It is currently Mon Mar 16, 2020 4:13 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 19 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next
Author Message
Post subject: Tube testing question
Posted: Mon Feb 13, 2017 10:55 pm
Offline
Aspiring Musician
Aspiring Musician

Joined: Fri Jun 20, 2014 2:07 pm
Posts: 303
Hi guys.

I am wondering about tube testers used by those who sell/resell NOS tubes.
Can the tester tell if the tube is microphonic?
And, can it tell if the tube will be scratchy when installed into a V1 or V2 position?

I ask because I spent a pretty penny to try out a pair of Yugoslav Ei 12a7 tubes, both are microphonic, one of them extremely.
I also got a pair of Raytheon 12ax7 and one of them is nice and quiet in V1 or V2 when adjusting the volume on either channel, and the other is scratchy in either channel.
I have a few pre tubes that do the same thing and I don't use them because of that.

BTW, the amp is a 68 CDR. I also have a 68 CVR, but I haven't tried any of the new tubes in that amp.

With those 4 tubes I also picked up an NOS 12at7 Mullard for the PI and that one works nicely.
Total cost was about $140, and out of 5 tubes only 2 are usable, and I hate wasting money on useless things that don't work.

I just want to know if a seller who claims to test these tubes before selling at these high prices can or SHOULD know if they very microphonic, and if the tube will create a scratchy volume control when in V1 or V2?

Thanks for your knowledge and help. :)


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Tube testing question
Posted: Mon Feb 13, 2017 11:44 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Buying NOS has become much more of a crap shoot, the last 5-10 years. There is no way to tell if a tube is noisy and/or microphonic without putting it into a working amp. Tube testers do not test for this.

I have several sellers that I trust, when it comes to NOS. There are a couple I like on EBay. Most others I avoid, unless it's a great deal. Worth the risk.

BTW... try the new issued Gold Lion tubes. I've used the 12AX7/B759 and the 12AT7/B739. Both are good tubes, that have much of the NOS RCA tone.

https://www.amazon.com/Genalex-Gold-Lio ... lion+12ax7

For the reverb driver, 12AT7, I like to use mil spec Sylvania 12AT7WA or WC. These are tough tubes that don't get noisy. Even in positions, like the driver, where the tube is driven hard.

http://tctubes.com/Sylvania-12AT7WA-triple-mica.aspx


Top
Profile
Post subject: Re: Tube testing question
Posted: Tue Feb 14, 2017 3:20 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
BMW2002Ti wrote:
Buying NOS has become much more of a crap shoot, the last 5-10 years. There is no way to tell if a tube is noisy and/or microphonic without putting it into a working amp. Tube testers do not test for this.


+1

The only method for determining if a bottle is microphonic is to install it then perform the "chopstick test". If light tapping against the glass envelope with a plastic chopstick, wooden popsicle stick, or other dielectric wand produces any audible noise at the speaker then the tube is likely not suitable for any audio applications. An exception for use would be a noisy-but-otherwise-good-testing 12AX7 which may be used in the V5 socket (tremolo oscillator) -- sometimes they're fine, sometimes not. Long-plate dual-triodes are the most susceptible to becoming microphonic and should be avoided.

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Tube testing question
Posted: Tue Feb 14, 2017 6:44 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
Rverb wrote:
Hi guys.

I am wondering about tube testers used by those who sell/resell NOS tubes.
Can the tester tell if the tube is microphonic? NO

And, can it tell if the tube will be scratchy when installed into a V1 or V2 position? NO


Tube tester just said if tube work, ( like a car in idle ) if tube is short or not.

Tubes tester can't tell you if tube work well ( like car test drive on highway)
Can't tell if it noisy or microphonic.

Experience when using tube tester may help to know more about tube under test.

Best (only ) test is to put a know good tube.


Top
Profile
Post subject: Re: Tube testing question
Posted: Wed Feb 15, 2017 4:38 pm
Offline
Aspiring Musician
Aspiring Musician

Joined: Fri Jun 20, 2014 2:07 pm
Posts: 303
Gentlemen, thank you all for your collective wisdom and advice.

The guy I bought the tubes from, on Ebay, seems very nice and genuinely wants to help out.
He is sending me new Ei tubes to try out. He doesn't have anymore of the Raytheon tubes so he offered an NOS RCA. He is being honest in that he apologizes that he can't guarantee about noise or ringing and such.
So I appreciate that, and he is paying return shipping and shipping to send the new tubes.
I respect people who want to do right even if the product is faulty.

I decided to send questions to about e Ebay tube sellers to ask if they actually test their tubes not just in machines but in actual amps. One straight up said he does not, and if it's test as new on his machine, then it's "new" in his opinion. Another, who claims to be an amp designer builder for over 35 years didn't answer my question about whether he tests his VERY expensive tubes in amps, but instead told me that my scratchy vol pot is dirty and needs cleaning, or the tube socket needs cleaning.
I respect those suggestions as he COULD be right.
However, I explained that the vol pots were quiet with the tubes that were in them, and when I installed the new tubes one of them became scratchy, and that I swapped that tube between V1 and V2 and depending on which position it was in that vol pot became scratchy.

I've experienced this before and posted about it on this forum a couple years back. I had never experienced such a think like that before. Maybe I was just lucky or it's something more common with Fender amps and they are more sensitive to certain aspects of certain tubes?
I don't know.

I'll take your advice and find a seller who actually deals with musical instrument amps and actually understands that testing a tube in an actual amp can tell a lot more than just a "Yes/No" tube tester. :)

BTW, the NOS 12at7 Mullard in the PI position sounds very nice. The NOS Raytheon 12ax7 in the custom/bassman channel has a very nice richness. It's a bit lower on bass with smooth, creamy mids, and a mellow top end, not overly bright at all. It lets me use my Strats tone control more as it actually responds better.

I've heard great things about the Gold Lions and I'm going to get some.
Do the gold pin versions really make a noticeable tonal difference?
Or, is it more of low corrosion thing?

My last question;
I don't use tremolo, but, does having a good tube in that position affect the amps tone even though trem is turned off?
My amps are modern 68 CDR and 68 CVR both silver-face.


Top
Profile
Post subject: Re: Tube testing question
Posted: Wed Feb 15, 2017 4:52 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
Rverb wrote:
Do the gold pin versions really make a noticeable tonal difference?


Turd polish, nothing more.

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Tube testing question
Posted: Wed Feb 15, 2017 5:31 pm
Offline
Professional Musician
Professional Musician

Joined: Tue Nov 27, 2012 6:56 am
Posts: 1677
Location: Coastal Bend, Tx.
Quote:
does having a good tube in that position affect the amps tone even though trem is turned off?

This tube position offers the least effect to overall tone; basically only drives the trem function. As long as its not really really bad, any 12ax7 will do the job. Put your least favorite and your favorite in a swap in/out test to see for yourself.


Top
Profile
Post subject: Re: Tube testing question
Posted: Thu Feb 16, 2017 1:02 pm
Offline
Aspiring Musician
Aspiring Musician

Joined: Fri Jun 20, 2014 2:07 pm
Posts: 303
Retroverbial wrote:
Rverb wrote:
Do the gold pin versions really make a noticeable tonal difference?


Turd polish, nothing more.

Arjay


That's what I would say too.
However, looking at the gold pin version compared to the standard pin tube, the internal parts are not the same.
The plates are larger and longer in the B759 gold pin version compared to the ECC83 standard.

So, the gold pins may not make a tone difference, but surely the different internal parts indicate a different tone.
Also, the gold pin version have "made in Russia" on them and the standard ECC83 is "made in China".

Anyone able to verify this?
And, is the Gold Lion the same as any other modern tube made in Russia but with a different label?
I've heard it's a unique tube based on the original Mullard design?


Last edited by Rverb on Fri Feb 17, 2017 3:32 pm, edited 1 time in total.

Top
Profile
Post subject: Re: Tube testing question
Posted: Thu Feb 16, 2017 1:38 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Rverb wrote:
However, looking at the gold pin version compared to the standard the internal parts are not the same. That plates are larger and longer in the B759 gold pin version compared to the EC83 standard.

So, the gold may make not difference, but surely the different internals make them not just a gold pin vs standard pin tube. Also, the gold pin version have "made in Russia" on them and the standard ECC83 is "made in China". Anyone able to verify this?

Is the Gold Lion the same as any other modern tube made in Russia but with a different label?
I've heard it's a unique tube based on the original Mullard design?



Gold pins do not add to sound or life length. Steel pin tubes are good enough. One caveat about gold pin plating. Some tubes, esp China made ones... do not fit sockets as well as the steel counterparts. Plating adds to the diameter of the pins. Some gold pins have too much plating.

Get the long plate B759. The reissued Gold Lion 12AX7 tubes made in the Reflector plant, in Russia are very good tubes. They are made to tolerance which is better than the standard Sovtek 12AX7.

China does make some nice 12AX7. I do not know about the "Gold Lion" branded Chinese ones. They are prolly made in Shuguang factory. These tend to be "sweeter" or more syrupy midrange than the Russian 12AX7.

If you want tested 12AX7 tubes, I recommend Jim McShane. He pre-tests and sorts all of his tubes, prior to sale. You can drop him an email, to see about availability and his thoughts on Chinese versus Russian Gold Lion 12AX7.

http://www.mcshanedesign.net/tubes.htm


Top
Profile
Post subject: Re: Tube testing question
Posted: Thu Feb 16, 2017 5:25 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
BMW2002Ti wrote:
If you want tested 12AX7 tubes, I recommend Jim McShane. He pre-tests and sorts all of his tubes, prior to sale. You can drop him an email, to see about availability and his thoughts on Chinese versus Russian Gold Lion 12AX7.

http://www.mcshanedesign.net/tubes.htm


+1!

I can't recommend Jim enough.

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Tube testing question
Posted: Thu Feb 16, 2017 10:05 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sun Sep 08, 2013 8:50 pm
Posts: 4602
Location: ˚ɷ˚
BMW2002Ti wrote:
Gold pins do not add to sound or life length. Steel pin tubes are good enough.

Correct. The only benefits of gold plated contacts are corrosion resistance and increased sales to those who think that gold must be better.
Due to the design of typical tube sockets, the pins are scraped when inserting them, so the corrosion resistance is unlikely to do anything.

BMW2002Ti wrote:
One caveat about gold pin plating. Some tubes, esp China made ones... do not fit sockets as well as the steel counterparts. Plating adds to the diameter of the pins. Some gold pins have too much plating.

Doubtful. We're talking microns here (typically 1.5-2 microns of nickel plus 0.5-1 microns of gold). Worst case, we're talking 0.00001", which is going to be far less than the thickness tolerances for the pins themselves.
Electroplating is a relatively slow process, and factories aren't going to waste time and gold on adding far more than needed.


Top
Profile
Post subject: Re: Tube testing question
Posted: Fri Feb 17, 2017 2:43 am
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Gold pins on tubes are commonly misunderstood. It isn't that they took a regular tube and gold plated the pins, and claimed some sonic improvement, but the pins were gold plated to denote a special tube.

The gold pins do nothing for sound, and that isn't the claim. So yes, if you see gold pins on a tube, likely it is a special tube beyond simply having gold pins. (I am surprised that many of you don't already know this :shock: )

Pay attention people! :D

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Post subject: Re: Tube testing question
Posted: Fri Feb 17, 2017 3:29 pm
Offline
Aspiring Musician
Aspiring Musician

Joined: Fri Jun 20, 2014 2:07 pm
Posts: 303
BMW2002Ti wrote:
Rverb wrote:
However, looking at the gold pin version compared to the standard the internal parts are not the same. That plates are larger and longer in the B759 gold pin version compared to the EC83 standard.

So, the gold may make not difference, but surely the different internals make them not just a gold pin vs standard pin tube. Also, the gold pin version have "made in Russia" on them and the standard ECC83 is "made in China". Anyone able to verify this?

Is the Gold Lion the same as any other modern tube made in Russia but with a different label?
I've heard it's a unique tube based on the original Mullard design?



Gold pins do not add to sound or life length. Steel pin tubes are good enough. One caveat about gold pin plating. Some tubes, esp China made ones... do not fit sockets as well as the steel counterparts. Plating adds to the diameter of the pins. Some gold pins have too much plating.

Get the long plate B759. The reissued Gold Lion 12AX7 tubes made in the Reflector plant, in Russia are very good tubes. They are made to tolerance which is better than the standard Sovtek 12AX7.

China does make some nice 12AX7. I do not know about the "Gold Lion" branded Chinese ones. They are prolly made in Shuguang factory. These tend to be "sweeter" or more syrupy midrange than the Russian 12AX7.

If you want tested 12AX7 tubes, I recommend Jim McShane. He pre-tests and sorts all of his tubes, prior to sale. You can drop him an email, to see about availability and his thoughts on Chinese versus Russian Gold Lion 12AX7.

http://www.mcshanedesign.net/tubes.htm


Yes, I agree on the gold vs standard.
I didn't intend nor would I imply the gold pin makes any tonal difference.

My point was in response that getting the gold pin version is pointless as the standard pin would sound the same, however, the actual construction of the gold pin B759 is not the same as the standard pin tube.

As you and I stated, the B759 uses longer plates. The whole B759 12ax7 looks different internally compared to the ECC83 12ax7 standard pin.
They aren't even the same tube, but a lot of places make the statement that you can get that "Gold Lion tone for much less money from the standard pin version".
To me that's extremely misleading as it implies that the only difference between those 2 tubes is the gold plated pins.

Yes, the Gold Lions I purchased are gold pin, 1 is the B759 12ax7, and 1 gold pin ECC81.
I wanted a lower gain Gold Lion as well.

As for the Ei's, that seller is sending me a new pair that he says he tested in a 15 watt, 10" combo and didn't get any ringing. So, hopefully that will be a good set.
And for the bad Raytheon he is sending a pair of NOS JAN GE 12at7WC tubes, as I told him I'd be willing to try any nice NOS 12at7 or 5751 tubes he may have.

I've got 2 amps, the CVR and CDR, so I'm happy to get as many tubes as I can for some evening fun of swapping tubes.


Top
Profile
Post subject: Re: Tube testing question
Posted: Fri Feb 17, 2017 3:36 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
It may take more than a single evening to get everything dialed in.

Grab a couple of twelve-packs of MGD and have fun.

:wink:

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Tube testing question
Posted: Fri Feb 17, 2017 3:45 pm
Offline
Aspiring Musician
Aspiring Musician

Joined: Fri Jun 20, 2014 2:07 pm
Posts: 303
BMW2002Ti wrote:

Get the long plate B759. The reissued Gold Lion 12AX7 tubes made in the Reflector plant, in Russia are very good tubes. They are made to tolerance which is better than the standard Sovtek 12AX7.

If you want tested 12AX7 tubes, I recommend Jim McShane. He pre-tests and sorts all of his tubes, prior to sale. You can drop him an email, to see about availability and his thoughts on Chinese versus Russian Gold Lion 12AX7.

http://www.mcshanedesign.net/tubes.htm


Thanks for the suggestion.
WOW, LOTS of tubes, and his prices aren't crazy like many others I've seen.

I think I got a good deal on the Gold Lions, both shipped for $55, which is a good bit less than most everyone else on Ebay.


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 19 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: