Ok, I will give it a shot - is it just that one zener regulator and 10uF SMT cap that you piggybacked onto? I would like a more elegant way of doing it but maybe tough given the nature of the SMT parts surrounding that IRS2092. Is adding 47uF enough? Would a nice 330uF SEPF OSCON make a difference as they are compact. Also, I have a dead TDA8932 board with four very compact 100uF 35V SMT can caps I can repurpose. Maybe start with those as they look very small and clean.
Here is some interesting information on the 2092.
http://www.connexelectronic.com/documents/IRS2092_Stereo_Amplifier.pdf
http://www.connexelectronic.com/documents/IRS2092_Stereo_Amplifier.pdf
Haha, love this from page 5...
"if the user is tempted to play with the input capacitor, and change it with some kind of audiophile potato size capacitor"
Hey X did you ever try the above mod(s)? If so, how did it turn out?
I've got a few of the same boards and an extra abeltec psu, and am curious if the above mod is worthwhile. My primary use, for the time being, would be for driving some alpha 15a's, so I'm not terribly concerned with hf as much as lf.
Thanks!
Help with project?
Hi all, very interesting thread, thanks. I'm looking for a bit of help with a project I'm thinking about.
I want to build an extensible multi-channel power amplifier using L15D IRS2092 boards, starting with 2 or 3 channels and ending up with 7 (or maybe 9) channels eventually as budget permits. The idea being to use an HDMI AVR as input controller, preamp and DSP, with its preamp outputs driving the new power amps, and to extend by buying more L15D boards and power supplies as I need (and can afford) them. And I want to do this all as cheaply as possible.
1) I'm looking at Switch-Mode Power Supplies for this project, firstly because a big enough linear power supply is going to be beyond my budget, and secondly because I can start small and add more SMPSs as and when I need them as I add channels. I like the look of the Abletec 900w SMPS mentioned in this thread- can anyone tell me how many L15Ds one of these would be able to power effectively and what would happen if it wasn't powerful enough?
2) Because of shipping costs to New Zealand, I may a cheaper option. So could I use one or more of these instead -
Aliexpress - 500W amplifier switching power supply board dual voltage PSU +/ 55V-
- and how many boards do you think it might be able to support?
3) Lastly, any tips on likely impedance (or any other) problems I'm likely to have connecting preamp outputs of an AVR to L15D inputs, and what I would need to do about this? And how to limit the output power output to a level where THD remains at an acceptable level?
Just starting to think about extensible chassis / case options too, so any ideas (and any other tips or advice) welcome.
Many thanks.
Hi all, very interesting thread, thanks. I'm looking for a bit of help with a project I'm thinking about.
I want to build an extensible multi-channel power amplifier using L15D IRS2092 boards, starting with 2 or 3 channels and ending up with 7 (or maybe 9) channels eventually as budget permits. The idea being to use an HDMI AVR as input controller, preamp and DSP, with its preamp outputs driving the new power amps, and to extend by buying more L15D boards and power supplies as I need (and can afford) them. And I want to do this all as cheaply as possible.
1) I'm looking at Switch-Mode Power Supplies for this project, firstly because a big enough linear power supply is going to be beyond my budget, and secondly because I can start small and add more SMPSs as and when I need them as I add channels. I like the look of the Abletec 900w SMPS mentioned in this thread- can anyone tell me how many L15Ds one of these would be able to power effectively and what would happen if it wasn't powerful enough?
2) Because of shipping costs to New Zealand, I may a cheaper option. So could I use one or more of these instead -
Aliexpress - 500W amplifier switching power supply board dual voltage PSU +/ 55V-
- and how many boards do you think it might be able to support?
3) Lastly, any tips on likely impedance (or any other) problems I'm likely to have connecting preamp outputs of an AVR to L15D inputs, and what I would need to do about this? And how to limit the output power output to a level where THD remains at an acceptable level?
Just starting to think about extensible chassis / case options too, so any ideas (and any other tips or advice) welcome.
Many thanks.
That's a pretty neat SMPS board, if it does as advertised. "500W" would imply it could handle two of the amp boards, maybe up to four if not all doing subwoofer duty.
Though, if it is really a 500W output supply and efficiency is around 90%, that means that it has to get rid of about 50W of heat in that situation. Those heatsinks look woefully inadequate for that, so I suspect the 500W output is only for short term (which would be appropriate for audio, still).
Though, if it is really a 500W output supply and efficiency is around 90%, that means that it has to get rid of about 50W of heat in that situation. Those heatsinks look woefully inadequate for that, so I suspect the 500W output is only for short term (which would be appropriate for audio, still).
I'll be using a separate powered sub, so the channels will be the usual n- of the n.1 setup (i.e. Left, Right, Center, Left Surround, Right Surround, Left Back, Right Back etc.)
If I run two (or more) boards off one SMPS, would I need to use a phase inverter on the input of alternate boards (& swap polarity of the speaker outputs) to avoid the 'bus pumping' that I've read about? If so, does anyone know where I can buy one (cheap), or is there a simple schematic. A veroboard-type layout would be useful too if anyone's already done this.
Thanks!
If I run two (or more) boards off one SMPS, would I need to use a phase inverter on the input of alternate boards (& swap polarity of the speaker outputs) to avoid the 'bus pumping' that I've read about? If so, does anyone know where I can buy one (cheap), or is there a simple schematic. A veroboard-type layout would be useful too if anyone's already done this.
Thanks!
If you use the L & R full range and at high power I would use a phase inverter .I made a simple PCB that works great . see : http://www.diyaudio.com/forums/clas...-irs2092-irfi4020h-200w8r-38.html#post2951879 and http://www.diyaudio.com/forums/class-d/294544-need-help-buying-amplifier-board.html#post4787354
Cheers ,
Rens
Compact Power Supply for this amp?
I'm seeing this so called 500w Power Supply on eBay. Anyone try it? Could use +-70 for this amp. Looks small, but they sold a bunch. Hmmm....
NEW 500W amplifier switching power supply board dual-voltage PSU +/-30V?+/-70V | eBay
I know this is off topic, but people are complaining about the large size of the Abletec supply for this amp. This might match well. So, what say you?
I'm seeing this so called 500w Power Supply on eBay. Anyone try it? Could use +-70 for this amp. Looks small, but they sold a bunch. Hmmm....
NEW 500W amplifier switching power supply board dual-voltage PSU +/-30V?+/-70V | eBay
I know this is off topic, but people are complaining about the large size of the Abletec supply for this amp. This might match well. So, what say you?
Picking a Power Supply
Power Supply Choices: Overall system performance is dependent on the amp and supply working well together. The humble power supply is about equal in cost to two of the 150w amp boards. So the choice of power supply is a serious matter. There are several supplies I've considered: the Abletec "900w", a Chinese generic "500w", and a pair of generic 48v 8A supplies.
Abletec: The Abletec is a great bargain at about $32. It's cheap, and it works. It is not really a 900w supply, continuously. That's a marketing claim. If you read the actual spec, it is rated half that for short term peaks, and about 150w continuously. For maximum output, it must be mounted to a very good heat sink and have fan cooling. It has a quirk: to make it work, you must put light loads on the two auxiliary outputs (5v, 12v) too, even if you don't use them. The Abletec works well for this amp, putting out +-53v @1.5A continuously, and perhaps triple that in short term peak power. It protects itself from overload by current limiting, so you can connect as many amps as you want, but they will not all play loudly continuously because the supply current limits. It is a surplus product being resold by a liquidator, Parts Express, so it's cheap, about $32 delivered in the US, more elsewhere due to higher ship cost.
Abletec, 900 Watt Peak Class D Audio Amp power supply +/- 53V DC #ALPO400-5301-D | eBay
Generic 500W: The so called "500w" board is unreviewed so far. But they have sold a bunch, and I don't see a rash of negative feedback for them on ebay, so it probably works OK. I suspect the true continuous rating is in the 125w range, but have not tested it. Once again, you need fan cooling to draw full power. The real advantage of this is tiny size, Dimensions : 100 * 133 * 50mm. If you need many, that small size is a crucial advantage. It costs a little more, about $42 delivered in US, and is sold direct from China, so shipping is slower than Parts Express.
500W Amplifier Switching Power Supply Board Dual-voltage PSU +/-55V | eBay
Dual 48v supplies: You could also use two of the generic 48v 8.3A supplies sold for about $20 each. Though bigger, two of these are much more powerful than one of the supplies above. They would give you a real 800 watts continuous. They are targeted at a high volume market, LED lighting, so they may be electrically noisy, but the power rating is continuous. Added capacitive filtering should solve any noise problem if it occurs. 48v lets the amp deliver a solid 125 watts per channel, and I doubt you could hear a power difference between this and 53v. I suspect dual 48v/400w supplies would drive 5-7 amplifiers very nicely.
400w 48v supply | eBay
You ask how many amps they will power. There is no exact answer. Most consumer AV receivers have a single wimpy shared power supply, which apparently is quite acceptable to most people for 5-7 channels in normal use. It really depends on how loudly you play music, room volume, speaker efficiency and if all channels are fully driven by your music. In reality, much listening is at low levels, under 1 watt output, but we must have clean peak power for loud parts. Most of the time a power supply is loafing, but will be called on to supply those peaks, which statistically are not equal in all channels. If you like it loud, or have inefficient speakers, or a large room, you need more power.
I can only say one Abletec powers two amps nicely for me, in my small listening room with quiet music. You can connect as many amps to one supply as you like, but they will not play loudly on all channels simultaneously. You must have more power for larger rooms, less efficient speakers, or if you really like it loud. For example, in a larger living room, I might use one supply per amp.
Inputs? This amp can be driven by just about any audio line level source. It has an unusually low input impedance about 3k ohms, but that does not seem to cause a problem for anything from a smartphone to preamp to avr outputs. No worries there.
Cases? I call this infrastructure, it bores me, and I go cheap here. Please feel free to spend $150 for a gorgeous box, but I get mine for $5-10. I use recycled cases, from retired amplifiers, receivers, and curiously, obsolete Tivo type digital video recorders or other electronic carcasses. Usually the amps and receivers are bigger than I would prefer, but they have a sturdy box, built in power supply, heat sink, and back panel connectors ready made. The DVR cases are more compact, but have fans and connectors, and plenty of space to suit compact digital amps and switching supplies. Be creative, you'll find interesting options. I'm happy with my recycled cases. I'd love to say I prefer to go green, which certainly is true, but really --I am just cheap.
Power Supply Choices: Overall system performance is dependent on the amp and supply working well together. The humble power supply is about equal in cost to two of the 150w amp boards. So the choice of power supply is a serious matter. There are several supplies I've considered: the Abletec "900w", a Chinese generic "500w", and a pair of generic 48v 8A supplies.
Abletec: The Abletec is a great bargain at about $32. It's cheap, and it works. It is not really a 900w supply, continuously. That's a marketing claim. If you read the actual spec, it is rated half that for short term peaks, and about 150w continuously. For maximum output, it must be mounted to a very good heat sink and have fan cooling. It has a quirk: to make it work, you must put light loads on the two auxiliary outputs (5v, 12v) too, even if you don't use them. The Abletec works well for this amp, putting out +-53v @1.5A continuously, and perhaps triple that in short term peak power. It protects itself from overload by current limiting, so you can connect as many amps as you want, but they will not all play loudly continuously because the supply current limits. It is a surplus product being resold by a liquidator, Parts Express, so it's cheap, about $32 delivered in the US, more elsewhere due to higher ship cost.
Abletec, 900 Watt Peak Class D Audio Amp power supply +/- 53V DC #ALPO400-5301-D | eBay
Generic 500W: The so called "500w" board is unreviewed so far. But they have sold a bunch, and I don't see a rash of negative feedback for them on ebay, so it probably works OK. I suspect the true continuous rating is in the 125w range, but have not tested it. Once again, you need fan cooling to draw full power. The real advantage of this is tiny size, Dimensions : 100 * 133 * 50mm. If you need many, that small size is a crucial advantage. It costs a little more, about $42 delivered in US, and is sold direct from China, so shipping is slower than Parts Express.
500W Amplifier Switching Power Supply Board Dual-voltage PSU +/-55V | eBay
Dual 48v supplies: You could also use two of the generic 48v 8.3A supplies sold for about $20 each. Though bigger, two of these are much more powerful than one of the supplies above. They would give you a real 800 watts continuous. They are targeted at a high volume market, LED lighting, so they may be electrically noisy, but the power rating is continuous. Added capacitive filtering should solve any noise problem if it occurs. 48v lets the amp deliver a solid 125 watts per channel, and I doubt you could hear a power difference between this and 53v. I suspect dual 48v/400w supplies would drive 5-7 amplifiers very nicely.
400w 48v supply | eBay
You ask how many amps they will power. There is no exact answer. Most consumer AV receivers have a single wimpy shared power supply, which apparently is quite acceptable to most people for 5-7 channels in normal use. It really depends on how loudly you play music, room volume, speaker efficiency and if all channels are fully driven by your music. In reality, much listening is at low levels, under 1 watt output, but we must have clean peak power for loud parts. Most of the time a power supply is loafing, but will be called on to supply those peaks, which statistically are not equal in all channels. If you like it loud, or have inefficient speakers, or a large room, you need more power.
I can only say one Abletec powers two amps nicely for me, in my small listening room with quiet music. You can connect as many amps to one supply as you like, but they will not play loudly on all channels simultaneously. You must have more power for larger rooms, less efficient speakers, or if you really like it loud. For example, in a larger living room, I might use one supply per amp.
Inputs? This amp can be driven by just about any audio line level source. It has an unusually low input impedance about 3k ohms, but that does not seem to cause a problem for anything from a smartphone to preamp to avr outputs. No worries there.
Cases? I call this infrastructure, it bores me, and I go cheap here. Please feel free to spend $150 for a gorgeous box, but I get mine for $5-10. I use recycled cases, from retired amplifiers, receivers, and curiously, obsolete Tivo type digital video recorders or other electronic carcasses. Usually the amps and receivers are bigger than I would prefer, but they have a sturdy box, built in power supply, heat sink, and back panel connectors ready made. The DVR cases are more compact, but have fans and connectors, and plenty of space to suit compact digital amps and switching supplies. Be creative, you'll find interesting options. I'm happy with my recycled cases. I'd love to say I prefer to go green, which certainly is true, but really --I am just cheap.
Nearly finished!
Thanks slowhands, very useful information. Just an update... I got 3x stereo L15D kits and 1x mono L15DSMD kit (7 channels total - can't seem to buy a mono version of the L15D itself) and have now assembled them all. Also got two of those cheap 500W +/-55V SMPS boards and 4x stereo speaker protection kits, a programmable IR mains switch and 5V supply (for remote on/off), the components for 4 phase inverters (to avoid bus pumping), plus various hardware, all from AliExpress. Put it all together in a homemade enclosure.
Those SMPS's work fine by the way, for anyone else looking for a cheap option (esp. with free shipping!), and they also come with useful +/- 15V and +12V outputs.
So how did it all go so far? First the bad news. I stupidly managed to short one of the L15D boards, which blew the transistors, IC, and zeners (ouch!). Also the short then (noisily) blew one of the SMPS's (MOSFETS, driver and fuse - double ouch!). Repairable, but just waiting for replacement components to arrive. Lesson: check all speaker and power connections for shorts BEFORE switching on.
Now the good news. Wired the other six channels up to the remaining SMPS (after testing individually). All channels working, sounds just fantastic, runs cool, draws almost no power for lots of volume. Can't wait for the spares to arrive so I can repair the two boards and finish this part of the project.
While waiting, I've also disassembled my Onkyo 7.1 AV receiver, cut & spliced in connections where the pre-amp connects to the power amps, to RCA sockets which I fitted to the back panel, so I now have 7-channel pre-amp outputs to drive my new amp (with wire links back to the Onkyo power-amp ins if ever needed in the future).
So my project is getting close to being finished and I'm planning to post some photos once complete, if anyone's interested.
Thanks for the help from people here!
Thanks slowhands, very useful information. Just an update... I got 3x stereo L15D kits and 1x mono L15DSMD kit (7 channels total - can't seem to buy a mono version of the L15D itself) and have now assembled them all. Also got two of those cheap 500W +/-55V SMPS boards and 4x stereo speaker protection kits, a programmable IR mains switch and 5V supply (for remote on/off), the components for 4 phase inverters (to avoid bus pumping), plus various hardware, all from AliExpress. Put it all together in a homemade enclosure.
Those SMPS's work fine by the way, for anyone else looking for a cheap option (esp. with free shipping!), and they also come with useful +/- 15V and +12V outputs.
So how did it all go so far? First the bad news. I stupidly managed to short one of the L15D boards, which blew the transistors, IC, and zeners (ouch!). Also the short then (noisily) blew one of the SMPS's (MOSFETS, driver and fuse - double ouch!). Repairable, but just waiting for replacement components to arrive. Lesson: check all speaker and power connections for shorts BEFORE switching on.
Now the good news. Wired the other six channels up to the remaining SMPS (after testing individually). All channels working, sounds just fantastic, runs cool, draws almost no power for lots of volume. Can't wait for the spares to arrive so I can repair the two boards and finish this part of the project.
While waiting, I've also disassembled my Onkyo 7.1 AV receiver, cut & spliced in connections where the pre-amp connects to the power amps, to RCA sockets which I fitted to the back panel, so I now have 7-channel pre-amp outputs to drive my new amp (with wire links back to the Onkyo power-amp ins if ever needed in the future).
So my project is getting close to being finished and I'm planning to post some photos once complete, if anyone's interested.
Thanks for the help from people here!
I don’t believe that the Abletec PS has a real “current limit protection” other than the slow blow 5A fuses on the outputs; on the contrary, a “generic SMPS” has it for sure, and it shut down the unit instantly when you try to get a current higher than the nominal value.
What is the difference?
Consider a half bridge class D amplifier powered at +/-50V that is pumping 200W on a 4 ohm load; suppose the signal is a 40 Hz sine and that you have a 10.000uF capacitor on each supply rail.
An LTSpice simulation (using a simplified ideal class D amplifier) shows that the current supplied by the positive output of the PS looks like a half sine, with a peak of 8.1 A and a RMS value of 3.4 A; this could be sufficient to activate the current protection of a “generic” SMPS with a nominal current of 8A, causing it to shut down, but it will not create any disturb to the Abletec PS
So, a “generic” SMPS with 800W nominal power and instantaneous current limit protection could be not adequate if you want to supply just 200W to a 4 ohm load.
In the same condition, the Abletec PS works without any problem; I’m quite sure of this because I tested this condition at bench just yesterday, pumping 225W on a 4 ohm load, using a “ 20$ IRS2092/IRFI4019 board” and an Abletec PS (I had to stop the test because of the smoke coming out from my Audio Power Meter).
Same here. using a 60Hz tone, I can put 28v into a 2R dummy load in 5 second bursts. Anything longer than that and the main 5A fuse blows... This is with 15,000uF per rail using an L15D modified with irfb5615 transistors and speaker protection bypassed.
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HOT IRS2092
When I was testing my IRS2092/IRFI4019 board (the same as in the picture in post #1), I realized that the area of the PCB (soldering side) exactly under the IRS2092 was hot; really, I couldn’t keep my finger in that point for more than 2 or 3 seconds, so I suppose the temperature was 60 – 70°C.
The upper side of the case of the IRS2092 was much less hot than the PCB under the IC, and all the other components near the IC was only warm.
The PCB under the IRS2092 becomes hot after only 20 or 30 seconds from power on and without input signal; the temperature apparently doesn’t change lowering the power supply voltage (from +/-53 to less than +/-40V) or changing the switching frequency (from the standard value of 400KHz); moreover, the idle current is regular (28 mA from positive rail and 50 mA from negative rail), according with the IRAUDAMP7 data sheet.
What I would like to know is:
- Is this (over-)temperature present in all the boards based on IRAUDAMP7 (L15, L25, …) or is it peculiar for Juan Ying boards or is it due to a malfunction of the specific board I have?
Note that a 60 – 70°C temperature on the PCB under the IRS2092 means a considerably higher internal temperature and this can affect the reliability of the circuit, making it not much suitable for some kind of application (for example, in PA or as amplifier for musical instruments).
When I was testing my IRS2092/IRFI4019 board (the same as in the picture in post #1), I realized that the area of the PCB (soldering side) exactly under the IRS2092 was hot; really, I couldn’t keep my finger in that point for more than 2 or 3 seconds, so I suppose the temperature was 60 – 70°C.
The upper side of the case of the IRS2092 was much less hot than the PCB under the IC, and all the other components near the IC was only warm.
The PCB under the IRS2092 becomes hot after only 20 or 30 seconds from power on and without input signal; the temperature apparently doesn’t change lowering the power supply voltage (from +/-53 to less than +/-40V) or changing the switching frequency (from the standard value of 400KHz); moreover, the idle current is regular (28 mA from positive rail and 50 mA from negative rail), according with the IRAUDAMP7 data sheet.
What I would like to know is:
- Is this (over-)temperature present in all the boards based on IRAUDAMP7 (L15, L25, …) or is it peculiar for Juan Ying boards or is it due to a malfunction of the specific board I have?
Note that a 60 – 70°C temperature on the PCB under the IRS2092 means a considerably higher internal temperature and this can affect the reliability of the circuit, making it not much suitable for some kind of application (for example, in PA or as amplifier for musical instruments).
Well, I finally finished the build of my 7-channel home theatre power amplifier using LJM's L15D kit boards, which I assembled myself. Sounds fantastic, very pleased with the result. Description and pics in the http://www.diyaudio.com/forums/class-d/87913-class-d-amp-photo-gallery-121.html#post4939897. Thanks to those here who provided ideas and help. Now I need a new project!
Hi serafis and others : is there a thread on the aliexpress/ebay generic audio 500w SMPS (+and-55V usually and sold about $40 shipped) ?
Does anybody know technically about it : is it a "soft switched half bridged resonant LLC" (with low EMI/ higher than 92% efficiency) perfectly suited for audio (bass in my use) ?
I mean is it technically in the same class (thanks to china generic mass conception /competition/cloning engineering) as the connexelectronic ones costing near double, or are we in a different simpler lower league technically speaking ?
Just looking for a but more info/feedback on it from reviewers (compared to connexelectronic ones would be excellent) before buying several of this ebay/aliexpress one (for IRS2092 amps in bass to probably mid).
(the abletec special one is harder to reach from europe)
thanks in advance
Does anybody know technically about it : is it a "soft switched half bridged resonant LLC" (with low EMI/ higher than 92% efficiency) perfectly suited for audio (bass in my use) ?
I mean is it technically in the same class (thanks to china generic mass conception /competition/cloning engineering) as the connexelectronic ones costing near double, or are we in a different simpler lower league technically speaking ?
Just looking for a but more info/feedback on it from reviewers (compared to connexelectronic ones would be excellent) before buying several of this ebay/aliexpress one (for IRS2092 amps in bass to probably mid).
(the abletec special one is harder to reach from europe)
thanks in advance
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