Home Forums Vintage EHX Mike Matthews Freedom Amp – resistors/capacitors question

Viewing 8 posts - 1 through 8 (of 8 total)
  • Author
    Posts
  • #84861
    max.the.cat
    Member

    Hi there,
    glad to be here, here’s my first post ;)

    I own a 1972 or 73 Freedom P.A. amp. The circuit board is the same as that of the regular Freedom amp but is missing the “Bite” control. I’d like to add that little circuit to my amp. Here’s how that area is looking at the Freedom P.A.:

    freedom-pa-board-bite.jpg

    From pictures I could find in the net I could figure out all the missing parts (some caps and resistors, two transistors, one pot) except for three parts that I don’t even know if they are resistors or capacitors. Two of the parts are only used in the “Bite” circuit, one is in the pre-amp’s Tone section – and the P.A. has a 3.3kΩ resistor there.

    I have found photos of two Freedom amp that show the right side of the board, and both have three yellow components with black text or digits (in normal size of a carbon resistor?):

    freedom-parts.jpg

    There is a schematic in the web, but it’s quite wrong. It does not have the one resistor both the guitar amp and the pa amp have (the one in the right circle). For the one in the left circle the schematic shows a 2.2kΩ resistor that goes to ground (different in the board) and the one in the middle circle is a 4.7kΩ resistor in the schematic.

    All the resistors on the board are common carbon resistors, brown with colored rings. My guess is that the three components in question are three resistors of the same value that has not been in stock in normal version. But have there been yellow resitors with text/digits instead of rings?
    Or are they caps? Mallory caps are yellow with black text, but I guess they are bigger. All the (other) bipolar caps on the board are Greenies or ceramic discs.

    Does anyone have an idea?

    Thanks a lot,
    Max

    #122769
    The EH Man
    Moderator

    Battery or AC powered?

    #122771
    max.the.cat
    Member

    Hey Ron, glad to hear from you! Does that matter? It’s an original ac and dc. One with that welded aluminum box…

    #122772
    The EH Man
    Moderator

    The PA version is fairly rare. I’d hate to see you modify it. Maybe you can find someone to trade a guitar version for yours. I think I have one but it’s DC only.

    #122775
    max.the.cat
    Member

    I think all of them are rare, it took me 2 years to find one at all. Do you know what the parts in question are?

    #122778
    The EH Man
    Moderator

    I’ve got an AC guitar model if you’re interested.

    #122779
    max.the.cat
    Member

    I’ll write you an email. I’m in Germany, postage is quite expensive.

    #122788
    max.the.cat
    Member

    To keep things updated here: I promised Ron not to modify the Freedom P.A. ;)
    Nevertheless I’d still like to know what the parts in the pictures are…

Viewing 8 posts - 1 through 8 (of 8 total)
  • You must be logged in to reply to this topic.