I have been working on another version of my AKAI/Roberts pre mods. I’m naming this one “The Boris”. An engineer in London contacted me and wanted a pair of Roberts pres modified, with a few twists. After several emails here is what we ended up with.

It has 2 channels and is still powered by a tube rectifier.

Preamp 1:
- EF86 Tube
- Mic input with Cinemag CMMI-7C input transformer 
- This transformer has a 50ohm tap for those low impedance Ribbon mics!
- Switch to select 200ohm or 50ohm mic input (Ribbon mic option)
- High impedance input (100K)
- Gain control
- Output level control (So you can push the pre if you want)


Preamp 2
- 12AX7 Tube (or most varities of the 12xx7 family currently has NEC 12AD7)
- Mic input with Shure M68 input transformer
- High impedance input (500K)
- Gain control
- Output level control.

You can gang the 2 togeter, as with my other versions, if you want lots O gain. (Just jumper the output of one stage to the high impedance input of the other stage)

This version also maintains the 6BQ5 (EL84) output if you decide you want a low power tube amp. (Speaker level)

Cinemag CMMI-7C Info: www.cinemag.biz/mic_input/CMMI-7C.pdf

Schematic:www.beyondsanityproductions.com/misc/Akai%20M7%20Right%20Schematic%20_MOD_BorisModel.jpg