[HT cOz]

I think a table like this would be really handy for people looking at the Class D amps.




Does it look right? Should I add any info?

[jtwrace]

May want to add that the prices shown are for the amp board only.  That's not including the transformer and power supply board. 

Great job!  Maybe you can spread it on the monster Class D thread.  ??

[wushuliu]

I think a table like this would be really handy for people looking at the Class D amps.




Does it look right? Should I add any info?

And that would be a GOLD STAR for you, sir!!! 

[HT cOz]

May want to add that the prices shown are for the amp board only.  That's not including the transformer and power supply board. 

Great job!  Maybe you can spread it on the monster Class D thread.  ??

So you're thinking of something like this?

[jtwrace]

So you're thinking of something like this?

You 'da man!  That's why you get the big bucks sir.   

[poseidonsvoice]

May want to flip the 4 ohm and 8 ohm columns around, just cause some of us think of an 8 ohm load first and of course the wattage is less...it's just a preference that's all.

Great work otherwise!

Anand.

[HT cOz]

May want to flip the 4 ohm and 8 ohm columns around, just cause some of us think of an 8 ohm load first and of course the wattage is less...it's just a preference that's all.

Great work otherwise!

Anand.

So this looks more like a normal description of amp power.



Think we are ready for the big time or should we add things like input impedance, power supply amerage, ideal power supply, etc?

[srb]

I'm still confused on the CDA-258/SDS-258.  Back in February when I inquired about the updated heatsink for this model, Tom at Class D Audio said that a larger heatsink was now standard, and that it (CDA-258) would output ~ 375W/channel at 4 ohms.  It did not double it's wattage like the other models because "the power will not double due to current limiting protection circuitry".
 
But the photo and corresponding description on the website were never updated.
 
Steve

[HT cOz]

I'm still confused on the CDA-258/SDS-258.  Back in February when I inquired about the updated heatsink for this model, Tom at Class D Audio said that a larger heatsink was now standard, and that it (CDA-258) would output ~ 375W/channel at 4 ohms.  It did not double it's wattage like the other models because "the power will not double due to current limiting protection circuitry".
 
But the photo and corresponding description on the website were never updated.
 
Steve

Thats very interesting maybe better values for these are:
250W 8ohm, 375W 4ohm, & 750w 8ohm bridged???

[Danny Richie]

I spoke with Gary about this earlier.

There was some issue with some of these amps really being able to deliver the current needed to power some of the line sources.

Gary said to be sure and use a power supply large enough to really allow them to reach full power.

[srb]

Thats very interesting maybe better values for these are:
250W 8ohm, 375W 4ohm, & 750w 8ohm bridged???

That's what I was told (~375W @ 4ohm for CDA-258), but perhaps there is a reason he did not want to make the change on the website?
 
Concerning bridging, Tom said: "Only the 250W X 2 into 8 ohms is not recommended for 4 ohm in full bridge mode. Our other amps will run 4 ohm with no problem, either stereo or bridge."
 
Steve

[Rclark]

Would something like this suffice:

http://www.hol4g.com/ac/product.aspx?number=AST-LS-18A-220&p=178192&sc=0

[poseidonsvoice]

So this looks more like a normal description of amp power.



Think we are ready for the big time or should we add things like input impedance, power supply amerage, ideal power supply, etc?

Including the input impedance is a great idea. I remember for the CDA series it was horrendously low, like 3K ohms. For the SDS series, it was mucho better at 47K ohms. Adding the overall gain would be a good idea too, like 27 dB etc...

In addition, you should include recommended toroidal transformers from Antek, with perhaps links directly to the PDF file from their website. For example, I ordered the 400VA AN-4232, which has dual 32V secondaries, which will give you 45V DC secondaries when rectified. Recommended power supplies really vary, I would use as a bare minimum Tom's premium power supplies which give you a total of 28,200 uf of capacitance (or 14,400 uf per rail). I'm using 20,000 uf per rail or about 40,000 uf total (but I am building my own). I think anything above 60,000 uf is a complete waste of money and that may be too much actually. You don't want so much capacitance that it trips your fuse at turn on.

Anand.

[tg3]

Very helpful.

Please save your images as PNG or GIF, to avoid the JPEG artifacts.

[HT cOz]

Very helpful.

Please save your images as PNG or GIF, to avoid the JPEG artifacts.

Like this?

[Danny Richie]

I can tell you guys (without a doubt) that these things sound as good as the power supply. Noise in noise out. I highly recommend considering running them on batteries. They sound really good that way.

[srb]

I can tell you guys (without a doubt) that these things sound as good as the power supply. Noise in noise out. I highly recommend considering running them on batteries. They sound really good that way.

Is anyone running the Class D Audio amps on battery power?
 
If so, what kind of battery and charging configuration are people using to deliver +/-45VDC to +/-60VDC bipolar supply voltages to the amplifier board?
 
Steve

[Danny Richie]

Is anyone running the Class D Audio amps on battery power?
 
If so, what kind of battery and charging configuration are people using to deliver +/-45VDC to +/-60VDC bipolar supply voltages to the amplifier board?
 
Steve

We were using one of them at LSAF and running it and a buffer off of a single 12 volt AGM battery.

[tg3]

Like this?

The artifacts are much better.

[poseidonsvoice]

I can tell you guys (without a doubt) that these things sound as good as the power supply. Noise in noise out. I highly recommend considering running them on batteries. They sound really good that way.

I may eventually head that route. First I'm going to try Mundorf E-lytics, then Jensen 4 poles, then possibly a regulated supply using Paul Hynes shunt regulators, and finally battery. Should be an interesting process. The designer (Tom) seems to think that the design is impervious to power supply variations. I've never found a circuit, tube or solid state to be impervious to power supply topologies and variations. I've only found that the superior designs that have excellent common mode rejection, etc...are less susceptible to power supply variations, especially 99% of the products out there rely on your A/C outlet.

Anand.