,with this info.

the green wire (+) and the yellow(-).

Did you discover why they sounded dreadfull ?

marmaliser wrote:Did you discover why they sounded dreadfull ?

yes,poor quality wax potting .today i will try solve this issue.

bajaman wrote: the "black wires" are just shadows of the green and yellow wires - lol

rcustoms

You may replace the opamp with one tl061 or another low consumption IC, it has the same pinout.
I suggest you to reduce the 200k resistors to something like 33 or 68k, this would increase the output and treble response

EddieTavares wrote:rcustoms

You may replace the opamp with one tl061 or another low consumption IC, it has the same pinout.
I suggest you to reduce the 200k resistors to something like 33 or 68k, this would increase the output and treble response

thanks eddie.i try your mod ,the pickups remain the same a lot hum with clean at maximun .chinese stuff bad ,bad clones

pf_fan wrote:I found it somewhere (probably at diystompboxes.com):

"Just a little FYI for everyone: the EMG SPC booster (Strat Presence Control) is virtually identical to the EC Strat midboost. Which came first, I don't know, but they're the same. Which is not that surprising really, since it's a dead simple cookbook type circuit!

Very old post, but for those interested; Bill Turner, brother of Rob from EMG, and co-founder of EMG, also worked for Fender, joining Fender R&D in 1995. The EMG SPC came first. Bill designed the Vintage Noiseless pickups in '98, which used that mid boost circuit. He also designed the S1 switch, and LSR roller nut. He passed away in 2011.

thanks for the info David

Sorry for bumping.
I'm a noob in electronics but I can solder decently. I built preamp that used first Bajaman published scheme - http://1.bp.blogspot.com/-dPwq0PLj_PA/T ... verlay.png
It works amazingly.

Think is I have Agile Septor 827 (with their own passive p-ups). As soon as I got it I changed the bridge to SD Blackout 8 and I wired p-ups with volume pots before the switch so I can use active Blackout bridge with stock passive neck p-up. As you probably know in middle position Blackout cancels out passive.
Today I made Bajaman design preamp + changed volume pot to 25K too. But still, on middle settings, there is no sound of the bridge p-up. What's wrong?
I'm planning to upgrade friends RG8 with preamps on both p-ups, will it work on middle position?

Hi guys, I made this preamp but I still don't understand the humbucker connection. I don't know if in series or parallel? if someone can give me a light i would appreciate

Talion777 wrote:Hi guys, I made this preamp but I still don't understand the humbucker connection. I don't know if in series or parallel? if someone can give me a light i would appreciate

One end of both coils does to ground. The other ends go to the (+) and (-) inputs on the op amp. So it's sort of parallel, except the two coils aren;t connected together on the hot side of the coil.

I have done so

green and white wire are the negatives of the humbucker
Black and red +
Black +1
Red +2
I did so but there is still some noise

Talion777 wrote: I did so but there is still some noise

Are you using a standard humbucker as a signal source?

The humbucker I use is 4 drivers + bare