Home Forums Vintage EHX EHX Small Stone issue J

Viewing 3 posts - 1 through 3 (of 3 total)
  • Author
    Posts
  • #83023
    t4796
    Member

    Hi,

    I picked up a small stone a while ago. It sounded great, but in the background i could hear the oscillator sweeping and it got worse when the colour switch was engaged.

    Fast forward to now, and I have replaced all the old electro caps (2x 33uf and 1x 10uf) ,the two larger 0.1uf ‘paktron’ polys, and six smaller 0.058uf green polys.

    I’m wondering if there is supposed to be another cap somewhere, say straddling the colour switch, to filter out the oscillator noise and if a previous owner has accidentally removed it during repairs.

    Thanks for any help.

    #119144
    Gplayer
    Member

    I don’t have the answer you’re looking for but I’m curious what effect the capacitors you changed had on the background sound? Was there any improvement?

    #119146
    t4796
    Member

    Hi mate,

    The background sound didn’t change when I changed the capacitors. I replaced them with the same values. Some of the originals were out of tolerance, and I’d hoped that replacing them would bring my unit closer to original working specs and remove the background sweep noise, but it did not. It didn’t get better or worse by my ears.

    I’ve noticed pics of a later J model online that seem to have a different coloured poly cap in the middle of the board, maybe it was factory change to improve the background noise, but it’s a long shot. I think more likely there are two possibilities, either who ever had the pedal before me changed the switch and forgot to replace a component, or one of my EH1048 ics are faulty. I guess possibly one of the cap values could be wrong but they seem to match what is printed on the pcb.

    I have some rca CA3094e on the way and I’ll be installing some sockets into my pedal for testing purposes.
    There’s a schematic online but who knows if it’s correct. I’m really reliant on the generosity of somebody at EHX for the authentic info on what may be missing from my board. I guess I’ll know for sure when I swap out the EH1048s :)

Viewing 3 posts - 1 through 3 (of 3 total)
  • You must be logged in to reply to this topic.