Technical Bulletin #3

RE: Hellhound 40/60 Output Jack Wiring Correction

This correction applies to most amps (combos and heads) with serial numbers below 00133. Contact your dealer to see if your amp has been corrected, or check for a small black dot after the serial number which signifies the correction has been made.

The 4 and 16 ohm speaker output jacks might be wired backwards. The red wire and yellow wire attached to the speaker jacks might have to be switched with each other. This possible error is a result of the transformer being built with inadvertently switched wire color codes.

Correcting the wiring will improve the sound of the amp, regardless of which jack (4, 8, or 16 ohm) is used. The result is a clearer, richer, and smoother sound, with less noise. We apologize for any inconvenience this may cause. Please feel free to contact us if you have any questions or concerns.

Procedure:

  1. UNPLUG POWER CORD!!!

  2. Remove front speaker grill (combo only). This is attached with velcro, simply pry off with fingers.

  3. Remove metal back panel. Remove top back corners (head only).

  4. Unplug speaker from chassis, and unplug reverb cables from reverb tank. Note: the cable end with the blue tubing should always go to the red jack on the reverb tank.

  5. Remove the two 6L6 power tubes. Be sure tubes are cool before handling!

  6. With cabinet in normal upright position, completely remove the four chassis mounting screws/washers on top of the cabinet. The chassis will drop down about a 1/2 inch, but will not fall out.

  7. Remove chassis by gripping the bottom of each transformer and carefully "wiggling" the chassis out towards you.

  8. Locate the YELLOW wire and RED wire attached to the speaker output jacks. Clip both wires as close as possible to the jack tab.

  9. Trim off approximately 3/16 inch of insulation from end of each wire. Tin exposed ends with solder.

  10. Solder the YELLOW wire to the 16 ohm jack tab (where the red wire was before).
    Solder the RED wire to the 4 ohm jack tab (where the yellow wire was before).

  11. Re-install chassis. Push chassis as far forward as possible before tightening mounting screws. Re-install chassis before re-installing speaker grill (combo only).

  12. Re-assemble amp. On the back of the chassis, apply a small black dot following the serial number. This signifies the wiring has been corrected.