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
h2oaudio
38 posts
 
Hi John,

Thanks very much for the tip on the microphone and the software. I will check it out.  Sorry you have to give back the Scintillas.

Erik, Agreed. The room plays a big part as well and among other things.

Kenny, Looking forward to your review, especially the difference compared to the Ncore.

If anyone here interested in hearing the H2O, I am willing to send it for you to test drive in your system. No string attached of course. I would be very interested to read your review on the differences, especially compared to the Ncore and other icepower amps that you have.  Please remember though, the H2O has 8 kohm input impedance so you should have an appropriate preamp to drive it properly.

Henry
erik_squires OP
15,996 posts
 
If it were possible to measure, I'd ask for these amps to be measured with a 1 Ohm resistor at 2.83 Volts. :)  About 8 Watts. Let's see that first.

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.

If we try to measure just the speaker/room we won't have any idea what is due to the speaker, and how much is due to the amp/impedance interaction.

If I remember where my oscilloscope is I may do this with mine.

Best,


E
erik_squires OP
15,996 posts
 
By the way, I just ran the numbers on that.

Based on output impedance, and assuming a 1 Ohm speaker impedance the ICEPower 250 A would droop around 2.2 dB at 20 kHz. That’s not unacceptable, and in line of what a tube amp would do to a lot of normal speakers.

Pro: A gentle glare reducing effect.
Con: Removes air, dulls top end.

A bigger concern to me would be the speaker efficiency and output power of the modules used.

Also, one not well known thing about these modules is that their cooling matters a great deal. The power rating increases with better heat sinks. Some manufacturers stick these in sealed speaker cabinets but the power gets derated.

Best,


E
doctor_lipp
13 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...
erik_squires OP
15,996 posts
 
Ah, fine. :) That's fancy.

All we really need is a signal generator, and voltage meter at a couple of frequencies.

Best,

E
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