A piece of trace which connects a base of MJE15035 TP6 with emitter of BC560.
White + shows the limits of the layout.
I made it little different.
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wires
The blue wires are not touching the pcb, they are in the air. So no short at the cap.
If you follow the schematic you will find out.
You don't need to make the wires from the outside groundplanes if you are sure that the heatsink is grounded at the pcb at 4 points. Transistors has to be isolated!
It is not my design, Mihai gave the eagle files in the thread, in eagle i took all layers visible and then you can see the component location. Then made the pdf.
The gif file i found else.
I didnot make the amp and the psu .....
Regards, Loek
The blue wires are not touching the pcb, they are in the air. So no short at the cap.
If you follow the schematic you will find out.
You don't need to make the wires from the outside groundplanes if you are sure that the heatsink is grounded at the pcb at 4 points. Transistors has to be isolated!
It is not my design, Mihai gave the eagle files in the thread, in eagle i took all layers visible and then you can see the component location. Then made the pdf.
The gif file i found else.
I didnot make the amp and the psu .....
Regards, Loek
Loek,
in that case, Mihai is way better at it than you.
www.diyaudio.com/forums/solid-state...-stage-audio-power-amplifier.html#post1349254
Phew, 4 years ago already.
in that case, Mihai is way better at it than you.
www.diyaudio.com/forums/solid-state...-stage-audio-power-amplifier.html#post1349254
Phew, 4 years ago already.
Understood! Thanks. I have oversized components, so I have to little change the layout.
Hi again
Would it be an idea to use PMBFJ620 dual J-FET instead of 2x2sk170 as input?
http://www.datasheetcatalog.org/datasheet/philips/PMBFJ620_1.pdf
Only problem as I see it is the forward transfer
admittance wich is 10 mS as min. where 2sk170 has typ. 22 mS.
It dosent have the very low noise figure, but that should not be a problem in a power amp input?
Would it be an idea to use PMBFJ620 dual J-FET instead of 2x2sk170 as input?
http://www.datasheetcatalog.org/datasheet/philips/PMBFJ620_1.pdf
Only problem as I see it is the forward transfer
admittance wich is 10 mS as min. where 2sk170 has typ. 22 mS.
It dosent have the very low noise figure, but that should not be a problem in a power amp input?
Look up the symasym schematic. Replace the FC-100 diode string and pot with the symasym's BD135 (or similar) and the resistive divider to its base.
SymAsym5 - Project
Hmm.
Maybe too low Gm, but that wouldn´t that just mean, that the openloop gain would be a little less, and therefor maybe the distortion figures a very small amount higher, as the feedback amount is reduced?
The cool thing about the device is that the two FETs track each other temperaturewise.
But again the drawbacks may be too servere.
Another candidate (I have in house!) could be 2sk363. Gm: typ 60 mS @ 15mA and IDss 5-30mA.
My problem is , that from the many 2sk170 I have here only very few has IDss > 9mA so I cannot match them good enough. Almost all of the 2sk363 has IDss > 9mA and the Phily dosen´t need to be matched, so they could be selected by highest Gm.
Hmmmm....
Maybe too low Gm, but that wouldn´t that just mean, that the openloop gain would be a little less, and therefor maybe the distortion figures a very small amount higher, as the feedback amount is reduced?
The cool thing about the device is that the two FETs track each other temperaturewise.
But again the drawbacks may be too servere.
Another candidate (I have in house!) could be 2sk363. Gm: typ 60 mS @ 15mA and IDss 5-30mA.
My problem is , that from the many 2sk170 I have here only very few has IDss > 9mA so I cannot match them good enough. Almost all of the 2sk363 has IDss > 9mA and the Phily dosen´t need to be matched, so they could be selected by highest Gm.
Hmmmm....