Adding Attack Control

[craigmorris74]

I'm wanting to implement an attack control for a Urei BL-40 in it's peak limiter section (which is relatively similar to an 1176). As it is right now, it's set for an extremely fast (5 microsecond) attack, much faster than the fastest setting on an 1176. I would like some type of control to be able to increase the attack time from 5 microseconds up to around 800 microseconds. Here's a schematic of the peak limiter section:

In the manual, there is suggestion for making the release shorter by reducing the value of C35. I'd like to possibly add a switch to give a longer option on it, but the attack is my main concern. Any suggestions are welcome.

Craig

 

[[silent:arts]]

[quote author="craigmorris74"]In the manual, there is suggestion for making the attack shorter by reducing the value of C35. Any suggestions are welcome.[/quote]

the furst would be: enlarge the value of C35.
or just compare the schematic to the 1176 and look at the attack / release section ...

 

[craigmorris74]

[silent:arts],
Sorry, there was a mistake in my original post, now edited. C35 changes the release. Attack and release controls are one thing I totally don't understand. For example, when I look at the 1176 schematic, I don't see a cap at the same spot that I see one on the BL-40.

Here's the 1176 for comparison:

 

[joe-electro]

Just off the top of my head, looks like R42, R44 and R45 would be good candidates. It appears that there is actually a dual time constant going on in this circuit, with C54 and C35 being the storage elements. Increasing the values of R42, R44 and R45 would increase the time it takes to charge those capacitors.

 

[craigmorris74]

Would those resistors (R42, R44 and R45) affect the release only, or the attack as well?

 

[gyraf]

Maybe change R47 (18 Ohm) for an Attack potmeter. Throw in a 1M pot in parallel with C35 for release..

Jakob E.

 

[Bryson]

Or maybe a pot between R44 and R45 (replacing the trace, or wire).

 

[craigmorris74]

Thanks for the suggestions guys. I'll open it up and try a couple of pots in the locations you've suggested and see what happens.

Craig

 

[PlasterPirate]

Hey Craig,

I just got one of these and was wondering if you were able to successfully mod yours for attack and release times. Thanks---

Joe

 

[hikowinter]

after all how to change attack and release in this circuit?