[sdiy] DC-DC Converters

[Czech Martin]

True. Class D amps go even so far to deliver switched current to speakers,
if it is done in the right way and for the right application,
it seems to work very good.

Like always: it depends on the little details.

m.c.

> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl
> [mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of 
> WeAreAs1 at aol.com
> Sent: Sonntag, 21. März 2004 20:39
> To: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] DC-DC Converters
> 
> 
> 
> In a message dated 3/21/04 11:26:05 AM, 
> harrybissell at prodigy.net writes:
> 
> << They are switching power supplies. The little ones (charge 
> pump type -
> no inductors)
> can supply only a small current.  Larger ones (with inductors) can
> supply large currents.
> 
> Electrical noise is an issue - the high frequencies can get into VCOs
> etc and cause strange
> issues. But there is NO reason to dismiss them out of hand. 
> You may need
> to do some
> experimenting, and possibly use more sophisticated power filtering
> techniques... >>
> 
> Indeed, there is no reason to dismiss them out of hand.  Many 
> of our favorite 
> music-making machines have switching power supplies, and 
> you'd be very 
> hard-pressed to ever hear that the power supply is causing 
> audible artifacts, or 
> tuning/stability problems with VCO's.  For instance, 
> everybody's favorite 
> polysynth, the Oberheim Xpander.  Almost every professional 
> synth and studio outboard 
> effect unit that Yamaha has made since around 1986.  Another 
> *very* popular 
> analog synth that contains one of the crappiest little DC-DC 
> converters ever is 
> the Roland TB-303.  That didn't seem to stop it from becoming 
> the world's 
> most desired oddball "cult" synthesizer, and being used to 
> great effect on 
> lterally hundreds (thousands?) of records.  (and please don't 
> try to claim that 
> "real" TB-303's get their magic mojo from that little DC-DC 
> circuit...Everybody 
> knows the mojo comes from the vinyl carrying case strap.)
> 
> Michael Bacich
>