Pathos DJ Mixer Pt.1

The Pathos Mixer is a near clone of the CMA-10-2DL. I have been working on this one for a few months and finally pulled the trigger on some prototype PCBs, which are working nicely.

Pathos Mixer – All six PCBs in the raw

The mixer is built around 6 PCBs connected together using IDC16 ribbon cables. The project was designed to minimize wiring as much as possible, for ease of construction and overall reliability. I managed to get it down to 5 short wires in the end, a considerable improvement over the FAE-1 Mixer. It is designed to fit into the attractive Hammond Mfg HWCHAS1310 enclosure which is easily available online from a wide range of suppliers.

The original mixer was designed around high quality circuitry and was built for long term and reliable use. In that spirit, I have chosen components that are of lasting and high quality like Alps RK27 pots for volume control, Grayhill 71 series rotary switches for the cue selection and Neutrik connectors.

There are a number of changes compared to the original mixer. I have removed the microphone inputs, balance controls and the signal processing loop. The original also had ‘soft start’ relays to mute the output when the mixer was turned on and I got rid of these too. Their use is eliminated by using a proper sequence when turning devices on (start at the source, end at the amplifiers). All channels except for the cue have their own 2 band equalizer, Identical to the original Bozak – +/-10dB at 50hZ and 10kHz. The Cue switching is now taken care of with a single 5 way rotary switch. The balanced XLR program outputs have been removed since the original ‘cheated’ balanced outputs by extending the wiring from the RCA connectors to the XLR.

I posted about this in the ‘Supporter Rotary Mixer’ facebook group and had quite a few inquiries about whether I would be selling PCBs for this one. The answer to that is yes, I’ll be selling sets of 6 PCBs and a front panel for approximately ~$300AUD. I’ve put together a mouser cart with almost all of the components, ~$430AUD. There are a few additional items that need to be purchased so overall the build cost is approximately $1000AUD ($750USD at time of writing).

Specifications:

4 x Input Cards
1 x Program (PRGM) Card
1 x Cue Card

Pathos Mixer – Input Card

Each Input card contains:
Phono Input
Line Input
RIAA preamplifier
Input switch
Bass and Treble tone control
Volume Control

Pathos Mixer – PRGM card

Each PRGM card contains:
Summing Amplifier
Bass and Treble tone control
Line Amplifier as output buffer
Master Volume Control
PRGM output (post volume control)
Tape output (pre volume control)

Pathos Mixer – Cue Card

Each Cue card contains:
Cue selection switch
Headphone Amplifier
Volume Control
Provision for Split Cue
Power Input

Pathos Mixer – Prototype front panel

For prototyping I’m using 3mm clear acrylic which was laser cut. For shielding I added copper tape. The final version will have an aluminium front panel.

Pathos Mixer – Front panel silkscreen

Pathos Mixer – Cards in Front Panel

Pathos Mixer – Cards in Hammond HWCHAS enclosure

There are a few changes to be made on all PCBs so I’ll be ordering another set of prototypes in the near future. If you are interested in purchasing one of the pcb/front panel kits then please get in touch and I will let you know when they are available. I will also be selling finished units at an as yet undetermined price.

See More:

Pathos DJ Mixer Pt.2

Pathos DJ Mixer Pt. 3

Pathos DJ Mixer Pt. 4