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On Tue, Dec 29, 2020 at 09:02 PM, Jeff Dutky wrote:

audio-nuts

Well... there you go... I'm glad you said it. And, that's why there really is no coherent answer to why people believe some old tubes, from an old oscilloscope, are going to make lots of money for them on Ebay.
Because of the non-sense... everybody loses.

On Wed, Dec 30, 2020 at 10:22 AM, snapdiode wrote:

eBay doesn't bill for ads

Ebay doesn't charge an "insertion fee" anymore?

On Tue, Dec 29, 2020 at 09:50 PM, Bill Perkins wrote:

Good, clean data on the 5687/6900 is available here

Posting a link to tube datasheets ... together with links to tube sellers who freeze tubes... that won't cause me to conflate scientific evidence with anecdotal evidence... or believe without any scientific evidence whatsoever... that freezing vacuum tubes makes them sound better.
If we take the tubes out of our 500s (sans the CRT) and cryogenically treat them... will the signals displayed on the 500 screens look better?

Good, clean data on the 5687/6900 is available here

Posting a link to tube datasheets ... together with links to tube sellers who freeze tubes... that won't cause me to conflate scientific evidence with anecdotal evidence... or believe without any scientific evidence whatsoever... that freezing vacuum tubes makes them sound better.
If we take the tubes out of our 500s (sans the CRT) and cryogenically treat them... will the signals displayed on the 500 screens look better?

Probably not, how good are your eyes :-)

The -point- of my post was to provide complete data on the 6900/5687. The data was referenced to give a sense for the likelihood of finding good NOS 5687s.

Period.

Clear ?

Bill

For pipsqueaks like me, it appears not. Apparently I get 200 free listings a month. So I've never seen that fee. But they for sure take a bite out of the final value that would make a loan shark blush.

For pipsqueaks like me, it appears not. Apparently I get 200 free listings a month. So I've never seen that fee. But they for sure take a bite out of the final value that would make a loan shark blush.

I LOVE the bit where they hit the quoted -shipping cost- as part of the Final Value Fee. That is theft, end of discussion.

Vinnie the Vig don't blush . . . :-)

Bill

eBay changed their policy in response to the 1$ items with 200$ shipping fees. I remember that from about ten years ago.

On Thu, Dec 31, 2020 at 07:43 AM, snapdiode wrote:

eBay changed their policy in response to the 1$ items with 200$ shipping fees.

Yes, and. E-Bay's own policies drive prices up and heavily influence the direction of the sellers; who inevitably get very creative to maintain their desired profit margin. Make a rule and there will always be those who find a way around it.

--
Michael Lynch
Dardanelle, AR

On 12/31/2020 02:10 AM, Bill Perkins wrote:

For pipsqueaks like me, it appears not. Apparently I get 200 free
listings a month. So I've never seen that fee. But they for sure take
a bite out of the final value that would make a loan shark blush.

I LOVE the bit where they hit the quoted -shipping cost- as part of
the Final Value Fee. That is theft, end of discussion.

Vinnie the Vig don't blush . . . :-)

Bill

That was done because people were selling things for $1 and $75 shipping to get around the FVF. While it's not much, I object to them charging tax then getting their FVF off of the price with the tax included.

Vince.
--
K8ZW

audio-nuts

No, "Audio Dumfuks" is more accurate.

Well... there you go... I'm glad you said it. And, that's why there really is no coherent answer to why people believe some old tubes, from an old oscilloscope, are going to make lots of money for them on Ebay.
Because of the non-sense... everybody loses.

I'm seldom one to directly contradict but occasionally needs must. Follow -this- thru to see what some pikers get for USED tubes, no guarantee, no returns.

==============

The guy below -- hanoitubes on eBay -- just tried to set himself as a dealer for my decades-running line of tube coolers.

First he wanted 500pcs of the 9-pin coolers so I gave him the 1,000+ pricing. Then, no, he only wanted 100pcs, buy more later, and what would be shipping to his CA point.

All-up the deal was $US500.00, with $US50.00 for shipping and the PayPal fees.

"Well, no," he said, "I think $US450 is fair". I said, "The price is the price, period; and STOP grinding for the last dollar."

Then I went looking to see who he actually -is-; here's a link to his recent sales on eBay:



Dig the $US499.00 sale for a pair USED Mullard 12AU7/ECC82s.

From the eBay description:

"You are bidding for One pair Mullard 12AU7/ECC82 Square getter Welded Plate, B4 code (1954), Used and are tested good on my TV-7D/U (about 74%and 78%), quite matched and sound wonderful in my hifi system. I cannot guarantee how they sound in your system or different values on other tube testers. What you see is what you get. Sold as is. Return is not accepted."

Here are the rest of his >450 listings, sorted highest price first:



read -that- shit and weep.

And he wanted to grind me for $US50.00 shipping and PayPal
fees . . . pfff.

Bill @ PEARL, Inc.

On Thu, Dec 31, 2020 at 04:06 PM, Bill Perkins wrote:

And he wanted to grind me for $US50.00 shipping and PayPal
fees . . . pfff.

Don't you just love these guys? unbelievable!

--
Michael Lynch
Dardanelle, AR

I wonder how all of these vastly different tubes are all used in and every one "sounds wonderful" in his high-fi system? I don't know much about tubes, but I would think that each different tube would require careful tuning for each of the important characteristics of the circuit to get the best performance? Kind of like re calibrating a scope after major components are replaced?

--
Michael Lynch
Dardanelle, AR

On Thu, Dec 31, 2020 at 12:19 AM Roy Thistle <roy.thistle@...>
wrote:

On Tue, Dec 29, 2020 at 09:50 PM, Bill Perkins wrote:

Good, clean data on the 5687/6900 is available here

Posting a link to tube datasheets ... together with links to tube sellers
who freeze tubes... that won't cause me to conflate scientific evidence
with anecdotal evidence... or believe without any scientific evidence
whatsoever... that freezing vacuum tubes makes them sound better.
If we take the tubes out of our 500s (sans the CRT) and cryogenically
treat them... will the signals displayed on the 500 screens look better?

I tried cryogenically treating the tubes in a 561A

Now all my sine waves look like so...


I'm not sure if I want to calibrate it back out.....

:-)

I wonder how all of these vastly different tubes are all used in and every one "sounds wonderful" in his high-fi system? I don't know much about tubes, but I would think that each different tube would require careful tuning for each of the important characteristics of the circuit to get the best performance? Kind of like re calibrating a scope after major components are replaced?
-- Michael Lynch Dardanelle, AR

In my view, the guy is a skank livin' large in audiophool La-La Land. Not that there aren't differences amoung tubes and not that some aren't demonstrably better than others but $US500.00 for a used, half-assedly 'tested' pair of unwarranted parts is daylight robbery.

As to "tuning": audio circuitry is generally pretty simple and one or another variant of, say, a garden variety 12AX7 will meet spec perfectly well.

That said, there are vast unit-to-unit differences amoung devices in respect of equiv input noise (often times an about 10 to 20dB range), microphony, heater to cathode leakage, grid current and vacuum quality in NOS parts.

As well the thru-glass pins on 7- and 9-pin parts have a default hard oxide that messes up contact quality and sounds like hell. If w/o incurring righteous opprobrium I might dare link to a page on my site, you can see the difference between raw and my electropolished pins near the bottom of this page:



In case anyone is interested: tubes range in equiv input noise between about 2 and 20nV/rtHz, numbers never spec'd back in the day.

The top section of this page provides a wealth of information:



Bill

I tried cryogenically treating the tubes in a 561A

You sure that wasn't a 570 Characteristic Curve Tracer

Now all my sine waves look like so...

I'm not sure if I want to calibrate it back out.....

Dude, I'm thinkin' it's seriously -in- cal' ....

:-)

Bill

My 561 has a bad HV XFMR, will cryo tubes and special audio cables fix that?

My 561 has a bad HV XFMR, will cryo tubes and special audio cables fix that?

Probably not. Posting for a friend. :-)

HAPPY NEW YEAR to everyone

Bill

No but it will sound fantastic, especially when you use oxygen free Tektronix Gold Plated Probes...

Harvey