what is this? Fender Prosonic content

Discussion in 'Amps and Cabs' started by macmax77, Oct 28, 2005.

  1. macmax77

    macmax77 Supporting Member

    Messages:
    10,733
    Joined:
    Oct 24, 2005
    Location:
    Pembroke pines-Santiago-Greenville
    IMPROVEMENTS- See all those little disc ceramic caps on the tube
    sockets? cut them out with extreme prejudice. Not needed, and the
    sustain and tone will improve. These do some funny business (Massive
    local feedback) that does affect the audible signal. I don't know quite
    what I was thinking here.


    Thanks
     
  2. macmax77

    macmax77 Supporting Member

    Messages:
    10,733
    Joined:
    Oct 24, 2005
    Location:
    Pembroke pines-Santiago-Greenville
    this are the mods

    Here are the Zinky fixes for stock issues
    PROSONIC POP

    Caused by a few things:
    1) Lousy relays. I have prototype #2 (Proto #1 went to the factory).
    It only pops if...
    2) Bad preamp tubes. Sovtek preamp tubes have a tendency to get
    heater to cathode hum. Makes for a signal level difference when you
    switch, which can give you the annoying "Pop". A spiral filament type,
    such as the Electro Harmonix 12AX7 is a good thing for the first two
    preamp tubes.

    MAJOR CAUSE:
    What you are getting is induced back EMF from the relays leaking into
    the audio. R19 (on the Footswitch jack) was designed to always have
    some signal flowing through the relays. Problem is, sometimes the value
    is too small and the relays hang, or sometimes it is too big and you get
    pop. Experiment with this value. 6.8k was the initial one, later
    changed to 9.1k (so the amps with abberent relays would still pass QC).
    [I now use very tiny low current 5V relays from NEC [ED2-5NJ] (mouser sells 'em).]
    ...

    ALSO:

    R13 Is 1 Meg. Reduce this value. This cap keeps the voltage at the
    input of this tube [V2a] down when the relay is switching, and the circuit is
    otherwise open. A lower value will reduce the pop. Gain will be
    reduced slightly as well.


    IMPROVEMENTS- See all those little disc ceramic caps on the tube
    sockets? cut them out with extreme prejudice. Not needed, and the
    sustain and tone will improve. These do some funny business (Massive
    local feedback) that does affect the audible signal. I don't know quite
    what I was thinking here.

    GAIN REDUCTION-
    Some people like to remove some or all of the cathode caps in the preamp
    section to reduce the gain. If you never need the high gain, it's
    something to try.

    ...

    Last Prosonic mod-

    I would change the stock transformer to our Zinky unit, model
    ZOT604816. This transformer will give much better bass response than
    the original, AND the overdrive will not have any of the "Buzzy" or
    "Fizzy" character you may hear with the stock one (Especially at low
    volumes. Clean tones will be bright and airy, the big changes will be
    on overdriven tones). Does not fit the standard bolt pattern (Slightly
    larger), so you'll have to drill. $150 but well worth it. Has 4/8/16
    Ohm taps. Will give you the liquid overdrive even at highest gain
    settings, even with high treble settings. Get dynamics AND tone....

    Bruce Zinky

    the one i don't understand is the one i listed above!!!

    someone has a pic or has done it?
     
  3. macmax77

    macmax77 Supporting Member

    Messages:
    10,733
    Joined:
    Oct 24, 2005
    Location:
    Pembroke pines-Santiago-Greenville
  4. 65bfdr

    65bfdr Member

    Messages:
    86
    Joined:
    May 5, 2005
    Location:
    redneck, Texas
    you might want to try http://www.fenderforum.com/forum.html and scroll to the "Fender amps 1985 - current" board. They have knowledgable Prosonic owners that should be able to answer your question. I'm actually a little curious to this myself as I'm also a Prosonic owner.
     
  5. macmax77

    macmax77 Supporting Member

    Messages:
    10,733
    Joined:
    Oct 24, 2005
    Location:
    Pembroke pines-Santiago-Greenville
    Thanks, i have been there, but have never seen a pic , so i don't know what he is talking about!:p
     
  6. 65bfdr

    65bfdr Member

    Messages:
    86
    Joined:
    May 5, 2005
    Location:
    redneck, Texas
    Here's what you could do. Take the chassis out and look for the tube sockets and you'll probably see one brown disc capasitor on each socket. Those, according to the description, need to go. I believe you can real carefully cut them with a pair of pliers.
     
  7. macmax77

    macmax77 Supporting Member

    Messages:
    10,733
    Joined:
    Oct 24, 2005
    Location:
    Pembroke pines-Santiago-Greenville

    ummmm have you done that to yours???

    Let me know as soon as you do, ehheehhe, i am afraid to jump from the boat first:D
     
  8. 65bfdr

    65bfdr Member

    Messages:
    86
    Joined:
    May 5, 2005
    Location:
    redneck, Texas
  9. macmax77

    macmax77 Supporting Member

    Messages:
    10,733
    Joined:
    Oct 24, 2005
    Location:
    Pembroke pines-Santiago-Greenville
    hahahahhaha, indeed, haahahaha:D :dude
     
  10. Laroosco!

    Laroosco! Member

    Messages:
    2,604
    Joined:
    May 28, 2002
    Location:
    Detroit, MI

    Post a link to the page you git this info from please. I might be buying a Prosonic in a week or so and I'll do some of these mods and report back. :D
     
  11. scottl

    scottl Member

    Messages:
    17,041
    Joined:
    Apr 11, 2003
    Location:
    Cherry Hill, NJ
    Sounds liek Zinky used "snubber" caps between pins 1 and 3 and 6 and 8 on the preamp tubes. They roll off the highs. If you send a pic to me, I can confirm what they are and what they do.

    Just note the values when you snip. Caps are 10 cents each so you can always put them back.

    Scott
     
  12. aeolian

    aeolian Member

    Messages:
    6,083
    Joined:
    Apr 5, 2004
    Location:
    Santa Cruz, CA.
    Max, some of these things are not difficult, and are reversible. But please do a search on safety and read the things on the www.ampage.com page. We like our members to keep their original hairdos! :)
     
  13. macmax77

    macmax77 Supporting Member

    Messages:
    10,733
    Joined:
    Oct 24, 2005
    Location:
    Pembroke pines-Santiago-Greenville
    ahahahahhahahhahahaha:D

    Thanks, you just made my day and i am laughing really hard right now!!!!!!

    That was great!!!

    Well , back to business, i talked to a friend of mine that is a tech and he said that with all of the info and scems and all that, he can help me .

    I might be only taking out the first cap in the V1 and if i don't like it, it goes back.

    Something else i am doing is the reverb mode

    Besides that, nothing else will be done, i will keep you posted as soon as i do, but it might take a week before i can come down to my friend's shop

    Take good care you all:D
     
  14. rockstah

    rockstah Member

    Messages:
    593
    Joined:
    Oct 10, 2005
    Location:
    austin texas
    dont go cutting those two resistors on the power tube sockets - THOSE NEED TO BE THERE - probably wont be readng this if you just grabbed a set wire cutters and cut them!

    i think he was talking, and only on some prosonics did they have some resistors on the PREAMP tubes - this is what he refering to
    personally if you dont what you are doing - take it to a tech with this information and have them look over it - there are a whole lotta volts stored up in an amp if not discharged and your body completes a circuit cause you are grounded and touch something you will DIE
     
  15. GuitarInnovations

    GuitarInnovations Member

    Messages:
    1,033
    Joined:
    Jan 20, 2004
    So, has anyone done these mods? The ones on the preamp sockets are of interest to me. I will be getting a prosonic head this coming week.

    I would love to get the link to the info, too, macmax. Where did you find it?
     

Share This Page