Active preamp?

[888guitars]

I have just been asked to build a preamp to add to passive pickups so this customer who plays with EMG pickups can get a similar tone with his passive pickups. I tried the EMG PA-2 booster but I dont really need more boost.

Anyone have any ideas? I have done some searching and came across the Alembic Stratoblaster but again it is really just a 20db boost.

[Albert Kreuzer]

Try the Tillman preamp Discrete FET Guitar Preamp. Moderate boost, but you can attenuate it with a trimpot instead of R4.

[David Schwab]

I have just been asked to build a preamp to add to passive pickups so this customer who plays with EMG pickups can get a similar tone with his passive pickups. I tried the EMG PA-2 booster but I dont really need more boost.

Anyone have any ideas? I have done some searching and came across the Alembic Stratoblaster but again it is really just a 20db boost.

The Stratoblaster will make it sound more like an EMG than the PA-2, insofar as the highs will be crisper. You don't have to use the boost function.

[CRU JONES]

20db is a gain of 10.

That should get you to the output level of an emg81. The not sure if the actual coils inside an emg81 are considered high output and they are connected to a preamp with a gain of 5.

The attached shows, basically the EMG81 circuit (x5 differential amplifier). Dave(above) could tell you more about this circuit.
LM4250.pdf

cru

[David Schwab]

20db is a gain of 10.

That should get you to the output level of an emg81. The not sure if the actual coils inside an emg81 are considered high output and they are connected to a preamp with a gain of 5.

The attached shows, basically the EMG81 circuit (x5 differential amplifier). Dave(above) could tell you more about this circuit.

cru

Each coil in the 81 is about 4.2K.

Here's the circuit.

[Mark Hammer]

Worth consulting all those back issues of DEVICE I have posted on my site. hammer.ampage.org

[David Schwab]

Worth consulting all those back issues of DEVICE I have posted on my site. hammer.ampage.org

That's a great service you did there. I was horrified when my full set of Device mags was destroyed when my basement flooded once.

Lots of goodies and ideas in those. Boy those were the days.

[888guitars]

Whew.... there was alot of info at that hammer site. Thanks for all of the incite. I will build a couple of these and see what gives.

[Mark Hammer]

T-Boy, the webmaster here, was kind enough to give me some space, and an interface, to post all that stuff, so thank him first. He was also nice enough to give me a new interface and better administration tool so that I can move all that content (and more) over to a more manageable and usable space. I better get cracking on that.

Glad I could replace your loss, David. I actually scanned and posted my copy of the old Jack Darr book too, a while back. But when the Glass Audio people re-issued the Darr book, I thought it inappropriate to leave the files up, so I took them down. One of these days I should scan and post my old Sam's Transistor Substitution book from 1976 or so, and my old Motorola HEP replacement guide.

[888guitars]

Well then, Thanks T-Boy!!!!