"Jim Lesurf" wrote in message
...
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',


They *do*....???

(How strange!! ;-)


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.


Yes, if not done at least reasonably well then best not done at all, like
most things. I don't think these cheap amps would suit the more demanding or
perhaps, more discerning user, but bearing in mind the price, the sound
levels do go up and down much like you'd expect them to when you press the
appropriate buttons (or turn the knob)!!



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


Yes, I can see that it might be a bit more complicated. Asitappens, I'm not
a great Tone Control user myself (apart from hacking the treble off a bit on
a *really* busy record) but I think it's always good to have the option.



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.


Sure...



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. :-)


Yes, I can see that it does but, as someone else has said, the cost of
fitting and manually wiring up an analogue pot is likely to be greater than
the cost of the necessary digital components on a PCB.

FWIW, I've had a fair amount of (mild) grief myself from carbon volume and
tone pots - not to mention hard-wired input selector switches!! When these
buggers play up it is a serious inconvenience (especially to non-DIYers) and
the effects on sound quality can be quite severe - silence on one channel or
the volume blasting through flat out on both, for instance!! (Been there,
done all of that!!)

Perhaps I'm naive, but I think the days of truly dodgy electronics are well
past us. It's still possible to buy crap of course, but mostly I think we
are getting more bang for our bucks than ever before and I don't think
manufacturers playing in an international arena are going to risk their grip
on the markets with anything too pooey....??

PCB appliances are generally pretty marvellous for what they cost these days
(ever scruted a computer card or motherboard closely?) and even the latest
hard-wired stuff like the Chinese valve amps seem to be of a very high
standard - I remember the pics of the internals of Fleetie's amp (the first
of the Chinky Cheepies in this group) and the response at the time was
generally one of people being quite impressed with all the gubbins inside
it. Since then, my own 'investigations' have proved that all the Chinese
amps I've seen so far have been built better than I could manage myself!!
(OK, not saying a lot, I know!! ;-)