View Single Post
  #6   Report Post  
Posted to rec.audio.tubes
Iain Churches Iain Churches is offline
external usenet poster
 
Posts: 462
Default Best Way to Attenuate


"west" wrote in message
news:uFLbi.6710$xg4.2401@trnddc08...
Can we take an off the shelf CD Player and install , let's say a 10K
stepped
attenuator or Alps type pot inside the CD player on the output line? Would
this make a cleaner audio input to the tube amp? The 2 alternatives are an
outboard passive "preamp" with let's say 100k attenuator or installing it
inside the amp. I tried the passive preamp route with mixed results but
got
straightened out from info in a previous thread by using a much shorter
interlink cable.


The answer became clear in the previous attenuator thread, I think.
If you must have an attenuator followed by a long cable then it should
have a cathode follower.

I have settled on a cathode follower signal selector/preamp
(just less than unity gain) with a balanced line output so that I
can run a cable from the top of the house down to my music room
on the lower ground floor when required with no losses.

I lent this same preamp (FR 10Hz to 100kHz +/- 0.5dB) to a friend
who had been using a passive controller with a long cable. He
thought the CF was "bright" ! Draw your own conclusions:-))

Normally, if I had a single signal source, say a CD player
I would forget about the preamp altogether, and have a stepped
attenuator (100k) on the grid of the first stage of the preamp and
built in to the same chassis (leads as short as possible) I did
this on my 25W amp.

I am still interested to try the transformer attenuator, but I guess
this will have to wait until after the summer now.

Regards to all
Iain