M670 compressor

[Silvas]

I used the cinemag CMLI 10/600 transformer and really am happy with their sound.

For both input and output ?

 

[duantro]

I used the cinemag CMLI 10/600 transformer and really am happy with their sound.

For both input and output ?

No just for the inputs. The edcor's work on the outputs. The edcor inputs seemed to be the grainy culprits

 

[Kingston]

Troubleshooting random transformer replacements is the best. No, you cannot use Autobot or Decepticon variants for the output.

 

[duantro]

I must stop by here again and say that this thing sounds so sweet now. Many thanks again for doing this Kingston. I plan on building another when I find  some nice looking meters!

 

[leadbreath]

...kingston is da man, man...

 

[dagoose]

As a nice 'making it through wintertime' I want to start redoing my (hardly used) PM670.
I was wondering about the 5687 tubes, I used it with 1 tube in the sidechain because it was hard to get it right. But now I wanted to start using all 4 of them again but found out that one of the tubes is gone.. 
So.. what are good 5687 tubes to go for right now that don't pull 20.000 of amperage and get to 23.000 degrees. 
Any other news on the M670 that might be of interest?

 

[dagoose]

Just a quick headsup to Kingston for this.

This afternoon I had some spare hours and did the basic 'mods' on one channel. So no PSU, no trannies, no T pad on input but the stepped switch before the input tranny (doesn't like the load), so basically just the extra resistors, caps and things. It worked on first start (hooray  ;D).
The meter tracks a lot better and compared to the other stock (both with scamp btw) the stock channel has quite a lot of distortion while the m670 channel still sounds pretty good at 10db of compression.

Still a long way to go to get it the way I want it, but thank you Kingston!

 

[stitch-o]

https://groupdiy.com/index.php?topic=28274.msg814377#msg814377

Jumping in here now...

 

[stitch-o]

https://groupdiy.com/index.php?topic=28274.msg814377#msg814377

Jumping in here now...

So the Time constant will need to be rewired as well...add to the list.
Prolly do a 'fast slow' release toggle instead of a rotary.

The 3 x 10UF can be electrolytic?

 

[dagoose]

OK, both channels are working in testmode.
I had one issue with one of the channels at first (the one that was already working) and it turned out that T1 , on the input had died..
One of the outter legs has a broken wire/doesn't make contact any more. Those edcors are cheap, and I know the reason why.  8)
I'm about to order cinemag CMLI-10/600 trannies so I don't worry to much now. I have sound on the input, but 6 db lower since I have only connected one side to centertap now. 
I had mine running with the SCAMP board, and I  left it that way since I like what it does.

There is one thing that I should be taking care of now, the input T pad. I want to make it into one set of controls, so one knob for gain L R and one knob for threshold LR and 1 switch for attack and 1 for release for both channels. I don't need seperate  control for LR.
So.. for a stepped T pad, I need a 4 deck switch (I have one) but just wondering what would be a good one when it comes to values. I found this https://groupdiy.com/index.php?topic=58750.0, but not sure if it's right or not. Anyone? Or maybe another option instead of T-pad? I want/need it stepped.

Overall, props again to Kingston, finally it's working the way it should be and it can be used the way it was meant to be 

 

[dagoose]

Still trying to figure out what the best solution would be for the 600r stepped input attenuator.
What would be the result if I use a regulator stepped attenuator of 600r (or maybe 1k with a sweet spot at approx 600r) instead of a t-pad? Do you think the cinemag tranny likes a lower load than 600r?
For me T-pads are new.

 

[dagoose]

Almost done with my Mu666 compressor.  8)
Cinemag on the input made a large difference compared to the edcor's, they simply suck, soundwise but also mechannically.
I went for the 600r stepped (23 steps) T pad on the input which works like a charm.
Things to be done: replace tbe edcor on the output with a cinemag.
For the rest, it really sound great now and already used it for doing some masters and it's clean though still 'tuby', whatever that is.

 

[Seeker]

I'm a bit behind the times, but I was thinking about doing a poor mans 670.... after reading this thread I'm going to do  a from scratch build of this instead. 8)

Thank you Kingston for all the time and energy you put in this, and for sharing it here!

 

[dagoose]

Just for a little headsup, the cinemag trannies will not work on the output.
https://groupdiy.com/index.php?topic=64800.0

 

[stitch-o]

Just for a little headsup, the cinemag trannies will not work on the output.
https://groupdiy.com/index.php?topic=64800.0

How about something like Sowter 9900 instead?
I was looking at the 9063 instead of the cinemag..

 

[Silvas]

Almost done with my Mu666 compressor.  8)
Cinemag on the input made a large difference compared to the edcor's, they simply suck, soundwise but also mechannically.
I went for the 600r stepped (23 steps) T pad on the input which works like a charm.
Things to be done: replace tbe edcor on the output with a cinemag.
For the rest, it really sound great now and already used it for doing some masters and it's clean though still 'tuby', whatever that is.

Looks great ! May i ask where you got the stepped attenuators ? Are they pre-made or you built them ? I'm slowly building one of this things on a giant breadboard to experiment with it but getting the stepped T-attenuators seems quite difficult (at least pre-made)

Thanks !

 

[dagoose]

Looks great ! May i ask where you got the stepped attenuators ? Are they pre-made or you built them ? I'm slowly building one of this things on a giant breadboard to experiment with it but getting the stepped T-attenuators seems quite difficult (at least pre-made)

Thanks !

Thanks! And works brilliantly now. So much difference compared to the original design..
I uild the att's myself, I used this one: https://groupdiy.com/index.php?topic=58750.0

 

[Silvas]

Thanks! And works brilliantly now. So much difference compared to the original design..
I uild the att's myself, I used this one: https://groupdiy.com/index.php?topic=58750.0

Appreciate it. Thanks ! Very useful information.

 

[stitch-o]

I went with Jensen JE-6110 for input.

PS is Kingston design and dual B+ working great!
Gutted and waiting for last heater circuit parts...
Working on comp board edits now.

Cheers and thanks!

 

[stitch-o]

Getting Boards done...