$175 Class D amp--120 wpc

mboxler · « **Reply #3100 on:** 3 Mar 2012, 03:28 pm »

Quote from: siava1018 on 3 Mar 2012, 12:47 am

What gauge wire runs between the power supply board and amp board?

I thought I'd share some info I received from Tom over the past year.

You should use about 16 gauge wire power and speaker outputs but can use smaller such as 20 gauge for inputs.

The blue LED’s are 3.4 volt and the yellow are 2 volt… don’t use LED’s with different voltages.

One other note (this may have been already been mentioned). Tom's website has been updated to include bare cases, bare cases with all connectors, as well as custom amplifiers. I may purchase a bare case with connectors just to see how complete the parts are. Can't seem to get away from the wooden base I started with!

Mike

siava1018 · « **Reply #3101 on:** 4 Mar 2012, 01:06 am »

is anyone here running their amp on batteries using class d's 12 car audio PS? I just hooked it up and its not working.

praedet · « **Reply #3102 on:** 4 Mar 2012, 02:50 am »

Hmmm, yeah, I have an SDS-254 running on the car audio PS and a SLA battery no problems. Did you hook up the gain pots correctly? Which amp?

siava1018 · « **Reply #3103 on:** 4 Mar 2012, 03:18 am »

I have one of the cda amps so no pots. The fuses on the PS have 12v but the led on the amp dont light up and i checked all the switches.

mboxler · « **Reply #3104 on:** 4 Mar 2012, 03:05 pm »

Looks like only the CDA-254 will work with the battery power supply. Is that the one you bought? The battery supply should be putting out +/- 50 volts, and the 254 series is the only amp that falls into that range. Any other amp will get too much/not enough voltage.

Mike

siava1018 · « **Reply #3105 on:** 4 Mar 2012, 04:07 pm »

Thats the one i got. I put my meter on the outputs and nothing. I should see -50vdc and +50vdc right?

mboxler · « **Reply #3106 on:** 4 Mar 2012, 04:23 pm »

Sorry...I don't have that power supply, but yes, the specs say 50 volts. Sorry for all the obvious questions, but here they come! Does that power supply have any lights that show it is on? Do you have the small switch on the side of the CDA in the on position? Any way to get a picture? I've made just about every mistake (including frying a CDA-224), so I've been there!

Mike

mboxler · « **Reply #3107 on:** 4 Mar 2012, 04:27 pm »

One more thing. Did you check the voltage on the input side (where the battery connects)?

Mke

siava1018 · « **Reply #3108 on:** 4 Mar 2012, 04:56 pm »

14.4 at the terminal and fuses on the board and no leds on the PS. Ive moved all the switches around and still nothing.

http://classdaudio.com/power-sppplies/12v-dc-switching-power-supply-500-watt-car-audio.html

mboxler · « **Reply #3109 on:** 4 Mar 2012, 05:28 pm »

Sorry I wasn't any help. I'd e-mail Tom...he's always been very helpful. Maybe you got a bad PS.

Good Luck!

Mike

siava1018 · « **Reply #3110 on:** 4 Mar 2012, 05:39 pm »

Yeh i sent them a email yesterday but i was hopeing we could get it running. Thanks guys.

siava1018 · « **Reply #3111 on:** 5 Mar 2012, 12:07 am »

Ok so I got the PS to turn on by touching 12v to the remote and some blue smd leds came on on the PS and only the yellows on the amp. So i cycled the switch on the amp and still nothing. Also the PS wont turn off untill i disconnect the power and theres a 1.1 volt difference between rails(-43.3/+42.2). I assume its a bad PS.

Redefy Audio · « **Reply #3112 on:** 6 Mar 2012, 04:23 pm »

hi guys,

i need some help to check and instruction for wiring the SDS-470. this is my first amp module build, so please bear with me

i got some questions :
1. Wiring Power Switch --- whats the best way to do this? Wired the trafo to switch -- then to AC outlet? if this is the case, which one should i wire (please see the pic attach)
2. Trafo 0 V = CENTER TAP? (the BLUE & GREEN taped together) -- on ANTEK TRAFO
3. GAIN POT wiring to the ALPS 50kohm Stereo Pot -- is that the right orientation?
4. Do i need to connect ground from Trafo to the AC outlet, or just connect together (blue and green) and leave it?

i appreciate very much for any help.

cheers
henry

Redefy Audio · « **Reply #3113 on:** 6 Mar 2012, 04:26 pm »

if anyone would like to see exodus hypex psu
they are well built.
http://www.diycable.com/main/pdf/mch.pdf

mboxler · « **Reply #3114 on:** 7 Mar 2012, 04:53 pm »

Hi Henry...

I meant to get you as many answers as I could last night, but spaced it out (sorry). Does your tranny have a purple wire? That's the ground wire that I connect to the AC outlet. I see no mention of a fuse??? What kind of power switch is that?

Anyway, I'll look at my setup tonight and answer as best as I can, unless someone else beats me the the punch!

Take care,
Mike

Redefy Audio · « **Reply #3115 on:** 8 Mar 2012, 02:41 am »

hi mike,

thanks. looking forward for ur directions.

cheers
henry

mboxler · « **Reply #3116 on:** 8 Mar 2012, 02:09 pm »

Hi Henry

Pot connections look good to me (as long as the pin on the left side of the picture is ground). I'll be curious how well a 50k Ohm pot reacts, as 10k is dead quiet. Don't forget to put some heat shrink on the wires before soldering...I always forget!

As far as the tranny connection, did the diagram from ClassDAudio not help? Here is the link...let me know what's confusing and I'll try to clarify. Again, I'm no expert!

http://classdaudio.com/documents/transformer_115VAC_instructions.pdf

Good luck. Hope this helps.

Mike

matt_garman · « **Reply #3117 on:** 8 Mar 2012, 02:41 pm »

Quote from: matt_garman on 2 Mar 2012, 10:52 pm

I got one of those infared laser thermometers and took some readings... What I found was that the PCB itself was hottest, moreso on the right side than the left. The PCB on the right side, near the output area was 150 degrees Celsius, but the left side was only 50 degrees Celsius. I asked Tom about this, but all he said was "If you're using a laser type thermometer you will get this kind of reading." I didn't want to bug him and ask for an elaboration... maybe someone on this thread can do that? I know these laser infared heat guns aren't the most accurate, but shouldn't a 3x difference from one side to the other be indicative of something?

Does anyone know what Tom means by his statement, If you're using a laser type thermometer you will get this kind of reading? I've since pushed for an elaboration, but haven't received any response.

As long as I don't wrap the unit in blankets, I don't have any audio issues. But the unit still runs quite hot, according to my thermometer. The other day, everything sounded fine, but I pulled the cover and took some readings. One of the big capacitors on the right output side read 160 degrees Celsius. But the left side was only 60 degrees.

Quote

The only other quirk is the SMPS800R makes a slight humming/buzzing sound. Generally it's quiet enough that it can only be heard when my ears are within about a foot of the unit. But sometimes it's a bit louder and sometimes quieter. I just asked Cristi about this over on the diyaudio forums.

His reply: The buzzing noise comes when the smps works in burst mode or discontinuous mode. this is a pulse-skipping operation mode implemented to reduce power consumption at no load or very low load. it starts to operate normal as soon as the load reaches 50-70mA on each rail or ~3-5W power. that's below most of the amplifier quiescent current, but some amps could draw less than that if they are muted.

So, all my issues are solved except for this heat issue. Note that if I switch inputs and/or outputs, it's still the right-channel side that consistently reads two to three times hotter than the left-channel. Assuming my thermometer is at least in the right ballpark, then I worry that the life of my SDS-470 could be dramatically shortened from running at these temperatures.

Barry_NJ · « **Reply #3118 on:** 8 Mar 2012, 02:54 pm »

Quote from: matt_garman on 8 Mar 2012, 02:41 pm

So, all my issues are solved except for this heat issue. Note that if I switch inputs and/or outputs, it's still the right-channel side that consistently reads two to three times hotter than the left-channel. Assuming my thermometer is at least in the right ballpark, then I worry that the life of my SDS-470 could be dramatically shortened from running at these temperatures.

If I were you I'd send the board back to Tom to be checked, it is possible you got a bad one...

J Payton · « **Reply #3119 on:** 8 Mar 2012, 04:35 pm »

Quote from: matt_garman on 8 Mar 2012, 02:41 pm

Does anyone know what Tom means by his statement, If you're using a laser type thermometer you will get this kind of reading? I've since pushed for an elaboration, but haven't received any response.

As long as I don't wrap the unit in blankets, I don't have any audio issues. But the unit still runs quite hot, according to my thermometer. The other day, everything sounded fine, but I pulled the cover and took some readings. One of the big capacitors on the right output side read 160 degrees Celsius. But the left side was only 60 degrees.

His reply: The buzzing noise comes when the smps works in burst mode or discontinuous mode. this is a pulse-skipping operation mode implemented to reduce power consumption at no load or very low load. it starts to operate normal as soon as the load reaches 50-70mA on each rail or ~3-5W power. that's below most of the amplifier quiescent current, but some amps could draw less than that if they are muted.

So, all my issues are solved except for this heat issue. Note that if I switch inputs and/or outputs, it's still the right-channel side that consistently reads two to three times hotter than the left-channel. Assuming my thermometer is at least in the right ballpark, then I worry that the life of my SDS-470 could be dramatically shortened from running at these temperatures.

Matt,

I had similar issues using 2 SDS470 units with 2 SMPS800R in a 1U enclosure. The right channels kept hissing after about an hour of play. This was definitely an issue with the chassis and not enough ventilation. I noticed your unit was confined in a small chassis as well but slightly taller than 1U. I tried a larger heat sink (larger outriggers) but this was not the problem.

I added a 12 volt fan inside my case and the anps run cool now.

I sent 1 amp back to Tom due the overheating and the one he replaced it with did the same things.

I think if you created more air flow in your chassis the problems will go away.

Joel