In Reply to: Sure sounds like a bad power tube to me. posted by Ralph on July 21, 2014 at 09:00:10:
Hi Ralph,
This is an MA-1 Deluxe with 12 tubes but was brought up to 3.1 spec by you a few years ago. It has two very big power transformers and has the large blue oil caps situated between. It may well be a bad tube as I could not leave well enough alone and replaced the "old" tubes on one amp with a bunch of NOS tubes I picked up and decided to try out to see the difference between the amps was noticeable. It wasn't. I then decided to keep playing the new tubes amd only noticed a problem when I tried,some days later to turn the amp on and the third LED,did not light. I conditioned the tubes for three days and all tubes were tested before insertion but who knows. I can try retesting the tubes but will certainly try what you recommend and see if it is the power supply. If a tube went bad during burn in will it show on the tester or is there a different criteria to see if a tube is likely to take out a fuse? The wires to the tube bases seemed intact but I'll have to check again. I suppose the new Chinese tubes are better than RCAs finest.
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- RE: Sure sounds like a bad power tube to me. - ChasLieb 19:05:48 07/21/14 (2)
- RE: Sure sounds like a bad power tube to me. - Ralph 08:29:02 07/22/14 (1)
- RE: Sure sounds like a bad power tube to me. - ChasLieb 17:01:05 07/25/14 (0)