$175 Class D amp--120 wpc

Steidl Guitars · « **Reply #80 on:** 25 Jan 2010, 12:21 am »

Steve and Avionic, thanks for the replies. Avionic I'll chase those links as soon as I finish this reply.

Quote from: steve k on 24 Jan 2010, 10:30 pm

Until you get the amp kit in a case with real binding posts, the little blue screw connectors will take up to a 14-16 ga. wire.

I guess I'm wondering what's considered ideal for the final build.

Quote from: steve k on 24 Jan 2010, 10:30 pm

Amp board to preamp--you can use any IC you want.

I asked Tom to leave off the input connectors on the board so I can install them on the chassis. He was happy to oblige.

So as a general rule, does that mean input wires should be narrow gauge (like ICs) and output wires heavier, like speaker wire?

steve k · « **Reply #81 on:** 25 Jan 2010, 12:27 am »

Quote

I have had the 125x2 8ohm version of the class d audio amp up and running for a few months now and I am really pleased with it. It sounds great and was very easy to get up and running. As mentioned earlier Tom from class d audio is extremely helpful and will answer all your questions quickly. IMO this is an extremely nice amp for the$$. I have added a few links to the chassis,power inlet and wiring that I used.

Excellent Avionic,

Can you tell us a little more about your system, what speakers you're driving with the amp etc. And your impressions of the sound quality?

Thanks,
steve

steve k · « **Reply #82 on:** 25 Jan 2010, 12:30 am »

Quote

So as a general rule, does that mean input wires should be narrow gauge (like ICs) and output wires heavier, like speaker wire?

Yes. In my case I used 24 gauge silver wire for the IC's and 16 ga. silver plated copper for the binding posts.

Nick77 · « **Reply #83 on:** 25 Jan 2010, 01:25 am »

Steve I powered up my amp and after about 15-20 sec it blows the fuse in the iec.
Tom suggested i use a 6amp slow blow fuse, is that large enough? I have triple checked all wireing.

jtwrace · « **Reply #84 on:** 25 Jan 2010, 01:26 am »

Quote from: avionic on 25 Jan 2010, 12:03 am

I have had the 125x2 8ohm version of the class d audio amp up and running for a few months now and I am really pleased with it. It sounds great and was very easy to get up and running. As mentioned earlier Tom from class d audio is extremely helpful and will answer all your questions quickly. IMO this is an extremely nice amp for the$$. I have added a few links to the chassis,power inlet and wiring that I used.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250501444095&ssPageName=STRK:MEWAX:IT
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200424519369
http://stores.ebay.com/Johns-Silver-Teflon-Wire-Shop
http://classdaudio.com/index.php/class-d-amplifier-kits/home-kits/250w-x-2-500w-x-1-amp-power-supply-transformer.html

Is the yellow wire the chassis ground? It's kinda hard to see...

Steidl Guitars · « **Reply #85 on:** 25 Jan 2010, 01:35 am »

Has to be ground, yeah?

steve k · « **Reply #86 on:** 25 Jan 2010, 01:49 am »

Quote

Steve I powered up my amp and after about 15-20 sec it blows the fuse in the iec.
Tom suggested i use a 6amp slow blow fuse, is that large enough? I have triple checked all wireing

I didn't fuse mine but I would think the fuse is big enough. Did you check your transformer taps? You have to get the correct blue and green together for the center tap. If you don't you'll cook the tranny. Believe me, I know from experience. Tom should tape the correct two leads together for the center tap but he didn't in my case and I guessed wrong.

jtwrace · « **Reply #87 on:** 25 Jan 2010, 01:50 am »

Quote from: steve k on 25 Jan 2010, 01:49 am

I didn't fuse mine but I would think the fuse is big enough. Did you check your transformer taps? You have to get the correct blue and green together for the center tap. If you don't you'll cook the tranny. Believe me, I know from experience. Tom should tape the correct two leads together for the center tap but he didn't in my case and I guessed wrong.

hmm. how do you know which ones go together?

steve k · « **Reply #88 on:** 25 Jan 2010, 01:52 am »

Well that's the question. I told Tom to tape the correct 2 together before he ships them out. Don't know if he's doing this now or not. If they're not taped together, I would ask Tom.

jtwrace · « **Reply #89 on:** 25 Jan 2010, 01:53 am »

Quote from: steve k on 25 Jan 2010, 01:52 am

Well that's the question. I told Tom to tape the correct 2 together before he ships them out. Don't know if he's doing this now or not. If they're not taped together, I would ask Tom.

Mine aren't taped together.

Nick77 · « **Reply #90 on:** 25 Jan 2010, 01:59 am »

Very interesting, i didnt think it mattered which blue vs green. Mine certainly were not marked

How the heck are you suppose to know which is which?

I emailed Tom to try and figure out which two go the center tap. Major heads up!

steve k · « **Reply #91 on:** 25 Jan 2010, 02:05 am »

Well I'm over my head here because I couldn't tell them apart either (help me out DIY'rs). You have a 50/50 chance of getting it right. If you get it wrong, the tranny will heat up pretty quickly and eventually smoke (like mine did). It works fine though and Tom assured me it could take the load that way--it would either work if it was OK or not if it was fried.

Or, if you get it right, it will work fine.

That's why I suggested to Tom that he mark the leads before shipping because this could happen to someone else and it looks like it did. So you can either role the dice or give Tom a call. That's the best I can do guys.
steve

avionic · « **Reply #92 on:** 25 Jan 2010, 02:08 am »

The wire I used for the rca's is 24 ga solid silver with teflon outer and the speaker wire is 3 twisted strands of 22ga silver plated copper stranded. I removed the rca connectors from the board and soldered directly to the board. As far as power wire goes I had an old 14ga power cord that I cut and used those indivdual wires fo power hook up. That way you can keep the color codes the same. Yes the yellow wire is a ground it is actually green and yellow. The amp is running some tweaked paradigm studio 40's through a modded onix xcd-99 and volume is via passive preamp. Sound quality to my ears is very good. Very smooth and extended with excellent bass response. Vocals sound great as well.
I have replaced the output capacitors on the amp with auricaps since the photos and that seemed to smooth things out even more. Who knows really, but it seemed to make a difference. The fuses that I have in the IEC module (dual fuse) are 6amp slow blow. The nice thing about the IEC module is that the plug,fuse holder and switch are all in 1 unit. Less wiring to do

avionic · « **Reply #93 on:** 25 Jan 2010, 02:13 am »

Quote from: steve k on 25 Jan 2010, 01:52 am

Well that's the question. I told Tom to tape the correct 2 together before he ships them out. Don't know if he's doing this now or not. If they're not taped together, I would ask Tom.

If you look at the transformer there are 2 sets of green and blue wires the most outward green and the most outward blue are a pair. The green and blue that are right next to eachother coming out of the transformer are the other pair. Clear as mud?

avionic · « **Reply #94 on:** 25 Jan 2010, 02:19 am »

You can kind of get an idea of what I am talking about by looking at the pic of my amp. Please shoot Tom an email though just to be 100% sure. He will answer right away.

Nick77 · « **Reply #95 on:** 25 Jan 2010, 02:19 am »

Quote from: avionic on 25 Jan 2010, 02:13 am

If you look at the transformer there are 2 sets of green and blue wires the most outward green and the most outward blue are a pair. The green and blue that are right next to eachother coming out of the transformer are the other pair. Clear as mud?

Thanks, I clearly didnt happen to just pick the correct ones randomly then. I am fresh out of fuses but i least my tranny didnt heat up.

steve k · « **Reply #96 on:** 25 Jan 2010, 02:23 am »

Quote

If you look at the transformer there are 2 sets of green and blue wires the most outward green and the most outward blue are a pair. The green and blue that are right next to eachother coming out of the transformer are the other pair. Clear as mud?

BRILLIANT!!! Thanks for clarifying that!

Nick77 · « **Reply #97 on:** 25 Jan 2010, 02:24 am »

Quote from Tom:

There are 4 wires from the transformer. Two blue and two green, the blue and the green wires in the middle go to the CT. The outer green goes to the AC-L and the outer blue goes to the AC-N.

avionic · « **Reply #98 on:** 25 Jan 2010, 02:31 am »

Quote from: Nick77 on 25 Jan 2010, 02:24 am

Quote from Tom:

There are 4 wires from the transformer. Two blue and two green, the blue and the green wires in the middle go to the CT. The outer green goes to the AC-L and the outer blue goes to the AC-N.

I am glad that Tom replied. For the record I smoked my first power supply board because I did not get that right the first time

Nick77 · « **Reply #99 on:** 25 Jan 2010, 11:53 pm »

Tom told me that he was taping the leads to identify the center tap but my trans shipped direct from Antec and wasnt marked. Hope to get it rewired and up later.
I did confirm also that it is indeed only 60 wpc, more than a little frustrating since i was looking forward to 120wpc.

Yeah! No more blown fuses after rewire on center taps.