vari-mu compressor without vari-mu tubes fairman tmc

shop deals on amazon
Shop deals on ebay
Advertise with us
GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
SUPERMAGOO

SUPERMAGOO

Well-known member
Joined
Mar 12, 2005
Messages
348
Location
argentina
that mystery!
a vari-mu compressor without vari-mu tubes. :eek:
intrigues me how it will work .... ::)
be like a super cascode totem?. be as prr compressor but with more tubes?
secret files say that the 12AU7 is a valve vari-mu?? ;D

tmc-126.jpg
 
as prr said, the au7 works great, until you get close to 20db GR, then it "craps out", which I'm not totally clear on what that means exactly. Does it cutoff at that point? Does it distort badly? I have my parts sitting here waiting for me to finish some other projects, then I'll havethe prr vari-mu on the bench, so maybe someday I'll find out. :)
 
And think about the words "small amounts of GR"  and "20db GR" in the same sentence.  20db would seem more than plenty for most apps anyway.
 
then the important thing is 12AU7 compressor works well in low and high GR.

then, would be good to try to make a compressor with a strong and fast with several AU7 GR in parallel?

and the circuit of the cascode or totem in tmc  generate much intrigue me! :eek:

The other valve is. 12AT7?

excuse my English, I use an automatic trasletor
 
then, would be good to try to make a compressor with a strong and fast with several AU7 GR in parallel?
Click to expand...


check out PRR's breakdown and comments on this subject here:


http://www.groupdiy.com/index.php?topic=10097.msg120754#msg120754
 
gyraf said:
The fairman TRC also uses a simple PRR-like ECC82 compressor. Works well for relatively small amounts of GR.
Click to expand...



I could find the schematic TRC.
but does not appear valves which are used.
the number 5 is ECC82?
 
I was watching the transfer curves pcc189, 6bc8, 12AU7 and 5670.
and gives me the impression that the best is "12AU7.
is that correct?
if it were correct.
Why? insist on doing with other valves in poorchilds??
 
perhaps they landed on thousands and thousands of really cheap tubes other than 12AU7. Not the first time some not-quite-perfect part is hacked outside its usual parameter range for mass production.
 

Similar threads

F
For Sale FS: Heikki's Transformerless Vari Mu Compressor partially assembled (SOLD)
Replies
4
Views
935
fazeka
F
C
what would be the most demanding tube preamp topology?
2
Replies
27
Views
3K
Mr. Moscode
M
z11111
PureAnalog M/SLevel Vari Mu Compressor (manual + schematic)
Replies
9
Views
3K
z11111
z11111
Heikki
For Sale Transformerless Vari-Mu PCBs for sale + some other boards
Replies
4
Views
3K
scott2000
scott2000
N
What to do with tubes?
Replies
1
Views
778
rock soderstrom
rock soderstrom

Latest posts

Back
Top