2009年7月10日 · The sudden change in bias indicates something's wrong. Try to find out where the glow is coming from exactly. See if you can look inside the tube, through the round holes in …

JJ KT88 tubes glowing bright yellow. Not open for further replies. I bought a matched pair of JJ KT88 tubes to use in my SET amp. It has no bias adjustment. I was using a matched pair of …

2015年3月25日 · It's heater glow. If you don't have a tube tester can you get a 6.3 volt supply, a octal relay socket and some kind of ammeter? Check it for current pull and check the others to …

2011年5月26日 · There is no 'lightning', just a blue glow at the very top of the KT88. No sound issues, no popping or any other anomalies. No volume drop. Help! Fitzgig tempts me in from …

2022年9月2日 · Another possibility to consider is that the 12AX7 driver tube for the channel affected (V4 or V7) failed with a heater cathode short. It can and does happen. When it does, it …

2022年10月13日 · Check the coupling cap on that channel for leakage at the grid of the output tube, check the grid resistor on that output tube and make sure it isn't open. I'd also check the …

2025年1月19日 · He also has a picture at beginning that shows some tubes with different heater filament glow levels (I tried to post a picture were the failed tube spot V6 glows brighter than …

2021年3月24日 · The KT88 tube base width is slightly wider than the 6550. Sound wise, the 6550s have that true Ampeg "punch in the gut feel" and the KT88 sound is less in your face. If …

2019年1月7日 · I've been really busy but have wanted to build the Kegger se kt88 for awhile now and after seeing blueglows youtube videos I'm sold. I enjoy my 5 watt se builds but have a …

A sudden sharp crack lasting only a second at start up or shut down may be one of the large power output tubes (EL34, KT88, etc). This is more serious than a noisy small signal tube. If …