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 Although I still have four 833 in the cupboard...
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...
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.
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.
Although I still have four 833 in the cupboard...
