Another vari-mu: Chiswik Reach Compressor

Hi Tubefreak
                  have you measured noise on your unit? Any figures?
Cheers

hey "Marteen"
please the "docs" you used for build your "vari-mu"
are all correct or they content some error?

Tubefreak said:

I've made mine with it. All the docs are here that explain it.
http://purusha.smokinggunrecording.com/XVXDY/
..........................................ise it's just trial and error.
Maarten

Click to expand...

there is no "error" there is only one side of the pcb missing which contains the heater and stereo link traces but you can connect them manually

Yeah I did some measurements, but didn’t write them down. Noise was below 90 dB iirc, the input pad has a slight influence on the freq response, overall the freq response was flattering flat (small smile curve). Biggest influence are the Sowters and NOS tubes imo. They impart a sonic improvement that is very subtle but can really transform a cold digital source to something more lifelike.

Did a mastering job a while ago where the artist only used a software piano. It sounded fake, clearly not a recorded piano. With some minor EQ and running it through the Varimu, the whole staging changed for the better.

Regarding the faults, PCB and docs are fine, just wire the heaters below. There is a clear image of how to do this.

Maarten

Maarten,
              mine is sounding fine too, but I have a bit more noise than I like ~-80dB-Aweighted.
Thanks for sharing the info, now I'm sure it's up to transforemer placement and/or grounding  (it's 50Hz hum).

Cheers
Milos

That could indeed be the cause. Just did a test with some tube swapping and without calibrating I easily got -97dB.

Tubefreak - did you end up just using the Conrad meters, or did you replace them?  I wasn't sure when I read about the mounting difficulties on your site.

Best,

Josh

i'm still in the middle of the build....i was lucky to buy some original thermionic 1/2ma meters

this one seems a nice build.
without knowing i almost have all the parts.
i have the T-pads, input transformer, turret board and tubes.

The only thing im looking on this side of the world its the output transformer...PP Triode to Line output

Anyone ?

It took some extra time to mount them properly. Eventually it worked out ok and the meters haven't caused any troubles since.

The input pad is a nice tip/trick btw, it changes the frequency curve slightly and can be a nice way to add some thickness. The whole unit saved the day on a sterile and harsh sounding track by reshaping the highs.

Killer unit, highly recommended.
Maarten

Hello!

I've built this comp too 2 years ago.
I cannot make it good...

It eats the transients, and cutting the high freqs in some way.
I also have a PM670 which is much more better, no problem with that one.

I tried the mods you wrote on your site, but didnt changed these problems.

If this topic will wake up, I will send some material into the comp to show the result.
Maybe you can help me finding the solution.

Please post some wavs. It would be handy to post one in bypass, one with te comp engaged and no compression and one engaged with compression.

What type of in- and output transformers and tubes are you using?

The unit is indeed a bit slow and doesn't work with all material. Sometimes is does wonders sometimes it doesn't.

Kind regards,
Maarten

Here's the one I completed about 6-months ago. I love it. It makes almost everything sound awesome.

http://www.moddefecation.com/images/crcomp/Chiswick%20Reach%20Coffin%20Vari%20Mu001.JPG

Here's More:
https://www.facebook.com/media/set/?set=a.566584430101894.1073741831.478520652241606&type=1&l=71a5846419

nice TonyMN very nice , whats that HFmod thing about
cheers

skal

On the 'normal/white' DIY case the switch is on the rear. It selects the high pass filter for the side chain. Looking at the pics, we both come to the same setting.

yeah get now

skal

I use Sowters, as it was in the BOM,

For more about the tubes, and sound samples I will post in a short time.

Thanks!

Can someone upload somewhere the original Purusha docs please?
The old link doesn't work any more.

Sure.

www.moddefecation.com/CR_COMP.rar

otherwise you could use the wayback machine.

https://web.archive.org/web/20100725153918/http://purusha.smokinggunrecording.com/XVXDY

Hope you get it working.

- Tony

Hey tony,
did you paint your frontpanel by hand? not sure since I can see what seems like a silkscreen mask in your pic here...looks pretty nice.