One Component You Would Never Change One Type You Would Return To

@elliottbnewcombjr thanks! The tubes that ARC sent me seem to sound better than the ones that were in there but it might be too early to tell. The original set of Sovteks were in regular use (2-3 hours a day) for over 30 years and showed no signs of wear. The new ones are Genelex Gold Lions. I'm keeping the Sovteks in storage, I might never need them again but it's nice to know they are there. 

I for myself wouldnt anything at my 3 equipments. It sounds more than satisfying. But I did change 2 Pairs of speakers. Falcon LS 3/5a instead of Leema Xen2 Mikro-Monitors. Both sounds different, but each of ist very good. Other Hifi-Chain: Swans M1S Monitors (premium-crossover with Caps by Mundorf and Jantzen plus oil-soaked Coil for Magnetostatic tweeter instead of Neumann KH 120A (I dont sell it too). First changes since 13 years. 

What I wouldnt change ever: Croft Integrated Phono (Phonosection with two Valves ECC 83, Line Stage with ECC 82), McIntosh MHA 150A Line and Headphone-Pre, Denon DP 3000 NE and Technics SL 1210 GR, two Denon DL 103 Standard, Ortofon SPU Stereo and Mono, Koetsu Rosewood Standard, Miyajima Zero Mono and Miyajima Kotetu Mono, Daniel Weiss Dac 204/I, Reclockers Mutec MC3+ USB,  Streaming Bridge Lumin U1 Mini, LPS Ferrum Hypsos (for Weiss DAC), Nagra Melody Phono with APCS LPSU, Speaker Cables by Tellurium (Black II and SilverQ), RCA-Cables by Kondo, TonstudiotechniK Funk (Berlin), Acoustic Revive, Tellurium Black, Neotech NA 1266, Powerdistributors by Nordost (QBase 4/III) and two Vibex ONE, Vibex Powerblock Rhodium, Speaker Stands MusicTools ONE (for LS 3/5) and Dynaudio Stand 4.

Every time I suggest a basic tester, good/bad/strength/shorts

here comes 'it's got to be mutual ....'

the cheapest Hickok on hifishark is $599. 

https://www.ebay.com/itm/127803106846?mkrid=711-53200-19255-0&campid=5338381866&toolid=10001&customid=f5e93a84-35b1-11f1-b59e-303461663738

I suspect MOST people will NOT spend that (or more)

I had a big Hickock, my little Accurate 157 always found the same as the Hickock, I gave it away! I like my small portable, primarily to rule out bad or weak tubes or shorts when something goes wrong, for myself and friends, just to have the confidence the problem is more than likely not the tubes. And, to test the new ones I buy before I put them in place.

Without a basic tester, you keep yourself BLIND.

......................................

here's an accurate 151, working, $95. bucks, delivered

https://www.ebay.com/itm/377064722132?mkrid=711-53200-19255-0&campid=5338381866&toolid=10001&customid=553c8486-35b3-11f1-aed2-646530326337

I've had the one my wife got me since 1983

For years people gave me used tubes, pulled from units being discarded, I have a heck of a lot of them, and most test good, they are great to use to keep listening while researching, picking, buying, waiting for a matched pair from someone other than Brent Jesse because sadly he closed.

I think the guys who pay ca thousands for a Hickok 539C or the like are essentially guys who collect tube testers per se. You can certainly get a competent Hickok that measures transconductance for less than $500. Just recognize their limitations especially for testing power tubes, or step up and pay thousands for a modern digitized tester.