Well I'll certainly agree with you about Groove tubes being lousy....they go straight in the round-file.renshen1957 wrote:Hi CW,CW wrote:OK, so what exactly is your point here?
Offended because of a different experience than yours? Kinda sounds like it...
Bottom line is this: my point to WB was to be careful, research it and know there are alternatives.
Thanks for the history lesson.
Was I offended? Nope. I didn't intend to strike a nerve.
WB wanted an alternative to EL34 with more headroom.
Either a KT77 or 6CA7 would have a harder vacuum and generally considered to have better headroom.
The alternative would be what the American distributor of Marshall ordered in 1972, 6550s and did this even when EL34 tubes available and still good.
I know of QC problems for a lot of tubes. These come and go. Twenty years ago other than NOS EL34, there wasn't a EL34 reliable tube available from anywhere.
Three years ago Diezel amps had rumblings of switching to 6550s, Egnater bemoaned quality issues about El34 from any manufacturer.
Forums are great and at the same time amusing. I've read people's posts complaining about the reliability about JJ power tubes and then praising the same tube as issued by Groove Tube. Google Groove Tubes sucks and see how reliable their screening process is. No, it's that tubes can and will fail.
Back when the only reliable power tube was NOS USSR military 5881 equivalents that didn't have the high failure rates of most tubes. One builder related at that time he had one 5881 failure out of a 100 tubes. These were sold as Sovtek. He stopped using Russian EL34 at that time as he experienced 75% failure rates. This was in the 1990s.
Before the price of RFT tubes went up, I used to purchase these frequently. They are great sounding tubes.
Will these give more headroom for WB?
My point with the testers was I have purchased pre-screened (supposedly burned in) tubes, tested on my stable of testers (vintage and more recent design) and still experienced tube failures. One of the reasons I burn in new amps with music signals during the infant tone period or 40-60 hours. There is nothing worse than having an amp go to a new customer and then have any issue, but especially tubes.
My experience is that most people don't expend the time or effort to leave positive comments on a product that works if it meets their expectations. These same individuals will go out of their way to complain about the same product if it doesn't. Who ever said that for every complaint there is five other complaints that were never reported must not have worked in retail.
CW, I didn't know (or for that matter had little interest to inquire) whether you sell NOS tubes or not. If you do sell tubes, I meant no offense.
Ampgarage isn't the only place I post, I have on a number of forums debated (on the pro side) for NOS stock tubes and other parts. And yes, it is good to let people know they have options. Why I mentioned the KT77.
QC issue or not JJ did take the time to re-introduce the KT77, produced a 6V6 (to handle the higher plate voltage) a 7591 (which has an issue as to whether it has the same power wattage).
The Gold Lion version maybe an excellent tube or not, I haven't had time to investigate if its a real KT77. I do have an issue with Russian tubes. Do you remember the Sovtek 7591xyz? Not a real 7591 tube just a re-pinned 6L6 variant. Not the only power tube that was re-pinned 6L6 and sold as another tube.
EH has re=issued a 7591A that does meet spec (if placed into a too tall envelope), but people have been posting about Thermal runaway for these tubes for a long time in McIntosh 1500, which NOS 7591 handle without a sweat.
As to tube failures, as I have posted before, I have purchased NOS 6SH7 JAN (you would think the tubes would have been tested before being sent to be accepted by the US Govt), and the entire lot was shorted. This isn't a slight to CEDIST, these tubes were made in the US circa 1944-47, still in their box untouched/unopened and evidently untested back six decades into US tube heyday.
I mention this again as to the importance of purchasing NOS tubes from a party that knows what they are doing.
Yes, do research, but figure since the world militaries aren't purchasing tubes in bulk any more, Solid State effectively made tubes as we know them obsolete, the market for cheap tubes just isn't there, QC isn't going to be what it ever was 1/2 a century ago.
Hopefully not another history lesson.
Best Regards,
Steve
PS I don't own stock in JJ
Yes I remember the fake 7591A...not good. I really don't think too highly of anyone "reviving" a brand name and then relabeling stuff that is not at all like the originals. Just doesn't sit right with me. But I guess it's all about the almighty buck right?
You comment about the mil tubes all being bad..yes..I can see that considering the time period they were made....definitely different contract methods/testing during war-time than the post-war era....no contest. Makes one wonder huh if those were critical and needed in the field.
I also have tested supposed factory matched pairs and quads..and they are all over the place....that's when I decided to build my own testing/burn-in rack...with all blueprinted components...so that when a pair leaves my house...it is matched!
I wish one of the manu's would go to 6550A.....I have the GE's.....but that supply is quickly diminishing and manus need good consistent sources of supply. The mil situation is this: there are still supplies in storage for those critical types, but big contracts...no. Like you say...a thing of the past. Too bad too. If Philips ECG would have had some forsight.....they could have made a huge supply of common types, stored them and made an absolute killing in the market of the last 20 years or so. But hindsight..you know?
What?...you're not a JJ Board of Directors member? Hmmm!
Just foolin!
No harm..no foul! I still think JJ's suck!!!!
CW