"Dave Plowman (News)" wrote in message
...
In article i,
Iain Churches wrote:
Fairly typical of AF valve circuits. Hum.

A common misconception.
With a properly designed PSU C-L-C-R-C and with
attention paid to layout and ground buss, one can build
valve power amps with no hum or thermal noise even EAS
(ear against speaker) And it plays music to please the
most discerning ears.

My 50W PPP tube amp has a noise floor of 80µV
that's -106dB

That's not typical.

I have a Lowther LL26 (EL 34's PP) 26W at 0.1% THD.
It is half the power of my PPP amp, but still the noise
floor is only 120µV a very presentable -98dB.
It cost £46 in 1968 and was a *very* typical amplifier
of the period.

Both my Radfords (STA 25 and STA 100) are silent,
ear-to-speaker, as are the TL12s.

Don't confuse them with the Dansette:-)

Best regards
Iain