nice work Hollowman, but unusual design, why are the power bipolars not at the edge and whats the idea behind a separate input board?
Thanks Luke,
the bipolars are placed centrally on the board mostly for better heat spreading and maybe also for a bit shorter signal paths. I should imagine that a thin copper foil between them and the heatsink would help too.
There's not just a separate input board, but also for the two bridge sections, which are mirrored, and the main board for the power supply and protection circuit.
There would be a connection anyway somewhere between the two sections of the bridge, so it is natural to physically separate them at the phase splitter which is that last point the signal is common to sections. If this part of the circuit was implemented in the amplifier pcbs, it would have to be unpopulated in one of the two sections, and a connection ran between the two. I though it would be neater with a separate input pcb, AW400 style.
the bipolars are placed centrally on the board mostly for better heat spreading and maybe also for a bit shorter signal paths. I should imagine that a thin copper foil between them and the heatsink would help too.
There's not just a separate input board, but also for the two bridge sections, which are mirrored, and the main board for the power supply and protection circuit.
There would be a connection anyway somewhere between the two sections of the bridge, so it is natural to physically separate them at the phase splitter which is that last point the signal is common to sections. If this part of the circuit was implemented in the amplifier pcbs, it would have to be unpopulated in one of the two sections, and a connection ran between the two. I though it would be neater with a separate input pcb, AW400 style.
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Thanks for the answer Hollow_man.
Yes it's gonna cost a bit, but still much cheaper than an original.
The reason I thougth about the SA1837/SC4793 is that I can get them easy, and I'm shure they aren't fakes.
I see the others from time to time, but when you click on the picture the number is right, but it's marked NTC or something on the case.
I want real Toshibas.
Maybe you or others have tips where to get them, and no fakes.
I have used Digikey whith good result, but they only have the 5200 pair and the 1837 pair.
For the small-signals, and everything else I use Elfa. But they don't have Toshiba powers.
Many firms you could relay on for nofakes will only sell if you have a firm yourself.
I'm trying to make a board in ExpressPCB freeware now. it's very timeconsuming, but I want to try to etch my own boards for this, so must do it. Your layout are very welcome, because it's a very differnt way of work than I'm used to.
Earlier I used veroboard, and p-p.
Yes it's gonna cost a bit, but still much cheaper than an original.
The reason I thougth about the SA1837/SC4793 is that I can get them easy, and I'm shure they aren't fakes.
I see the others from time to time, but when you click on the picture the number is right, but it's marked NTC or something on the case.
I want real Toshibas.
Maybe you or others have tips where to get them, and no fakes.
I have used Digikey whith good result, but they only have the 5200 pair and the 1837 pair.
For the small-signals, and everything else I use Elfa. But they don't have Toshiba powers.
Many firms you could relay on for nofakes will only sell if you have a firm yourself.
I'm trying to make a board in ExpressPCB freeware now. it's very timeconsuming, but I want to try to etch my own boards for this, so must do it. Your layout are very welcome, because it's a very differnt way of work than I'm used to.
Earlier I used veroboard, and p-p.
Styrkv,
with regards to fakes, there indeed is a large problem. You can not rely on your local electronics shop. I have had good luck by choosing the best national electronics distribution company, where I ordered all the actives. I also got some aluminium oxide transistor insulators, which work very well. I think you will find that excellent thermal conductivity between an output device and the vbe multiplier is imperative for this design. You are looking roughly at >100 euros just for the actives.
Please be aware that the pcbs I have designed rely on plated-through holes, and I am not sure you can have these with manually produced boards. Perhaps you can sweat it by attempting to solder the required componets on both sides of the pcb, and solder links to join sld and cmp where required, but the end result will not be very pleasing asthetically and perhaps from a reliability point of view. Of course it will depend on how skilled a job you can do.
Personally I use eurocircuits.com. Quality is most satisfying while cost is lower than I have seen elesewhere (for comparable quality). But still, they will not be cheap.
Sadly, my current situation does not allow me to proceed any further with the design so, although I feel confident, it remains unverified as yet.
with regards to fakes, there indeed is a large problem. You can not rely on your local electronics shop. I have had good luck by choosing the best national electronics distribution company, where I ordered all the actives. I also got some aluminium oxide transistor insulators, which work very well. I think you will find that excellent thermal conductivity between an output device and the vbe multiplier is imperative for this design. You are looking roughly at >100 euros just for the actives.
Please be aware that the pcbs I have designed rely on plated-through holes, and I am not sure you can have these with manually produced boards. Perhaps you can sweat it by attempting to solder the required componets on both sides of the pcb, and solder links to join sld and cmp where required, but the end result will not be very pleasing asthetically and perhaps from a reliability point of view. Of course it will depend on how skilled a job you can do.
Personally I use eurocircuits.com. Quality is most satisfying while cost is lower than I have seen elesewhere (for comparable quality). But still, they will not be cheap.
Sadly, my current situation does not allow me to proceed any further with the design so, although I feel confident, it remains unverified as yet.
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No, it is not a bridged AW120. This would yield 4x120W=480W IF the output devices could sustain the required current, which they can not.
So, a bridged AW120 does not give you an AW250.
So, a bridged AW120 does not give you an AW250.
By all means, call it what you like!🙂 Personally, I wouldn't call it 'a scaled aw120' but if you must, you could say that each bridge section is fairly close to an aw120, save for extra output device pair, bias adaptation to the lower rail voltages, extra current sources/separate input stage, discrete open loop regulator for the voltage amps, completely own protection circuitry and pcb design of course.
But, let us not forget that EC's underlying principles are the same amongst all its designs (open loop transimpedance input stage / parallel shunt feedback etc).
Cheers.
PS. speaking of protection circuitry; can anybody suggest a good DPDT relay for the job?
But, let us not forget that EC's underlying principles are the same amongst all its designs (open loop transimpedance input stage / parallel shunt feedback etc).
Cheers.
PS. speaking of protection circuitry; can anybody suggest a good DPDT relay for the job?
The schematic has the same boardcode as my AW100DMB but Hollow_man added one more outputpair. The AW120 can be bridged to become one AW 400. Look at the Electocompaniet website for Classic line, AW120, 2 channel.
As I see it, a bridged aw120 would be rather underprivileged in its current suppling abilities. This would make it suitable only for very easy loads, which kinda defies the purspose of having a high-power amp!
I am mostly inclined toward 250W for my clone, plus the extra output pair should give it an iron grip on any reasonable load.
I am mostly inclined toward 250W for my clone, plus the extra output pair should give it an iron grip on any reasonable load.
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For the protection relay maybe Panasonic JM Series for inductive load can be used.
Rated at 20A, 70A peak. Overkill perhaps, on the other hand it increase reability.
Could we get away with one pr channel?
The speaker dont care if the circuit is broken on one of the sides or both I think.
Rated at 20A, 70A peak. Overkill perhaps, on the other hand it increase reability.
Could we get away with one pr channel?
The speaker dont care if the circuit is broken on one of the sides or both I think.
Of course we can get away with one relay, and it is preferable so long as a suitable one is found.
sounds interesting. is this what EC uses?
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I have just taken the top of my AW 250.
The relays are Goodsky RE-404, 48 VDC.
I must replace the speaker-relays because they have bad contact whith low volume.
The Panasonic JM seems to be some sort of motor-relay. Maybe not suitable at all for low volume.
Tyco Electronics have goldplated 16A relays. RT 1 and 2.
The relays are Goodsky RE-404, 48 VDC.
I must replace the speaker-relays because they have bad contact whith low volume.
The Panasonic JM seems to be some sort of motor-relay. Maybe not suitable at all for low volume.
Tyco Electronics have goldplated 16A relays. RT 1 and 2.
Hi Hollow_man, I came upon this topic while searching for Electrocompaniet...
I was wondering how did you fare with making your own amp ??
How is it sounding ?
Unfortunately I am a complete noob on this front, It would be very interesting to make it, as the real thing is so damn expansive...
How much does it cost in parts actually when building yourself ?
I was wondering how did you fare with making your own amp ??
How is it sounding ?
Unfortunately I am a complete noob on this front, It would be very interesting to make it, as the real thing is so damn expansive...
How much does it cost in parts actually when building yourself ?
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Hi Normanu,
it certainly not going to be cheap...that's why I have put if off. We are talking upwards of 1000 euro just for the parts, if they are to be purchased from a reputable source. That would include pcbs and transformers, but not the metalwork.
Also let us not forget that possibly tens to hundreds of manhours are required for that sort of thing. How do we establish a cost for these?
it certainly not going to be cheap...that's why I have put if off. We are talking upwards of 1000 euro just for the parts, if they are to be purchased from a reputable source. That would include pcbs and transformers, but not the metalwork.
Also let us not forget that possibly tens to hundreds of manhours are required for that sort of thing. How do we establish a cost for these?
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