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Old 23rd March 2013, 04:07 AM   #41
rade95 is offline rade95  United States
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Quote:
Originally Posted by rade95 View Post
Hi LJM_LJM,
Just got my boards and started examining the circuit. There are several problems with the components marked on the PCB. First the PCB is NOT desigbed for IRFP9240/240 because if IRFs were used the PCB would connect two source pins of the MOSFETs. Look at F5 PCB and you will see what I am talking about. F5 PCB connects middle pins of the IRF MOSFETs which are drains not sources. If you use Toshiba K1058/J162 lateral MOSFETs (probably a better choice anyway) the pin layout IS CORRECT. Next in the driver stage there are 2 2N5551 close together. The pin layout of 2N5551 like 2N5401 is EBC looking at the flat front of the transistor. However the PCB layout for 2N5551 drivers has middle pins connected, if they are BASE this makes no sense. Looking at the schematic in post #5, 2N5551 drivers have COLLECTORS connected indicating that the pin layout is ECB not EBC, which for 2N5551 is _wrong_. I don't know if there are any suitable transistors that would match ECB pin layout. I can bend the pins and fix that but why was this done? I don't get it. A mistake of the PCB designer I guess. The bigger problem is that the PCB and the IRF MOSFETs supplied do not match the pin layout of the IRFs, so there is no way on Earth that this PCB would work with the IRFs without modifying (cutting) the PCB pads. For the sake of making this kit buyers happy, LJM_LJM can you please comment on this.
Did some readings. That was a very silly comment by me, the F5 is a common source class A amplifier and L7 is a common drain class AB amplifier. There is nothing wrong with the circuit, or the components supplied including IRFP MOSFETs. 2N5551 has ECB pin layout but this is not a big deal.
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Old 13th April 2013, 03:39 AM   #42
ljm_ljm is offline ljm_ljm  China
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Quote:
Originally Posted by rade95 View Post
Hi LJM_LJM,
Just got my boards and started examining the circuit. There are several problems with the components marked on the PCB. First the PCB is NOT desigbed for IRFP9240/240 because if IRFs were used the PCB would connect two source pins of the MOSFETs. Look at F5 PCB and you will see what I am talking about. F5 PCB connects middle pins of the IRF MOSFETs which are drains not sources. If you use Toshiba K1058/J162 lateral MOSFETs (probably a better choice anyway) the pin layout IS CORRECT. Next in the driver stage there are 2 2N5551 close together. The pin layout of 2N5551 like 2N5401 is EBC looking at the flat front of the transistor. However the PCB layout for 2N5551 drivers has middle pins connected, if they are BASE this makes no sense. Looking at the schematic in post #5, 2N5551 drivers have COLLECTORS connected indicating that the pin layout is ECB not EBC, which for 2N5551 is _wrong_. I don't know if there are any suitable transistors that would match ECB pin layout. I can bend the pins and fix that but why was this done? I don't get it. A mistake of the PCB designer I guess. The bigger problem is that the PCB and the IRF MOSFETs supplied do not match the pin layout of the IRFs, so there is no way on Earth that this PCB would work with the IRFs without modifying (cutting) the PCB pads. For the sake of making this kit buyers happy, LJM_LJM can you please comment on this.
I know why you think like that.

But it's a little secret.

I can only say that a lot of parts, they don't look so simple on the surface of the model.

You can be at ease completely, about is a very stable, and very reliable power amplifier.
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Old 7th May 2013, 03:32 AM   #43
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Quote:
Originally Posted by Tinface View Post
I bought a couple of kits, reverse engineered the PCB and have created schematic. Should I publish here?
I'm definitely interested as well. Can you PM me or send to my email?
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Old 7th May 2013, 02:20 PM   #44
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Interested in the schematic,can you send to my email?
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Old 29th May 2013, 03:05 PM   #45
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Hello,

Do you know if this module can work fine with a 30V transformer (42VCC then) ?
I have a couple of surrounds to power and I am wondering if a L7 based amplifier would do the job or if I should buy a L15.
I'm not a quality addict when talking about HomeTheater.

Extra question : Do you think one module could power a passive subwoofer (4 ohms, 25cm) with a 300VA transformer ?
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Old 6th June 2013, 12:28 PM   #46
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Anyone ?
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Old 26th June 2013, 02:49 PM   #47
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I made a amp with 47 dc supply. The amp burned in one channel and the speaker too. Impedance off speaker not below 5 ohms.
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Old 26th June 2013, 04:02 PM   #48
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Quote:
Originally Posted by Erlend Sæterdal View Post
I made a amp with 47 dc supply. The amp burned in one channel and the speaker too. Impedance off speaker not below 5 ohms.

Billede 023.jpg
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Old 26th June 2013, 10:53 PM   #49
rade95 is offline rade95  United States
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Quote:
Originally Posted by Erlend Sæterdal View Post
Woow, thanks for heads up. I built one channel but have not tested it yet since I still don't have a PS. Did you place transistors and FETs exactly as printed on the PCB? It really sucks we don't have a complete circuit.
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Old 27th June 2013, 03:47 AM   #50
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Everything was done right. It played fantastic for a while and suddenly .......... The speakers used is impossible too repair. So the owner is very sorry. Do not use more than 36 vdc I think.
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