Subject: RE: [linux-audio-dev] New plugins, fixes etc.
From: Helin Mikko.A (NET/Tampere) ("Helin)
Date: Fri Jan 18 2002 - 17:17:31 EET
To be precise VOX AC-30 is push-pull but also Class A. Difference is
that with Class A amps both power tubes (on AC-30 both PAIRS or power
tubes) are working all the time, with Class AB amps only some time and
with Class B amps only half a time (other tube/pair works when Uin >= 0
and the other when Uin <= 0). But yes, Class A amps doesn't suffer from
x-over distortion. Actually x-over dist doesn't sound so good and though
many patents discuss this subject the common concept is that it's not a
thing which makes the tube sound. Anyway, many people like Class-A or AB
sound better, and fortunately it's quite easy to convert AB/B amp to
Class A amp just by using self cathode biasing in power stage (as in
AC30) vs. fixed biasing of Fender and Marshall amps (older Fender amps
like Deluxe that were p-p were actually self-biased but has less power,
then Fender updated the design in favour of output power and clean
sounds). I've got Blues Junior but haven't done any mods for it yet.
There are btw. amps which are switchable from self-biased to fixed
biasing and vice versa.
-Mikko
> -----Original Message-----
> From: ext Paul Winkler [mailto:pw_lists_AT_slinkp.com]
> Sent: 15. January 2002 21:48
> To: linux-audio-dev_AT_music.columbia.edu
> Subject: Re: [linux-audio-dev] New plugins, fixes etc.
>
>
> On Tue, Jan 15, 2002 at 09:32:43PM +1100, Erik de Castro Lopo wrote:
> > On Tue, 15 Jan 2002 11:16:57 +0200
> > mikko.a.helin_AT_nokia.com wrote:
>
> > It should be noted however that some of the really famous
> guitar sound
> > (ie Eric Clapton's Cream work) was done on Class A
> amplifiers which are
> > not push-pull at all :-).
>
> And lots of others... probably the most widely used Class A amp was
> the Vox AC-30, used by (among many others) early Beatles, Brian May,
> the Edge (U2). For many people, class A tube power amps are the holy
> grail of guitar amp distortion. Witness the price of a new Matchless
> DC-30 (basically a handmade AC-30 from highest quality parts).
>
> OTOH, we're probably more used to the push-pull sounds of most
> high-power tube amps: Marshall, Fender, et al.
>
> --
>
> paul winkler
> home: http://www.slinkp.com
> music: http://www.reacharms.com
> calendars: http://www.calendargalaxy.com
>
This archive was generated by hypermail 2b28 : Fri Jan 18 2002 - 17:10:51 EET