Re: M670 compressor
« Reply #160 on: May 22, 2017, 08:17:52 AM »
Gentlemans, so, what a final choice for the trafos?

Cinemag CMLI 10/600 for input,
Edcor XSM / Lund 1676 for out (and what is the best?)
Edcor WSM or XSM for SC? (and can I just reverse 600:10K for T4, or revers 10K:600 for T3?)

Another stupid question: Is it possible to use WSM 15k/600 | 600/15k for the IN/OUT/SC?

Thank you so much)
« Last Edit: May 22, 2017, 09:05:39 AM by EvilFuzz »


stitch-o

Re: M670 compressor
« Reply #161 on: May 22, 2017, 10:59:00 AM »
The XSM are fine enough to get going for SC, out
Id stick with designed values. There are lots of suggestions in this thread.
I'll report back on the Jensens for input once mine is up and going.
The recommended at Lundahls so Im sure those are exceptional, as well.

Once everything is sitting and working well, I might play with output transformer choice.

I have a few cap questions:
The release caps: what voltage rating is minimum?
The 10nF cap at the link switch-1n4007-1M resistor: is 50V ok for this cap pos?
Also, how egregious is subbing the HV rails 10uf's (off the 100r) with electrolytics?

I see C4 can be pulled and the attack-release switch leads can be wired there.

 Heres the (Ithink) finished comp boards




Cheers!
« Last Edit: May 22, 2017, 11:25:45 AM by stitch-o »
I'll apologize in advance

mdainsd

Re: M670 compressor
« Reply #162 on: June 02, 2017, 06:24:45 PM »
Hello forum.

Im thinking of putting one of these together. I have the boards, but I think I'd rather do point to point.

QUESTION: Has anyone measured what the B+ supply current really runs at for these boards. The schematic has a total of 300mA  that's huge! Do these things really need more power than an original 670 with it's 22 tubes?

thanks!

EmRR

Re: M670 compressor
« Reply #163 on: June 02, 2017, 06:55:24 PM »
Says 80mA for two in the original thread.   I measured one at 38mA, so that's in line.  Some 5687's were drawing double the expected current - don't know if anyone got to the bottom of that. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

mdainsd

Re: M670 compressor
« Reply #164 on: June 02, 2017, 07:08:07 PM »
Thanks EMRR! that helps a bunch. That will make the transformer issue much easier to deal with!

Kingston

Re: M670 compressor
« Reply #165 on: June 03, 2017, 11:51:08 AM »
The schematic has a total of 300mA  that's huge!

That's just the maximum the regulator can handle. I'm using it in lots of projects since it's cheap, reliable and generic - but never actually needed that much power.

Kingston

Re: M670 compressor
« Reply #166 on: June 03, 2017, 11:54:29 AM »
Also, how egregious is subbing the HV rails 10uf's (off the 100r) with electrolytics?

Of course you can do that. It's just my preference to have as little electrolytics in a project as possible. Less maintenance and worries.

stitch-o

Re: M670 compressor
« Reply #167 on: June 03, 2017, 12:10:58 PM »
Of course you can do that. It's just my preference to have as little electrolytics in a project as possible. Less maintenance and worries.

Cheers and thanks!

I'll start with the EL caps for space and cost constraints.
Im waiting on last 2 caps for release switch then onto completion.

THANK YOU KINGSTON for this amazing work!
I'll apologize in advance

Kingston

Re: M670 compressor
« Reply #168 on: June 04, 2017, 04:56:24 AM »
Just had a quick review of the schematic and I think those 2X 4K7 resistors on input transformer secondary might have been a typo. They should be more like 47K. If there's a center tap on the input transformer secondary the control voltage can be wired directly there with no need for these resistors - which is what I ended up doing after a few revisions.

dagoose

Re: M670 compressor
« Reply #169 on: June 13, 2018, 05:49:43 AM »
digging up an old one for now .  8)
I love my M670 the way it right now, kinda use it day in day out.
But one thing annoyes me is that I have a slight channel imbalance in level between L and R, about 0.3db which I want t get rid of.
The tracking itself is quite good, so the imbalance is consistent no matter how much you push it.
I tried chaning out some tubes but that didn''t really help so I suspect one of the transformers.

I was wondering what would be a good place to put a leveltrim (multiturn trimmer) to balance things a bit more
Da Goose Music Mastering http://www.dagoosemusic.nl


dagoose

Re: M670 compressor
« Reply #170 on: June 14, 2018, 03:32:23 AM »
digging up an old one for now .  8)
I love my M670 the way it right now, kinda use it day in day out.
But one thing annoyes me is that I have a slight channel imbalance in level between L and R, about 0.3db which I want t get rid of.
The tracking itself is quite good, so the imbalance is consistent no matter how much you push it.
I tried chaning out some tubes but that didn''t really help so I suspect one of the transformers.

I was wondering what would be a good place to put a leveltrim (multiturn trimmer) to balance things a bit more
Forget about it, found a nice place to add trimmers. In between the input tranny and the T-pad.
Da Goose Music Mastering http://www.dagoosemusic.nl

Re: M670 compressor
« Reply #171 on: June 14, 2018, 07:02:47 AM »
Who asked about P-t-P? ;)
From dr. Weird laboratory... M660!
« Last Edit: June 15, 2018, 11:46:00 AM by EvilFuzz »

Re: M670 compressor
« Reply #172 on: June 15, 2018, 11:55:03 AM »
Sorry, something wrong with pics...






shabtek

Re: M670 compressor
« Reply #173 on: June 15, 2018, 03:05:25 PM »
Nice

Looks like fun
"really fine players do not use stomp boxes or master volume, they match the amp to the room and turn it up to 11.  Stevie Ray, BB King, Albert King, Duane Allman, Dicky Betts, Louis Armstrong"
   -CJ

Re: M670 compressor
« Reply #174 on: June 15, 2018, 04:11:47 PM »
Nice

Looks like fun

Yeah, it's absolutely fun. Chassis from soviet  generator, trafos from DDR measuring equpment, other components from trash and garbage. But it works!)

Script

Re: M670 compressor
« Reply #175 on: June 16, 2018, 01:14:52 AM »
Love the inside and the overall approach  ;D

Personally, I'd probably buy some cheap but cool looking pvc sheets -- or how about some thin wood sheet (maybe withered cos from garbage  8) ) -- for use as faceplate with inspirational logo?

Many possibilities cos does not have to be aluminium e.g.


 

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