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Little Dot MKIII Tube Rolling - Page 179

post #2671 of 2867

Hey,

 

@Bombay: where did you get those Amperex Bugle Boy EF92 from? Can't find them on ebay but I'm very interested in listening to them.

 

The Haltron 6ag5 (EF96) have arrived a few days ago. At the moment, after having them burned in,  I'm listening with all kinds of music. Soon after I'll compare them with the best EF95 tubes as reference. Without a direct comparison I can confirm they don't do anything wrong. Pretty dark and strong bass, a piano sounds like a piano and voices sound natural too. Not sure about the quality of the treble yet.


Edited by infinity650 - 3/26/12 at 9:13am
post #2672 of 2867
Quote:
Originally Posted by infinity650 View Post

Hey,

 

@Bombay: where did you get those Amperex Bugle Boy EF92 from? Can't find them on ebay but I'm very interested in listening to them.


I picked up 8 of them for $4 each from ABC Vacuum Tubes. They were the ONLY place I could find them. I searched everywhere, and eventually just started calling different tube manufacturers in the US. You'll have to give them a call to see if they have any in stock still (I got mine about 2 years ago now): http://www.abcvacuumtubes.com/contact_abcvacuumtubes.html. I ended up selling off my extra ones about a year ago, so I've just got the 2 in my amp and 2 that are unused. 

 

If it's any help, they go by the name of 6CQ6 as well as EF92. Good luck!

 

 

post #2673 of 2867

 

Quote:
Originally Posted by infinity650 View Post

@Bombay: where did you get those Amperex Bugle Boy EF92 from?


Looking at the photo and assuming that "Made in Gt. Britain" is true, those seem to be Mullard-made tubes. The codes on the tubes should tell the truth. The print on them doesn't change their sound.

 

post #2674 of 2867
Quote:
Originally Posted by Oskari View Post

 


Looking at the photo and assuming that "Made in Gt. Britain" is true, those seem to be Mullard-made tubes. The codes on the tubes should tell the truth. The print on them doesn't change their sound.

 


All of the text on the tubes are:

Amperex

66

20

Made in Great Britain

 

Text on the box:

EF92

 

I thought that the orange logo tubes (from the 70s I believe) and tubes without the bugle boy logo were re-branded, but that these were true Amperex tubes?

post #2675 of 2867

Hey,

 

thanks for the information. I already got the Mullard EF92 (6CQ6) and really like them. So I think I won't buy another predictably equal build EF92 tube and go on looking for a bargain on the Mullard M8161 (CV4015).

 

@Bombay: the 66 20 should be the 20th calender week of 1966 as the date of build


Edited by infinity650 - 3/26/12 at 1:01pm
post #2676 of 2867


 

Quote:

@Bombay: the 66 20 should be the 20th calender week of 1966 as the date of build


Yup.

 

My question here is whether ANY Amperex tube made in Great Britain is actually made by Mullard? I had no idea a true Bugle Boy tube could be a re-brand. Anyone have any insight on this?

 

post #2677 of 2867

 

Quote:
Originally Posted by BombayTheIndian View Post

All of the text on the tubes are:

 

Please take a closer look. See http://www.head-fi.org/t/276757/little-dot-mkiii-tube-rolling/1785#post_5597821
 

Quote:
Originally Posted by BombayTheIndian View Post

I thought that the orange logo tubes (from the 70s I believe) and tubes without the bugle boy logo were re-branded, but that these were true Amperex tubes?


Nope. At this point Amperex was owned by Philips just like Mullard, Valvo, etc. They made some types in their US factories but also sold lots of tubes made by other companies of the Philips group.

 

The Dutch factories were not Amperex factories, they were Philips factories. Mullard was "Philips UK", Valvo was "Philips Germany", and so on.

 

post #2678 of 2867
Quote:
Originally Posted by Oskari View Post

 

 

Please take a closer look. See http://www.head-fi.org/t/276757/little-dot-mkiii-tube-rolling/1785#post_5597821
 


Nope. At this point Amperex was owned by Philips just like Mullard, Valvo, etc. They made some types in their US factories but also sold lots of tubes made by other companies of the Philips group.

 

The Dutch factories were not Amperex factories, they were Philips factories. Mullard was "Philips UK", Valvo was "Philips Germany", and so on.

 

 

Whoa, you're like the Tube Whisperer! Thanks for the insight and the recommendation of looking closer. I peeked at all remaining 4 tubes I have, and only 1 had barely legible print at the bottom:

HI(?) Possible H1

R6C3
 

So R=Mullard, 6=1966, C=March, and 3=3rd week of month?

 

Really interesting stuff.

 

Next question, then: my Mullard EF91 are large shield military spec. Is there any difference between these and the Mullard M8083? The M8083 go for ~$60/pair on ebay, I think I got mine for ~$25/pair a couple years ago.

 

post #2679 of 2867

Seriously though, it felt like I was in National Treasure and I was uncovering some old mystery when I found the codes on that single tube. "The clues were right there in front of you the entire time..." Lol, thanks Oskari!

post #2680 of 2867

Just had this discussion about the different EF91 / M8083 / CV 4014 tubes in another thread. Conclusion was something like: Go for the cheapest Mullard, they're all the same. Had two different labeled pairs here, they were exactly the same.

 

I cann recommend something like that: http://www.ebay.de/itm/M8083-CV4014-EF91-MULLARD-TUBE-VALVULA-USED-/140535416679?pt=LH_DefaultDomain_186&hash=item20b8904767

 

or even cheaper. Got mine for about 10 bucks / 4 tubes.

 

So in my opinion you can stay with your pair and don't think too much about a tube just labeled differently.

post #2681 of 2867
Quote:
Originally Posted by infinity650 View Post

Just had this discussion about the different EF91 / M8083 / CV 4014 tubes in another thread. Conclusion was something like: Go for the cheapest Mullard, they're all the same. Had two different labeled pairs here, they were exactly the same.

 

I cann recommend something like that: http://www.ebay.de/itm/M8083-CV4014-EF91-MULLARD-TUBE-VALVULA-USED-/140535416679?pt=LH_DefaultDomain_186&hash=item20b8904767

 

or even cheaper. Got mine for about 10 bucks / 4 tubes.

 

So in my opinion you can stay with your pair and don't think too much about a tube just labeled differently.


Sweet, that's exactly what I was thinking. I was hoping I got a deal on mine. 25/pair matched compared to 60 is pretty good, but you can't beat 8/pair like you ended up getting beerchug.gif

 

post #2682 of 2867

Quote:
Originally Posted by infinity650 View Post

Just had this discussion about the different EF91 / M8083 / CV 4014 tubes in another thread. Conclusion was something like: Go for the cheapest Mullard, they're all the same.

 

Not so fast...

 

CV138 by Mullard = EF91

CV4014 by Mullard = M8083

 

Compare these

 

http://frank.pocnet.net/sheets/154/e/EF91.pdf

http://frank.pocnet.net/sheets/129/m/M8083.pdf

 

The General Notes on Special Quality Valves can be found here

 

http://frank.pocnet.net/other/Mullard/PD/rxspqual.pdf

 

There's the material; see for yourselves what the difference is! devil_face.gif

 

post #2683 of 2867

You're absolutely right, my fault. Just the 4014 and M8083 are equal in my opinion.

post #2684 of 2867

 

Quote:
Originally Posted by BombayTheIndian View Post

HI(?) Possible H1

R6C3
 

So R=Mullard, 6=1966, C=March, and 3=3rd week of month?

 

The first line must be hard to read because that can't be correct, but you are correct regarding the second line. R = Mullard at Mitcham.

 

This is where the Mitcham factory was: http://g.co/maps/f3wh9

 

Check the street names in that area!

 

The Philips codes are all in here: http://frank.pocnet.net/other/Philips/PhilipsCodeListAB-v10.pdf

 

post #2685 of 2867
Quote:
Originally Posted by Oskari View Post

 

Not so fast...

 

CV138 by Mullard = EF91

CV4014 by Mullard = M8083

 

Compare these

 

http://frank.pocnet.net/sheets/154/e/EF91.pdf

http://frank.pocnet.net/sheets/129/m/M8083.pdf

 

The General Notes on Special Quality Valves can be found here

 

http://frank.pocnet.net/other/Mullard/PD/rxspqual.pdf

 

There's the material; see for yourselves what the difference is! devil_face.gif

 

 

Great info, thanks so much for clarifying! That's really cool with the link to the old factory, too - too bad it's now just another suburban looking development :( Those street names are great though, at least there's a little piece of history left in the area!

 

Thanks for the educational session today, Oskari. It's sometimes hard to find people who are insightful without being condescending.
 

 

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