[mordy]

Hi MisterX and Mechans1,
 
I can certainly understand your skepticism of what these measurements mean and you have very valid questions.
 
I am only quoting the answers I got from Dan at Langrex where I bought my pair of Mullard 6080 tubes. It seems to me that somebody measured the tubes regarding two sets of measurements and wrote these measurements down on little stickers on the glass envelope of the tubes.
 
It appears to me that each dual triode was measured for two different tests, hence the 4 readings on each tube. Oskari sent me a link to these measurements of 10 different 6N23P tubes which are dual triodes.:
 

№	Plate current	Transconductance	Plate current	Transconductance
1.	13,3mA​	8,6mA/v​	13,6mA​	8mA/v​
2.	13,2mA​	8,6mA/v​	12mA​	8mA/v​
3.	13mA​	9,6mA/v​	11,4mA​	7,6mA/v​
4.	14,4mA​	9.8mA/v​	16,8mA​	12mA/v​
5.	13,6mA​	7,8mA/v​	14mA​	9mA/v​
6.	14mA​	10,6mA/v​	12mA​	9mA/v​
7.	13,2mA​	8,6mA/v​	16mA​	9,6mA/v​
8.	18mA​	8,2mA/v​	13,2mA​	8,4mA/v​
9.	11,6mA​	8,6mA/v​	12mA​	9mA/v​
10.	12,4mA​	8,6mA/v​	14,4mA​	10mA/v​

As you can see, each triode has two measurements. Don't know if they correspond to the values listed for my 6080 tubes.
 
The 6N23P is said to be the same tube as a 6DJ8. For the 6DJ8 the plate current is 15mA, and the transconductance is 12.5mA which seems to be in the range of the above tubes.
 
Bottom line: I still don't understand the measurements of the Mullard tubes.....

 

[thecrow]

   
Speaking of which, don't you have the G.E.C. on your WA2?
How would you rate them? Were they worth it to you?
 
I have the Western Electric 421A's & the only reviews & comparisons I read were that Western Electric & the GEC's were on the same level.

 

Apart from the stock power tubes I have only heard the Gec tubes that I have and some tung sol 5998s which I listened to briefly.

As others have described the tung sol are punchy with a good bit of weight/bass/ kick/timbre (kind of) to them so I enjoyed them when I briefly listened to them.....But when I then put the Gec tubes back in there was definitely an improvement in layering and details and extension. Still rich and pretty much neutral in nature but a real classy tube.

I've just ordered some we421a tubes that should be here any day. I'll post again when I spend a little time with them.

In a nutshell (I'm currently thinking) if I was to only have one pair I would have the Gec tubes for that "audiophile" sound, whatever that is, but the we421a/5998s are for that meatier sound when that's sought

And I love how the hd800's lets this all come through


What driver tubes do u use with the 421a's and how do u find them?

okay with hd800s and amperex 6922 pq's in place, tonight's listening shows:
 
the 421a tubes are a little more punchy and on the slighter warmer side but still lively but with that added touch of warmth and kick. it does have a higher gain i believe.
it does tame some highs that sometimes can stick out i'm finding - i have been pleasantly surprised on some albums of this that i thought the gec would have been hands down better (eg thomas dolby albums - astronauts and heretics on right now and it's great)
 
the gec 6as7g have a more neutral sound, more neutral (on that spectrum) and still lively. extended highs and definitely slightly better layered. overall a little more natural sounding too
 
 
if you are happy with the 421a tubes no need for the gec tubes. if you can splurge and you want a little more brightness and clarity then go for the gec tubes
 
for me i prefer the gec's but the 421a's will get a run too at times.
 
 
 
i would also say for my set up and my prefs the gecs will be more versatile - ie enjoyed with a broader range of music
 
i have also read from other members here that the gec are the preferred choice for hd800, whilst the TS5998/we 421a are better for the t1
 
 
having heard what i've heard tonight, would i spend a bucket load of money on getting both of these premium tubes? - probably not but, hey, it was a Christmas treat for me
will i now use both? - Yes, happily.
 
 
that's my initial two bob's worth

 

[Oskari]

  Bottom line: I still don't understand the measurements of the Mullard tubes.....

 
Let's look at the 68/69. Presumably, that gives a plate current of 68 mA. This is specific to the (unknown) test conditions of the (unknown) tester. Next question: 69? They could have taken another reading of the same: plate current of 69 mA. Or this might be a transconductance reading, either unitless or in units of 0.1 mA/V, i.e., 6.9 mA/V. Or it might be something else.
 
Bottom line: I don't know either.

 

[mcandmar]

Just to chuck a spanner in the works, those figures might not be a ma figure at all, do we know what they used to test the tubes?
 
Ex military TV series tube testers, and Hickok testers use there own arbitrary scale, which can be converted into micromhos.  For example with my TV-7 tester a 6AS7 tube has a minimum pass reading of 36, but in my experience healthy tubes test in the 60-80 range.  68/69 would be a perfectly healthy, and well matched tube.

 

[Oskari]

Still 8 test values for 2 tubes, 4 triodes.
 
They did mention mA.

 

[Thenewguy007]

   

okay with hd800s and amperex 6922 pq's in place, tonight's listening shows:
 
the 421a tubes are a little more punchy and on the slighter warmer side but still lively but with that added touch of warmth and kick. it does have a higher gain i believe.
it does tame some highs that sometimes can stick out i'm finding - i have been pleasantly surprised on some albums of this that i thought the gec would have been hands down better (eg thomas dolby albums - astronauts and heretics on right now and it's great)
 
the gec 6as7g have a more neutral sound, more neutral (on that spectrum) and still lively. extended highs and definitely slightly better layered. overall a little more natural sounding too
 
 
if you are happy with the 421a tubes no need for the gec tubes. if you can splurge and you want a little more brightness and clarity then go for the gec tubes
 
for me i prefer the gec's but the 421a's will get a run too at times.
 
 
 
i would also say for my set up and my prefs the gecs will be more versatile - ie enjoyed with a broader range of music
 
i have also read from other members here that the gec are the preferred choice for hd800, whilst the TS5998/we 421a are better for the t1
 
 
having heard what i've heard tonight, would i spend a bucket load of money on getting both of these premium tubes? - probably not but, hey, it was a Christmas treat for me
will i now use both? - Yes, happily.
 
 
that's my initial two bob's worth

 
Thanks for that. That's the first real comparison I read online between them.
fyi I use the '74 reflector 6N23P driver tubes.
 
I had some crap stock 6922 driver tubes before them & with them, the Western Electrics did add more bass/a fullness to the sound over he stock RCA 6080. Maybe extended the highs a bit & added some clarity over the stock power tubes. The soundstage felt more congested though & I noticed some sibilance. Overall, I wasn't impressed, especially considering the price of the tubes.
 
Then when I received the '74 reflectors, they completely transformed the Western Electrics!
Soundstage opened up, the sibilance was gone. New added layers of dynamics. Plus it added impact/slam to the bass. Before them, bass felt very soft & lacked authority. Now it hits hard. Total upgrade in that aspect.
 
Gain was drastically improved as well. Before the reflectors I had to turn the volume knob to 2 or 3 O'clock to get enjoyable listening levels. After the reflectors, I get the same loudness at 9 O'clock on the volume knob.
 
The reflectors improved the Western Electrics drastically more than they did to the stock RCA 6080. The RCA power tubes did get an improvement, but just a small bit.

 

[thecrow]

S

Thanks for that. That's the first real comparison I read online between them.
fyi I use the '74 reflector 6N23P driver tubes.

I had some crap stock 6922 driver tubes before them & with them, the Western Electrics did add more bass/a fullness to the sound over he stock RCA 6080. Maybe extended the highs a bit & added some clarity over the stock power tubes. The soundstage felt more congested though & I noticed some sibilance. Overall, I wasn't impressed, especially considering the price of the tubes.

Then when I received the '74 reflectors, they completely transformed the Western Electrics!
Soundstage opened up, the sibilance was gone. New added layers of dynamics. Plus it added impact/slam to the bass. Before them, bass felt very soft & lacked authority. Now it hits hard. Total upgrade in that aspect.

Gain was drastically improved as well. Before the reflectors I had to turn the volume knob to 2 or 3 O'clock to get enjoyable listening levels. After the reflectors, I get the same loudness at 9 O'clock on the volume knob.

The reflectors improved the Western Electrics drastically more than they did to the stock RCA 6080. The RCA power tubes did get an improvement, but just a small bit.

ounds like the 6922 tubes were stuffed.

On the Gec tubes my volume goes to about 11 o clock. On the 421a tubes it was about 10 ish

Coming from a soloist amp when I heard the wa2 with the stock tubes I thought "wow, this is smooth and detailed !" And then I put the Gec tubes in was blown away from my previous offerings

I've read about the reflektors here.

Ive now spent enough $ on tubes. I needed to get the 5998 or these 421as to satisfy that curiously and that's now done.

I also picked up a pair is Siemens ccas (early-mid 70s) off eBay pretty cheaply (I believe) and they've come up pretty interesting too and more lively than the Amperex PQs. Last night as a quick first impression the PQs sounded better matched with the WE's rather than the ccas but that was first impressions so I'll try them again.

The ccas have grown with me over time and aren't as bright as I first found them - that could be me and the tubes at work

I'll also try them with sone cheap bugle boys I've picked up to say if there is a synergy there. They haven't impressed me as much with my gecs.

My only remaining question is whether I should grab some (uk)!mullard tubes for fun?

I wish there were woo meets here in Sydney just for tube rolling purposes/ideas.


If you ever get a chance to hear the gecs, particularly with the reflektors, let me know what your impressions are. They are something really special with the hd800's. They are effectively on the same job/page as the tube

 

[thecrow]

I'm looking at some mulled 6080 tubes.

I've noticed some of these tubes also have cv2984 on them and some don't. Are there any differences?

Some also have different getters. Some twin getters others not.

Eg:

http://www.ebay.com.au/itm/6080-MULLARD-NOS-BOXED-VALVE-TUBE-/311478749131?hash=item48859487cb:g:lK4AAOSwwbdWOe-m

http://www.ebay.com.au/itm/6080-CV2984-MULLARD-NOS-BOXED-VALVE-TUBE-/311154206725?hash=item48723c6805:g:7rkAAOSwF1dUUiu7

Anyone know if there is much difference in what these offer?

Thanks in advance

 

[abvolt]

I'm looking at some mulled 6080 tubes.

I've noticed some of these tubes also have cv2984 on them and some don't. Are there any differences?

Some also have different getters. Some twin getters others not.

Eg:

http://www.ebay.com.au/itm/6080-MULLARD-NOS-BOXED-VALVE-TUBE-/311478749131?hash=item48859487cb:g:lK4AAOSwwbdWOe-m

http://www.ebay.com.au/itm/6080-CV2984-MULLARD-NOS-BOXED-VALVE-TUBE-/311154206725?hash=item48723c6805:g:7rkAAOSwF1dUUiu7

Anyone know if there is much difference in what these offer?

Thanks in advance

 
No there the same tube I have both  the CV is a European  type military tube code that's all, the mullards are really fine sounding tubes..Enjoy

 

[hpamdr]

I'm looking at some mulled 6080 tubes.

I've noticed some of these tubes also have cv2984 on them and some don't. Are there any differences?

Some also have different getters. Some twin getters others not.

Eg:

http://www.ebay.com.au/itm/6080-MULLARD-NOS-BOXED-VALVE-TUBE-/311478749131?hash=item48859487cb:g:lK4AAOSwwbdWOe-m

http://www.ebay.com.au/itm/6080-CV2984-MULLARD-NOS-BOXED-VALVE-TUBE-/311154206725?hash=item48723c6805:g:7rkAAOSwF1dUUiu7

Anyone know if there is much difference in what these offer?

Thanks in advance

CV2984 are labeled for military use, regular 6080 are for consumer market. As said by gibosi the most important are production date and factory. Basically you have two version AJ0  and AJ1 where you can have a variant with one or two getter.  If you want a pair it is better to have same factory code and date and you can have them matched !
// I personally like the first version but some others prefer later one all should be made at Mitcham ( R code )

 

[mcandmar]

Interesting tidbit there about the AJ0 and AJ1, only ever seen the 1's myself.
 
Personally i would always give preference to CV stamped tubes as i believe they would have undergone more stringent testing. Datasheet for the CV2984 http://www.r-type.org/pdfs/cv2984.pdf

 

[gibosi]

  Interesting tidbit there about the AJ0 and AJ1, only ever seen the 1's myself.
 
Personally i would always give preference to CV stamped tubes as i believe they would have undergone more stringent testing. Datasheet for the CV2984 http://www.r-type.org/pdfs/cv2984.pdf

 
The construction of the AJ0 is quite different than the AJ1, so it is very easy to tell the difference. Below, the AJ0 was manufactured in 1957 and the AJ1 next to it was manufactured in 1966. The AJ1 sports a single getter and I believe that double getters appeared sometime later. While mcandmar may well be right about CV labeled tubes, personally, I always go for the oldest production.
 

 

[thecrow]

No there the same tube I have both  the CV is a European  type military tube code that's all, the mullards are really fine sounding tubes..Enjoy

CV2984 are labeled for military use, regular 6080 are for consumer market. As said by gibosi the most important are production date and factory. Basically you have two version AJ0  and AJ1 where you can have a variant with one or two getter.  If you want a pair it is better to have same factory code and date and you can have them matched !
// I personally like the first version but some others prefer later one all should be made at Mitcham ( R code )

Interesting tidbit there about the AJ0 and AJ1, only ever seen the 1's myself.

Personally i would always give preference to CV stamped tubes as i believe they would have undergone more stringent testing. Datasheet for the CV2984 http://www.r-type.org/pdfs/cv2984.pdf

The construction of the AJ0 is quite different than the AJ1, so it is very easy to tell the difference. Below, the AJ0 was manufactured in 1957 and the AJ1 next to it was manufactured in 1966. The AJ1 sports a single getter and I believe that double getters appeared sometime later. While mcandmar may well be right about CV labeled tubes, personally, I always go for the oldest production.

This info is great. Thanks. I couldn't find any of this info on the Internet.

How do you think the 1975 tubes would compare to previous decades? I've emailed the seller (valvetubes I believe) to get more info on the markings on these. There's not many photos here

 

[JamieMcC]

The old AJO turns up reasonably regularly on line and often for peanuts they seldom have and markings or if they do its often hard to make out as the old style paint can be very chalky and fragile and often comes off when handling. Because of this they often just get listed as vintage british 6080 tube or something along those lines. I would say its also the nicer sounding tube of the two and am pretty sure I have a double top getter version somewhere. I also have a bunch of the AJ1 some of which have the Mullard quick flasher start up when cold feature and some don't. The Mullard 6080 was apparently  made in a number of location both in the UK and Europe so there could be quiet a wide range of slightly differing examples about.

 

[thecrow]

I also just found that there has been discussion for these specific tubes/buyer before in this thread particularly around page 171 that was also useful