Butta's 3630 secret recipe

how does this mod improve over Buttachunk's?

More capacitance at the output of the regulators means more energy storage. This reduces the need for transient tracking of the output current and voltage by the regulators and greatly reduces or eliminates the dreaded regulator sound, which is modulation of the DC (adding audiable artifacts to the sound) due to the inability of the regulator to follow load transients. This effect has been well documented by Jung and others. The added diodes are needed to prevent regulator failure when the regulators have large values of capacitance at their outputs. Othe things see my previous post
VinceNY

So, I just did butta's mod on two 3630 compressors. Very easy to do and boy does it make these things sound good. They are actually usable!

I would like to note that I found a 9vac wall wart that fits the current jack in the back. It is made by Harmon Pro, model P50913B-120 and is rated at 9vac, 1.3amps. I found a couple on ebay. They make the mod even easier.

I got one of my 3630s from a local studio who has all the shizzle (including a Neve 8068 board) and he gave it to me because he thought it was a hunk of junk, which they are stock. But now I'm going to take it back to him and let him hear what it sounds like now! I think he'll be mightily impressed.

Cool mod! Thanks!

i'd like to try this but it looks like the recipe has gone missing. can anyone repost details or does anyone still have the bla mod they can scan/send?

all i can find is:
http://web.archive.org/web/20051018193530/http://www.recording.org/e-mag/article_81.shtml
http://web.archive.org/web/20031211030834/http://www.blacklionaudio.com/alesis_3630_modifications.htm

thanks.

Hi audiovisceral,
please see my post on page 2 of this thread.
It describes essentially all changes of the original recipe:
- beefing up psu caps
- pin2 to ground mod for the vca
- opamp beef-up
- bigger wallwart psu.
If you like, you may bridge the +4/-10 switch....

Kind regards,
Martin :thumb:

[quote author="VinceNY"]The added diodes are needed to prevent regulator failure when the regulators have large values of capacitance at their outputs. Othe things see my previous post
VinceNY[/quote]

Aye,

Indeed, the datasheets for those regulators recommend those diodes be utilized to protect the circuits from both input and output power surges.

on the gates...i actually put a 10k pot with a click on/off opening or closing the circuit...
I put in mc33079's in all 3 spots and beefed up the caps in the power supply....also changed the 1n4001 to uf4003 diodes.
I changed the that 2150's to that 2180's.

Sounds alright...
I use a the 9vac power supply from my podxt...it has like 2or 3 amps...works fine.
I have a few 9vac 1 amp power supplies and they fit the plug just fine. You can probally find a decent 10-12vac at a thrift store.

Messing with that alesis is actually how i came to find this board!

Hey

does anyone have a complete list of the mods...
is hard to find scattered pieces of data all around the net

when you have limited time due to your work schedule

thanks
Rolo.