[oqvist]

EF86 6267 MULLARD~LONG MESH PLATE~D GETR~TUBE AMPLIFIER - eBay (item 120386633297 end time Mar-15-09 18:00:00 PDT)

and this Mullard CV491/12AU7 long plates Square getter double cr - eBay (item 130291385604 end time Mar-13-09 14:59:48 PDT)

Essentially the same or different? what a jungle with all the codes.

 

[Skylab]

Good lord NO! The EF86/6267 is a pentode. Put that in your EF1 and something will blow up or catch fire. Seriously.

I know it's a jungle, but here are the ONLY 12AU7 equivalents (any of these may come with an "A" or "W" on the end):

12AU7, 5814, 6189, 6680, ECC82, CV4003, 5963. Anything else is not a direct equivalent.

 

[olblueyez]

Quote:

Originally Posted by olblueyez /img/forum/go_quote.gif I think what your looking for is an ECC82 (European version of the American 12AU7/A) or a 12AU7. Some of those are 12AX7, that you dont want. For long plate mullards, round getter or square it doesnt matter, both are great. Good tube to start with, save you a lot of hit or miss, you just cant go wrong with that tube.

Quote:

Originally Posted by oqvist /img/forum/go_quote.gif EF86 6267 MULLARD~LONG MESH PLATE~D GETR~TUBE AMPLIFIER - eBay (item 120386633297 end time Mar-15-09 18:00:00 PDT) and this Mullard CV491/12AU7 long plates Square getter double cr - eBay (item 130291385604 end time Mar-13-09 14:59:48 PDT) Essentially the same or different? what a jungle with all the codes.

Lots of information here. www.tubeworld.com

 

[theBigD]

Quote:

Originally Posted by lennybrisco /img/forum/go_quote.gif I received my EF1 this week and have put about 80hrs of burn-in on it. There are some things I love about this amp's stock sound signature (the mids are fantastic) but some faults, for my own particular tastes, that I would like to correct. I hope someone here can help. For me, the stock sound is not well defined. The music often starts to become a wall of sound with voices and instruments overlapping instead of having their own space on a black background. The notes/voices seem too wide and are also soft around the edges. Too describe it a different way it is like turning off crossfeed after being used to having it on. The music seems to stretch into a wider, less defined space. As a result, the overall effect is a generally - for me - uninvolving sound with lack of PRAT. It's too polite if you will. I also feel that the bass is rolled-off at the very bottom end and lacks a little slam and texture down there around 62Hz. I have not seen these comments elsewhere, could mine have some sort of anomaly? I suspect not, so I'll try tube rolling. Can someone recommend a tube that will: Add definition and a more black background (my biggest concern) Add bass extension and a (mild) boost to the slam. Keep most/all of the awesome mids of the stock tube (if possible). I have a 110V amp with the stock CONN/RCA tube and D5000 HP's. Willing to try opamp swaps as well if anyone can help me with that. I have zero experience with it. TIA everyone, -LB

I think what you are desribing is primarily the limitation of the stock op amp. i find the op 275 to not be as resolving as the hdams that ive used. the hdams are not simple to swap with stock and require a solid connection and extension to the board as there isnt much room in the ef1. Hi-flight had an op amp solution, the ad743 opamps that he was selling that ive heard are supposed to be pretty good.

I finally got the earth hdam to work in my ef1 and had to play with connection to get it to work just right. It seems to have more forward midrange and more dynamics compared to the moon hdam i used before. I still have less than 50 hr burn in with it so i hesitate to comment much further on sound compared to moon. but either hdam is much cleaner and faster sounding than the stock op275. the thing that is kinda interesting is the earth has twice as much guts internaly as the moon, maybe this is why it is so finicky with the connection.

edit: for tubes i would recommend the sylvania tube. it has more slam in the bass than the rca clear top has. i think it has a better midrange as well. In fact as i typed this i realized i was checking out a new ac/dc album and using rca clear top. swapped to sylvania and WOW big improvement in the slam department! Makes my d7000 sing

 

[lennybrisco]

Thanks for the reply, theBigD. Much appreciated.

I mistakenly said the stock tube was a CONN/RCA. It is, actually, the CONN/Sylvania you suggested. And, I agree with you on that tube with the new AC/DC disc. Phenomenal with D5000's. I wish every disc sounded that good with the stock set-up.

I'll keep checking around on op amps and contact Hi-flight to see what his combo can do.

-LB

 

[oqvist]

my EF-1 ships with the sylvania sounds good then

Also btw how do these tube tests works. This is used but "as new" 12AU7 ECC82 Mullard 1958 long plate Blackburn Test NOS - eBay (item 110359117258 end time Mar-10-09 10:35:37 PDT)

70 of 74 meaning? And now you don´t bid on this one it´s mine

 

[Skylab]

Quote:

Originally Posted by oqvist /img/forum/go_quote.gif my EF-1 ships with the sylvania sounds good then Also btw how do these tube tests works. This is used but "as new" 12AU7 ECC82 Mullard 1958 long plate Blackburn Test NOS - eBay (item 110359117258 end time Mar-10-09 10:35:37 PDT) 70 of 74 meaning? And now you don´t bid on this one it´s mine

Actually he was not saying 70 of 74 when he said "70/74" - he was saying triode #1 = 70, triode #2 = 74. Since he says on his tester 70=NOS levels, this is a good result, although the triodes are not perfectly matched.

I have one of these and they sound nice, definitely on the warm/lush end of the spectrum.

 

[oqvist]

Well I hope there wasn´t anyone here that stole it from me... exxx2 that person lol.

As for price is that a high or low price for such a tube? Generally you have some idea what things are worth...
Is these in decent condition? http://cgi.ebay.com/ws/eBayISAPI.dll...%3D4%26ps%3D41

 

[wahchile]

Wow guys, I got a GE 12au7a made in GT Britain (I guess it's a rebranded Mullard) and it's nice! The bass feels fuller, it has a little more kick to it. Nice and smooth tube.

Keep your eyes out, because I definitely didn't pay Mullard prices. It was like $12 on Ebay.

 

[K_19]

I've actually come to a dilemma where I'm liking two different tubes with my two main headphones, the K701 and HD650.

I'm definitely favouring the K701 now with the Sylvania black top, as it somewhat sets back the midrange which is a VERY good thing with K701 with their upper mid spike and warms the entire range considerably which really benefits the lack of warmness of the headphones. On the flipside, K701 with the Mullard short plate sometimes brings the upper mids way too forward, making them painful for me to listen to, although they do add definition and warmth.

With the HD650's, I definitely prefer the Mullards as they bring out the mids out of their slight "veil" (keep in mind mine isn't nearly burned in yet), and adds hell of a lot more definition to it. It rolls off the highs a bit and shrinks the soundstage a bit but it's worth the midrange boost that it receives. With the Sylvania, I do like the soundstage boost, but it makes the HD650 WAY too laid back and it loses the midrange detail the Mullards would give them. Both of them are silky smooth, with maybe Sylvania being more so (perhaps too much), so I prefer the extra midrange edge the Mullards give with these headphones.

This all brings me to one question I want to ask: Is it safe to continuously roll different tubes on a daily basis? Thing is, I have both headphones on a daily rotation where one gets one day of headtime and the other one the next... and I'm worried that if I change the tubes on the daily basis I might make the connectors go bad or something. Any definitive word on this would be appreciated.

I've also bid on the Hungarian Tube that Olblueyez suggested so hopefully I can win it and have it be a nice middle ground between these two tubes.

Edit: I should also mention that my Mullard short plates are 12au7A, the one that supposedly has a higher gain (is this even true? If not, what's the main difference between regular and the "A"?). Could this be why K701 gets too harsh (too much gain with its average impedence) and HD650 sounds perfect? (with their much higher impedence)

 

[Skylab]

It is NOT a good idea to tube roll daily, no. You will wear out the tube socket. Maybe this is acceptable to you, as tube sockets can be replaced. You could also have someone make you a "socket Saver", basically a socket you will plug into the amp's socket, and thus when you wear it our, you just get a new one.

If you are careful, you probably won't ever damage the tube, but those are easy to replace anyway.

Or just get a Tung-Sol black-glass, and then you will only need one tube

 

[K_19]

OH great, just when I bid on the Tungsram tubes!! Evil, this place, I tell you!

...I'll look into it. *walks away like sheep*

Thanks for the tip, I'll leave the tubes alone for now. I do like my Mullard/HD650 combo slightly better than my Sylvania/K701 combo so I'll keep the Mullards in and EQ what I can with K701 in foobar or something.

 

[plonter]

Hey guys..another "tube noob" here and i am going to buy the EF1 soon and i want to clear all the details before buyng it. do i really "roll" the tube after getting it to the sockets?? or do i just push it inside and that's it?

 

[Skylab]

Don't just push down. Gently roll it as you push. Very small gentle motions.

 

[plonter]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif Don't just push down. Gently roll it as you push. Very small gentle motions.

thanks skylab.