DIBsed77 (2K)
Guitar and Instrument Preamps
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About Me:
  I built my first audio amp in 1977. My band needed an amp for the monitor speakers so I built one. Wasn't great but it did the job. In the 47 years since then I have designed and built hundreds of audio circuits. Most of that time I was working for small companies designing products for them. Now I'm working for myself bringing you useful products based on solid and often original designs.
2024 Update:
  I've done a lot of R&D this year. I've improved the sound quality and prototyped some new models like the FETRON model.
Here is my current product plan: DIBsGuitarPreamps.pdf.
My White Paper on preamp design: Three Aspects of Preamp Design
You can contact me also on my Facebook page: DavidIBaldwin
Guitar Preamps and Buffer Amps
GPA-2 and GPX-2 preamps.
GPA2-GPX2-02T (15K)
  While hosting the Java Café and Fox & Goose open mic's, I frequently had a problem with guitars and mandolins that didn't put out enough signal when they were plugged into my PA system. Acoustic guitars with Dean Markley pickups are almost always a problem. Well, I don't have that problem anymore. I have designed and built several different guitar preamps and buffer amps that I use at my shows now. I had three different preamp models with me last night (11/29/04) at the Java Café open mic and used them with a dozen different guitars and a mandolin and never had a level problem all night. And Yes, they all Sounded good too. No more of that tinky sound. I built one for Ken Burnett and one for Craig Kincaid, below is what they say about it:
  I built one last month for Steve Krohn too.
  Dave Baldwin created this preamp for guitars…it’s magic…made all guitars “young “ again..,,probably get additional ones since makes such a difference…contact Dave or even SJK should you want one…makes guitar feel like it’s not amplified…
Steve Krohn
  When I bought a new Weber mandolin a few months ago I installed a top of the line pickup in it hoping that would solve all of my amplification problems. I play a lot of music with many full bands, and amplification of my instrument has always been a problem. With the addition of Dave Baldwin's fine pre-amp system I have finally found the most natural sounding and versatile addition to my top-line instrument. I couldn't be happier with the results. My sound is as good as it is when I just play into a microphone, and so much easier to control my sound when I have to play loud in any situation.
Ken Burnett
  After getting my GPA-2 preamp from Dave, the sound of my Martin D18 has never been better. And what's even more impressive is in the studio. When I plug directly into the board, the sound of the guitar is so nice; don't need much gain on the input to get the nice sound either. When I use an amp, it's the same. Such a warm and full sound. Thanks Dave for creating this great pre amp.
Craig Kincaid, Singer/Songwriter

GBA, GPA, and GPX series
These buffers and preamps use all discrete NOS components and class A circuits.
Note that these are Original designs. They are NOT copies of anyone else's circuits.
GBA/X Series GPA Series GPX Series
Primarily for electric guitars with adequate signal levels. The GBA/X series is basically a unity gain high to low impedance converter. GBA's preserve the signal and tone while driving long cables and accessories. GBA uses one 9-volt battery. GBX uses two 9-volt batteries for greater headroom. Originally intended for acoustic guitars with add-on pickups. They've been found to enhance the sound of electric guitar also. The GPA series has a high input impedance and a gain of 10 dB. It uses one 9-volt battery and will fit in your pocket or on a belt clip. Maximum output level is about 1 Vrms. With it's eXtended dynamic range, the GPX series is a good preamp for connecting guitars to PA system line inputs. The GPX series has a high input impedance and a gain of 10 dB. It uses Two 9-volt batteries for extended dynamic range with a maximum output level of 3 Vrms. The GPX+2 version adds an AC adaptor.
GBA/X - price not set yet. GPA-2 - $55 GPX-2 - $66
GPX+2 - $77 with 12 VAC power adapter

These preamps use bipolar transistors or integrated circuits.
BPA/BPX Series GOA/GOX Series FETRON Series
The BPA/BPX preamps use bipolar transistors for a different sound. They are designed to drive the cables well.
Still in development.
GOA/GOX series are based on ICs instead of discrete transistors. Maximum output level for the GOX is about 4 Vrms (very high output).
Still in development.
The FETRON preamps are based on a solid state tube replacement device. They act somewhat like tubes without drawing all that power to heat them up. They do require higher voltages (36VDC) to operate.
Still in development.
BPA/BPX - price not set yet. GOA/GOX - price not set yet. FETRON series - price not set yet.

Dave Baldwin is DIBs Electronic Design, providing design support for Audio, Analog, Digital, and Microprocessor systems.
Contact Dave at DIBs Electronic Design