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  • A/DA Flanger REISSUE

    I really need the schematics for the A/DA Flanger Reissue 1995. I have the original one but the reissue seems to have a quite a bit more complex circuit.

    If anyone can help me I appreciate.

    Thanks,

    mfgobbi

  • #2
    What BBD chip does it/yours use?

    Comment


    • #3
      ada Reissue with mn3010

      It uses an mn3010, but the circuit looks different from everything I got from adadepot, including the older versions with mn3010. My reissue seems to have more components than what appears in the schematics.

      Any clue?

      Thanks.

      Comment


      • #4
        One of the issues (either #3 or #4), has a slightly more complicated limiter circuit, involving more dioes., but the basic sweep, filter, gating, and delay circuitry is pretty much the same.

        RE: limiter circuit. Whenever you have a recirculated signal (found in flangers but not chorusses) added to the real-time input signal, there is always the risk of the two summed/mixed signals exceeding the headroom limitations of the delay chip. When the circuit uses a compander chip like the SA/NE570/571, the recirculated signal is fed back through the compressor section which assures that headroom limits are not exceeded. In the case of pedals like the A/DA unit, which does not use companding, the stage where the input and regen signals are combined (prior to feeding the filters and BBD) has a crude soft limiter comprised of a number of diodes and series resistors, intended to keep a ceiling on level. As a diode clipper it can introduce some distortion when signal levels get hot, but the series resistor tends to keep such clipping to a healthy level. If you look at the schematic for the BOSS BF-2 flanger or any of a variety of other makes from that generation, you will see a similar sort of soft clipper at the same point in the circuit. I don't have my schem collection handy or else I'd send the relevant schems to you. Suffice it to say that the soft clipper/limiter circuit was a little more complex and thoughtful in one of the issues of the A/DA than in some others. I'm pulling numbers out of my hat here, but I seem to recall about a 6-component difference in complexity.

        The key elements of the A/DA, however, such as the role of the filtering in the regen and overall delay paths (more filtering for regen), the gating of the delay signal (simple noise gate to cut out delay signal during quiet passages), and the clock/sweep circuit are virtually identical.

        Comment


        • #5
          Originally posted by Mark Hammer View Post
          One of the issues (either #3 or #4), has a slightly more complicated limiter circuit, involving more dioes., but the basic sweep, filter, gating, and delay circuitry is pretty much the same.

          ....
          Mark, I appreciate your help, but I believe you are talking about diferent version of the original (late 70's early 80's) of the ADA flanger. The reissue flanger (1995) has a one extra IC, parts at completely different locations, and is hard to track because it's board is 2-sided. Look at a picture of my reissue - at

          http://www.lemma.ufpr.br/gobbi/DSC01576.jpg

          If you can help me still I would appreciate it.

          M. Gobbi

          Comment


          • #6
            Compare with the original:

            http://www.lemma.ufpr.br/gobbi/ADA-F...7331-page2.pdf

            Comment


            • #7
              I see your dilemma. I can't quite make out all the chips in the photo, but I gather the two just to the left of the MN3010 are a CD4007 and CD4047. The other chips are all either dual or quad op-amps, totalling, by my count, 18 op-amps. As near as I can tell, the PDF of the original you linked to shows three quads and a dual, equalling 14 op-amps overall.

              Big difference. Being unfamiliar with the re-issue, I'm really at a loss as to what is different and what to say. I'll dig around my stuff at home later this evening. Maybe I have a schem from a re-issue, though I don't think so.

              You still haven't stated WHY you want/need the schem. Is there a problem that we can work through in the absence of the particulars for that issue? It may well just be something generic to flangers.

              Comment


              • #8
                Originally posted by Mark Hammer View Post
                I see your dilemma. ...
                You still haven't stated WHY you want/need the schem. Is there a problem that we can work through in the absence of the particulars for that issue? It may well just be something generic to flangers.

                I [with the help of a friend] am thinking about cloning it into a smaller package, with external power... so we'd like to know why the differences...

                Do you happen to know if there is a workaround using the mn3010?

                Those are about 40 dollars a piece, when you can find one.

                Thanks.

                Comment


                • #9
                  Okay, that's clearer now.

                  The MN3010 is probably one of the hardest to find BBDs. It is a dual 512-stage unit. By coincidence, so is the SAD1024. Realistically, there is no difference between an analog sample sitting for a couple dozen microseconds in a teeny tiny cap on this chip or that one. The differences between the Matsishita and Reticon chips are more in terms of the support circuitry needed. In the case of the Matsushita chips, the input capacitance on the clock pins (where the HF clock pulse goes) is on the highish side, so you'll generally see low-ish clocking limits (e.g., max clock rate of 100khz) in their datasheets. As it turns out, if the user provides proper buffering and boosts the current of the clock pulse, you can get past that limit and clock those suckers pretty high. The specs shown in the datasheets generally assume one will be clocking with an MN3101 or MN3102 chip which does the division and complementary pulse thing nicely but lacks the buffering. So the clocking limits shown in the datasheets tend to be well below what is possible using something other than Matsushita's chips.

                  The Reticon chip does not appear to need as much "help" in reaching higher clocking speeds (which mean shorter minimum delays and a wider potential sweep range - what the A/DA is famous for). A friend I unfortunately haven't talked to in a while, cloned an A/DA (early issue, not reissue), using a Reticon SAD1024, and I've seen and heard it close up. Pretty spectacular sweep, part of which is due to the use of the 4007/4047 combo. So, it CAN be done. I may have a layout for that somewhere, although some of the guys over at the Diystompbox forum would probably know too. Stephen Giles is probably your best contact on that one.

                  Sadly, the SAD1024 market, at least for regular guys like you and I, is pretty much coming to a close. Steve Daniels, at Small bear Electronics, tells me he is having a devil of a time finding stock, even in dribs and drabs. Some of the big manufacturers, like Electro-Harmonix, pretty much cornered the market on NOS some time ago, in order to keep their premier products like the Electric Mistress alive for a while. As a result, the NOS supplies sitting in corners here and there are getting used up.

                  I'm assuming your move to a smaller package would be from the A/DA recessed panel chassis, to a 1590BB? A buddy of mine currently produces a Boss CE-1 clone, that he has also successfully shrunk into a 1590BB box, by moving the power supply off-board, as well as using some other space-conserving tricks. So, your goal is not unattainable.

                  I wouldn't fret too much about the reissue. After all the reissue only existed because of the legend stemming from the original. So, if you clone one of the original issues, using an SAD1024, you'll be in fine shape. If you swap some of the dual DIP op-amps for SIP-package duals, you'll also be able to save a lot of space as well as find layout a lot easier to do.

                  Comment


                  • #10
                    http://img.photobucket.com/albums/v3...da_MI_1024.jpg

                    This is the SAD 1024 version with extra buffering of the clock signal to achieve higher clocking and therefore nearer to thru zero flanging.

                    Comment


                    • #11
                      You guys probably already know about this but just in case:

                      http://www.visualsound.net/bbd.htm

                      Comment

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