Fender “Twin Amp” Retube Kits

Fender “Twin Amp” Full Retube Kits. Often called the EVIL Twin, these superseded the Red Knob series in the early 90’s.

All of our Fender “Twin Amp” full Retube Kits are designed specifically for these amps. Every kit is configured to provide a specific sound/experience.

The Default power tubes for these kits use the Special Double Mica version of JJ’s 6L6GC-DM (found only at ET). The Double Mica modification has no effect on the sonics of the tube, it simply helps to reinforce the internal assembly to minimize the chance of tube rattle. However you can use the Power Tube drop down to select the JJ 5881’s. The JJ 6L6GC-DM’s will maintain the OEM headroom/breakup point for the output stage. 6L6’s are known for their bold cleans, deep bass, crystalline highs, and naturally scooped mids. The JJ 5881’s will drop the output power by about 20%. 5881’s have less bass extension, a crunchier mid-range, and bright jangly highs that compress when pushed.

The Standard Retube Kit is as close to OEM as possible. Maintaining the amps stock level of headroom and gain while providing a warm but even handed overall sound. The kit includes one matched Quad of JJ 6L6GC-DM’s by default, five Standard ECC83S’s for V1, V4, V5, V6 and V7. Two Standard JJ ECC81’s for V2 and V3, and one current Balanced JJ ECC81 for the phase inverter in V8, farthest from the input jacks.

The Gold Pin Retube Kit uses the JJ ECC83S Gold Pin variants to provide a smoother, creamier, and more singing overall sound. This option is less aggressive and has less “teeth” when driven hard. If you like a classic raunchy gritty overdriven tone, we recommend looking elsewhere… If sweet, open, and more refined is what you’re after this kit will do it. The kit includes one matched Quad 6L6GC-DM’s by default, five Standard Gold Pin ECC83S’s for V1, V4, V5, V6 and V7. Two Standard Gold Pin JJ ECC81’s for V2 and V3, and one current Balanced Gold Pin JJ ECC81 for the phase inverter in V8, farthest from the input jacks.

The ECC803S Option Retube Kit The JJ ECC803S is a long plate 12AX7 variant. These are a little lower in gain than the go-to JJ ECC83S. They have a very fat mid with more top-end which gives them a very vintage tone with lots of chime. This kit contains a matched Quad of the 6L6GC-DM’s by default, five Standard Long Plate ECC803S’s for V1, V4, V5, V6 and V7. Two Standard JJ ECC81’s for V2 and V3, and one current Balanced JJ ECC81 for the phase inverter in V8, farthest from the input jacks.

The ECC803S Gold Pin Option Retube Kit A vintage vibe with more chime and a smoother overdriven sound. This kit contains a matched Quad of the 6L6GC-DM’s by default, five Standard Gold Pin Long Plate ECC803S’s for V1, V4, V5, V6 and V7. Two Standard Gold Pin JJ ECC81’s for V2 and V3, and one current Balanced Gold Pin JJ ECC81 for the phase inverter in V8, farthest from the input jacks.

**These amps are adjustable bias, and the bias should be checked and adjusted as necessary anytime you swap power tubes.

All you need to adjust the bias on your Twin Amp is a multimeter. Set power switch to high with nothing plugged into the input. Turn all gain and volume controls down to one. If your amp has vibrato set both speed and intensity to one. Foot switch unplugged.  Reverb down to one.

Now stick the red lead into the middle test hole and leave it in there. Stick the black lead into the hole marked BIAS 0.08V. read what you have on the meter, and adjust the trim pot marked “OUTPUT BIAS ADJUST” until your meter reads .080 volts (80mVDC), use .075V for the JJ 5881’s. Now pull out the black lead and stick it in the hole on the right marked “BALANCE 0V” and adjust the meter to read zero. Let the tubes get hot and settle, then check and readjust if necessary.