Impedance Question: Tube Preamp with SS Power Amp


Having researched this issue with the archived threads, I am still having difficulties understanding the problems of impedance mismatch between Pre and Power amps. As a budding audiophile moving onto my first separates Pre/Power, I want to know more about impedance matching. I have several questions that I hope veterian audiophiles can help me out with.

1)Is the 10:100 ratio between the output impedance of preamp and input impedance of the power amp an absolute rule?

2)What would happen if impedance mismatch do occur? Will the sound be any less satisfying?

3)I understand that Tube preamps generally have higher output impedance values compared to SS, so does that make it problematic to use it with a SS power amp even though tubed preamps are often priased over their SS counterparts?

I ask these questions because I recently purchased a tubed Preamp (Musical Design SP-2B)that has an impedance of 2K Ohms. I want to match that with a SS power amp with an impedance value of 20K Ohms. Am I cutting it too close? (exactlly 10:100 ratio) Or are all of these issues irrevalent and I should just listen to that setup and hear for myself if it would work or not? Thanks in advance for the answers.
speedracerucr

Showing 6 responses by johncusick

Hmmm:
So I'm looking to hook up my AR Ref one MK2 with a pair of Krell 350mc's. Is this a mismatch? Must I do the internal jumper changes that Krell recommends?

Thanks
John
So where do I go to find out if my AR Ref One MK2 is one of those tube preamps that puts out too much DC ???
Just to follow up - I spoke to Leonard at ARC and he clarified for me the fact that the Ref One has DC capacitors in it's output to filter DC from the Amp. So unless a tub blows or some such crisis the Krell's should be ok. He thought it to be a reasonable gamble to leave the jumpers in the Krell so as to keep the capacitors out of the signal path.

Thanks all
John
Vladimir you're piqued my curiosity.
Can someone walk me through how to assess the impedance charactreristics of both my Krell 350mc's and the ARC Ref One Mk2. I'm sure I can go to the owner's manuals but I just don't have a clue as to what I'm looking at.

Thanks
John
Ok. Thaks for that. And if I go to my ARC manual, in the Spec section under Output Impedance it states:
400 ohms Balances, 200 ohms SE main(2),
20K ohms minimum load and 2000pF maximum capacitance.

In the Rated output section it states:
4V RMS (2V RMS SE) into 100K ohms balanced load.

My proplem is I don't know how to make sense in comparing the two.

AGH!!!!, so you wanted to be a carpenter...grasshopper

Thanks

John
Thank you. It all makes sense once it's explained to me.
They sure sound great together.

John