C2300 Tube Test Day

[jdandy]

Originally Posted by miner

Dan,
Was this tube testing in preparation for your new amps?

Kevin......Yes and no. By that I mean yes, I knew the new amps were on the way and I wanted to ensure the C2300 performance wasn't being held back by weak tubes. The no part of the answer is I normally have an annual schedule for preventative maintenance that I usually perform each year in June. I was lax this year and let June, July, and August slid by without doing my due diligence. This has been a tough year for me. Here it is September already, so the arrival of the MC75's triggered me to get in gear.

When I perform my annual tube testing I keep records of each tube's numbers, i.e. transconductance, gain, and in the case of the small tubes, noise. That way when next year's tests are done I can refer back to the previous year's numbers for reference. I also test and record the information on all new tubes purchased, again as a reference point for testing annually once new tubes are put in service. I also test new tubes to ensure that when I pay for matched tubes they actually are matched. I have found a couple instances where one out of four matched tubes was way off the mark. I buy from reputable tube venders so getting a replacement happens without an issue. Like everything else, some things require specialized tools. Owning tube preamplifiers and tube power amplifiers practically demands that a tube tester be available.