Ebay Classic organs

Collapse

Announcement

Collapse
No announcement yet.

Mylar (red) capacitors from a "H100" tone generator for recap of an '59 A100TG?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Mylar (red) capacitors from a "H100" tone generator for recap of an '59 A100TG?

    hi,

    this is my first post.

    i recently bought a chopped A 100 for stage gigs that seems to have a lot of "stage mileage". it doesn't have a decal with serial number....but by the pre amp and wax capacitors on the TWG it looks early sixties or late 50's. my tech took it apart for cleaning, rewiring where needed due to corrosion, cleaning the percussion switches, buses of the manuals, changinge tubes etc.

    it works perfectly fine, but it sounds a little mellow (no bite) on the upper end, when compared to my other consoles (B3 1970's and A100 about 1968 both very "low mileage" and little stage wear and tear and a lot of love and care over the decades that i owned them).

    by reading the forum, i learned that this problem might be due to the old wax paper capacitors on th TWG going out of specs.

    recently i "stumbled" on ebay over a complete TWG from a H100 with red Mylar capacitors that i bought just in case.

    now my question:
    can my tech use the red Mylar capacitors from the H 100 TWG and use them on the A100 ? without calibrating....?


    thanks a lot for your input

  • #2
    The answers to your questions are yes, and maybe.

    The values of the caps are the same. The mylar caps hold their values better than the wax caps so they should be OK.

    It still may need to be recalibrated, however.
    When the TG was built, caps were matched to the coils. Caps have a tolerance, the older ones I believe were more generous with the tolerance than the mylar caps, but there is still a tolerance.

    If you put a cap that is on the high end of the tolerance into a coil/pickup that was calibrated for a cap on the lower end, you will have a tone that is louder or softer than you want.

    It is a gamble to think that one can replace all the caps and not have to recalibrate any of the tones.

    The other option is to measure and match the proper exact value to each tone, in which case recalibrating would be less likely, but if you only have those caps from the H to work with, this is a moot point.

    Bob
    In theory, there is no difference between theory and reality.
    In reality, there is.
    '54 C-2 & Pair of 122 Leslies
    H-324/Series 10 TC
    '35 Model A (Serial# 41) with a 21H
    Look at some of my rescues:
    https://www.flickr.com/photos/58226398@N03/albums

    Comment


    • #3
      Originally posted by Doc Hammond View Post
      can my tech use the red Mylar capacitors from the H 100 TWG and use them on the A100 ? without calibrating....?
      As Bob says, probably not. Also, there was nothing particularly special about the "red" Mylar (polyester film) capacitors that Hammond used in the 60s. They were simply what was available at the time, and you will pay your tech more to desolder them than you would compared to using new Mylar film capacitors. There was matching between coils and capacitors, but that was between individual coils and individual capacitors, not between all coils and all capacitors. You could do it, but your results would be a roll of the dice.

      I don't support fetishizing vintage components. There's far too much of that in the guitar world.
      I'm David. 'Dave' is someone else's name.

      Comment


      • #4
        Originally posted by Doc Hammond View Post
        ...can my tech use the red Mylar capacitors from the H 100 TWG and use them on the A100 ? without calibrating....?
        Not sure what the distaste towards re-calibrating might be. Certainly if your TG is out on the bench, it doesn't present too big a deal if you are methodical and careful. There is lots of information out there, especially in regards to Kon's spreadsheets. If you are contemplating buying the H100 just for the caps, why not grab it to practice re-calibration on? Then you can just buy some new caps for your A100 and re-calibrate it with confidence..

        Not only that, you will then also have a new found skill !!!

        Peter
        1966 C-3 / 925
        1965 M102 / 145
        1967 M111A / 330

        Comment


        • #5
          Originally posted by Doc Hammond View Post
          now my question:
          can my tech use the red Mylar capacitors from the H 100 TWG and use them on the A100 ? without calibrating....?
          Your tech must have to desolder a capacitor and measure it.
          Mylar capacitors remain within their tolerance.
          Paper capacitors values increase up to 10 x the value. Replacing this capacitor by new ones wil give a great and may be sufficient amelioration.

          Because wires are wrapped, it is not very easy to dessolder all the capacitor without breaking a wire a lug or worst a coil.
          I think you had better to buy news ones and cut the wires of the olders

          JP

          Comment


          • #6
            Originally posted by Jyvoipabo View Post
            Mylar capacitors remain within their tolerance.
            Paper capacitors values increase up to 10 x the value.
            Not entirely true.

            Both paper and Mylar capacitors can drift in value via the same mechanism, water infiltration into the dielectric. Mylar does absorb water, too.

            The key difference between the earlier paper capacitors Hammond used (wax dipped) and the later Mylar capacitors was that plastic shells are much more effective at keeping ambient humidity out than wax.

            The higher-quality paper capacitors Hammond used in their preamps and power amps are often still close to their nominal values, but they were much more expensive at the time. Hermetically sealed paper capacitors like Vitamin Q and others don't drift. (This is why some unrestored Hammond preamps and amps have not suffered the failures they otherwise would have by this point.)

            People believe that Mylar is inherently a better dielectric, but that's not the whole story. I've seen Fender amps with Astron Mylar capacitors where every Mylar capacitor has failed. What was happening in the industry was that all capacitors were becoming more reliable due to overall improvements in manufacturing from the 1950s into the 1960s.
            I'm David. 'Dave' is someone else's name.

            Comment

            Working...
            X