From: "Ruud Broens"
Subject: Linestage, pre-stage revisited
Date: zaterdag 27 december 2003 8:28

~~hum seems to be the problem~~
-separation 2 --

A new challenge has just entered the marketplace, tube lovers:

The Krell $3000,- list price SACD player !!
Some spec's (by hearsay, might be off somewhat, check the web):
.. 120 dB s/n at 2 V rms output
.. 110 dB channel separation
.. discrete output stage with 1 MHz bandwidth, switchable
output filtering, i guess up to 80 KHz @ -0.5 dB output
.. sounds better than the 'reference' USD 17K player...

So , assuming this to be your signal source, what do we
want to design a line-stage our pre-amp stage for ?

pre stage
assuming a 10..50 * amplification, line input 20 Vrms

line stage
needs a noise + hum level below 20 microV then.
unless your balancin' act is of uncanny precision, i'dd
say that excludes DH tubes, unless DC or HF heating
is used. Ruler flat transfer up to at least 80 KHz.
distortion & - characteristics..there is some of the Art..
60 microV rms crosstalk is tough, too, very well regulated
supply requirements.


Etc., etc.

Anyone has any suggestions, build stages possibly measurements
we'd like to know.

Rudy et RAT

"Rudy"


A new challenge has just entered the marketplace, tube lovers:

The Krell $3000,- list price SACD player !!
Some spec's (by hearsay, might be off somewhat, check the web):
. 120 dB s/n at 2 V rms output
. 110 dB channel separation
. discrete output stage with 1 MHz bandwidth, switchable
output filtering, i guess up to 80 KHz @ -0.5 dB output
. sounds better than the 'reference' USD 17K player...

So , assuming this to be your signal source, what do we
want to design a line-stage our pre-amp stage for ?


** Spec chasing is just as mindless as a dog chasing its own tail.



pre stage
assuming a 10..50 * amplification, line input 20 Vrms

line stage
needs a noise + hum level below 20 microV then.


** Gobbledegook.


unless your balancin' act is of uncanny precision, i'dd
say that excludes DH tubes, unless DC or HF heating
is used. Ruler flat transfer up to at least 80 KHz.
distortion & - characteristics..there is some of the Art..
60 microV rms crosstalk is tough, too, very well regulated
supply requirements.


** This puppy is going round in very tight circles.






.................. Phil

I can't help but shouldn't the "K" be replaced with a "T" and the
"e" with an "o"? ;-)

Kind regards, Eike