The proof is the etched code as Kay Piranha said.
Like light bulbs also tubes were made by several for several. No news here. A usual some labels are more popular because of emotions/audio blah blah but the tubes can be 100% equal. Thankfully the labels wear off easily 🙂
Like light bulbs also tubes were made by several for several. No news here. A usual some labels are more popular because of emotions/audio blah blah but the tubes can be 100% equal. Thankfully the labels wear off easily 🙂
Tubes were a commodity. Some brands were better, but they would sound the same unless the plate curves differed. I sold tubes when they were new, current manufacture. Believe me, there were junk tubes available!
Some brands were better for noise or microphonics. The better the brand, the more consistent their tubes were from sample to sample. Yes, factories sold to each other.
Some brands were better for noise or microphonics. The better the brand, the more consistent their tubes were from sample to sample. Yes, factories sold to each other.
Brands at the time were intermixed: they re-labelled, they co-produced, they competed, etc. - there was everything.
Most miniature valves and octal valves we still have in production today were in continuous, large-scale production for nearly four decades: from the forties up until the seventies. Over such a long timespan, all kinds of things changed: processes, profit margins, market demand, taxes, tariffs, materials' availability, people (remember these were handmade, not made by robots).
When buying a NOS valve today, you have no way of knowing what you're getting unless you're a valve connoisseur or have quite expensive test equipment (even a basic valve tester is far from cheap and most are quite beat up).
Most miniature valves and octal valves we still have in production today were in continuous, large-scale production for nearly four decades: from the forties up until the seventies. Over such a long timespan, all kinds of things changed: processes, profit margins, market demand, taxes, tariffs, materials' availability, people (remember these were handmade, not made by robots).
When buying a NOS valve today, you have no way of knowing what you're getting unless you're a valve connoisseur or have quite expensive test equipment (even a basic valve tester is far from cheap and most are quite beat up).
I have zero experience with Chinese valves - although I do own a pair of 845s that I have never used.
I do regret not having sought to get a few of the Sovtek and Sveltana 12AX7s and their variants back when they were still produced (and a few other valves of these two brands).
But why would one buy new production Chinese small signal valves when there are still so many available from the good ol' days? I mean, I understand getting a Chinese 2A3 or a 300B etc. but anything else, why?
Right now I really like what comes out of the Reflector factory. Very, very consistent and generally reliable. I'll gladly take going market for my NOS tubes and replace them with Electroharmonix or similar.
I think the situation now is ten times more confusing than it was back then - and there are less than a handful of factories in operation.
I was always under the impression that Electroharmonix sold re-branded Chinese valves. I was wrong: checking their website reveals they were always marketing Russian valves. In fact they now own both Svetlana and Sovtek brands. I'm still not sure where the Svetlana valves are made and where the Sovtek valves are. I thought one of the ex-soviet factories closed down.
Anyway, checking out the prices of Sovteks and Svetlanas, on the Electroharmonix webpage, it's crazy: prices are five times what they were two decades ago.
I was always under the impression that Electroharmonix sold re-branded Chinese valves. I was wrong: checking their website reveals they were always marketing Russian valves. In fact they now own both Svetlana and Sovtek brands. I'm still not sure where the Svetlana valves are made and where the Sovtek valves are. I thought one of the ex-soviet factories closed down.
Anyway, checking out the prices of Sovteks and Svetlanas, on the Electroharmonix webpage, it's crazy: prices are five times what they were two decades ago.
Sovtek were rebranded Russian tube types. Excellent quality but not identical to US markings.
Electroharmonix and the other Reflector brands are reverse engineered from top US brands, like RCA for example. Those are exactly what they are marked as. Mike marketed to musicians first, and his tubes had to be tough. They really are. Remembering failure rates of GE, RCA, Westinghouse and others, New Sensor tubes are more consistent, and more reliable than ever. That's what I use, and I have NIB tubes I can use instead, but I don't.
Electroharmonix and the other Reflector brands are reverse engineered from top US brands, like RCA for example. Those are exactly what they are marked as. Mike marketed to musicians first, and his tubes had to be tough. They really are. Remembering failure rates of GE, RCA, Westinghouse and others, New Sensor tubes are more consistent, and more reliable than ever. That's what I use, and I have NIB tubes I can use instead, but I don't.
After your post I had, naturally, a long and deep discussion with Microsoft Co-pilot - a very courteous fella indeed.
I'm back to my initial assumption: you still need an accurate, calibrated instrument to know what you're getting - and a good pair of eyes.
Back on the search for the holy grail: according to Co-pilot the last Tek 570 sold on ebay on August 11th, 2023 for a measly $1,500. Ouch!
But, for the rest of us down on earth, a multimeter and some common sense should suffice.. and a certain healthy amount of tolerance for the odd duds and misrepresented items.
Yes, correct. I use a Stark 9-66 and have a spare unit. I can rig up the Tek 577 to run curves, would rather not.
I would say, use a tube tester to match transconductance. Use your meter and mind to make sure circuit conditions make sense. Use your THD meter or audio analyser to confirm proper operation.
As for misrepresented items ... buy new from authorized distribution if you can't test things yourself. Buy outputs in matched sets. Any dollar wasted is a dollar wasted, avoid doing that.
I would say, use a tube tester to match transconductance. Use your meter and mind to make sure circuit conditions make sense. Use your THD meter or audio analyser to confirm proper operation.
As for misrepresented items ... buy new from authorized distribution if you can't test things yourself. Buy outputs in matched sets. Any dollar wasted is a dollar wasted, avoid doing that.
Fist time I've heard about this tester. Looks nice and more than adequate. The 577 is a scary beast.
The other thing is one must check the valves and test them immediately upon arrival rather than put them on the shelf and .... forget about them.
Ideally, record keeping of the measurements, dates, origin, price etc. will help avoid needless pain in the future. I wish I had done that... rather than preach about it.
Hi stelios,
Yes, the 9-66 is a Hickok made under license. They didn't sell Hickok here, the Canadian armed forces used these testers. That is where I got mine.
I've dealt with New Sensor since the 80's when Mike Mathews contacted me. Excellent product, very few failures but they do happen. I'd say the same for any new parts, especially active devices. Problem is, I get so many I don't have time to test each one. It takes too much time simply checking the order off! THat's why I only buy from good vendors, I can't afford to worry about it. If I get the odd failure, it's cheaper than testing everything.
Yes, the 9-66 is a Hickok made under license. They didn't sell Hickok here, the Canadian armed forces used these testers. That is where I got mine.
I've dealt with New Sensor since the 80's when Mike Mathews contacted me. Excellent product, very few failures but they do happen. I'd say the same for any new parts, especially active devices. Problem is, I get so many I don't have time to test each one. It takes too much time simply checking the order off! THat's why I only buy from good vendors, I can't afford to worry about it. If I get the odd failure, it's cheaper than testing everything.
Thanks Anatech
I wish there was a tube tester equivalents table somewhere as there seem to be at least 2-3 names for the most well known models. Well, I guess that's what they invented the Co-pilot for...
I now have a stockpile of used and NOS valves mixed together. I know most of my valves are NOS but then I got the odd mixed lot where I was really after one or two valves and the rest were just thrown in. So, you don't want to be in this place... Essentially it means you might have to look for that rare valve you thought you already had. The very least one should keep is a sheet with dates of purchase, quantity, vendor and price paid.
I wish there was a tube tester equivalents table somewhere as there seem to be at least 2-3 names for the most well known models. Well, I guess that's what they invented the Co-pilot for...
I now have a stockpile of used and NOS valves mixed together. I know most of my valves are NOS but then I got the odd mixed lot where I was really after one or two valves and the rest were just thrown in. So, you don't want to be in this place... Essentially it means you might have to look for that rare valve you thought you already had. The very least one should keep is a sheet with dates of purchase, quantity, vendor and price paid.
lol!
I know what you mean about the collection of tubes. I'm in the same boat. I am ruthless, if it doesn't test good, out it goes. I can't afford holding onto "sorta good" tubes. Testing takes too long, so if the first half of a dual is iffy - bye! For a repair, I use only new or an old new-in-box that I test first (new and old). For me, it's the same except I'll use a tuner tube that tests very good.
I do not re-use capacitors or resistors. This makes no sense at all.
The best list is to look at the Hickok models. I found the equivalent to the 9-66 tester (I have it listed somewhere). You need "Dynamic Transconductance". Emission testers are not really useful except with rectifiers. I also have a TV-2/u I have to rebuild. Cool instrument. Heavy.
Anyway, we should get back on topic here ...
I know what you mean about the collection of tubes. I'm in the same boat. I am ruthless, if it doesn't test good, out it goes. I can't afford holding onto "sorta good" tubes. Testing takes too long, so if the first half of a dual is iffy - bye! For a repair, I use only new or an old new-in-box that I test first (new and old). For me, it's the same except I'll use a tuner tube that tests very good.
I do not re-use capacitors or resistors. This makes no sense at all.
The best list is to look at the Hickok models. I found the equivalent to the 9-66 tester (I have it listed somewhere). You need "Dynamic Transconductance". Emission testers are not really useful except with rectifiers. I also have a TV-2/u I have to rebuild. Cool instrument. Heavy.
Anyway, we should get back on topic here ...
If you already have a TV-2, you can afford to have any other tester you like as a spare (as long as you can understand the inscriptions/markings on it)!
lol!
I do understand it. But it needs rebuild, and I already own it - that means I'm poor now!
It comes down to fast, accurate testing. Time is money, doubt is time. I think one of the new computer controlled ones would be better. Almost instant setup, accurate answers.
I do understand it. But it needs rebuild, and I already own it - that means I'm poor now!
It comes down to fast, accurate testing. Time is money, doubt is time. I think one of the new computer controlled ones would be better. Almost instant setup, accurate answers.
Talking about curve tracers that do run the tubes up to operating temperatures. Pulse testing is for power semis without heat sinks. Like a normal tube tester does.