"Mytek Empire monoblock power amps, with GaN based technology."

Just got an email back from admin, they can’t do it.

Input impedance is too low for many good tube preamps. 10k is just too low. I really dislike it when I see amps with input impedances that low. Just a shame and should be avoided by the builder.

Yes I mentioned this also in another thread, that it’s not tube preamp friendly or passive pre friendly.

It’s just wrong and there is really no reason (except one) to design poweramps to have input impedances this low, they should all be >47kohm (which was the industry standard) like many tube and even SS amps are.

I said "except one" reason.
Years ago, there was a power amp manufacturer that did the same silly low input impedance, and it gave his 10ohm output impedance preamp the sonic edge into his poweramp/s  over all other preamps in and A/B shootouts. (marketing ploy??)

Cheers George

GFi

Ask to have Tammy contact you. She is the one who authorized taking down my thread about the EVS 1200 after Ric asked that I take it down as he was no longer physically capable of continuing to make them

10K Ohms is too low for tube preamps? Since when? That’s relatively, but not absolutely, high. Low impedance to me is in the 600 to 5K range.

Please keep in mind that a "low impedance amplifier" is not the same as with low impedance speakers. The amps present a flat, resistive load. This means that there are no hills and valleys in the response curve like with a speaker attached to a tube amp.

Worst case scenario for most tube preamps is that you will lose a little bass due to the output coupling capacitor which is in the 1uF to 4uF range and a little maximum gain (which you don’t use anyway).

A tube pre with 1uF output caps could be down around 5 dB at 20 Hz (I’m in the middle of a few things so my math could be a little off). With 2uF caps around -2.9 dB. This may actually be helpful in the right room!

Look at this example:

https://www.stereophile.com/content/zesto-leto-ultra-ii-line-preamplifier-measurements

It handles 600 Ohms output just fine.  My point is, we can't universally exclude 10K input impedance amp from use with tube pres.  Some may do awful with it, but I suspect many will be fine.

Our preamps can drive 10K ohms no worries. Our MP-1 and MP-3 can driver 600 ohms no worries.


Having said that a 10K input impedance will exclude ARC preamps and a good number of other tube units as well as sources if a passive volume system is used. I don't see why the input impedance would be that low for consumer gear; the input circuit is opamps anyway, which can be set up to have input impedance as high as 1M.

the input circuit is opamps anyway, which can be set up to have input impedance as high as 1M.

Higher impedance = higher noise, but 25K to 50K is more typical than 10K for a solid state amplifier. It’s not exactly low either to me... it is still 17x more than 600 Ohms.

I'm not surprised at all your preamps can drive 10K. ;-) Most should.