Members Umma Gumma Posted July 2, 2006 Members Share Posted July 2, 2006 I really dig my AD202 .. I opened the unit and maxed, out, the clock trimmer and got someadditional delay time out of,,, and it's not too gritty, either. David Barber talks about stacking opamps in tube screamer styledpedals to get more gain; and/or swapping various kinds of chipsalso. Basically you stack 2 or more chips together aligning theirpins, and then soldering them together, and plugging the stackback into the chip socket . With this general principle in mind, I'm wondering if I can addBBD chips to my AD202 along w/ the driver chips and get moredelay time ? The interior of the unit is cavernous, so unlike a pedal there isdefinitely plenty of room ... is it not quite that simple ? Will stacking a few more chips together, produce the desired effect,or do they need to be wired into the circuit board differently ? Link to comment Share on other sites More sharing options...
Members dot-dot-dot Posted July 2, 2006 Members Share Posted July 2, 2006 That won't work - each chip would need to be addressed separately. Link to comment Share on other sites More sharing options...
Members Umma Gumma Posted July 2, 2006 Author Members Share Posted July 2, 2006 I figured it wouldn't be that easy .. Link to comment Share on other sites More sharing options...
Members Seth Carmody Posted July 3, 2006 Members Share Posted July 3, 2006 How much extra time did you get? I've got an AD100 here and heve never even bothered to open it up. I might for 100ms though Link to comment Share on other sites More sharing options...
Members Umma Gumma Posted July 3, 2006 Author Members Share Posted July 3, 2006 It seems to be at around 5-600ms, now, which is pretty good. Prolly at the lower end of 500ms,though; haven't officially clockedit .. Link to comment Share on other sites More sharing options...
Members Seth Carmody Posted July 3, 2006 Members Share Posted July 3, 2006 Nice. Is there just the one pot is is there many? if so, which one is the one to tweak? Link to comment Share on other sites More sharing options...
Members Umma Gumma Posted July 3, 2006 Author Members Share Posted July 3, 2006 I haven't peeked inside an AD-100 but, given the era, and that it's the same company, I don't see why it'd be any different.. so .. The trimmers are right on the circuit board and are labeled, as to what they're for . IIRC, I turned the 'clock' trimmer, down, in the section marked "delay". The unit was plugged in, along with my guitar strapped 'round my neck, so, I immediately, heard the delay time stretch, out, as I turned the trimmer . Link to comment Share on other sites More sharing options...
Members Seth Carmody Posted July 3, 2006 Members Share Posted July 3, 2006 Originally posted by Umma Gumma I haven't peeked inside an AD-100 but, given the era, and that it's the same company, I don't see why it'd be any different.. Exactly what I was thinking Originally posted by Umma Gumma so .. The trimmers are right on the circuit board and are labeled, as to what they're for . IIRC, I turned the 'clock' trimmer, down, in the section marked "delay". The unit was plugged in, along with my guitar strapped 'round my neck, so, I immediately, heard the delay time stretch, out, as I turned the trimmer . Ahh cool, labelled makes it easier. I had a Ibanez DML10II that had 7-8 trims but they were labelled in shorthand or something Thanks Link to comment Share on other sites More sharing options...
Members Seth Carmody Posted July 4, 2006 Members Share Posted July 4, 2006 Well I opened her up and the trim pots were labelled. I tweaked the clock trim and only had marginal success in extracting more delay time - no more than 100ms at best. I't's hard to gague by ear. I didn't notice any serious degradation in the repeat quality...because my attention was distracted by the chip whine that had developed, especially when the delay knob was rolled past 75%. So I tweaked the trim back (I think even further back than it was set when I opened it up) until the whine was just barely noticeable with the delay pot maxed. Doesn't sound like it has any less delay time than pre tweak and the whine is completely absent with the casing back on. This makes me wonder how far I could have tweaked it since the casing appears to provide some kind of shielding role against noise, but I don't have the patience for that so will just let it be. Also, the MN3005 chip was socketed. Is that usual, or is it likely my unit has already been taken for repair and the socket is the work of a technician? In hindsight I should've checked the soldering at back of the board for a clue.. Link to comment Share on other sites More sharing options...
Members Umma Gumma Posted July 4, 2006 Author Members Share Posted July 4, 2006 Originally posted by Seth Carmody Well I opened her up and the trim pots were labelled. I tweaked the clock trim and only had marginal success in extracting more delay time - no more than 100ms at best. I't's hard to gauge by ear. I didn't notice any serious degradation in the repeat quality...because my attention was distracted by the chip whine that had developed, especially when the delay knob was rolled past 75%. So I tweaked the trim back (I think even further back than it was set when I opened it up) until the whine was just barely noticeable with the delay pot maxed. Doesn't sound like it has any less delay time than pre tweak and the whine is completely absent with the casing back on. Chip whine ? Hmm, I haven't noticed that .. I wonder if I should listen for it ? Nahh, I better, not . Also, the MN3005 chip was socketed. Is that usual, or is it likely my unit has already been taken for repair and the socket is the work of a technician? In hindsight I should've checked the soldering at back of the board for a clue.. I can't remember if mine has sockets, or not; it's been a few weeks since I was inside, there. Link to comment Share on other sites More sharing options...
Members dbx Posted July 4, 2006 Members Share Posted July 4, 2006 Link to comment Share on other sites More sharing options...
Members basscracker Posted July 4, 2006 Members Share Posted July 4, 2006 looks like you could swap the MN3007 for another MN3005 for more delay time. Link to comment Share on other sites More sharing options...
Members dbx Posted July 4, 2006 Members Share Posted July 4, 2006 Originally posted by basscracker looks like you could swap the MN3007 for another MN3005 for more delay time. You're probably right but you'll play hell trying to calibrate this if you don't have an o-scope..could be fun to try 'though...(stock delay time is 40-400ms) Link to comment Share on other sites More sharing options...
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