2. amps-preamps
  3. 1040514389

Matching CD out to Amp input 2v/20db ?

I want to run CD direct into my pass aleph 3 amp. Most of the CD players I have been looking at (mail order) run 2 v output. The Pass has 20 db of voltage gain. How can I calculate if this is going to be a match? I would like to run direct with no volume, but at most would want to use a passive preamp. Would this work, and if not what sort of output will I need from my CD player?

Thanks, Shawn
sargon2003
2 responses Add your response
sogood51
2,157 posts
 
I am going to try a passive transformer volume control in my system (sony xa777es player and krell ksa-250 amp). I have it on order from bent audio and it should be here soon. Transformer volume controls may be the way to go if you go passive. I will post on what I think after I check mine out. My cdp is 2v output also.
kr4ef94
208 posts
 
1. A voltage gain of 20dB is equivalent to 10x the voltage. This means that with full 2v input, the amp will try to put out 20v. Into an 8ohm load, that means 2.5 amps or 50watts.

2. As for a passive, which seems preferable since CDs do vary in their levels and running direct cannot let you compensate, that depends on the output impedance of the transport and the input impedance of the amp. What are they?
Log in to respond
More to discover
80x80
Ayon Audio AYON CROSSFIRE P/A STEREO AMP
80x80
TriangleART L200 MK2 Dual Mono Tube Preamplifier
80x80
Mark Levinson No 433