Q8 stands on a printed circuit board, at any temperature of the output transistors, the deviation is 0.1-0.3 mV. I think it's not about the Q8 thermal contact.
I'm finishing a 28B clone and I'm looking for schematics/parts list for power supply and input section, if anyone can help me out with these items it will be much appreciated. Thanks
If I'm not mistaken the 28b uses the same input board as the 4b, and the schematic are in this thread
Q6-Q8, Q9 Q12 are put on a common radiator. Q5 Q6 changes perfectly to
2SA1380-2SC3502 or similar. There will be no worries about the module.
The common radiator is intended only for the input module.
I give advice from personal experience.
2SA1380-2SC3502 or similar. There will be no worries about the module.
The common radiator is intended only for the input module.
I give advice from personal experience.
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For some reason I'm not understanding the prints for this input board. Q9 and Q10 require the same devices but the schematic is showing different devices, both with heat sinks. 2N5551/2n5401 cannot be heatsinked. Input schematic doesn't show both channels only one side. Unless these prints aren't correct?? Any answers?
Looks like there are a couple of differences in the various versions of the schematics.
On the schematic I posted (which I think is V2 boards), Its Q9 (MJE182) and Q12 (MJE172) that require a heatsink, both are for the power supply. Also Q7 (MJE 182) and Q8 (MJE 172) on the output can get warm and would probably benefit from a heatsink, although I haven't had any problems without a heatsink.
The input board itself is simply mirrored and the labelling is pretty good.
On the schematic I posted (which I think is V2 boards), Its Q9 (MJE182) and Q12 (MJE172) that require a heatsink, both are for the power supply. Also Q7 (MJE 182) and Q8 (MJE 172) on the output can get warm and would probably benefit from a heatsink, although I haven't had any problems without a heatsink.
The input board itself is simply mirrored and the labelling is pretty good.
I would post pictures but I get prompts that "file too large to upload " . Am I doing something wrong uploading?
