I was planning to go that route, but after I picked up a mortgage I couldn't swing the cost anymore. I think it would be a glorious pairing with my 1101 audio amp. That, and something else happened (long story) to dissuade me from making further investments in any of my audio gear recently...

I'm quite certain that some sellers, eBay or otherwise, keep tabs on threads like this. If people are talking up a tube as a must-have the eBay prices will magically double and/or there will suddenly be more listings for that type of tube. Or how a certain seller located in India with a...

I bought a pair of KR KT150 tubes from an authorized distributor and one of the tubes suffered heater failure the 2nd time it was ever turned on. Both tubes had obvious quality issues, in the one whose heater failed the filament had fallen below the slot in the mica that was meant to hold it in...

I would expect this tube to sound and perform almost exactly the same as the older coke bottle VT-94A Tung-Sol. If you can get your hands on them for a reasonable price they are definitely a good buy.

In this case there is no difference. VT-94 is the military part number for a 6J5. Some mil-spec tubes do have construction differences, often extra support rods or different mica structure intended to make the tube more rugged and resistant to vibration based microphonics. The Raytheon 6J5WGT...

I think the first year for 6J5 was '37 or '38. I honestly think when it comes to KT66 one can grab a pair of new production Gold Lions and they're missing out on very little. I'm usually not very impressed by new production tubes but these get it right, and the build quality is outstanding...

What you're describing is pretty much what the older Raytheon 6J5 tubes sound like to my ears. Particularly the old 6J5G versions, but the WGT metal base with the brown bottom caps also sound this way, just a bit different flavor of it. I have yet to hear a pre-WWII Raytheon tube of any type...

@reg66 If you're trying to get warmer than the Brimar then a Raytheon 6J5WGT brown base would be a good bet. Or it's older cousin the VR67 version. The Ken-Rad made 6J5G are also quite warm though ones that are truly made by Ken-Rad and not just a re-label with their name on it are hard to...

My own amp gets hot enough that it triggers the hot-stove touch reflex if I put my hand on the top plate after it's been on a while, I can only imagine how much heat your PSU would be generating in that config. The fans are definitely a nice addition. I actually think more tube amps ought to...

This Tung-Sol branded 3DG4 has been in almost continuous operation in the amp since about 2012. I only really rolled rectifiers during the first year then decided to keep the 3DG4 as a known quantity and stick to rolling the other tubes. Especially in recent years the amp is on 8 hours a day...

In Japan you can still go to University, in the year 2024, to get a degree in COBOL programming. There is actually high demand for it there to keep those old financial systems going.

This is an interesting topic. I've often wondered how much right or left side dominance can affect senses like our hearing. I recently noticed that I've apparently lost all of my leading eye dominance. When I was younger I had a clear right eye dominance when doing the "pointer" test. Now I...

I'm sure we succumb to expectation bias in tube rolling like anything else. I threw my "worst" 6J5 into my amp a while back without thinking about it much while I already had my "worst" power tubes in there. Not even sure why, I didn't have an intent, I just did it at random. One night while...

That round top mica with no teeth is a bit tough to place. Doesn't match up with the known styles a lot of the brands use. Could be RCA, could be a variant of Japanese production. Could be eastern European import. I think the plate is consistent with RCA tubes of the era, but not the rest of...

I would suspect they are Japanese made Hitachi based on the physical construction. Given Tung-Sol's manufacturing history I would be surprised if they were still making their own 6J5s by this point in time, it's more likely they were re-branding.

This sounds almost exactly like the snapping sound of an electric starter on a grill. I'm pretty sure it's a short but was curious what other people thought too. The soldering on the pins on these always looked really iffy to me too. A shame since I think these tubes sound really good but the...

Recently one of my Sophia EL34ST tubes has begun producing a snapping sound just as it comes on bias. About like snapping your fingers but faster and higher pitch. Do you think this is a cathode short developing? It's grown in intensity the last 3 power cycles as well so whatever it is it is...

Thanks for mentioning the matte black embossed tops on the Lorenz. It's important to look for the matte ones if a person is looking for the more mellow sound. I had forgotten to mention that detail.

The tonal difference between a Siemens and a Lorenz C3g tube is pretty substantial. For those worried about brightness, if you start with Siemens and find things are little too bright up top there's a good chance the Lorenz version could cure that for you. That said the Siemens being bright is...

You definitely need grid stoppers to use 6AV5 family tubes in a triode application without oscillation issues. It should be possible to implement adapters for them that way. I remember reading once along time ago that at the very end of 6B4G production they were actually just substituting 6AV5...

If it had been a quality GE tube it never would have rusted in the first place..... Bill needs to stop hoarding all those good GE tubes. ;)

I personally wouldn't operate a tube that has rust on the internal plate. There has to be oxygen for there to be rust and oxygen inside the glass envelope means the tube isn't safe to operate. Even if it happened when the tube was originally made and not due to air sneaking in over the years...

I'm leaning towards the isolation transformer route right now, but like everything in audio there are cheeleaders and booers for every type of passive and active filtering so it's hard to know what will be effective.

As the great Bob Ross would say: "We don't make mistakes, we just have happy accidents." :)

Nice to see people enjoying their gear. I'm taking a forced break from mine at the moment. A new house was built next to me and the electricians did something to the distro box that feeds my place and ever since then every piece of audio equipment I own sounds terrible now. I'm currently...