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How can a chap build a ring modulator?

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  • How can a chap build a ring modulator?



    Evening all!</P>


    There were certain sounds in the grand seventies tradition ofHammond abuse which I'd thoughtwasa leslie being treated badly, but it may in fact have been a ring modulator in use. This is a sound I particularly want to use,alas, I don't have hundreds of dollars to buy a ready made...</P>


    A member of the forum was about to lay on me the secrets of the RM, based on the maestro circuit but replacing the now rare chip with an AD633 by Analog Devices, but he has been missing these three months past.</P>


    I've found the schematics and PCB layout for the maestro, but I don't know a BIT about what I have to do to substitute this or that... I need the whole darn thing spelled out for me.</P>


    Haveany electronic buffs out there had the joy of building such a modulator or are keen to give it a whirl?</P>


    Major Bloodnok would be proud of you... prepare to put your pliers to the ring modulator tango (:to the tune of "The Modern Major General").</P>


    -Brendoon</P>
    -1958 Hofner 550 archtop guitar -1959 C3 and PR40- -1964 Busillachio Harmonium- -1964 M101-
    -1967ish Leslie 122- -1975 T500 (modded..chopped, and reassembled!)-
    -DIY 760 FrankenLeslie/rat hideout-
    -1980 Electrokey Electric Piano- -Yamaha electric Harmonium (early 80's?)-
    -1990 Jansen GMF150 amp- -1992 Korg 01W/fd- -1992 G&L S-500 geetar.

  • #2
    Re: How can a chap build a ring modulator?



    Try a MC1495 </P>


    It is nothing more than multiplying two analog signals together. There should be lots of ap notes on use of the MC1495 multiplier chip.</P>

    Comment


    • #3
      Re: How can a chap build a ring modulator?



      Gday Fred!</P>


      The MC1495 was the one in the actual Maestro recipe here:</P>


      http://www.generalguitargadgets.com/...&amp;Itemid=26</P>


      but the chap said it took him a while to find one and cost him quite some dough!</P>


      I should do a search before I take his word though, eh!</P>


      I'll take a look.</P>


      Cheers!</P>


      -Brendon</P>
      -1958 Hofner 550 archtop guitar -1959 C3 and PR40- -1964 Busillachio Harmonium- -1964 M101-
      -1967ish Leslie 122- -1975 T500 (modded..chopped, and reassembled!)-
      -DIY 760 FrankenLeslie/rat hideout-
      -1980 Electrokey Electric Piano- -Yamaha electric Harmonium (early 80's?)-
      -1990 Jansen GMF150 amp- -1992 Korg 01W/fd- -1992 G&L S-500 geetar.

      Comment


      • #4
        Re: How can a chap build a ring modulator?



        I found another interesting page on recreating the maestro:</P>


        http://topopiccione.atspace.com/PJ01MaestroMR.html</P>


        This chap says the MC1495 can be substituted with another IC but then the circuit has to be redesigned around it.</P>


        In truth, I don't even know whatthe ring modulator does... I just heard some sounds I'd like to make.</P>


        I suspect the maestro doesn't even have to be the model to copy.</P>


        JonC3, the member who has gone MIA said this back in November 2008 before I was ready to build anything: </P>


        "my AD633 ring isbased on Maestro. Unfortunately I have lost the PCB files. If I find my camera I would post the PCB pictures, you would be able to reproduce it in CAD...[snip] The Ring Modulator produces also a nice distortion if good dual opamp is used in place of MC1458 (I used OP270 from Analog Devices). 741 is a common single opamp. Use dual 100k audio pot for pitch control (the pot you play with), single 47k linear for modulation depth control and single 47k audio for volume control. An +15/-15 +12/-12 power supply is shown on the schematic. I've removed the little noise (carrier gate) included in the original RM-1A because it is hard to find a good small signal P-channel FET and AD633 is real a low-noise chip..."</P>


        He did supply photos but they were from a cell phone and terribly blurred.</P>


        However this isn't enough info to make up the circuit with the substitute parts, because surely there would be more to change on the original board?</P>


        I'm okay assembling parts, but I'm no electronicist (professional cartoonist in fact, I'm afraid) perhaps I DO qualify as a "skilled labourer" though when it comes to soldering bits n pieces together!</P>


        Would you like me to post up the information I HAVE found?</P>


        Cheers,</P>


        -Brendon</P>
        -1958 Hofner 550 archtop guitar -1959 C3 and PR40- -1964 Busillachio Harmonium- -1964 M101-
        -1967ish Leslie 122- -1975 T500 (modded..chopped, and reassembled!)-
        -DIY 760 FrankenLeslie/rat hideout-
        -1980 Electrokey Electric Piano- -Yamaha electric Harmonium (early 80's?)-
        -1990 Jansen GMF150 amp- -1992 Korg 01W/fd- -1992 G&L S-500 geetar.

        Comment


        • #5
          Re: How can a chap build a ring modulator?



          Hi Brendon,</p>

          I love to design and build stuff too and certainly don't want to discourage you on this DIY project but here's a thought for you... Are you familiar with the Behringer DSP2024P Virtualizer Pro? It's a stereo DSP, rack mount, MIDI interface, something like 70+ sound algorithms (including ring modulation), various parameter knobs to twiddle and the best thing is that it's cheap, works good and is a heck of a lot of fun to play around with. I've seen new ones now for under $100 USD and I picked up a "like new" used one a year or so ago for around $60. If you Google the manual you'll see it lets you play with everything from mild to wild including reverbs, trem/vibrato, Leslie sim, vocoder, amp simulations, pitch shifting, etc, etc,etc. </p>


          </p>
          Gary

          Current: Rodgers 340 "Special", Gulbransen Rialto K (Both Versions), Allen Theatre Deluxe, Rodgers Olympic 333, Roland Atelier AT70 (I hope)
          History: Rodgers 321B, Rodgers 740B, Gulbransen Theatrum, Hammond H-133, Thomas Malibu, Heathkit/Thomas Paramount

          Comment


          • #6
            Re: How can a chap build a ring modulator?



            Thanks Tinker!</P>


            I'll keep my eye on the auctions with that in mind, but our budget at this point only allows the odd dollar or two two slip towards electronic items... so my thought in doing the DIY was to gradually build this beast without actually put a bulk amount of dough anywhere until some more sizeable contracts come in. </P>


            erm..You don't perchance want any Illustrations, cartoons,covers or even, good gracious, graphic design (not so much fun, but hey, a unit which can make funny sounds on my Hammond is at stake here!)?</P>


            Uhm,Never mind..</P>


            Ciao!</P>


            -Brendoon</P>
            -1958 Hofner 550 archtop guitar -1959 C3 and PR40- -1964 Busillachio Harmonium- -1964 M101-
            -1967ish Leslie 122- -1975 T500 (modded..chopped, and reassembled!)-
            -DIY 760 FrankenLeslie/rat hideout-
            -1980 Electrokey Electric Piano- -Yamaha electric Harmonium (early 80's?)-
            -1990 Jansen GMF150 amp- -1992 Korg 01W/fd- -1992 G&L S-500 geetar.

            Comment


            • #7
              Re: How can a chap build a ring modulator?



              Jameco.com has the MC1495 at $10. They are harder to find than many chips.</P>
              <P mce_keep="true"></P>

              Comment


              • #8
                Re: How can a chap build a ring modulator?



                The ring modulator essentially amplitude modulates one signal with another. A four-quadrantring modulatoralso reverses the phase of the modulaTED signal when the modulaTING signal is in the negative swing of its waveform.</P>


                The two waveforms are mathematically multiplied together to get the output. In the front end of radio receivers you usually have a "mixer" which does the same thing. Mixing two frequencies results in the output of the modulator containing the orginal two frequencies, plus the sum and difference frequencies.</P>


                The freqency spectrum is a "carrier" at the high frequency being put in one port, with two sidebands spaced from the carrierby the frequency of the second port.</P>

                Comment


                • #9
                  Re: How can a chap build a ring modulator?



                  Wahoo! Thanks Fredy.</P>


                  Thanks for the location and pricing of the chip. I Guess I can't do a thing without it! </P>


                  I'll order it and get it shipped, once my "budget advisor" and I find a spot to fit it in.
                  (I'm a luxurymerchant in a tight belt zone...a self employed illustrator!)</P>


                  However, you've just pointed out something I've been getting a sneaking suspicion of....</P>


                  Two wave forms are required. The Hammond organ is only one waveform!
                  In the recordings and videos of 70's organists, theymust be gettingtheir secondsignal from somewhere, but where might this be?</P>


                  Ah! No, it's fine. I've just found the answer. Apparently the maestro circuit has a built in carrier generator.</P>


                  I'm starting to get an inkling of whatwe're playing with here...</P>


                  As an experienced chap in this field, do you find pots or sliders more effective in this application... for on the fly adjustments?</P>


                  Cheers!</P>


                  -Brendon</P>
                  -1958 Hofner 550 archtop guitar -1959 C3 and PR40- -1964 Busillachio Harmonium- -1964 M101-
                  -1967ish Leslie 122- -1975 T500 (modded..chopped, and reassembled!)-
                  -DIY 760 FrankenLeslie/rat hideout-
                  -1980 Electrokey Electric Piano- -Yamaha electric Harmonium (early 80's?)-
                  -1990 Jansen GMF150 amp- -1992 Korg 01W/fd- -1992 G&L S-500 geetar.

                  Comment


                  • #10
                    Re: How can a chap build a ring modulator?



                    For FINE bias adjustments, multiturn trimpots are the best. </P>


                    The MC1495 is an analog chip and one needs to take care in regards to static destroying it. Do all the wiring ahead before plugging in the chip.</P>


                    Verify power supply before plugging in the chip.</P>


                    Suggest you use a socket for the chip rather than soldering directely.</P>

                    Comment


                    • #11
                      Re: How can a chap build a ring modulator?



                      Thanks so very much, Fred!</P>


                      You've no doubt just saved me a lot of bother...</P>


                      I'll return here once I get this project started, and exercise your warnings conscientiously. I hope it's sooner rather than later, funds dependant!</P>


                      Expect me againafter an indefinite lapse......</P>


                      -Brendoon</P>
                      <P mce_keep="true"></P>
                      -1958 Hofner 550 archtop guitar -1959 C3 and PR40- -1964 Busillachio Harmonium- -1964 M101-
                      -1967ish Leslie 122- -1975 T500 (modded..chopped, and reassembled!)-
                      -DIY 760 FrankenLeslie/rat hideout-
                      -1980 Electrokey Electric Piano- -Yamaha electric Harmonium (early 80's?)-
                      -1990 Jansen GMF150 amp- -1992 Korg 01W/fd- -1992 G&L S-500 geetar.

                      Comment


                      • #12
                        Re: How can a chap build a ring modulator?



                        Okay, I'm committed now. I have an account with Jameco and I've ordered the MC1495 andthe other chips and sockets....</P>


                        I expect the rest can all be found locally.</P>


                        Odd sounds,here we come!</P>
                        <P mce_keep="true"></P>
                        -1958 Hofner 550 archtop guitar -1959 C3 and PR40- -1964 Busillachio Harmonium- -1964 M101-
                        -1967ish Leslie 122- -1975 T500 (modded..chopped, and reassembled!)-
                        -DIY 760 FrankenLeslie/rat hideout-
                        -1980 Electrokey Electric Piano- -Yamaha electric Harmonium (early 80's?)-
                        -1990 Jansen GMF150 amp- -1992 Korg 01W/fd- -1992 G&L S-500 geetar.

                        Comment

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