So ... here is mine...
Before everything.... i have to say thanks and send all my respects to Martin, who helped me a lot in this project, and i know that i have been a f....ng annoying guy during all the time i was building it...
in fact yes... i think specially for an 8 tracks rack, you have to think very well to every details before doing anything... cause you can't easily come back on a hole badly placed...
And then you have to solve a lot of problematics to make everything entering the case.
By my side, the rack case is longer than martin's one, but i had to face the fact to add 8 "go between" to add Pad, Phase and 48v and every channel. i maybe worked like 3 weeks on the front panel just to be sure everything would feet perfectly inside the box... and as martin said about his rack, i had seriously the feeling to play Tetris for the panel to look nice, but with no problem beside.
you can see that i sent the front AND rear panel for drilling and engraving...
i decided to put extra power switch in the rack with condenser on all 48v and 24v circuits.
for the ACDC , after wiring boards i measured 280 mA needed for 4 boards, with a 2sec peak at 1,2 Amp at startup. as new ACDC boards can be boost to 1,5 Amp, i used only 2 boards for the full pack. which seem to be enough up to now.
i had 3 problems to solve (with one still in standby for now)
- i had wrong transistor voltage on a board, which was easily solved when i saw i mixed 2 legs of a transistor.
- i have burn a 47R on a second board... but after having replace a lot of component around it's still burning... i have 14v in 47R entrance, same as tr3 collector, and turning the 5k pot doesn't change anything. the 18k res seems to act weird also.... so if someone had same problem.. i would be curious to know how to solve it...
anyway... as i planed to make a second rack, i had 8 extra boards ready... for now i simply replaced the board.. but i will have to find a solution anyway.
the last pb i met was a very low signal on track #1 compared to 7 others... at first i was testing only hiss at higher gain and i was so happy to have really less noise on track #1... up to the moment i plugged a mike to compare all track... i had something like a 40 dB difference in signal level...
after checking voltage, bypassing the "go between", and replacing the lo1166.... i finally found out that the input transformer was defective.... simply had to replace it.
i added a fan on rear panel too... but i noticed it's making a light buzz at higher gain ... for now i just unplugged it.. but.... after tests in studios... i see now i will NEVER use higher gains... so maybe i will plug it back cause my rack is not as martin's one and i have no ventilation.
Yeah... the sound... it's simply ... woooow
i'm sound engineer and composer in studios for several years now... and as soon as u use those boards in your session... u see how good they are compared to the hardware u usually use. i have compare them to a lot of preamps now, and they sounds far better than a lot of "good" preamp... and compared to original Neve preamp.. well.... it's a Neve !!!
never thought i could built a so good preamp by myself one day !!!!
BUT... for me the pad is "must have" when u use those boards. as when u record a drum... u nearly peak on lowest gain position... and u will easily peak depending of your drummer or your mics....
Anyway, hope that will help someone...
i will soon start my second rack....
and again Martin... thanks... a lot
Sylvain.
