2. amps-preamps
  3. 129238-20253

Class D is just Dandy!

I thought it was time we had a pro- Class D thread. There's plenty of threads about comparisons, or detractors of Class D.

That's fine, you don't have to like Class D amps, and if you don't please go participate on one of those threads.

For those of us who are very happy and excited about having musical, capable amps that we can afford to keep on 24/7 and don't require large spaces to put them in, this thread is for you.

Please share your experiences with class D amps!
erik_squires

Showing 5 responses by doctor_lipp

doctor_lipp
12 posts
 
George,

Not only is it 1ohm @100hz, but it has a massive -90 degree phase shift at 100hz also, these two together mean almost a dead short as see by the amp. 

Where do you get your data on the Scintillas?  I owned a pair and measured the impedance magnitude and phase (scroll to the bottom):
http://www.lippaudio.com/apogee-scintilla/

No 90 deg phase shift at 100 Hz.  A very well behaved 1 ohm in that region.

- John
doctor_lipp
12 posts
 
Kenny
Unfortunately, I am not very well equipped with instruments to perform such tasks.

Do you have a computer / laptop with audio out?  Then all you need is REW (Room Equalization Wizard) which is free and a mic.  You can get a USB mic with a reference curve here for a very reasonable price.
http://cross-spectrum.com/measurement/calibrated_umik.html

- John
doctor_lipp
12 posts
 
Henry

It is very rare to find a Scintillas owner.  Are you located in Texas?

Former owner I'm afraid.  Parted with them many years ago - the original owner wanted them back.  Today I have a system based on the BG72 ribbon and 6 Carver hex cone woofers, and I just finished restoring a set of Carver Amazing Platinums with NOS ribbons and new woofers.  

- John

P.S.  Yes, I'm in Texas, the DFW area.
doctor_lipp
12 posts
 
Erik said:
REW is great, but measuring the speakers adds a ton of confounds. I say this as a speaker maker and integrator. And that's fine, but what I'm personally after is to understand how well these amps do electrically, as that will be the most clear. 

You can use REW to measure impedance and electrical transfer functions too (since Ver5).  Nice link on impedance measuring:
http://www.avsforum.com/forum/155-diy-speakers-subs/1340740-lilmikea-s-diy-impedance-measurement-jig...
doctor_lipp
12 posts
 
@erik_squires wrote:
One really interesting thing about the Technics however is the heavy DSP processing they rely on to flatten the electrical amplitude and phase response. I'm tempted to do this with a miniDSP to see if I hear any benefits.
I have been using a miniDSP nanoDIGI (stereo digital in, quad stereo digital out) to equalize and bi-amp / tri-amp.  Its very flexible.  Using it I was finally able to tame the wild bass modes in my listening room.  Get one, you won't regret it :-)  
More to discover