glass or sand

SCompRacer

sucks2beme wrote: »

600a
it hasn't been calibrated in a very long time.

I've got the successor to that, the 6000. I got it from Brent Jesse Recording & Supplies fully tested and calibrated along with some nice tubes I purchased. He sells a 6L6 calibration tube for $65. It can be used to calibrate as well as test accuracy of the tester.

http://www.audiotubes.com/testcal.htm

Main thing with tube pres and SS amps, watch the impedance. Some folks recommend the amp be 4-10 times higher than pre amp output. The result of a high impedance source driving a low impedance device is the bass will roll off.

My tube pre amp outputs are 600 Ohms balanced, 300 Ohms SE and Audio Research recommends a minimum of 20k Ohms amp input impedance. I run balanced out and my Krell KSA-250 has 47k Ohms input impedance so I'm well above min and it sounds great.

tonyb

SCompRacer wrote: »

[The result of a high impedance source driving a low impedance device is the bass will roll off.
.

Cha-ching....a topic we don't talk enough about anymore. Todays gear maybe not so much but when we start combining tubed/ss gear and especially of vintage heritage, something to consider. Should maybe make a good explanation and make it a sticky.

voltz

^^^^^

Agree, good stuff here - great info!