$175 Class D amp--120 wpc

roymail · « **Reply #1720 on:** 27 Jul 2010, 10:28 pm »

Jason, is the 258 a TI board or IR board? I was thinking the IR board sounded better.

Is that not true? Thanks!

jtwrace · « **Reply #1721 on:** 27 Jul 2010, 10:57 pm »

Quote from: roymail on 27 Jul 2010, 10:28 pm

Jason, is the 258 a TI board or IR board? I was thinking the IR board sounded better. Is that not true? Thanks!

The IR does sound better....

roymail · « **Reply #1722 on:** 28 Jul 2010, 12:54 am »

Quote from: jtwrace on 27 Jul 2010, 10:57 pm

The IR does sound better....

Thanks, so is the 258 an IR?

dwk · « **Reply #1723 on:** 28 Jul 2010, 03:01 am »

Okay, quick and probably dumb question - what is the difference between the various SDS boards? Looking at the images on the site they all look the same. Voltage tolerances on the caps? Heatsinks? (though those all look the same). Maybe there are different driver chips hiding under the heatsinks? I'm just slightly puzzled as there isn't anything obvious to account for the 2x power handling diffence.

Also, is the gain control simply altering the R2 value (or is it R8 maybe?) in the feedback relationship? I'm wondering whether it's possible to just jumper a resistor in place rather than use the pot - I can't imagine having those long wires picking up stray EMI would be the best idea.

wushuliu · « **Reply #1724 on:** 28 Jul 2010, 04:19 am »

Quote from: roymail on 28 Jul 2010, 12:54 am

Thanks, so is the 258 an IR?

Yes

roymail · « **Reply #1725 on:** 28 Jul 2010, 04:31 am »

Quote from: dwk on 28 Jul 2010, 03:01 am

Okay, quick and probably dumb question - what is the difference between the various SDS boards? Looking at the images on the site they all look the same. Voltage tolerances on the caps? Heatsinks? (though those all look the same). Maybe there are different driver chips hiding under the heatsinks? I'm just slightly puzzled as there isn't anything obvious to account for the 2x power handling diffence.

Also, is the gain control simply altering the R2 value (or is it R8 maybe?) in the feedback relationship? I'm wondering whether it's possible to just jumper a resistor in place rather than use the pot - I can't imagine having those long wires picking up stray EMI would be the best idea.

Probably Tom at Class D Audio could answers these questions best.

However, steve k, wushuliu, jtwrace, gitarretyp, avionic, others who are more familiar with the boards can help, too.

roymail · « **Reply #1726 on:** 28 Jul 2010, 04:32 am »

Quote from: wushuliu on 28 Jul 2010, 04:19 am

Yes

Thanks, AC.

jtsnead · « **Reply #1727 on:** 28 Jul 2010, 09:21 am »

Quote from: toxteth ogrady on 27 Jul 2010, 06:27 pm

I noticed your power supply has different capacitors than what's shown on the website. Care to share what you've replaced them with?

I changed my board th this one from connex, I noticed an improvement
at first but more later on I quess after the caps burned in more, the values
are 80 volt x 10000uf

Nick77 · « **Reply #1728 on:** 28 Jul 2010, 11:15 am »

Quote from: toxteth ogrady on 27 Jul 2010, 06:27 pm

I noticed your power supply has different capacitors than what's shown on the website. Care to share what you've replaced them with?

Another option is to replace the stock Nichicon caps with better caps, several of us have used Panasonic TSHA series caps with good results. Mostly improved dynamics in the lower end.

motosapien · « **Reply #1729 on:** 28 Jul 2010, 11:18 pm »

Quote from: jtwrace on 27 Jul 2010, 01:14 am

Very cool Which custom enclosure? It should work very well...

Was thinking of one of your enclosures that is featured on the Class D website. It will be mid September before I order though because we are fleeing the left coast for chilly & cheerful Minnesota.

jtwrace · « **Reply #1730 on:** 28 Jul 2010, 11:56 pm »

Quote from: motosapien on 28 Jul 2010, 11:18 pm

Was thinking of one of your enclosures that is featured on the Class D website. It will be mid September before I order though because we are fleeing the left coast for chilly & cheerful Minnesota.

dwk · « **Reply #1731 on:** 30 Jul 2010, 08:25 pm »

wow - ordered Tuesday arrived Friday. Pretty good service.

Nick77 · « **Reply #1732 on:** 30 Jul 2010, 08:29 pm »

Quote from: dwk on 30 Jul 2010, 08:25 pm

wow - ordered Tuesday arrived Friday. Pretty good service.

Whatcha get??

dwk · « **Reply #1733 on:** 30 Jul 2010, 08:43 pm »

Quote from: Nick77 on 30 Jul 2010, 08:29 pm

Whatcha get??

SDS-224 kit - just the little guy since I'm looking at it for a nearfield/desktop setup.

poseidonsvoice · « **Reply #1734 on:** 30 Jul 2010, 08:51 pm »

Quote from: jtwrace on 28 Jul 2010, 11:56 pm

motosapien,

See my note here.

Anand.

dvenardos · « **Reply #1735 on:** 31 Jul 2010, 10:05 pm »

This is the site he is talking about:
http://connexelectronic.com/index.php/cPath/25_45?osCsid=e3nv7lugvcdhrhqnqj9taec2q2

dvenardos · « **Reply #1736 on:** 31 Jul 2010, 10:57 pm »

I don't know, but the owner (Christi) has a forum over at DiyAudio and he is knowledgeable and responsive.
http://www.diyaudio.com/forums/connexelectronic/

soundnoob · « **Reply #1737 on:** 5 Aug 2010, 01:35 am »

Quote from: Paul B on 27 Jul 2010, 03:22 am

Yep he sure did. I have a new amp board on the way. Hopefully by the weekend I will have good news to report.

The amp appeared to be wired correctly and I was seeing normal DC levels from the power supply. The problem was the amp board, where I was seeing normal DC readings on input side, but zero AC at speaker side.

I will report back when I found out what happened from Tom.

Any updates?

pjchappy · « **Reply #1738 on:** 5 Aug 2010, 03:26 am »

For anyone interested, I'm selling 2 brand new CDA-254 amps for a discount.

You can find my AC ad here: http://www.audiocircle.com/index.php?topic=84348.0

Paul

Paul B · « **Reply #1739 on:** 5 Aug 2010, 05:12 am »

Hi soundnoob,

I received a new amp board from Tom this week and it works fine. I offered to pay for any damage i caused to the old one but Tom said not to worry - 5 star customer service I would say.

I'm not sure what happened to the old board. The wiring is the same now as it was in the beginning. The only difference is that when I first set up the amp, I was short a little wire, so from the power board to amp board, on the "+" leg, i extended the copper wire with about 2 inches of silver wire. When i turned it on i saw a spark originate from near the yellow light for the right channel, and it was damaged from that point.

I don't know if it was the copper/silver combo wire that caused the damage. Regardless I have learned my lesson and I should be more patient with these things.

I can't comment on the sound just yet, my Dodd buffer is only working from one channel. I need to take a closer look at the RCA board.

Paul