WAD KaT34 pre question

[Gromit]

Hi - I've been offered a friend's WAD KaT34, and am sorely tempted to snap it up as a. It's going for what seems like a good price (it's silver-wired and in as-new condition) with 2 sets of EL34's and b. I've heard it in my system and loved what it does.

Quick question - was the 34 originally designed to be used with a passive or active pre? I'm using an NVA P90sa passive with which the 34 sounded wonderful, no lack of dynamics certainly. Ian used the amp with an Audion Premier active valve pre. I'm wondering what may be the best combination. I know absolutely nothing about impedance matching etc but if it sounds right surely it's working right?

Thanks for any information.

[Ali Tait]

I don't know the specs. of the amp off the top of my head,but if it sounds great with the passive,then I'd say go for it.If there was an impedance matching issue,I'm sure you would have noticed it,given you have tried it with an active also.If it sounds good to you,then it is good! I don't think you can go far wrong wth a WAD amp of any kind.

[Gromit]

Thanks Ali - I'm pretty sure I'm going to go for it, especially as it was happy driving my Royds which aren't the most efficient speakers around (I think they're around 85-86db/1w). In fact it surprised me at its ability to get a grip of them where some amps I've had have curled their toes up slightly.

It was either this or getting myself a KEL84 kit - only trouble is that my soldering skills are non-existent.

[Ali Tait]

Well I would say the 34 will have more power than an 84,though I have an 84 and it drives my statics no problem.You could buy a built version though it would cost a bit more.

[RobHolt]

Richard, if this is the later version with chrome topped transformers its a very fine amp and very similar to the kit/kat 6550 that followed. In fact I think it's just a matter of swapping out a few inexpensive resistors and caps to turn the KAT34 into a KAT6550 - should you wish to.

My 6550 drives anything from easy 95dbw impulse horns, through Quad 57s to little 83dbw micro monitors.

Input impedance is high and input capacitance very low so it will work perfectly with the passive pre. In fact, the integrated version of these amps just put an alps 50 or 100k pot in front of the power amp.

Rob.

[Gromit]

Thanks guys - I'm seeing Ian tomorrow so will hopefully be enjoying some glowing bottles in the living room by the end of the week. The other choice would naturally have been the built KEL, but I do feel the Royds like something with a little more conviction in the power dept - of course I could be doing the little 84 a disservice here. I'm well aware of its capabilities though having owned one a couple of years ago. I stand by the fact that, within its comfort zone, it's quite possibly the most musically satisfying amplifier I've owned. It was driving Audio Note AX2's (90-91db/1w) at the time which seemed to be a wonderful match.

Another question (sorry!) do either of you happen to know the spec in terms of power output of the KaT34? I'm presuming it's in the region of 30w/ch?

Edit: Sorry Rob, meant to say the KaT's the chrome-topped one.

[RobHolt]

KAT34:

Power - 32wpc
Frequency response 15hz-85khz (-3db)
THD - 0.05%
Input sensitivity - 300mv

Clips very gently and the dynamic power output is far in excess of the RMS figure.

[Gromit]

Good work Rob - thanks.

[Gromit]

Here it is playing away...



Sounds very good - I'm slightly aware of a lack of control when the going gets heavy, wondering if the Royd Minstrels are perhaps asking a little too much of its power reserves. Will put the Merlins on tomorrow as they're slightly more efficient.