Liverpool Talk

[gktamps]

All the recent discussions about Liverpools had me realizing that over the years I'd been using mine less and less in favor of my various styles of Rockets. Until recently, I couldn't really pinpoint why, but it seemed like it had great distortion character, but had developed a rather thin tone that got hard to listen to after a half hour of playing. Recently, a friend came over to play through some of my amps, and after a few minutes through the Liverpool it was clear from the fizzy trailing notes that something was amiss.

After reading recent threads, I figured it was time to open it up and check it out. Put it on a 'scope, and found some less than healthy waveforms. Checked voltages. Moved the feedback wire a tiny bit and tacked down. Checked all components, including electrolytics for value and ESR. Pulled tubes and checked voltages again.

Then I decided to put the tubes on my Hickok 752 tester, not really suspecting them because they were low-mileage RFT preamp and power tubes, but guess what? PI tube was way unbalanced, with second section well below minimum specs. V1 was also mismatched and gassy. One of the power tubes was also way down, and gassy. Another power tube had initially good transconductance that dropped after a few seconds of testing.

After selecting a mix of new, matched section tube for the PI and high-testing vintage Bugle Boy and Mullard for V1 and V2 and matching up 4 nice Russian 6P14P tubes from my stash and putting the chassis back in the cabinet, it was time to play through the amp.

Well, it never sounded so good. I've been playing it as much as my time allows over the last 3 days, and the tone and response is like a different amp. Having really high-quality European tubes that sounded great in the amp when it was new and playing it infrequently fooled me into thinking the trouble couldn't be the tubes, but I should have known better. This isn't the first time NOS or good vintage tubes have tested and performed well in one of my amps, but after hours of use at full voltages, have developed problems that made them perform poorly. While it's a shame to toss the bad RFTs in the bin, the sound with the Russian tubes is really delicious - all of the best things we know about Trainwreck amps, and that lovely EL84 chime to boot.

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