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SSDIY 11th April 2011 12:16 AM

5W Single Ended Class A Power Amp From Mark Houston
1 Attachment(s)
I have built this 5W Class A power amp designed by Mark Houston and feel happy with it's sounding performance. I am wondering now if I could use 2SK1058's complementary pair 2SJ162 to build one more power amp as the supplier sell them together. Please advice.

lineup 11th April 2011 07:04 AM

1 Attachment(s)
You can replace resistor 15R with a current source based on 2SJ162.
It should give like 0.8A current.
You need 2 resistors and a transistor besides 2SJ162.
See diagram

This will improve the amplifier considerably.

lineup 11th April 2011 08:56 AM

The 820mOhm, 0.82 Ohm, resistor sets the current ~ 0.8A

ElecronicsEdC 11th April 2011 12:09 PM

nice for head phones

Bigun 11th April 2011 12:27 PM

I think SSDIY is looking for a way to build another amp not improve this one. The answer lies in using the complimentary part as an active device with resistive load of course, only you have to put the active device on top and the resistor underneath.

toprepairman 11th April 2011 01:03 PM

Hate to disappoint, this is not a 5W amp, 1 W rms is closer.

toprepairman 11th April 2011 01:06 PM

With the constant current mod, it will come up to 2.5W rms.

SSDIY 11th April 2011 04:22 PM

Hi guys

Thank you for all your inputs. What I mean is to replace the 2SK1058 by 2SJ162 and apply a -24v to it. Other parts and components remain unchanged. Would the circuit work properly with this change? Please advice.

lineup 11th April 2011 04:41 PM

No, it is made for both 2SK1058 and SJ201.

But sure is possible to make such circuit.
It will be kinda upside down because 2SJ162 is P-channel transistor.

lineup 11th April 2011 05:35 PM

1 Attachment(s)
Here is a version for 2SJ162.

Note that power supply V+ is connected to GROUND.
And so GROUND is the upper part.
But as long as you note polarity of electrolytic capacitors
it should not be a problem.

A stereo system should be 2 such with 2SJ162
as 2SK1058 has a bit different caracteristic from 2SJ162.

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