Okay, I received the PCBs from the fab.  It's pretty.  Measuring a tiny 2-1/2" by 2-1/8".

I'm selling a few extra PCBs as I ordered a few more than what I needed. Cost is $20 per board.

I test-built one of the PCBs to test that it's working properly. Here's my completed prototype PSU (+44V) and (+48V) for phantom power, suited for those racking their Yamaha PM1000 channel strips.

And here's a shot of the bare PCB.




I have a few extra PSU boards so if you're interested, the cost of the PCB is $20 each, +cost of shipping fees. I'll include a Bill of Materials with Digikey part numbers along with your PCB so you can order the parts direct from Digikey or Mouser or wherever.

Email me if you're interested to buy. Thanks!

I just gutted the guts of a Yamaha PM1000 channel strip. I will try to rack them in a standard 19" rack case. I'll be adding a custom power supply, and the usual XLR/TRS input and output jacks, phase, phantom switch, filter cutoff low-pass, hi-pass, etc...

So far, I'm successful in my testing after ripping and soldering everything together and adding a few modifications (i.e. using simple DPDT switches instead of 3Pole selector switches).

The Yamaha PM1000 are usually called Japanese "Neves" because of a similar approach in design. Just like the Neves, this is all discrete transistor and uses an input transformer and output transformer.

The EQ section is especially sweet because there is not a single IC on this preamp. The EQ section uses inductors and capacitors... totally analog manipulation and shaping of your frequency. (circa 1974)

I've tested them on drums and vocals and they really make the sound FAT. The EQ section shapes your sound anywhere from slight barely noticeable to extreme gain/reduction. Bass frequencies are solid. Of course, being an analog EQ, it is not as precise in shaping the sound as IC chip Equalizers. But the curve is smoother I would think.

This is what a PM1000 mixer looks like (circa 1975). Note, I did not use my fully operational 16 channel vintage mixer for this project. I have a few (8) spare PM1000 modules I got from eBay. I also have 2 master strips.

The SC-1 Mic Preamp is a THAT 1510/1512/SSM2017/SSM2019/INA217 based Mic preamp with phantom power, DC servo and Balanced line output driver.

Rev.1.00 PCB Design for the SC-1 Preamp

Introduction

The THAT 1510 is a high performance audio preamplifier suitable for use in microphone preamp application. It is pin compatible with the now discontinued, Analog Devices SSM2019 and SSM2017 IC chips, and the Texas Instruments INA217 and INA163 mic preamp chips.

Designed from the ground up in THAT’s complementary dielectric isolation process and including laser-trimmed Si-Chrome thin film resistors, the THAT 1510 improve on existing integrated microphone preamps by offering lower noise at low gains, wider bandwidth, higher slew rate, lower distortion, and lower supply current. The parts feature internal ESD overload protection on all critical pins.

In short, the THAT 1510 provide superior performance in a popular format at an affordable price.

Features

* Low Noise:
1 nV/ ÖHz input noise (60dB gain)
34 nV/ ÖHz input noise (0dB gain) (1512)
* Low THD+N (full audio bandwidth):
0.0005% < 40dB gain
0.005% @ 60dB gain
* Low Current: 6 mA
* Wide Bandwidth: 7MHz @ G=100
* High Slew Rate: 19 V/µs
* Wide Output Swing: ±13.3V on ±15V supplies
* Gain adjustable from 0 to >60dB with
one external resistor
* Industry-standard pinouts