Impedance matching between 2k ohm phono pre and 100k ohm amps via passive pre


Howdy - 

I have a noob question about passive preamps.  

I am running my Wright Sound wp200c tubed phono stage (2k ohms output) through a passive preamp into two Dayens Ampino mono blocks (100k ohms input).  

It sounds good to my ears, but just wondering if this raises red flags to anyone?  Tortuga Audio says the ratio of amp to source should be more like 100:1, and I'm at 200:1 right now.  Cables are less than three feet. 

Thanks!
128x128subterranean6
The output impedance of the source is 2kohm, so the load it should be at least a 20kohm passive. The the output of the passive will be fine with the 100kohm input of the poweramp.

George -

Ah ok - that makes sense.  Noob that I am, it did not occur to me that passive pre's have in and out impedance.  

Seems I'll either have to change pre-amps or the phono pre.  Maybe.  I have a Schiit Valhalla 2 that I can try too, but there's no spec on input impedance.  


George - 

If I'm putting 2k ohm into a passive pre with an input impedance rated at 10k ohm, it means I'm not going to get 100% of the bandwidth? Signal?  

George -

If I’m putting 2k ohm into a passive pre with an input impedance rated at 10k ohm, it means I’m not going to get 100% of the bandwidth? Signal?
Yes you will.
Just that you may loose a "little" total level (no dynamic loss) from the output of the phono stage.
 As it’s "starting" to become a voltage divider with 2kohm into 10kohm, if you have plenty of voltage (>2v) to start with, it doesn’t matter.
But from my experience a phono stages generally has less voltage output than cdp’s or dac’s.
So better to go a 20kohm passive volume control.

Cheers George
George - 

Thanks so much for your response!

It seems this phono pre is a little weird in having 2k ohms out.  Manual does say it can "drive loads down to 600 ohms".  And it has gain knobs I can play around with.  

I'll keep playing with it.