Archive 2

Quad Eight MM403
Featuring the same input amplifiers and EQ section as the famous Quad Eight 312 series. With additional Fet based HP and LP filters and phase reverse. All Quad Eight input and output transformers. Mic input, Line input and output. 30dB gain range on gain pot, maximum 70 dB gain on mic input and output level “fader”. Pad and phantom power. Fully recapped and serviced. Modules in excellent condition. Internal power supply.

Quad Eight MM-61

Rola / Byer 66
take the audio module from a 1950’s Australian made mono tape recorder and covert it to a smoking mic pre / DI / Line amp, with inbuilt speaker 2 watt amp and metering.
This unit has more tube character than you can shake a stick at!

Auditronics 110A
Racked Pair. Transformer Input and Output. Mic / Line Inputs. Phantom Phase reverse. HP and LP filters. 3 band inductor based EQ – bass extrension mod on low band.

Quad Eight 248
later era Quad Eight modules, mic / line inputs. 3 Band EQ and HP-LP filters

Auditronics 110B
-they just keep coming!

McCurdy Fet Compressor
a unique compressor module from a McCurdy broadcast console. Fantastic solid state FET compressors

Siemens V275/0 summing amps
front end IC was a lowly 741, replaced with a 5534, modified gain structure and removed Low Pass filtering ( which knocked the response down to -12dB @ 20kHz !! ) Added +/- 6dB gain trim controls. Setup for 4 x stereo inputs and 4 x mono inputs

Quad Eight EQ312 Modules
Mic-Pre added with gain range 20 to 75dB. Using a Neve BA283 clone amp for the last 20dB of gain. Mic in / DI / Line in, Pad / Phase / +48V

Pair of Quad Eight MM312 modules

Quad Eight
Combining CA-127 line amps, converted to mic-pres with EQ333 modules

Australian made EMI 4 channel mic mixer, originally designed for portable “OB” mixing. Added 4 channels of direct out balancing amps and upgraded PSU. Pad / Phase / Phantom added on each channel
Here’s what the owner had to say : “Hey Rob, just wanted you to know that the EMI OB1 mixer is fucking fantastic! Those mic pre’s have really come alive – they sound much better through your new direct outs than they do through the original transformer. Really quiet, deep, and silky as hell. I think I dig them more than my 610!”

Auditronics 110A and 110B modules
racked with some cool led meters

Neve 51 Series Stereo Channel strip
racked into a 1 unit case, all original toplogy kept. The phase invert switch was changed to add an additional 20dB gain. This enables the stereo EQ to be teamed with the passive mix ( available through Broadcast ) as a makeup gain amplifier and mix EQ

Auditronics 110A modules
A30 output driver cards included. All Jensen transformer in and out. Echo send A – now an output level control. Solo switch – now extends the bass response of the low EQ

Neve 51 Series console channels
one set from a 5116 and the other from a 5114. Mic / Line, soft and hard limiter and gate, HP/LP filters and 4 band parametric EQ

Oh yes…it’s another MCI JH-500 rack!
6 channel version with internal PSU and channel metering. More info / photos of MCI JH-500 racks here

EMT 256 Compressors
custom meters and variable input output level controls added, IC’s upgraded

Another Quad Eight MM403 hits the streets

Harrison Channel Strips- racked pairs
Discrete high performance mic-pre, transformer balanced output, 4 band parametric EQ, sweepable HP / LP filters. Output level control with mute and cal switches.

Racked pairs are available for sale

Quad Eight CL22 Compressors
refurbished with de-ess modules attached. Dual mono or linked stereo.

Bellerophon – a kit based project from Prodigy-Pro. The mic-pre’s are essentially clones of Langevin AM-16’s.

Joseph stuffed the pcbs, Ryan did most of the essential hole cutting and wiring. I conceived the front panel design and hung around and watched it all come together.
Joesph’s comments on the finished unit “uh, yeah. UH, HELL YEAH! You went balls deep…I love it! I don’t know if you remember long ago, my saying to keep it silver and simple to give it a prototypical aircraft console feel… but you nailed it!! That pre is a beaut! There’s no Pilot Eject button, but hey…”

Quad Eight MM312
a ‘triplet’ ?? of Quad Eight modules modified with mic pre’s added, re-capped, output level control and Sifam metering.

Fairchild 600 ( Conax )
This unit had been extensivley modified by a previous owner, including changing the contents on the mysterious conax module that contains all the magic. The unit was restored to it’s original topology and the conax module rebuilt. A hard bypass was added.

Quad Eight Auto Mix 2-B Stereo / Dual Opto Compressor
Fully serviced – recapped, new mains transformer to minimise hum pickup, aligned. Threshold sensitivity reduced and 4:1 ratio corrected to yield true 4:1 compression ratios. Meter module strapped to top of unit with Sifam meters for reading output levels and gain reduction. Hard relay bypass added.

Quad Eight MM403
from a Quad Eight Console built to spec for the Australian Broadcast Corporation in 1978. A Pair of MM403 Channel Strips, modified and racked. The input stage gain structure was changed with a continuously variable, 30db range gain pot added, balanced line input added, pad, phantom. The echo send pot now operates as a output level control.

Discrete class AB amplifers, 3 band inductor based EQ

ADM 780 Preamp and 1540 EQ Modules

Neve 1272 Pair with JLM 1073 kit

buffered VU meters, +48V, Pad , Phase, 6dB Trim


These broadcast modules were originally designed to work together and the fundmental relationship between them was maintained. The compressor was heavily modified to shift the threshold down to a more useable range and a variable threshold control added. Originally the compressor had a quite hard ratio of ~ 20:1, this was reduced to ~ 4:1 with a soft knee. A three way selection of release time was added.
The limiter was left largely unchanged, only the fixed release time was significantly shortened. The original soft bypass was changed to a hard bypass of the limiter unit as the limiter was the archilles heel in terms of technical performance.
The BA-43 has plenty of gain available and so the unit was fitted with a mic and line input.

Four Channels of “Green” Mic-Pre’s

This is a DIY kit from the LAB. Cactus stuffed the pcbs and sent them to me. I modified the original design slightly, adding BP caps to the audio path, changing the level control to a +/- 10dB trim control and adding phantom power on leds and increasing the gain control DC blocking cap to 10,000uF. The pre has a gain range from -8dB to 76dB, no pad required, maximum input level is ~ + 24dBu and maximum output level before clipping is ~ +30dBu. Distortion is better than 0.002% and EIN ~ -128dBu

The boards mount upside down in the case, so the internal photo is taken with the bottom of the case removed.

The PSU is in an external case, providing +/-18V and +48V

These are worthy mic-pres, very clean, low distortion, wide bandwidth.

RCA BA-71 and BA-73
two early transistor line amps from RCA, modified to make mic-pres.
quote from the owner “they have incredible personality the pres dont sound like anything else i have, for guitars they sound big and fat, they are gritty when pushed hard or really robust and large when you leave yourself some headroom”

Byer 66
take the audio module from the deck of a 1956 Australian built Byer 66 mono tape deck, pull it all to bits and rebuild it as a Mic-Pre / DI / Line amp, with phantom, -20dB pad, balanced out, tone control, metering, internal amp and loudspeaker….nice!

Quad Eight mic-pres
8 channels of AM-10 based mic-pres built up from modules from the Coronado console

Was it possible to get an SSL-6000 ( 4000 ) input channel strip into a 1 unit rack case?

channel strip with front panel and sub-modules removed
motherboard cut into sections
sub-modules loaded back into the cut down sections of motherboard and the re-wiring and fun begins
all coming together in the rack case.
Internal PSU. The orange donut is a Neve V series output transformer.
Yep it sure is possible….it ain’t easy, but what a unit! All original functions retained. Balanced output courtesy of a Balanced driver circuit feeding the Neve output transformer to give a maximum output level of +28dBu. Rotary ‘fader’ added for level control.
Mic / Line in /Compressor / Expander / Gate / 4-band EQ / HP + LP filters / Compressor pre or post EQ / EQ into Compressor sidechain