Sure-Electronics.com class d amps

Status
Not open for further replies.
Jump to Latest
#81
Hi,
I received my amp yesterday and have had some time to play with it. I used a 15v 4A laptop power supply for some low volume tests but I have ordered a 13.8v DC 12A Regulated Switching Power Supply
as well as a 12VDC 29A Regulated Switching Power Supply both from Sure Electronics.

I'm (spanking) new to amplifier building and was initially interested in this Amp due to its size and efficiency ( being cheap was certainly a bonus)

Some one asked the question earlier if this amp can be bridged. The answer that was the posted was

It is already bridged, hence the single supply and two inductors per channel.

You might be able to parallel the channels for more current with low impedance loads.
Click to expand...

Can all 4 outputs be connected to get say 200-300 watts @ 8R ?

What is the physical wiring required to achieve this?

I will be using this with 2 Carlsbro NlighN
NXT flat panel speakers and powering with other speakers with my big amp.

The amp and the power supply will be built into a 1U 19 inch rack.

Thanks
 
#82
Class D Student said:
Hi,
Can all 4 outputs be connected to get say 200-300 watts @ 8R ?

What is the physical wiring required to achieve this?

Thanks
Click to expand...

Yes you can, provided the gain of paralleled amps should be equal and also you need to insert 0.22 Ohms 5W resistors at the outputs of number of amps paralleled and then joined/sum the outputs together to get high current output, only if you want to drive low impedance 2-4 Ohms speakers!!
 
#83
steely3 said:
The Sure EUA2005 look like a potential portable headphone amp.
Any idea of what chip is on here? Does anyone think these will work at headphone impedances?
Click to expand...

I read somewhere that class-d is a bad idea for headphones... but then I read that a class-d headphone amp is coming out soon over at headfi... go figure... 😕
 
#84
Workhorse said:


Yes you can, provided the gain of paralleled amps should be equal and also you need to insert 0.22 Ohms 5W resistors at the outputs of number of amps paralleled and then joined/sum the outputs together to get high current output, only if you want to drive low impedance 2-4 Ohms speakers!!
Click to expand...
Just seen this...

So if I wanted to power a 4ohm sub, I could simply use two channels for twice the power? Would you use a resistor for both + and - speaker outs? Or is it wired in parallel? Does this change the impedance at all?

Also, am I right in thinking this amp is 2 ohm stable? It mentions 2 ohm on the e-bay page ("150W 4CH C 2"), but I want to be sure I don't kill the amp by running it at 2ohm (been there, done that, cheap crappy car amp thankfully)... :hot: I'm more than happy with 4ohm power tho, if it turns out to be 4 ohm stable....

EDIT: Class D student, I think you will get more power out of this amp running it at 24v instead of 12v... Don't quote me on that tho. 🙂
 
#85
MikeHunt79 said:



EDIT: Class D student, I think you will get more power out of this amp running it at 24v instead of 12v... Don't quote me on that tho. 🙂
Click to expand...

I think the amp runs on 12v anyway. Isn't that what the MBR1660 does (or is it just a diode). I assume the amp has a voltage rectifier (if that is the correct term). I believe the amp rating relative to the voltage is the most important factor here.

Thanks for your reply Workhorse, thats helpful.

What will happen if there is a difference (between ch 1 & 2 fro example) in line-in level if I am bridging them. Possible damage?
 
#86
Re: Audio1st

h82missafire said:
audio1st, could you provide front, side and pack pics?
Thanks
Click to expand...
It is just an old food warmer..😉
 

Attachments

  • sure4.jpg
    sure4.jpg
    89.8 KB · Views: 1,429
#90
Workhorse said:
Yes you can, provided the gain of paralleled amps should be equal and also you need to insert 0.22 Ohms 5W resistors at the outputs of number of amps paralleled and then joined/sum the outputs together to get high current output, only if you want to drive low impedance 2-4 Ohms speakers!!
Click to expand...
Quite a few people have asked about bridging... could someone confirm the wiring I've posted will work?
 

Attachments

  • aaaaaaaaaaamp.gif
    aaaaaaaaaaamp.gif
    78.4 KB · Views: 1,328
#91
MikeHunt79 said:

Quite a few people have asked about bridging... could someone confirm the wiring I've posted will work?
Click to expand...

No, I believe it should look like the pic below.

BTW, to not start or continue any confusion this is to parallel the channels. Each individual channel is already a full-bridge.
 

Attachments

  • aaaaaaaaaaamp2.gif
    aaaaaaaaaaamp2.gif
    79.8 KB · Views: 1,302
#92
theAnonymous1 said:


No, I believe it should look like the pic below.

BTW, to not start or continue any confusion this is to parallel the channels. Each individual channel is already a full-bridge.
Click to expand...

Thanks for clearing this up! 🙂 I've only ever seen paralleling with drivers (eg 2 x 8ohm drivers wired to an amp channel and has a 4 ohm load). This is the first time I've seen amp channel paralleling, I'm learning new stuff all the time on here... 😎

Does this amp channel paralleling affect the impedance at all, or will both amp channels operate at 4 ohms when driving a 4 ohm speaker?

Finally, may I ask what the resistors are for? Do they help balance the load between the channel, or just raise impedance?
 
#94
Class D Student said:


I think the amp runs on 12v anyway. Isn't that what the MBR1660 does (or is it just a diode). I assume the amp has a voltage rectifier (if that is the correct term). I believe the amp rating relative to the voltage is the most important factor here.
Click to expand...


No the 16A 60V Schottky diode is there as an 'idiot protector', so that no damage is caused if someone attaches the PSU the wrong way round.
 
#95
anyone else see a problem?

printed on the PCB, its listed as needing 6 - 26 volts... 6 - 12 amps...

so, even if it was to draw 12 amps, at 26 volts, at 90% efficiency, that will still only give 70watts per channel output, and yet they list it as 150watts into 2 ohms?

I suppose its possible for it to give about 60watts rms per channel, into 4 ohms...
 
#98
buzz1939 said:
Perhaps there are two different meanings of the word bridged being used here. What the rest of the audio world typically calls bridging is referred to as "parallel" above.
Click to expand...


no, the "normal" definition of bridging is when one amplifier channels input is inverted, so therefore, the output is inverted, and then the signal from the speaker is taken from both channels effectively in series...
 
#99
Hello! I'm new at this forum! I have tried this amp using car cirarett lighter supply 😀 ( 12.5...14.5v DC) - not impressed! I used 90W 8 ohm speakers http://www.karu15.ee/vep/s90b.jpg and Ipod as signal. It works nice but difenetly not 100, 70 or 50W. It gives no more than 20-25w IMHO:xeye: but very nice and clear sound. Bridging or paralleling gives nothing! This paralleling http://www.diyaudio.com/forums/attachment.php?s=&postid=1365815&stamp=1196647421 gives nothing! Same sound as single 1ch. and amp is still alive 😀 !!! This bridging http://www.diyaudio.com/forums/attachment.php?s=&postid=1365775&stamp=1196644105 without resistors give same effect :att'n: Then i tried it on old 30w 4ohm fiat coupe speaker! And amp gives 30-35w of power IMHO:devilr:
I think, that only way to get 70-100W of real power is to use 24-26v DC and 4-2ohm speakers. It is non bridgable amp 😕
Sorry 4 my english 🙄
 
#100
This amp works well, but the maximum output per channel is about 60W.

Just consider. The amp has a bridged output, and the maximum pk-pk voltage swing on each half of the bridge is about 2V less than the supply voltage. So that would be 22V pk-pk on each half when running from 24V. The total pk-pk across the output is then 44V. This is approx 15.6V rms for a sine wave.

If the load is 4R, then the power is (15.6 x 15.6)/4 which is just under 61W.

It's one of those 'laws of physics' things :-(
 
Status
Not open for further replies.
Top Bottom