• TGP is giving away a Strat, Tele, and Jazzmaster. Click Here for full details.
    Click Here to upgrade your account and enter today!

Recent content by catalin gramada

  1. C

    Bad OT?

    Hi Cirrus. thank you. that have pretty much sense. but the real think I cannot imagine is how this voltage is induced in secondary side as time the primary was in open circuit (power tubes was pulled off). just primary center tap of OT was conected. Thanks Catalin
  2. C

    Bad OT?

    Hello everybody. I have seen a weird phenomena regards the OT in one of my Plexi project looking for potential hum sources. Each time when I power on the HT ( with all tubes pulled off) I recorded a sort of short slight "thump" in speakers for second and progresively disapear after. I did a...
  3. C

    Aiken's Reactive Dummy Load.

    Hallo You can also try to rise the signal out ground with a small value resistor:10-47 ohm for instance, for humm ground issues.sometimes works pretty well. Catalin
  4. C

    Aiken's Reactive Dummy Load.

    Hi, very useful infos there. Thank you. Catalin
  5. C

    Aiken's Reactive Dummy Load.

    Hallo. can someone explain what is happen with impedance when the cone reach the maximal excursion into a guitar speaker, please ? it is as constant when the speaker breakup taking in consideration just one single frequency , for instance ?or it is vary somehow depends of position of coil into...
  6. C

    Aiken's Reactive Dummy Load.

    Hello. everything well known and elementary. thank you. I used the plot graphs presented here by James Freeman resulting from his measurements on a Framus speaker and the same values, tested on a Framus CB 212 as he allready did. So everything was matched almost perfect taking in consideration...
  7. C

    Aiken's Reactive Dummy Load.

    Nice work , congrats ! One sugest, with you permission. If you leave the air core coil fasten as so the measurement will be influenced. better to raise 1 inch over the bottom fasten on a non el-magnetic material support(plastic, wood block or some). use nylon straps to fasten it. a metalic screw...
  8. C

    Aiken's Reactive Dummy Load.

    Hi , two Hammond in series works for me, but think Erse-(ilya-v can tell you more)-is build with tight tolerances - from 3 pcs Hammond I had values between 8-9mH at 100 Hz. but smaller resistance 0,16 ohm and bigger curent capability 5A 200uF is too much. look for something in 100-150uF range...
  9. C

    Aiken's Reactive Dummy Load.

    Happy New Year to All, nice parallel RLC calculator here : http://www.amanogawa.com/archive/CircuitsA.html think is pretty difficult to predict the reponse when you mix reactive elements in series/parallel configuration cause each one will come with its own characteristics canceling one to...
  10. C

    Anyone Been Able to Try a Surh SL68

    Hello 100% agree. is better to use acoustic coupling instead electric coupling into a loop using modulation effects. More-better to use a separate decoupled cabinet instead to use diferent speaker into one cab.Or best - to use two separate left /right cabs for real panning modulation effects...
  11. C

    Aiken's Reactive Dummy Load.

    ..more ... http://www.patent2pdf.com/pdf/04937874.pdf http://home.comcast.net/~tamivox/dave/speaker/graphs.html
  12. C

    Aiken's Reactive Dummy Load.

    Hello, useful link : http://www.reocities.com/sunsetstrip/studio/2987/speaker.html some building considerations: keep an eye on RLC meter when you mount inductors in a case. The inductance will vary with position in metal box and also is relative with distance from another electromagnetic...
  13. C

    Aiken's Reactive Dummy Load.

    Hello maybe I'm wrong but have a Marshall Power Brake schematic with a resonance LC circuit centered at 113 Hz and not in around 350 hz as it was presented in a plot of http://www.soundsmith.com/fake.htm. Also confused to compare diferent impedances loads on the same plot graph. Light me please...
  14. C

    Aiken's Reactive Dummy Load.

    Hi You're right, the power of resistors is direct proportional with thermic dissipation. For instance my 150w are not rated more than 50 w without a proper sink, and that in 25*C ambient conditions (ca.77*F) and not in hot air closed box- more important as we run "almost DC" on output. The...
Top