Peavey Invective 120 Retube Kits

The Peavey Invective 120. The kits we offer here are the most distinctive in tonal character, forged from many years of research. Every kit is configured to provide a specific sound/experience.

These amps are adjustable bias, and finally Peavey has built an amp with test points that actually measure plate current via one ohm resisters! This means that you can adjust the bias with reasonable accuracy. Although not as accurate as measuring with a bias probe it’s a huge leap for Peavey. They state in the manual that 26mA or mV is optimal. It’s actually dirt cold. A matched quad of JJ 6L6GC’s should be between 34 to 38mA. If you want to be more accurate then measuring the plate voltage would help. The range of the bias trim pot is not real wide to these amps need hotter tubes especially when running EL34 type tubes. The JJ 6550’s can be biased between 48 to 54mA.

If you want to be more accurate you can use either our “Pro One” All-in-one bias probes or one of our 30.00 bias probes and a Multimeter to bias the amp without removing the amp from the cab. The probe will fit under one of the tubes while it’s in the cab so biasing is literally a 5 minute job.

EL34’s, EL34II’s, E34L’s, KT77’s, 6CA7’s and 6L6GC’s should all be biased between 34mA to 38mA. The JJ 5881’s should be biased between 32 to 36mA. You can use the bias video we did on a PV JSX for reference.

The default power tubes for all the Peavey Invective 120 kits are the JJ 6L6GC’s. The JJ 6L6GC tubes follow the classic 6L6GC sonic archetype with big lows, smooth mids and crystalline highs. What sets them apart is their low end clarity, mid-range detail and very clear highs without being overbearing or harsh.

Other 6L6 family options include the JJ 5881’s. The JJ 5881’s are a Classic 23 watt 5881 in a traditional stubby bottle. “Jangle” for days and a very warm full tone. Right in-between the JJ 6L6GC and the JJ 6V6S in power. If you’re looking for that early-breakup “tweed” era character these are it.

You can also use EL34 type tubes. The JJ EL34’s are known for their mid range bloom and have a slightly looser feel when compared to the E34L’s. However you can use the Power Tube drop down to select the JJ E34L’s, the JJ EL34II’s, the JJ KT77’s or the JJ 6CA7’s. Thru the years the JJ E34L’s with their added punch and articulation have become a favorite here at Eurotubes and with our customers. They are very tight with an extended low end over a standard EL34. The JJ EL34II’s are not as aggressive as the E34L, but they are a little fuller in the lows and low mids than the EL34’s. The JJ KT77’s have an extended frequency response with big/chunky lows (even deeper than the E34L’s) and chimey/present highs. The mids are very smooth for an EL34 type tube and when driven they’re extremely rich and complex. The JJ Big Bottle 6CA7’s have big lows (on par with the KT77’s), an emphasis in the lows mids, and very round/natural highs. This gives the tube a very thick and round character that’s as close to crossing a standard EL34 with a 6L6 as you can get.

Peavey states in the manual that you can use big bottle tubes like KT66’s, KT88’s and 6550’s. However we do not recommend KT66’s or KT88’s because the tubes will literally touch each other! 6550’s however are a go with enough clearance to run.

Note: Peavey has again shuffled the “V” numbers so we made a very descriptive tube chart so that the tube positions make sense.

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’s by default, one Balanced JJ ECC83S for the phase inverter (V4, closest to the power tubes), and five Standard JJ ECC83S’s for V1 – V2 – V3 – V5 – V6.

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 to the Standard or High Gain option. If sweet, open, and more refined is what you’re after this kit will do it. The kit includes one matched quad of JJ 6L6GC’s by default, one Balanced JJ ECC83S Gold Pin for the phase inverter (V4, closest to the power tubes), and five Standard JJ Gold Pin ECC83S’s for V1 – V2 – V3 – V5 – V6.

The High Gain Retube Kit uses our hand picked high gain selected JJ ECC83S’s. If you’re looking for maximum crunch and grind this is where you want to be. Sonically this setup is very similar to our Standard Retube Kit but with a little extra gain on tap. The kit includes one matched quad of JJ 6L6GC’s by default, one Balanced JJ ECC83S for the phase inverter (V4, closest to the power tubes), and four High Gain JJ ECC83S’s for V1 – V2 – V5 – V6.

The ECC803S V1 Option Retube Kit uses the Long Plate JJ ECC803S in the clean channel position which Peavey calls “V6”, reference our tube chart below. The JJ Long Plate ECC803S has a little lower gain with big thick mids and a little more sparkle in the highs. The kit includes one matched quad of JJ 6L6GC’s by default, one Balanced JJ ECC83S for the phase inverter (V4, closest to the power tubes), four Standard JJ ECC83S’s for V1 – V2 – V3 – V5  and one Standard JJ ECC803S for V6 (closest to input jack).

The Gold Pin ECC803S V1 Option Retube Kit uses the Long Plate Gold Pin JJ ECC803S in the clean channel position which Peavey calls “V6”, reference our tube chart below. The JJ Long Plate ECC803S has a little lower gain with big thick mids and a little more sparkle in the highs. The kit includes one matched quad of JJ 6L6GC’s by default, one Balanced Gold Pin JJ ECC83S for the phase inverter (V4, closest to the power tubes), four Standard Gold Pin JJ ECC83S’s for V1 – V2 – V3 – V5, and one Standard Gold Pin JJ ECC803S for V6 (closest to input jack).