A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

[Curly]

A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

FYI:
http://www.tubesandmore.com/tech_corner/12ax7_comparison_of_current_made_tubes

(note: you may want to open the pdf link, which is larger / easier to read)


for comparison, here's an updated list from Myles Rose



here's the link:
http://la-economy.blogspot.com/2013/05/current-production-12ax7-tubes-ten-of.html

He notes that all current production tubes have high reject rates, so it's even more important to use a good vendor

 

[jeremy]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

sweet thanks curly!

 

[Curly]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

I saw this chart on facebook, and commented that it would be interesting to see a similar chart of NOS tubes. The fact is, I HAVE seen such charts ... and many of the familiar NOS tubes hit or EXCEED the benchmark gain of 100u.

 

[STRATDELUXER97]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Great info...Thanks pal! Haven't used the Mullards,but I do like the Tung Sols in my Fender amp.

 

[Surgeon]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

I've used nothing but tung-sols since 2005ish... love them!

 

[STRATDELUXER97]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

I've used nothing but tung-sols since 2005ish... love them!

I find them to have the right amount of gain and they seem warm and round to me.I still have original Mullards in my Marshall though.

 

[Curly]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

I like the Tung Sols too, as far as current production ... that chart suggests that tube has slightly less gain, but also less noise. Fairly logical, but at least worth knowing.
I suspect the Mullard is the Groove Tube ... it had kind of a spotty reputation upon its introduction -- a lot of anticipation, then disappointment when different lots varied in spec. Maybe they've got the bugs worked out now.

 

[Hank-]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

That Mullard is a New Sensor product in the chart I bet. I'm surprised it's got that much gain in their testing. The EQ points seem a little off to me. The one I have is not very balanced in EQ, it's got lot of bass, low mids & rounded highs(more than the JJecc83S for sure but less than a Tungsol RI). Mine doesn't behave nicely if I use it in my first gain stage, tends to squeal under high gain :scratchch Not very high gain tube either but a alot more compressed than the Tungsol RI or JJecc83S or Tad 7025. My laney amp had tad's in it stock, but compared to the chart the 7025 had more highs & less bass, sorta opposite to their findings while the tad ecc83 had more white noise & more balanced EQ with a touch more bass & mids.

Oh well, it's fun to have a few different ones in the drawer collection, my amp can be too bright with Celestion 70/80s, I found the JJecc83s worked wonders throughout in it.

EDIT: Have any of you guys noticed that New Sensor preamp tubes are a little difficult to get seated in a traditional socket(the one with a metal kinda thing. There's hardly any room to rock the tube, it has to be pushed hard & one of the pins always ends up getting slightly bent. It's even worse when trying to pull them out.

 

[STRATDELUXER97]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

I like the Tung Sols too, as far as current production ... that chart suggests that tube has slightly less gain, but also less noise. Fairly logical, but at least worth knowing.
I suspect the Mullard is the Groove Tube ... it had kind of a spotty reputation upon its introduction -- a lot of anticipation, then disappointment when different lots varied in spec. Maybe they've got the bugs worked out now.

Agreed....I think there were unreliability issues with some of the Mullards on earlier/new release 12AX7s.

 

[Lucy Diamond]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

I dropped page 3 into photoshop and cropped it to just the tube and the part names and I'm going to frame it and put it in my rehearsal space as art.

So beautiful.

Thank you man, this article was awesome for me.

~LD

 

[Dirtbagg]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Sweet thanks Curly

 

[Diego]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Today I rolled Ruby 12AX7AC7 HG and Tungsol 12AX7s in the V1 of my Tweaker.

The Tungsol seems to clean up a bit better when you roll back the volume on your guitar,
plus it goes a lot hotter than the Ruby when hit with a boost in front, it's more sensitive. Wasn't expecting that at all.
Anyone else noticed this with Tungsols or it's just me?

EQ-wise I noticed almost no difference except for maaaaybe a bit more crack in the high mids with the Tungsol.

 

[hermetico]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Even that each tube has its own character, none behaves the same in same amp and same position.
Usefull info needs to specify amp and tube position.

 

[Curly]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Even that each tube has its own character, none behaves the same in same amp and same position.
Usefull info needs to specify amp and tube position.

You have a good point, but in this case, the information is what it is, and you'll need to apply some common sense and draw your own conclusions. Every study can't be 'all things to all players'.

There are several vendors that do have more specific guides. One example is the Fender pre-amp guide at KCA NOS:
https://www.kcanostubes.com/content/fender-amp-preamp-tube-layout-and-recommendations

Of course, not everyone plays a Fender.
Another guide for pre-amp tubes is Myles Rose's :
http://guitaramplifierblueprinting.com/12ax7.html

But any good tube vendor should be able to answer any specific question you have that you can't figure out on your own.

 

[Jolly_Rancher]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

LOL - I still have this open in my browser, but I never thought of posting it here. Good idea!

 

[Hank-]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

They actually did specify the amps & positions of tube, you have to scroll down on the webpage, near the second half they explain the process & stuff used for noise, gain & listening tests respectively.

 

[Gearjoneser]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

I just wish I owned the custom switch box they used for listening tests. Sometimes, it's hard to tell the difference between pre tubes when you've got to shut the amp off, pop another tube in, heat it up, and start playing. The lapse between tubes makes it hard to compare.

(from the link)
A custom 12AX7 switching box was constructed to allow for a quick switch comparison of six tubes at a time while plugged into the V1 socket of a Marshall JCM800 2203 guitar amplifier. A separate filament transformer was used on the switching box to simultaneously heat all six comparison tube filaments without overheating the amplifier's power transformer. A shielded cable was constructed to plug into the amplifier's V1 socket and transfer its pin 1, 2, 3, 6, 7 and 8 connections to one tube socket at a time in the switching box. Listening tests were then conducted while playing guitar and switching between the tubes at various amplifier control settings to come up with tonal descriptions for each tube.

 

[Curly]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

I just wish I owned the custom switch box they used for listening tests.

yeah, I hear you ... I made a note of that too ... a real A/B test in real time

 

[Johnny-DK]

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Re: A COMPARISON OF CURRENT PRODUCTION 12AX7 TUBES ®2013

Good find Curly. Thanks for sharing!