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Coolaudio BBDs/analog delay

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  • Coolaudio BBDs/analog delay

    Hello, I am new to the forum. I joined as I am currently researching analog delay. I have been studying both vintage and modern circuits. Obsolete chip sets/modern bbd chips, etc . . . I have been aware of the Shanghai Belling BBD chips, but the Coolaudio chips are new to me. Does anybody have any experience with these? Seem they are used in some Behringer and BBE stomp boxes. There is not much info on these chips/company and any and all info would be appreciated. Here is my experience--

    I had a dead Boss DM-3. One side of the compander had failed (upc1571). I swapped it for a Coolaudio v571d compander and it is working like a charm. Full functionality and classic, great tone. Perfect pin matches, that easy.

    I am thinking about building some different delays/effects and using these chips. They are very affordable, which, I guess for some reason, makes them suspect. Any thoughts?
    Last edited by mrscientificterms; 12-09-2009, 09:04 PM. Reason: typo

  • #2
    MXR Carbon Copy

    I do not have one of these, I should score one. For the time being, does anybody have a schematic (I know this is a long shot), or a good, clean gut shot?

    I am curious as to the chips in these. The gut shot I have seen is kinda fuzzy, I think I see an SMD Phillips SA571 as the compander. I can't make out the BBD chip. I am curious how they get the 600ms, are they using two chips?


    • #3
      Hey, sorry to jack your thread, was looking for a current production BBD to try and resurrect my old DOD 690 and I guess these Coolaudio clones are just the ticket. Reading around it seems the MN3207 or V3207 needs a complementary clock pulse, whereas the SAD512D doesn't.

      To my fried brain, if I take the signal from pin 8 or 9 of the CD4001 NAND gate it's being used solely as an inverter, so that would give me my complimentary clock?

      Given that the pinouts are totally different, but the spec's are similar, I'm hoping this is an easy patch in.


      • #4
        I can't answer your question, but there is a group buy of coolaudio chips over at • View topic - CoolAudio Group Buy


        • #5
          Panasonic abandoned bucket brigade chips a decade or so back.

          Behringer needed those chips to produce low-cost clones of "classic" pedals (almost all of their pedals are essentially note-for-note copies of Boss, Line 6, MXR, and EHX pedals). And if you have any sense of the sheer volume that Behringer aims for, they needed LOTS of those chips. And Behringer aren't the only ones who use/need them. So, Behringer essentially bankrolled Coolaudio, who make clones of the Panasonic chips.

          Is it possible that batch X performs differently than batch Y of Panasonic chips from the 90's? Sure, just like it is possible that batch X performs differently than batch Y from Panasonic/Matsushita's own production circa 1986. So, for all intents and purposes, consider the Coolaudio chips as if they were Panasonic chips, except that Coolaudio only resurrected that portion of the MN32xx series that they felt would have steady use by customers. They have not resurrected the MN3209 or 3204. What we have available to us through them are the 1024, 2048, and 4096-stage chips and the clock chips.

          And yes, to answer mrscientificterms' question, it takes a pair of V3205 chips to get you 600ms. You can get that delay with one chip but you would need to trim back on the bandwidth so much it would sound like you were listening to a telephone through a pillow. The nice thing about the Coolaudio chips is that it makes use of 8192 stages of delay economical, and permits manufacturers to aim for the sort of bandwidth that digital achieves.

          Bottom line? Buy them with confidence.


          • #6
            In the cold light of dawn it looks like there could be some serious work involved patching a Panasonic MN chip into a circuit designed for the Reticon SAD. Primarily it looks like the operating voltages of the Panasonic are way below that for the SAD.

            The DOD 690 runs of a 15V regulator which is hooked straight to VBB and VDD of the SAD512D, so even if I could use a voltage divider to drop down the voltage for the V3207 to run (operating voltage 4-10V) the input signal would be too high and the output too low. Though the op-amps on the output could be tweaked to compensate I imagine.

            Are there any other BBD's currently in production that might be more suitable for the task, or am I looking at a serious re-work here.