Cqwet Dbdfte
Well-known member
- Joined
- Oct 2, 2023
- Messages
- 405
The audiophillies do not trust measured specs presented by marketing geniuses, as a listening test may render measured numbers irrelevant. Psycho acoustics has some ways to go and should not be dismissed. Old tube equipment may measure "bad" and still produce good results.
THD, noise, IM can be measured easily, but scores what's wrong with equipment and implies a reciprocal would be goodness on a linear scale.
Not so fast. The ear generates its own harmonic distortion.
Some harmonics sound OK, som do not, this should be weighted on an applicable value scale.
Static measurements would be OK for AC power delivery, but not music and speech with very high peak to average ratio. FTC got into the picture in the 70's to regulate audio power amps like they were toasters, which set off a chain of unmusical events in the development of power amps. Not sure we have recovered.
A uA741 with gobs of feedback beats any tube preamp, until you listen to them.
Very few tubes are needed for a lot of gain, with no feedback needed, and by virtue of a few hundred volts supplied to the tubes the clipping level is not much of an issue.
Getting 100dB of clean gain with vanilla OP amps requires lots of feedback, with many transistors in signal chain making intermods a rough landscape.
If there is bad data it may not need to be presented, some favorable single operating point may be enough.
Pro audio is different than consumer audio, the customers are tougher, but have budgets, time limits, and other concerns.
Their perceptions and expectations may not align with the average music consumer.
Tubes are long from dead and OP amps are getting better.
THD, noise, IM can be measured easily, but scores what's wrong with equipment and implies a reciprocal would be goodness on a linear scale.
Not so fast. The ear generates its own harmonic distortion.
Some harmonics sound OK, som do not, this should be weighted on an applicable value scale.
Static measurements would be OK for AC power delivery, but not music and speech with very high peak to average ratio. FTC got into the picture in the 70's to regulate audio power amps like they were toasters, which set off a chain of unmusical events in the development of power amps. Not sure we have recovered.
A uA741 with gobs of feedback beats any tube preamp, until you listen to them.
Very few tubes are needed for a lot of gain, with no feedback needed, and by virtue of a few hundred volts supplied to the tubes the clipping level is not much of an issue.
Getting 100dB of clean gain with vanilla OP amps requires lots of feedback, with many transistors in signal chain making intermods a rough landscape.
If there is bad data it may not need to be presented, some favorable single operating point may be enough.
Pro audio is different than consumer audio, the customers are tougher, but have budgets, time limits, and other concerns.
Their perceptions and expectations may not align with the average music consumer.
Tubes are long from dead and OP amps are getting better.
