X10v3 vs XCANv3

[traf]

Hi All

1st post so please be gentle

I've been a bit of a MF tweaker for a while now - having modded various bits including X24K, XDacv3, XPrev3 and A5 DAB tuner convertion to a rather decent DAC. I currently own a KW250S and XCanV3. The KW has been modded to upgrade most of the caps, rectifier bridges and opamps (to great effect, surprisingly as it was pretty good to start with). Final tweaks on the valve front make it just about perfect driving my old Castle Severn 2s - I have settled on some NOS USA Amperex 7308s having tried Mullard CV2492, CV2493 (in 'GB' and 'Holland' Amperex E188CC form) and Siemens Halske E88CC.

I have recently purchased an XCanV3 which is currently 1/2 way towards having the full RG mod fit, but I can't help thinking that the valve buffer stage in the KW does much the same thing. The output circuitry is a bit different, but not much.

I briefly experimented last night and drove my (albeit ancient) Sennheiser HD420s directly from the pre-out sockets on the KW using a makeshift adaptor (speakers were unplugged first as 'mute' switches the pre-out off as well). The pre-out impedance is quoted as <50Ohms into the HD420s 300Ohms so it should be OK.....and it sounded very much OK. Very much like the XCans but with a bit more oomph/less flab, if you know what I mean. This is probably down to a better power supply in the KW. It doesn't go quite as loud but I think there is a series resistor on the pre-out which might explain this, or the Xcan circuit just has gain whereas the buffer hasn't.

So the question here is: Do I go the final step and further modify the KW to tap into the internal pre-out line to feed a headphone socket (thus being able to switch the speakers off without disconnecting them) or am I liable to damage something by continuing to drive my cans like this.

Put simply has anyone used an X10v3 as a headphone amp successfully?

I usually work on the principle that if it sounds OK, it is....except with valves it sometimes isn't.

thanks in anticipation - great forum by the way!

simon

[sometrolls2]

I've been hoping someone would try the 10V3 type output as a headphone amp.

[dejanm]

Aug 26, 2008 16:07:00 GMT traf said:

Hi All



So the question here is: Do I go the final step and further modify the KW to tap into the internal pre-out line to feed a headphone socket (thus being able to switch the speakers off without disconnecting them) or am I liable to damage something by continuing to drive my cans like this.

Put simply has anyone used an X10v3 as a headphone amp successfully?


simon

Hi Simon,

I do not know the layout of your MF KW unit, so I can put only some general comments to your first question.

I believe you can do that what you want. Probably you will have to put a switch (with relay) in order to have the possibility to select either headphone or speaker output. If done properly this aproach should work. I wouldn't do it though. First of all, putting anything in addition into a signal path is not a good idea. Especially not a switch or relay. I would go for a separate headphone amp.

Concerning your second question - no I haven't tried it. It is though viable idea. But again - I wouldn't do it. If you want a dedicated headphone tube amp then I would go for something that is SE(T) working in class A, without feedback. MF X-10D has a rather strong feedback - that is how this unit actually converts the impedance to the very low level at the output. Theoretically that means that if you are looking for ultimate transparency and you have very good phones, then SE(T) without feedback is a way to go ... But it has a price ...