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Gear / Technical Help => Playback Forum => Topic started by: dmonterisi on January 21, 2004, 02:03:57 PM

Title: digital amplifiers
Post by: dmonterisi on January 21, 2004, 02:03:57 PM
anyone know of some background reading on digital amplifer technology?  shit's pretty confusing just based on manufacturer's websites.  thanks.
Title: Re:digital amplifiers
Post by: MattD on January 21, 2004, 07:30:31 PM
I couldn't find a good link, but can explain the basics to get you started:

Most amps are class A/B. Class A means that there is always current in the output stage going to the speakers, so long as the amp is on (even if no signal from the input stage). At higher levels, additional current needs to be turned on (Class B). However, it is this switching on and off that is inefficient. An amplifier functions best when it is either 100% on or 100% off. Anything in between is usually wasting a lot of energy as heat.

All on or all off ... 1 or 0 ... sounds like digital! Indeed, a digital amp works by controlling the switching between the current stages. In the same way that if you sample at a high enough frequency, it sounds continuous, if you switch the higher current on and off fast enough, it sounds continuous. My amp, which is a digital switching amp (PS Audio HCA-2), switches at 500 kHz - way fast enough!

The input and output stages are still the same as many other amps, but the current control is what changes (that's the digital part - the on/off current switch).

HTH. If you want to listen to one, let me know :)
Title: Re:digital amplifiers
Post by: dmonterisi on January 22, 2004, 10:24:34 AM
thanks matt...that makes sense.  given that so many of these are getting good reviews at good prices, i'm debating what the next step is for my home system...want to bring your amp over so i can hear my speakers with it?
Title: Re:digital amplifiers
Post by: Nick's Picks on January 30, 2004, 07:42:25 AM
Read this review of the PS-Audio HCA2 digital amp..it explains digital amp technology pretty well, and is a gushing review of this relatively short money amp.  

http://www.positive-feedback.com/Issue9/hca2.htm

Carl is looking to buy one of these suckers to drive his new VR4jrs
Title: Re:digital amplifiers
Post by: Nick's Picks on January 30, 2004, 07:43:53 AM
fwiw...I just found out that Von Schweikert (albert himself...) voices all of their speakers with digital amps.
go figure!

I hear great things about the Bel Canto 200.2 amp.  They usualy go used for about a grand or there abouts.  I'm toying w/the idea of picking one up, but I really want to try out some tube power !!
Title: Re:digital amplifiers
Post by: carlbeck on January 31, 2004, 05:17:13 PM
Well I really want to TRY a digital amp but my dealer will not let me :) He wants me to try some tubes, we shall see but for the money I think any of the digital amps will give you a huge upgrade.
Title: Re:digital amplifiers
Post by: dmonterisi on January 31, 2004, 06:59:04 PM
it's funny, mattd brought his HCA-2 over to my apartments, we're listening now, sounds very very nice.
Title: Re:digital amplifiers
Post by: Tim on February 02, 2004, 11:59:48 AM
Damon, you liked the amp?
Title: Re:digital amplifiers
Post by: dmonterisi on February 02, 2004, 01:36:51 PM
yes, very much...it had a deep sound, very full, but also laid back and nonfatiguing...very nice indeed, am strongly considering picking one up.
Title: Re:digital amplifiers
Post by: Tim on February 02, 2004, 02:08:08 PM
the technology is very intriguing. thanks for the mini-review
Title: Re:digital amplifiers
Post by: Wes on February 03, 2004, 11:03:32 AM
Damon,
If your amp shopping you may want to look into krell.  I just picked up a kav-2250 and am loving it.  A kav-250 can be found on audiogon for cheaper than a hca-2 and according to this review the 250 outperformed the hca-2  
http://www.soundstage.com/revequip/psaudio_hca2.htm
Title: Re:digital amplifiers
Post by: dmonterisi on February 03, 2004, 11:06:57 AM
thanks for the heads-up wes...i'll look into the krell...it's so difficult, you can't audition everything.
Title: Re:digital amplifiers
Post by: scb on February 03, 2004, 11:25:48 AM
damn wes, ditching the arcam so soon...

i'm loving mine :)
Title: Re:digital amplifiers
Post by: Wes on February 03, 2004, 11:31:10 AM
damn wes, ditching the arcam so soon...

i'm loving mine :)

I'm actually trying to put together a seperate dedicated stereo setup, but I'm not sure its going to materialize, I may end up replacing the p4 with a 5 channel krell, i'd really like to add a couple of monoblocks to the setup as well..  if i only had $15K ::)