On 01/11/2012 09:41, Jim Lesurf wrote:
In articlec7mdnS1LOMpxEAzNnZ2dnUVZ_sSdnZ2d@giganews. com, Arny
Krueger
wrote:

"Jim wrote in message
...
In , Eiron
wrote:
On 31/10/2012 16:11, Jim Lesurf wrote:


Once they start, I'm sure we could coax some of them into deeper
waters...

Like building a SET power amp?

That's up to them, but I doubt I'd suggest that as the next step. :-)

Ab inito, though, I'll stick with suggesting projects that only use a
few AA cells and keep the voltages and powers down.


Idea: Build an amp that runs off of AA cells but puts out more clean
power than your average megabuck SET.

As a project it is an intriguing idea. However I'm not sure it would suit a
newcomer who'd only just managed to make a HeadDAC-2! It would probably
end up looking like a switch-mode convertor driving a 'digital'sic amp
module. [1] Possibly easy to assemble, but then end up wiping out radio and
TV reception for all the houses in the street! ;-

My thoughts would be more along the lines of an RIAA stage or a preamp with
genuine tone and balance controls. Easy to drive with batteries but allow
the more confident and capable to add a main psu. And of course, could have
its own headphone amp. :-)

TBH I can't say I personally have much interest in SET, and people still
can (I think) get the kits that first appeared in HFW if they are keen to
experience burns and high voltage shocks. ;-

What I have wondered about is a simpler and more conventional low-output
transistor 'Class A' circuit as again these are (in component terms) easy
to build. The snag is the need for decent heatsinking, so it puts the
burden on suitable metal-bashing. Alas, that's not my strong point as you
can tell from the, erm, 'inventive' use I made of a place-mat. 8-]

Slainte,

Jim

[1] I did wonder about a more extensive 'modification' of the design that
ended up being HeadDAC-2. To change the choice of op-amp and include a
small convertor (5V in to dual 12V out) so it would give more output.
However it would have ended up like a new design rather than a simple
're-paint' of the Velleman mini-kit. And might also have had 'rf' problems
due to the convertor. But I may have a play one day... Athough currently
most of my time is directed to looking into DTTV (and 4G) rather than
audio. Yesterday I borrowed an HP8591 analyser from my old group so I can
check the signals I get and calibrate some other kit I've bought.



I must remember the smiley next time I make a joke here.
Doesn't anyone remember the real McCoy and his sockpuppets
trying to get beginners to build dreadful one-triode amplifiers?

--
Eiron.