Dissing DSD?

The subject of PCM vs DSD is huge one, but to summarize, I've havent heard compelling evidence that DSD sounds any better than high rate PCM, plus I was impressed with tracks converted from DSD to PCM.  I also have some technical background here ---- having written algorithms and simulated them to see what happens spectrally with BDM (bit density modulation, a.k.a. pulse density modulation) vs PCM.  Theoretically, there is more information in PCM.  So, if PCM isn't "broken", why fix it?  The BW issue is addressed by high sample rates, especially above 100kHz Fs.  Please, no throwing things, DSD fans!  Don't get me wrong, I'm a big fan of one-bit, but mostly in the world of A/D and D/A conversion "guts" (nowadays, what happens "inside the chip")....

Audio Enthusiasts and Audiophiles ---- Meetup Group

Well, friends, I've concluded that someone else needs to take over this group:
http://www.meetup.com/Audio-Enthusiasts-and-Audiophiles/

Just not enough time in the day lately to do it justice.

Looking for a volunteer to take over as leader.  The group has 25 members, and could easily be grown with proper advertising.

Thanks.

-Tommy O

Revitalization !

Welcome back, bloggers!

We're getting ready to post about "sticky topics" in audio....  You may have seen our "TRUTH in Audio" thread, one of the most popular threads ever on Audio Circle.  Well, that's what we're talking about!

Stay tuned.

For offers/info on Cherry Amplifiers and other great audio hardware, sign up HERE:


Thanks.

-Tommy O

Does the Cherry Amp sound like tubes?

Customers have said that it sounds much like the smoothness of tubes but with the authority and transient response of Class-A.

One customer said: "While the amp does not posses that warm, liquid, syrupy sound of a single ended triode, it is similar to an ultra linear tube design in sound"

Another said: "I switched my VAC amp back in yesterday, and while it certainly does things that people like tubes to do, the soundstage is narrower and at the same time more diffuse"

And another: "I find the Cherry to be the best compromise I've heard between tubes and SS in my systems"

So there you have it....  Somewhat like tubes, but better.

Other places to get Digital Amp Co. information

We are thinking of transferring the content here to other places. Please feel free to comment....

We have a web site (needs work as of today):
http://www.digitalamp.com/

We have a facebook page:
http://www.facebook.com/DigitalAmpCo

We have a circle on Audio Circle:
http://www.audiocircle.com/index.php?board=174.0

It's a daunting task to manage all these things, so we're thinking of consolidating.

-Tommy O

A word about load dependence...

There is no such thing as "completely load insensitive"...

Also, it takes wrapping feedback around the output filter to REDUCE load dependence, and in our experience, this affects the sonic quality of the amp in a negative way --- no pun intended. In fact that "too much negative feedback" sound (sometimes associated with Class-AB amps) is just what you get with all the phase margin compensation that's required to do so. As long as you're not driving a ridiculously low impedance, a low feedback design sounds so much cleaner than one designed to do better on the bench than into your ears. We can all agree that bench measurements don't tell the whole story. Without writing a book on this topic here, lets just say that we started with a design that was excellent on the bench, then tweaked it over several YEARS to get it to sound the way it does.

I have been designing Class-D amps (and listening to them) for more than 20 years, and these opinions are not based on some fly-by-night theories. There are many misconceptions regarding Class-D technology, and companies that take the risk of designing their own Class-D amps from scratch can easily fall short from inexperience. Same goes for pre-fab module makers. I have seen audio companies employ switching power supply designers that have never designed an amplifier in their life to build their "proprietary amp technology". It is also important to know analog amplifier design in order to make a good "digital" amp. Yes, I know there will be somebody out there to once again point out that Class-D doesn't mean the same thing as digital, blah, blah, blah. I designed my first analog audio amp when I was in grade school, by the way... Designing analog amps is a good way to learn what results in good sonic performance versus good bench measurements. It can be considered a good lead up to digital amp design --- a prerequisite.

-Tommy

2.5mm plug for remote power control

If you'd like to connect external power control and make your own connection at the amp side, try the CP3-1001-ND solder type plug from Digi-Key.

Here's a link:
http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.z_homepage_link=hp_go_button&KeyWords=CP3-1001-ND

How to use external power control is explained earlier in this blog. Thanks.