In article , Keith G
wrote:

"Jim Lesurf" wrote in message
...
[big snip]


That's all very interesting but a little way wide of the point - forget
expensive, 'laser cut' options, my curiosity here is that in an amp
costing only 60 quid (and which includes 6 inputs, headphone socket,
phono stage as well as all the necessary ADC/DAC circuitry, power
supply &c.) there is a very useful *digital* (ie cheap) way of
controlling volume/treble/bass/balance/muting/'loudness' with some of
the major functions (not all) available on the (included) remote
control.

Yes, I'd agree. I was just pointing out that some people have an aversion
to anything 'digital', and that a 'digital attenuator' may have flaws, so
should assessed with due care. But the silicon for one is cheap, and should
be able to give good results if well done.

Note also that applying tonal changes (treble, bass, etc) is slightly more
complex, so again should be fine if well implimented, but...


If 'properly implemented' means that any artifacts, digital 'rounding
off' or whatever are *inaudible* there might be the possibility of an
inexpensive digital 'front end' which offers the convenience of remote
control on the main functions as well the additional capability to
adjust tone/balance/loudness/muting &c. (An amusing concept on a valve
amp!!)

Yes. However the above comment should be applied with caution in practice
since it starts by assuming that the imperfections *are* "inaudible". The
snag is that they may not be. For example, a digital volume control will
have a clipping level in a way that an analogue one does not. This may not
matter for some applications, but be vital in others. Hence "inaudible"
will depend both on the volume control and the specific use.

I don't have any real objection in principle to 'digital' controls. Indeed,
I tend to prefer processing signals in digital form when the process needs
flexibility, etc. However the reality is that an ADC-process-DAC-psu-clock
combination is electrically more complex than a pair of resistors. Hence it
gives the poor designer/maker more options for making errors. :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html