Welcome to my Blog about Recording Equipment!

DSC_3983-2 On this page you will find information about my Handmade Recording Equipment.
My DIY projects include: Discrete Transistor Preamplifiers, Tube Microphone Preamps, Audio Transformers, Vintage Preamp Circuits, Inductor Based Equalizers and more…
Thank you for looking!
- Bart

MP2184 | Hybrid Transistor Microphone Preamplifier


Detailed, accurate but still sweet and musical.
Equivalent Input Noise (EIN) is low as -129dBu | THD<0.04% @ +60dB of Gain

This design solution ensures that signal will be clear, detailed and close as possible to the source.

MP2184 input stage is using low noise transistors and specially designed balanced input circuit.

MP2184 is very accurate but not clinically clean. Circuitry design based on discrete transistors will add subtle warmth and colouration which makes MP2184 perfect match for every microphone.

Learn more about MP2184

MP6148 | 6 Channel Classic Transistor Preamplifier

DSC_8226 Design based on MP2148 discrete technology with DOPA'48 – Single Ended Input Discrete Operational Amplifier. The circuitry is completely transistor based. Inputs and outputs are transformer coupled.

In this six channel microphone preamplifier I have used my custom made audio output transformers. The sound is more detailed and natural compared to vintage Carnhill transformers.

Lear more about MP6148

CS2848 | Dual Mono Recording Channel Strip


The CS2848 is unique recording / mastering completely discrete transistor channel strip with transformer coupled inputs and outputs, inductor based EQ and classic opto-compressor. The design features fully discrete signal path - no Integrated Circuit is used.

This is my new design based on the MP2148 transistor discrete circuitry. CS2848 has improved output stage. I have added new improved output transformer driver which reduce low frequency distortions

The preamplifier section and EQ section uses DOPA'48 single ended input discrete Opeartional Amplifiers.

Learn More about CS2848

Racking Neumann V 472 Preamplifiers Modules

Neumann 472 - 2 unit front g- Bart HRK

Neumann is well known name in the world of professional studio recording equipment. V72 is probably the most famous preamplifier made by this manufacturer.

V472 is transistor based microphone preamplifier. Each module contains two independent channels with the gain up to 40dB. Inputs and outputs are transformer coupled.

Neumann V472 can be found on eBay or from other online retailers. Usually modules comes without power supply and without input or output connectors. This means that preamps are useless.

This article presents racking solution which converts V472 modules in to the very valuable studio equipment.

Learn More about V472 Preamp.

EQ2484 | Mastering / Recording Inductor Based Equalizer


EQ2484 is a Truly Handmade inductor based 4 band dual mono equalizer for mastering or recording purposes. The design is based on hybrid transistor technology.

The circuitry is completely analogue and input and output is transformer coupled.

This type of design was very popular in vintage transistor mixing desks from 60's and 70's. The circuitry idea used EQ2484 is a improved approach similar to vintage designs.

Learn More about EQ2848 

MP2148 | Classic Transistor Microphone Preamplifier


MP2148 is a classic transistor dual channel microphone preamplifier inspired by vintage transistor recording equipment. Each channel has low noise transformer coupled microphone preamp, transformer line input and high impedance instrument input.

I have always wanted to build completely discrete transistor preamplifier. I do believe that it is possible to build transistor preamlplifier which will outperform IC's based designs in terms of parameters and sound quality. Looks like MP2148 proves that!

The idea was to keep the character of classic transistor preamps, but achieve better sound quality and fidelity compared to vintage preamps.

Learn more about MP2148