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Afterlife mods

Started by shawnee, March 02, 2013, 07:30:53 AM

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shawnee

Hello guys,
     I just got the afterlife board from Brian and wanted to do a little experimeting with it. I haven't built it yet but have been thinking about options. I really like Midwayfair's idea to adjust R7. I was going to just put a 100K pot there but I think his idea is better with a 24K + 50K pot in series. My question is about C3 (release). Because it's such a high stock capacitance value (100K), it seems that it would be easy to use Joe Gagn's variable capacitor design that he uses on his Easyface and put a low value cap (maybe 1uF) and a 220uF on a 100KB pot and use it as a blend. Wouldn't that work for a release control? Half way would be around 110uF and be close to the stock value. Is this worth trying?

midwayfair

I *think* you may run into issues with the resistance preventing the cap from charging properly. In a design like this, the cap "fills up" with positive charge and holds onto it for a bit. If you were to put a resistor in parallel, it would prevent the cap from filling up (that is, it would control the decay). If on the other hand you have resistance in series, that would prevent the cap from filling up. Series resistance like this has caused some problems in other designs I tried it in. However, I also don't know what parallel resistance will do to the LED in the afterlife. It could very well prevent it from working. In fact, given that decay resistor is so common, I'd be surprised if it worked and Hollis just decided to leave it out.

You could get some useful millage out of a three-way on/off/on switch without much additional work. Replace the 100uF with a 22uF cap (for 1/4 the decay). Wire up a 47uF on one side of the switch, and a 100uF on the other side. Now you can get a shorter, slightly shorter, and slightly longer decay. You won't have the stock setting, but the difference between 100uF and 122uF in this case will be pretty minimal. You may need to play with the values to notice much difference.

shawnee

I don't totally understand what you said but I will take it to mean that it probably wont work right. I may socket C3 and try different values to see if it's worth adding a switch with different cap values. Thanks you very much Jon!

Dman

Hey guys;

Yeah, I'm a newbee (here, at least), and it look like a great site for discussions/observations!

Good thoughts on the cap/resistor issue. I tend to concur with you, as R and C really aren't the same thing in that context of the circuit (when are they really, with exception of changing things up in an audio crossover, for example?).

Not trying to hijack the thread. I had originally sent an email to the Madbean himself, had not gotten any response, so I figured I'd register and start asking away!

Has anyone tried the Afterlife with better/different op amps like Burr Browns? I'm asking as I have a bunch of them (OPA-2132 for eg.) "kicking around" the parts bins and thought why not ask before taking the dive and do a build up on this!

Also, have you guys (or know anyone around her that has) who has tried a different Vactrol LDR like the 5C2 or 5C9? The Hollis website suggests using the 5C2 for bass guitar vs the 5C3 as listed in the schematics here.

Having just completed a SSM2166-based compressor from another site, I'm pretty stoked on different compressed tones now. While that compressor has a very CS-2/Orange Sq. sound (to me, as a bass player at least), I was looking for something just "different" and am highly considering the Afterlife as well...

Thanks in advanced!
Dman

I welcome any thoughts, good bad or indifferent on the circuit and part subs...