With ±68 we might run into clipping with friends with bigger low efficiency speakers in their soundproofed listening rooms but for my other pals and myself that might do (in a mono block driving a passive crossover) as these days I have keep the volume down a bit. If I get the active cross over sorted then I'd have to get another pair of SMPS I guess.
± 85 would be better though. Is that too much?
Sounds to me like you or your friend or whoever would ideally want a different amp for those speakers. Its not totally diy, its off topic but it is made by forum sponsor and could fit your needs - HPA-NXV1200 1200 watt MOSFET Audio Amplifier Module
FWIW. I have a regulated 800W smps by coldamp to power two of the nxv203 amplifiers by aussie amps. The sound is quite enjoyable. Those amplifiers have 40ma bias current though so obviously don't run into the startup condition issues that have been discussed here with opc's amplifier.
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Hi Guys,
Wow... lots of excitement. I'm going to sit this one out for a bit and see where it goes.
I would like to clarify though:
The temp comp is not needed because I'm using lateral mosfets. This is very important, as any other sort of output device, mosfet or BJT, is going to need temp comp to work properly. This board and circuit is only suitable for use with lateral fets, as they posses a negative temperature coefficient above a very low bias point, which prevents thermal runaway.
It's also the reason there are no emitter resistors.
If you build this up with BJT or standard mosfets, it will quite literally melt itself within 30 minutes.
As for bias, I have always been referring to the pair of dual-die lateral fets needing 360mA total bias. If you want to break it down to a per-die amount, it's roughly 160mA per pair of dies (one P and one N die) if you use discrete devices.
Regards,
Owen
Wow... lots of excitement. I'm going to sit this one out for a bit and see where it goes.
I would like to clarify though:
The temp comp is not needed because I'm using lateral mosfets. This is very important, as any other sort of output device, mosfet or BJT, is going to need temp comp to work properly. This board and circuit is only suitable for use with lateral fets, as they posses a negative temperature coefficient above a very low bias point, which prevents thermal runaway.
It's also the reason there are no emitter resistors.
If you build this up with BJT or standard mosfets, it will quite literally melt itself within 30 minutes.
As for bias, I have always been referring to the pair of dual-die lateral fets needing 360mA total bias. If you want to break it down to a per-die amount, it's roughly 160mA per pair of dies (one P and one N die) if you use discrete devices.
Regards,
Owen
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You should fit each gate resistor as near as you can to each MOSFET, ie, don't have the gate resistors on the PCB and run wires to the gates.
I suggest using small pieces of VERO type board and solder the MOSFET pins to those. This contains the pins and prevents them touching the heat sink. You can then easily attach a gate resistor to each, and if using older lateral mosfets such as the 2SK1058 and 2SJ162, you can solder a 22pF polystyrene across the gate and drain pins to stop high frequency stuff.
You could, if you wanted, also attach a small capacitor or two onto there between supply rail and ground. But that adds the complexity of taking a ground wire to each.
I suggest using small pieces of VERO type board and solder the MOSFET pins to those. This contains the pins and prevents them touching the heat sink. You can then easily attach a gate resistor to each, and if using older lateral mosfets such as the 2SK1058 and 2SJ162, you can solder a 22pF polystyrene across the gate and drain pins to stop high frequency stuff.
You could, if you wanted, also attach a small capacitor or two onto there between supply rail and ground. But that adds the complexity of taking a ground wire to each.
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My plan is to wait for your good self to complete your SMPS work and for a few people buy and try these and give their repost with their various setups. Then it appears I and some others have an option for a higher bias and slightly higher supply rails SMPS with the 500S (which I can only assume will sound the same?) which will do for a somewhat higher power amp with more output devices like a couple of my pals could just now do with before their upgrade need has them buy a commercial product.
Hi,
Sorry if I'm intruding in this argument (SMPS play good sound), of course answer with independent interest, only technically.
a lot of work was needed to achieve the following points,some not simple as in contrast with the nature of switches):
1)output with low harmonic content (especially in the first 100kHz band.
2)high suppression of the signals on the AC main.
3)Fast regulation from main AC
4)Fast Vs output load regulation
These 4 points are fundamental to a sound spectrum, unmodified (especially on class D) where the harmonics present on the rail, are mixed with those of the oscillation (carrier fo). to output.
Normally we know that the marketing decision (forcing) if a product is really good. independent from reality.
Personally I think you have to measure (it's right, since it can be compared with other measures that have the same range.
As the wire amp Opc. is really good, because schema and certain components are allowed to have some great features. no need to say (perhaps not good)
This I have said, contains a "concept".
Perhaps someone has never seen the measures to a conventional SMPS, maybe it's a coincidence that many builders on this forum, never published, even a simple fft output. (I'm sure that can not say on this, magic word as "measure not good but...sound very nice)
Regards
Sorry if I'm intruding in this argument (SMPS play good sound), of course answer with independent interest, only technically.
a lot of work was needed to achieve the following points,some not simple as in contrast with the nature of switches):
1)output with low harmonic content (especially in the first 100kHz band.
2)high suppression of the signals on the AC main.
3)Fast regulation from main AC
4)Fast Vs output load regulation
These 4 points are fundamental to a sound spectrum, unmodified (especially on class D) where the harmonics present on the rail, are mixed with those of the oscillation (carrier fo). to output.
Normally we know that the marketing decision (forcing) if a product is really good. independent from reality.
Personally I think you have to measure (it's right, since it can be compared with other measures that have the same range.
As the wire amp Opc. is really good, because schema and certain components are allowed to have some great features. no need to say (perhaps not good)
This I have said, contains a "concept".
Perhaps someone has never seen the measures to a conventional SMPS, maybe it's a coincidence that many builders on this forum, never published, even a simple fft output. (I'm sure that can not say on this, magic word as "measure not good but...sound very nice)
Regards
I am not capable of designing an SMPS.
I am afraid of expending resources on an item that I don't understand.
I will rely on the braver Members to test and report on the various AP2 offerings.
In the meantime I follow with interest what is happening and being proposed in this Thread. I have already got myself down for the amplifier PCBs and component kit.
Once I have allayed my misgivings, I may join in a PSU Group Buy, but not yet.
Does that make me a skeptic?
Probably, but an open minded skeptic !
I am afraid of expending resources on an item that I don't understand.
I will rely on the braver Members to test and report on the various AP2 offerings.
In the meantime I follow with interest what is happening and being proposed in this Thread. I have already got myself down for the amplifier PCBs and component kit.
Once I have allayed my misgivings, I may join in a PSU Group Buy, but not yet.
Does that make me a skeptic?
Probably, but an open minded skeptic !
Your thinking is right, my post did not want to push to increase the group list. but to reflect, understand and see with their eyes.
If a company has made sacrifices and spent lots of money on proprietary technologies, it is normal that has an interest in seeing things as they are, instead of hide. is in your best interest to call for measures of SMPS. This may push some companies to do better. apart from that I think a SMPS, a critical component for safety etc..
Regards
If a company has made sacrifices and spent lots of money on proprietary technologies, it is normal that has an interest in seeing things as they are, instead of hide. is in your best interest to call for measures of SMPS. This may push some companies to do better. apart from that I think a SMPS, a critical component for safety etc..
Regards
Excuse me but i haven't read all 92 pages and propably i am wrong...but, when looking in the pcb, the schematic and the datasheet, there is something which requires clarification to me:
The mosfets on the pcb have their pins with the order G-S-D. This is opossite from all the other mosfets (G-D-S). The power supply is obviously in the D, which means the further on the right pins. But in the schematic it seems that the power is in the S and in the pcb also in S ( the middle ones).
So, what is happening?
Maybe there is another newer version of the pcb that i haven't noticed? I believe there is a perfectly reasonable explanation, but i really need someone to explain...
The mosfets on the pcb have their pins with the order G-S-D. This is opossite from all the other mosfets (G-D-S). The power supply is obviously in the D, which means the further on the right pins. But in the schematic it seems that the power is in the S and in the pcb also in S ( the middle ones).
So, what is happening?
Maybe there is another newer version of the pcb that i haven't noticed? I believe there is a perfectly reasonable explanation, but i really need someone to explain...
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Did you look at the datasheet of the lateral mosfets?
If not, click any TO-247 mosfets from Lateral Mosfet and take a look at the datasheet.
If not, click any TO-247 mosfets from Lateral Mosfet and take a look at the datasheet.
As noted on the first page and the title of the thread, the design uses LATERAL MOSFETS and i dont think this needs any further clarification; but just in case
"The Wire AMP" Class A/AB Power Amplifier based on the LME49830 with Lateral Mosfets
specifically the SEMELAB/ALFET in this case ACD103PDD/ACD101NDD
the GSD pinout is standard for all the lateral mosfets ive ever come into contact with. i'm sure there are some different though as that isnt very many
"The Wire AMP" Class A/AB Power Amplifier based on the LME49830 with Lateral Mosfets
specifically the SEMELAB/ALFET in this case ACD103PDD/ACD101NDD
the GSD pinout is standard for all the lateral mosfets ive ever come into contact with. i'm sure there are some different though as that isnt very many
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haha hey i didnt use any exclamation marks
Impressive showing of restraint there, esp for you
115VAC Version
Hi,
After test on 115Vac version (both models), max voltage output possible is +/-48-50V for power DC output. (np for aux).
This range ensures that performances remain as original.
Unfortunately, these 2 SMPS, do not use the double capacitors in high voltage cell, then you can not use as duplicator.
---------------------------------------------
2nd samples were sent to OPC. (dps-400 complete as version for wire amp)
well, everything is ready, waiting for the measures to opc.
Regards
Hi,
After test on 115Vac version (both models), max voltage output possible is +/-48-50V for power DC output. (np for aux).
This range ensures that performances remain as original.
Unfortunately, these 2 SMPS, do not use the double capacitors in high voltage cell, then you can not use as duplicator.
---------------------------------------------
2nd samples were sent to OPC. (dps-400 complete as version for wire amp)
well, everything is ready, waiting for the measures to opc.
Regards