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Peavey Special 130 no reverb

Discussion in 'Shock Brother's DIY Amps' started by MervsMods, Jan 21, 2021.

  1. MervsMods

    MervsMods TDPRI Member

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    Hey guys and gals,

    I just picked up a Peavey Special 130 on the cheap because the reverb was not working. I thought I knew why because the pan was missing! :eek: However, I put in a known good Peavey part number correct reverb pan in, and no 'verb.

    Disconnected the OUTPUT RCA cable from the pan, touched the tip and got noise. To me that would indicate that the issue it's on the input side.

    The amp has the Burr Brown mod, no cracking pots, and all solder connections seem solid.

    Y'all got any idea where I could start? Does the foot switch (which I do not have) circuit automatically shut off the reverb without a footswitch? I can't tell by looking at the schematic (attached).

    Thanks in advance for your advice/input!
     

    Attached Files:

  2. MervsMods

    MervsMods TDPRI Member

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    Fixed! Issue was with the +15V Zener in the power supply. All the IC's were getting 6.4V on Pin 8, instead of +15 per the schematic. While I was in there replacing the zener, I overhauled the power supply section - new caps, new rectifier diodes, yadda, yadda, yadda... Now the amp is LOUD and quite punchy for a SS amp!

    Interesting find - with the IC's only getting the +6v, the overall output of the amp was quieter (and no reverb). I had to turn up the volume on the clean channel to like5 or 6 to get the amp as loud as some has stated they had the volume knob up to 1.5 or 2 and it was shaking the windows. Amazing how less than 10 volts can have on the overall effect of the amp.
     
    RB522, Timmay and Mexitele Blues like this.
  3. Timmay

    Timmay Tele-Meister

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    Congrats on getting it straightened out. Plug that sucker into a good cab if you have one on hand that'll take it. That heavy MDF cabinet kills the low end. Plugged into my VHT 2x12 loaded with Eminence Texas Heats my 130 is THUNDEROUS on 2!!! Awesome SS amp.
     
  4. MervsMods

    MervsMods TDPRI Member

    Age:
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    Thanks @Timmay ! I have a Swamp Thang installed and it takes care of the low end. Actually, the Swamp Thangs and Texas Heats are my favorite speakers!

    It is an awesome SS amp!
     
    Timmay likes this.
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