Seymour Duncan Twin Tube Classic Pedal Refurb

This pedal was making a strange, whooshy noise. Could the Unbrokenstring Crew fix it? Let’s find out!

There are many pictures on the Web of the top of the pedal, but nothing about the back. Here it is! We haven’t missed much.

The bottom of the unit slides off. Four screws hold the bottom plate on the unit. I love that big non-skid pad on the bottom of this pedal!

An interior view shows the pair of 6021 tubes and the circuitry to support them. Most everything else is switching, tone and volume controls.

I located a stash of NOS RCA 6021 tubes from a resale shop on eBay. I purchased all they had.

Here are two volunteers from the group.  The individual wires are soldered to eyelets, rather than having pins that fit in a socket.

One screw removes a bracket that holds the tubes in place.

I cut one of the old tubes out, then unsoldered the pc board terminals.

This is a roll of Teflon tubing.  Some of this will be slipped over each lead of the tubes to keep them from touching each other.  This stuff dates back to my NASA days.

Pieces of Teflon tubing are cut to length and slipped over each tube lead.  The leads are then threaded through the holes in the eyelets, where they will be soldered.

Just a couple more leads to thread into the eye of the needle!

Each lead is pulled through the eyelet until the tube is seated in its final resting place.  Each wire will be hand-soldered and the excess lead trimmed.  As you might suspect, the second tube is replaced in a similar manner.

Having all the knobs pointing the same direction is a nice touch.

Sean and his beautiful bride pose for a pic!

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Thanks for reading all the way to the bottom.

CONTACT : David Latchaw EE