Have I mismatched my preamp/amp?


Hey all; I recently purchased a Cary SLP-50B which I will be mating to a Rawson clone of the Pass Aleph 2. When I started doing the math, I know I'm slow, I looked up the output impedance of the Cary and its Aleph 2 from the Pass site and it's 2.2 K Ohms I checked the Pass site for the Aleph 2, being I don't have the exact spec on the Rawson, and the input impedance is 10 K Ohms unbalanced and 25 K Ohms balanced differential. The Cary only has unbalanced outputs. So, how mismatched is this? I understand the 20:1 rule and I'm way off. My point was to use the Cary to warm up the sound a bit of the Rawson, its brutally sharp and I thought warming it up was a good idea. Advice/Comments are welcome. Jack
fz1jmp
There is nothing wrong with making and selling clones in accordance with a
licensing agreement; misappropriating intellectual property and selling for a
profit is worthy of criticism - as is theft in general. I'm not saying Rawson did
this (I don't know what arrangements exist between him and NP).

Now if you made a DIY project for yourself from NPs recipe book, than decided
to sell it to recover your costs and time, that would seem fair and ok in most
anyone's book. However, a production line of "F5" clones brought to
market, absent a license to do so, would not be ok. And it is also not Ok to buy
a product if you have full knowledge that it is the result of the "theft" of
intellectual property (which for some reason some seem to find
unobjectionable) -- intellectual property is just as real and worthy of
protection as tangible goods IMHO.

Now if there is no inventiveness in the Pass designs, and simply an application
of a public domain circuit design, then I suppose anyone can use them, but
even then I'm not sure it would be ok to sell it and brand it as a clone of a
better know company with credibility and brand equity. If you want to serve the
needs of budget segment anyone is free to do so, but not by copying someone
else's work without a licensing agreement (the Robin Hood model).

Again, I'm not saying one way or the other if Rawson falls into one camp or the
other here as I am not privy to any information on arrangements made with NP
- I understand he is a hobbyist and does this stuff for fun - though there does
seem to be an awful lot of Rawson stuff out there for a mere DIY hobby - so
maybe he has some licensing rights to copy and sell Pass/First Watt clones.
Rrog,
I've always been under impression that Cary is good but for each good Cary there's a better Quicksilver as a matter of fact.
Those are pretty amazing output impedances for any preamp, let alone a tube one, how does he do it? I enjoyed everything I ever owned by Quciksilver.

I believe NP designed (but did not build - designed to a price point specificed by Adcom) the Adcom 555 (not the mkII which was altered by Adcom) and no other Adcom amp. Is that the one you were not impressed with? Pretty cheap amp if I remember correctly - but touted as one of them giant killers at the time.
Those are pretty amazing output impedances for any preamp, let alone a tube one, how does he do it?

Lots of feedback. But if you check the 20Hz output impedance you will find it to be higher.
Atmasphere,
Isn't it more important to have minimized feedback on power amp vs. preamp?
As far as I know, the differential preamp stages have 100% feedback... Why do engineers need to avoid it technically?