Simple DiodeBridge Compressor

[abbey road d enfer]

What is not convicting you?
I m curious

This: "We use Schottky barrier signal diodes and I chose these because they have the sound I wanted which was a bit more punchy than standard silicon diodes."
I'm not questioning the outcome, but I would like an explanation as to how the characteristics of Schottky diodes (particularly the lower forward voltage) results in more punch.

 

[richiyobs]

but i get only problems....
in the attach R45 & C6 are for dual elememt release... according to what i learned R45 should be no more than half of R19....
so i replaced R45 with 10k and c6 to 100u to obatin 1sec
in this way i got this when engaged:
meter totally down to -20 even with no signal
putting signal, seems only attenuated and muddy

but leaving it as i drew, no problems , and the compression smooth...
i can t measure, or i really dont know wich signal need to verify autorelease

 

[richiyobs]

This: "We use Schottky barrier signal diodes and I chose these because they have the sound I wanted which was a bit more punchy than standard silicon diodes."
I'm not questioning the outcome, but I would like an explanation as to how the characteristics of Schottky diodes (particularly the lower forward voltage) results in more punch.

Really don t know... But I will try it and measure... I ll build a second vca and switch between them to compare.... Can you advice me any Schottky for this test?

 

[Spencerleehorton]

I may have a look inside my stereo 2254 and see what diodes I used!!!

 

[dogears]

maybe adding something like this in front of your threshold...

 

[richiyobs]

maybe adding something like this in front of your threshold...

View attachment 89099

HI Dogears, looks interesting... I ll try!
Have you got any suggestions for autorelease implementation?
Best
Richi

 

[richiyobs]

I may have a look inside my stereo 2254 and see what diodes I used!!!

Great thanx

 

[abbey road d enfer]

but i get only problems....
in the attach R45 & C6 are for dual elememt release... according to what i learned R45 should be no more than half of R19....
so i replaced R45 with 10k and c6 to 100u to obatin 1sec
in this way i got this when engaged:
meter totally down to -20 even with no signal
putting signal, seems only attenuated and muddy

but leaving it as i drew, no problems , and the compression smooth...
i can t measure, or i really dont know wich signal need to verify autorelease

Is it the schemo of something that actually exists? Is it supposed to work? Simulation shows almost no difference with or without.

 

[richiyobs]

Simulation shows almost no difference with or without.

you re right, the idea for autorelease is from what i learned
also trying to follow this example in the attach
best
richi

 

[richiyobs]

in spice i left the Rel pot value to max...
setted to minimum to get faster response, and now can see something... but cant judge on my own
red input, green out , blue SC feed
thanx for attention
best

 

[richiyobs]

in any case engaging auto , the device goes crazy as i described in previous post

 

[abbey road d enfer]

in spice i left the Rel pot value to max...
setted to minimum to get faster response, and now can see something... but cant judge on my own
red input, green out , blue SC feed
thanx for attention
best

It's quite difficult to observe these screen shots. I monitor current in resistor R31. It does something, but I can't really tell what in terms of sonics.

 

[abbey road d enfer]

in any case engaging auto , the device goes crazy as i described in previous post

Yes, that's strange. Is the signal only distorted or does level varies erratically also? In the document in your post #62, auto-release also switches the primary time-constant to fastest, which seems to do very little.

 

[richiyobs]

Is the signal only distorted or does level varies erratically also?

something in between....
the strange thing is that in simulation i never was able to verify the rel time, but in the real proto it works!.... once i setted the .tran time to have the right visualization of the initial transient, in that way i saw the shape of relase really doing something to the wave, but the file is lost somewhere in my hd, or saved in aonother manner!
yes the switch set the fastest release
cheers

 

[richiyobs]

attached 33609 recovery value, and only now noticed the use of diodes!
C13 is the timing cap, right?
sorry for boring you, but i d like to understand
are these diodes a usefull solution for my problem post #62

 

[richiyobs]

simulated and got the same figure on both timing caps now, only offset in current

 

[richiyobs]

Adding diodes got this...
Engaging auto... The meter needle goes down but slowly rise to zero!
The audio if fine.... And on vocal seems controlling better the body and the range 600 till 1k is quieter

 

[richiyobs]

After signal passed even switching on off auto... The needle finally rest to zero

 

[richiyobs]

finally audio is fine, diodes removed.... i think i did some short at beginning
at turn on it takes about 12 sec before needle starts rising
18k and 100u, 1,8s

 

[xmission]

Complete newbie here. Neat thread.

Is the schematic in the first post still relevant, or were there a lot of changes?