New Class-D High Power amp boards @ PE...thoughts?

[lucasa.miller]

Anyone have any thoughts on these (http://www.parts-express.com/wizards/searchResults.cfm?searchFilter=classd_high_power_a mp_boards) boards?

I was looking at the 6x100 amp board but in the manual it states you can't send the same signal to more than two of the outputs. I would have used it with Mini DSP to go active on my L-C-R speakers.

[mintos]

I think they're re-badged Lepais. I think i saw similar stuff on lepai's own site.

[jclin4]

Looking at the 50W @ 8 Ohms board: 10% THD. The price is so low compared to the ClassDAudio CDA-224 board I'm using, I had to go back check the latter's THD specs: 0.02%

So I guess you get what you pay for (in this case).

[XtremeRevolution]

Looking at the 50W @ 8 Ohms board: 10% THD. The price is so low compared to the ClassDAudio CDA-224 board I'm using, I had to go back check the latter's THD specs: 0.02%

So I guess you get what you pay for (in this case).

Don't quote me on this, but I'm fairly certain it will produce output with much lower distortion below that maximum power rating.

[lucasa.miller]

Looking at the 50W @ 8 Ohms board: 10% THD. The price is so low compared to the ClassDAudio CDA-224 board I'm using, I had to go back check the latter's THD specs: 0.02%

So I guess you get what you pay for (in this case).

The power ratings on the Class D amps PE is selling are a little misleading. The 2 x 300 watt amp here (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=320-309) is comparable to the CDA-224

The 2 x 300 watt amps specs are on Sure's website here (http://www.sureelectronics.net/goods.php?id=1584)

50w @ 4 ohms .02% THD
100w @ 4 ohms .03% THD
200w @ 8 ohms .4% THD

It's $99

[jclin4]

The power ratings on the Class D amps PE is selling are a little misleading. The 2 x 300 watt amp here (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=320-309) is comparable to the CDA-224

The 2 x 300 watt amps specs are on Sure's website here (http://www.sureelectronics.net/goods.php?id=1584)

50w @ 4 ohms .02% THD
100w @ 4 ohms .03% THD
200w @ 8 ohms .4% THD

It's $99

I wasn't sure if I was comparing apples to apples, but the specs you posted are much more in line. Even at $99, it is still cheaper than ClassDAudio.

But the fan! I would worry if it could be noisy; don't know.

[natehansen66]

Anyone have any thoughts on these (http://www.parts-express.com/wizards/searchResults.cfm?searchFilter=classd_high_power_a mp_boards) boards?

I was looking at the 6x100 amp board but in the manual it states you can't send the same signal to more than two of the outputs. I would have used it with Mini DSP to go active on my L-C-R speakers.

Like any amp, you can route the inputs however you like. It would work fine with the miniDSP or any pre-pro etc.......

[neildavis]

Looking at the 50W @ 8 Ohms board: 10% THD. The price is so low compared to the ClassDAudio CDA-224 board I'm using, I had to go back check the latter's THD specs: 0.02%

So I guess you get what you pay for (in this case).

There is a discussion of some of these amps in this thread: http://techtalk.parts-express.com/showthread.php?t=229808

The real standout in this group is the Sure 2x250W IRS2092 amp. It appears to be about the same as the CDA-258, but at a much lower price. Not made in America, of course, but when the price is less than half, you have to think twice about your ideals :o.

[Pallas]

There is a discussion of some of these amps in this thread: http://techtalk.parts-express.com/showthread.php?t=229808

The real standout in this group is the Sure 2x250W IRS2092 amp. It appears to be about the same as the CDA-258, but at a much lower price. Not made in America, of course, but when the price is less than half, you have to think twice about your ideals :o.

You mean this one? (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=320-313%20%20%20%20%20%20%20%20&FTR=irs2092)

Hmm...what would it take to make a 6-channel amp out of those? Just find the right PS (which is?) and wire everything up? Or is it more involved?

Home amp, as in for 2-way LCR mains with active crossovers.

[jcpahman77]

I've done a little research on these amps and have also come across seemingly misleading information about their distortion characteristics. From what I've read they make their rated power with the highest rated input power (30v IIRC). Could these work in a mobile application with just 12-14.4v?

[woodtradesman_audio]

I'm surprised nobody has mentioned it but some of those sure amps have 10% THD. that's insanely high THD.

[neildavis]

I'm surprised nobody has mentioned it but some of those sure amps have 10% THD. that's insanely high THD.

This was addressed in the link I posted. Audiophile amps are usually not specified at 10% THD, but that level is commonly used for HT and automotive amps. The amps are actually fairly clean at lower output levels. Look at the attached chart--this chart is in the Sure manual for the "1x600W" amp.

21156

[blank264]

There is more info on these boards at diyaudio. I've read a few things about the sure boards that leads me to believe they are not up to par:(the tas5630 based board) 8th January 2012 ' I would be very careful about them. It looks like they designed new models, but a while ago i read this post on the TI e2e forum. Look at the files he included. The name on the schematic tells that it is from sure electronics. The routing is quite messy and the inductors they used(they changed them in the new module) were not up to standard.

I don't know if they improved it in the new design(and this is the 1x600W), but if the designer is the same, i would be careful about trusting the boards ' 10th January 2012 ' @petemate: Interesting link from the TI forum, confirming my suspicions about the SURE designer Interesting that the inductors they used on the board whose photo is at the TI forum are the old 10uH from the TK2050 series - those cooked here on 32V, I would hate to see them on 50V. I measured a 40 degrees C temperature rise at 32V/390KHz... '

I'm not saying they don't work and I'm not really an audio snob so these might be fine for the average user and if you don't mind desoldering and soldering in better components, these might be pretty awesome. The tas5630 and tas5613 based boards appear to be more delicate than the irs2092 boards.

I don't own one so I can't really say. I just don't want to spend $100 on something that I might not like.

[neildavis]

You mean this one? (http://www.parts-express.com/pe/showdetl.cfm?Partnumber=320-313%20%20%20%20%20%20%20%20&FTR=irs2092)

Hmm...what would it take to make a 6-channel amp out of those? Just find the right PS (which is?) and wire everything up? Or is it more involved?


That's an interesting question. The IR application notes talk about the need to make the self-oscillating frequency different for each channel, by at least 25KHz, to reduce noise (this is also recommended for the Tripath amps for the same reason). A way around having multiple self-oscillating frequencies is to synchronize all of the channels to a common external clock. IR shows how to design the amps to latch onto an external oscillator, and it is relatively easy, although the external clock option is not supported in the IRAUDAMP7S reference design on which the Sure board is based.

It is not clear to me how much noise results from multiple amps with various power supply options. One of the archived reference designs at IR shows the effects self-oscillating vs external oscillator on distortion for all-channels-driven (ACD). There is a clear jump in distortion at low power levels for self-oscillation and ACD, although it is not a huge jump (.05% to .1%, if I remember right, where the distortion is due to noise). On the other hand, for one channel driven the self-oscillation mode resulted in much lower distortion. Obviously, multiple power supplies could be used to minimize the noise, but it is not clear whether power supply regulation would help, and if so, by how much...

Anyway, the simple answer to your question is "no". But what is required to make a good quality 6-channel amp using these boards isn't clear, at least to me. It might take some experimentation to better understand what happens when multiple channels of high-powered oscillating amps get together on a single power supply.

[Pallas]

Thanks for the answer, Neil. Sounds like a project a bit above my comfort level.