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Guitar Preamps sounds	Preamps sounds with an acoustic guitar
Preamps sounds with an bass guitar	Preamps sounds with a Stratocaster

All of these preamps and effects circuits are Original designs. They are Not copies of other people's circuits. 2025 Updates: New members of DIBs guitar circuits are the GOA-DD1A multi-mode distortion unit and the GTB Treble Boosters. Current products - 2025-05-25 GOA-DD1A 2024 December Update: The GPH-2448 which is powered by phantom power from 24 to 48 volts. No Batteries! GPH-2448 GPH-2448 The circuit boards for the GPA-2Z2 versions of my guitar preamps are here. These will be available with fixed gain or an adjustable gain pot. They're here! The GPA-2Z2 with fixed gain is $55 and the GPA-2Z2+ with variable gain is $66. These are improved versions of the GPA-2 units. 2024 News:   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. My White Paper on preamp design: Three Aspects of Preamp Design You can contact me also on my Facebook page: DavidIBaldwin Ultimate Guide to Buffer Pedals Development and Testing Click on pics for large pic.   With adjustable gain Fixed gain External Power Unity gain buffer Treble boost 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. Guitar Preamps and Buffer Amps GPA-2 and GPX-2 preamps.   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. GPX-2 and GOX-2 preamps.   Just bought the GPH2448 on Tuesday. I tried it out with an electric guitar (single coil pickups) and an electro-acoustic (piezo pickup with on-board battery powered preamp. Both sound good through the GPH into a mixer mic preamp, more clarity and fullness than if plugged directly into the mixer. I got it to serve as a Hi Z buffer into mixers that lack Hi Z inputs. After I've had more chance to use it, I'll report my findings. Dan Feldman   GPA-2 for me! I use it with my Eastman mandolin and been using it with my electric guitars as well. Andrew Foster   I bought the basic preamp and it sounds great.  GPA-2Z2 with Breedlove guitars and Martin D18 using Fishman pop-in humbucker pickup. Rusty Sterling   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   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 enhance the sound of electric guitars too. 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-2Z2 - fixed gain is $55 GPA-2Z2+ - variable gain is $66	GPX-2 - $88 GPX+2 - $99 with external power adapter

BPA/BPX, GOA/GOX, and FETRON series
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.

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

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