Ultimate Ears...

For anything about cans, and the amplifiers that drive them
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JamesD
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#1 Ultimate Ears...

Post by JamesD »

Just had to splash out on new phones. I need them for audio assessment at work and the bottom end was very important as we have had some issues with sub 100Hz noises. They had to be completely sound isolating both ways...

Of course I need them for listening and relaxing when away staying in a hotel which is 4 days a week for me on average.

As it was work related I managed to try quite a few pairs aand I decided on the Ultimate Ears Super.Fi 5 EB. A ridiculous name for a rather good pair of phones. They are inner ear phones so not for everybody. The EB stands for extended bass and they hvae more sense of bass weight than most phones I tried.

On the road I use an EMU 0202 USB DAC to drive them.. I guess I need to build something smaller than Nicks 211 headphone amp :D Although I still have four 833 in the cupboard...

James
Andrew
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#2

Post by Andrew »

Hi James,

Good to hear from you...

211 Headphone amp is a bit hard to take with you when travelling ;)

What about something smaller?

I've finally cottoned to what you were saying about the darn clever Russian chaps, they really have some hidden treasures out there.

You wouldn't believe the fun I've been having with the 6C45 and a few programmable shunts.

And look at the curves on this chappie.
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triode.jpg
JamesD
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#3

Post by JamesD »

Wow!!!

Nice straight curves and evenly spaced. There is a lot to be said for the 6C45 - it even works at very low voltage like 25 V on the anode...

I'm thinking a nice little travelling amp is on the cards - weight is the big problem so maybe it time to go OTL...

James
Andrew
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#4

Post by Andrew »

Ah but that's not a 6C45....... ;) Tho' I admit it could be....looking at the lines.

Onto the 6C45, its running about 215V @ 45 mA and that little valve makes a cracking spud amp.
Last edited by Andrew on Sun Feb 01, 2009 3:56 pm, edited 1 time in total.
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pre65
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#5

Post by pre65 »

Andrew wrote:Ah but that's not a 6C45....... ;) Tho' I admit it could be....looking at the lines.
.
I suppose someone had to ask !

What valve is it then ?
Life is what happens to you while you're busy making other plans. John Lennon

G-Popz THE easy listening connoisseur. (Philip)
Will
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#6

Post by Will »

Andrew
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#7

Post by Andrew »

Its a tetrode, triode connected, 6E5P.

-- Andrew
JamesD
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#8

Post by JamesD »

Ahh, that makes sense now. I was trying to work out the gm but not knowing the grid voltage spacing made it a guess...

I haven't used this one but it has a great reputation as a gutsy driver - used by no less the Romy the Cat...

It would make a great headphone amp too...

I'm still thinking OTL, so maybe differential CF with dc servos... The phones are 21ohms impedance so driving them from a similar value would work or even higher as the power loss means nothing they are so sensitive...

James
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#9

Post by Andrew »

Yes, the gm is about 30, mu 30-35 so should make a reasonable cathode follower.

I was thinking of trying it is the second stage of a tx-coupled Akido as the gain isn't quite enough for a 300B on its own, unless you run it as a tetrode. However, the tetrode curves had a bit of a slope on them so I suspect its a better triode than a tetrode.

http://www.tubecad.com/2006/08/blog0074.htm - 4th diagram from the top, using a pentode for gain.

cheers,

-- Andrew
JamesD
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#10

Post by JamesD »

Yes its neat, inplace of the 12B4? that would make a great driver for 300B

and a nice little power amp in its own right :D

I'm chewing over options for the headphone amp... I might even go with FETs this time and make it wallwart powered...

James
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ed
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#11

Post by ed »

this promises to be the biz....

need more than a walwart though

http://www.diyaudio.com/forums/attachme ... 1192313549
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#12

Post by Andrew »

JamesD wrote:Yes its neat, inplace of the 12B4? that would make a great driver for 300B
Yes, for the pentode gain stage of th Aikido I intend to work my way through the list on P Millet's pentode pages.

and a nice little power amp in its own right :D
Yes, I suppose it would...

I'm chewing over options for the headphone amp... I might even go with FETs this time and make it wallwart powered...

James
Be interested in that, could be a nice little item for the office.

-- Andrew
JamesD
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#13

Post by JamesD »

I like the First Watt amps. but their a bit over the top for headphones that are 120 dB/W sensitive!

For the office, hotel and car if I can get it to work :)

James
richardcooper2k
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#14

Post by richardcooper2k »

i think you brought that emu thing to one of the fests didn't you james ?

if i've got it right there is a school selling 21 of them off on ebay

here's one :

http://cgi.ebay.co.uk/Emu-0202-USB-Audi ... 240%3A1318

i'm tempted.....

new prices seem to have dropped too :

http://www.imusician.co.uk/acatalog/inf ... m=00057336
JamesD
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#15

Post by JamesD »

Hello Richard,

Yes, thats the beastie I used at the fest. Its an excellent little box and better than many commercial DACs. It is also fully recognised by the latest version of Ubuntu and drivers can be hacked to work with any of the linux flavours (OSS drivers).

The class A op amp outputs drive headphones very well.

At £64 it is a bargin and you can record through it too...

I guess I should go through my media pc setup - full multi-channel PVR, Internet streaming and capture, music library and all that tosh plus proper audio quality playback... I do it in the computer audio section though.


James
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