MC76 "finished". Need help on minor issue.

I finished my first Purple Audio MC76 today. And it's working!!! :razz:

Only problem is that I have not figured out how to do the connections for the bypass function. I use a rotary for the meter switching. I have the GR-metering and +4 VU done but I'm not sure how to do the bypass connection, and I need that for calibrating the unit, right?

Thanks

Richard

Congrats on your finished Mc76

Point 22 goes to Point 23 for normal operation. Point 22 to Ground gives bypass/gain reduction disable.

If the gain reduction, VU and bypass are on the same switch you'll have to short Point 22 to ground with an extra piece of wire for calibration. (with the switch set to VU)

Congratulations! How about posting some pictures :wink:

Thanks,

I will take it to my studio for some testing tonight. I did not put to much work into making this unit good looking, but I can post a picture tonight. :wink:

Richard

Well, all I have to say is WOW!!!! :shock:

I have not calibrated it yet but my first impression is that this is a major improvement for me recording sounds. Tested it on bass (Great River MP2NV to MC76), acoustic guitar and snaredrum. I sounded great!!! Rich and full before going into my DAW. Just what I have been looking for. I like my UAD-1 limiters, but this is really something else.

I know it's a ugly thing but....it's sooo great!!!








Richard

[quote author="sintech"]Congrats on your finished Mc76

Point 22 goes to Point 23 for normal operation. Point 22 to Ground gives bypass/gain reduction disable.

If the gain reduction, VU and bypass are on the same switch you'll have to short Point 22 to ground with an extra piece of wire for calibration. (with the switch set to VU)[/quote]


Can't find point 22 on the board. Is it the "out end" of the ratio switch?

...and I'm sorry but I did not understand that last thing about shorting point 22 to ground in VU-mode. :?

Thanks anyway,

Richard

Hey Richard,

Point 22 marked on the Mc76 schematic (although not as clear as the rev D/E 1176 drawings) is.. I guess the 'out end' of the ratio switches that connects to point 23 (sidechain/C17). Point 22 to either: 23/Ground makes Compression/GR disable.

If the Bypass and VU and GR are on the same rotary switch, you are unable to select multiple options at the same time. With two crock clips and a bit of wire you can patch 22 to ground whilst still leaving the switch reading VU.
This acts the same as turning the Attack knob to the off position on a Urei 1176 or Purple as described for calibration.

Any chance for some hi-res pics, if pos? :thumb:

Wouldn't that be a switch of 23 to ground, which is the input to the side- chain? At which point 22 would be switched to open (no connection)? That' s the way it looks on my schematic.

Yes, sorry...your absolutely right 23 to ground

I can't make sense of step 7 & 8 in the MC76 calibration sheet. Just playing with the input and output controls. Nothing adjusted on a trimmer or anything? What am I missing? Other than this confusion my unit seems to be ready for a box!