Fully restored, this unit was stripped back to just the chassis and audio transformers. Metal film resistors used throughout, polypropylene capacitors in the audio path. All valve sockets and pots replaced. NOS JAN 6BA6 and 6AU6 tubes and Sovtek 6V6 output and sidechain tubes. Attack and Release controls added. Input impedance raised to 10K differential, output impedance ~ 40R. Originally all front panel controls were 'screwdriver' adjust, these are now user friendly knobs!

The Power Supply was built from the ground up. Featuring Regulated heater supply and extensively decoupled HT. The power sequence is fully automated with a soft start heater supply and time delayed HT.

Performance of this unit is quite outstanding.
Noise floor at typical operating levels is > -80dBm 400~20kHz or -74dBm 10~ 30kHz.
Frequency response within 0/+2dB from 15Hz to 30kHz ( there is a couple of dB lift at very low and very high frequencies ).... There are no less than four transformers in the audio path!
Maximum output level > +32dBm
Distortion at typical levels ~ 0.03% @ 1kHz( this is the 'trimmed' distortion, the vari-mu stage can be "unbalanced" using front panel controls to give a distortion level of ~ 1.2% of 2nd harmonic
Maximum limiting attenuation of ~ 23dB, with distortion rising to 0.1% @ 1kHz

Here is how the insides looked before I got my large cutters out!

Oh yeah! This unit has a maximum of 60dB of gain with a noise floor still at ~ -60dB.... Mic Pre anyone?

Here is the schematic, including mods...the attack and release setup is provisional.....time will tell!

Some waveforms showing Attack and Release Performance