bias adjust

  1. kipper15

    Bias pot on a Fender Super Champ X2

    I'm looking to get one of these amps. Can someone confirm if the bias pot can be accessed from underneath the chassis, without the need to remove it? Now I don't intend to replace/upgrade the power tubes on day one! But it will be useful to know all the same...
  2. 8len8

    Bias Help - Fender Custom Deluxe Reverb?

    I've get a Fender Custom Deluxe Reverb that I've biasing up. Something doesn't seem right, so point out what I'm doing wrong. It has GT 6V6-S tubes in it. The plate voltage measures 407 V. It's fixed bias. When I try to adjust the bias the pot tops out at about 23 mA. I've read where...
  3. Mark Douglass

    Blackstar Artist 15 - Power Tube Replacement Help

    Hello, I've got a 6-year old Blackstar Artist 15 combo amp that has developed a nasty case of popping the HT Fuse shortly after power up. At first, I thought it was just the fuse but after buying a pack of 10 and seeing them blow (and after some reading), I realize that I probably have a messed...
  4. kipper15

    Fender '68 Custom Princeton Reverb questions

    Last year I started to consider replacing my Fender Hot Rod Deluxe with a better amp and was considering the '65 PRRI as per the thread I started here: For numerous reasons, I had to delay...
  5. gerrickreidenbach

    Is any 50k pot usable for permanent bias adjustment?

    I have a Silvertone 1484 arriving next week and the mods for this amp presented in GW's book All About Vacuum Tube Guitar Amplifiers caught my eye. He recommends using a cermet pot for the bias adjustment mod but will any pot work?
  6. Emopunk

    Blackstar HT Venue MkII - any tube biasing esperience yet?

    Good evening to all of you. I read that some of you own some HT Venue MkII amps like I do (in my case, it's a 50w head). I just wonder if any of you had some attempt at biasing these new amps. Do they have trim pots on the PCB like the previous generation did? Any help will be highly...
  7. USGMP

    Help with Bias! Used DCV instead of DCA and something blew

    I got a bias probe, hooked it up, flipped it on. POP. Tiny amount of smoke. No sound. Guessing it is because I was hasty and had it on DCV instead of DCA (which EuroTubes has NOT VOLTS in all caps... moron...) Anyone know what was most likely to blow in this scenario before i just start...
  8. R

    Allen Accomplice - what the $@#$ is this clear slotted knob?

    Does anyone know what the clear plastic knob is, and what I may have done by turning it? I was re-biasing for the first time and I stupidly thought the clear slotted knob was the bias adjust knob, so I turned it a lot. I tried to return it back to it's original position, but I have no idea...
  9. J

    Need Help Re-Biasing Suhr SL-67

    My SL-67 started popping HT fuses a while back. Thought it was the power tubes, replaced them, still kept popping fuses. I contacted Suhr and was told to check the bias of the new tubes. To find the proper terminal from which to get a reading I was told the following: "Using a multimeter, you...
  10. brennanmcnally

    '64 Super Reverb — Rebias even for same make of tube?

    So I bought a blackface Super Reverb on Reverb, and it arrived with one smashed power tube (tubes boxed separately... but not particularly well-packed). According to the seller, the amp was re-capped and retubed professionally fairly recently. I ordered a matched pair of the exact same kind of...
  11. C

    Retubing & rebiasing my DRRI - Question about the "Hand in pocket" rule

    I understand its value in that it prevents me from sending 500VAC straight across my chest. But does it not apply when I'm pulling or inserting power tubes? With the metal clamps, I don't seem to see a way to do it with just one hand. Am I safe in assuming that since the amp will be off and...
  12. Jonah Samuel

    Mesa Boogie Subway Blues Bias Adjustment / De-Doping / De-Gooping

    Hi guys! While doing a basic setup on a customer's Subway Blues, I noticed the damn thing is ramping up the tubes to a whopping 120% MPD, and the bias supply circuit seems to be encased in one of these Mesa's notorious epoxy sarcophaguses. Has anyone successfully de-gooped one of these...
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