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  3. 1323999458

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
mapman's avatar
mapman
21,924 posts
 
My rule of thumb is to look for 40Kohm input impedance minimum or higher as a general indicator to expect good performance with a tube pre-amp. I view it as an insurance policy to help achieve the kind of sound that I like, ie tight, clean, detailed, with good dynamics.

Based on that the ops gear does not appear to be a mismatch.
marakanetz's avatar
marakanetz
5,473 posts
 
Unsound,
Just to make you aware that Nelson Pass publishes his obsolete designs so the followers would still build components based on his design. Consumers will purchase the "cloned" products that match their budget. So having respect to Nelson Pass implies respecting his products and clones as well.
fz1jmp OP
33 posts
 
Well, thanks for all comments! I have not received the Cary yet, so I can't share my listening results, I will when I receive the pre of course. I know my ears are the ultimate judge.
I looked up the Pass Aleph 2 specs online and the low impedance was correct. However, Tim corrected me for his clone. Almarg; I thank you personally for that detailed explanation. I somewhat understand what your saying, basically where it needs the "headroom" it has it and should be fine. The cable runs are < 1 meter, so pretty short.
As for the "respect" comment; I was a) under the same understanding of what Marakanetz wrote and b) believing in a) allows me to enjoy the Pass sound within what I can afford.
mordante
511 posts
 
Unsound. Most of the designs by Pass are not that unique as some people think they are. I have spoken with some electronic engineers and according to them most of his designs are just text book. Like 99.9% of all amp designs.
unsound
7,315 posts
 
If that were the case, why are they marketed as "Pass clones"?
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