Thanks Damir.
The last update on the tracking was;
10/12/2019. 13:23:43 CROATIA HRZAGB ZAGREB 10003
I assume it might arrive next year because of the busy season. I'm starting to collect parts from Mouser but can't buy all them since the transistors were already discontinued or obsolete. Is KSA a good substitute for the 2SA, 2SC transistors? like 2SA992 - KSA992.
The last update on the tracking was;
10/12/2019. 13:23:43 CROATIA HRZAGB ZAGREB 10003
I assume it might arrive next year because of the busy season. I'm starting to collect parts from Mouser but can't buy all them since the transistors were already discontinued or obsolete. Is KSA a good substitute for the 2SA, 2SC transistors? like 2SA992 - KSA992.
Yes Freddie, you can use KSA992F and KSC1845F instead.
About shipping it says "insert item into bag" means it's out on its way.
I have another question again on the BOM. Damir dont get tired of me ok? I know its self explanatory but I'm just trying to clarify before I buy the parts. On the BOM it says;
R37 560R 8W (four 560R 2W 1% metal film in parallel), based on the schematic it is 560 ohms. So if resistor 560 is paralleled then it will end up to 140 ohms? Is that supposed to be 2.2K 2W?
R37 560R 8W (four 560R 2W 1% metal film in parallel), based on the schematic it is 560 ohms. So if resistor 560 is paralleled then it will end up to 140 ohms? Is that supposed to be 2.2K 2W?
Hi Freddie, if you look at the PCB layout some post back you can see that 560R came from two 560R in parallel and then in serie with other two 560R in parallel, so total is again 560R. That is a part of improvement to lower resistor voltage coefficient.
Marry Christmas and happy diy to all.
Damir
Better to have matched transistors, DC servo could goes out of serving otherwise.
Damir
Hi Dadod,
I'm slowly populating my PSU Board. I'd been busy these days and didn't have much time to do DIY.
I noticed that you have two R26 on the board, see pic attached. The R26 that I circled might be R29 based on the schematic. This connects to D9 but no D10? Can you show me where is that located on the board?
Second question, matching transistor on the amplifier Q11, Q12 Q15, Q17 Q16, Q19. Is hfe matching good enough? And what hfe do you suggest?
I'm slowly populating my PSU Board. I'd been busy these days and didn't have much time to do DIY.
I noticed that you have two R26 on the board, see pic attached. The R26 that I circled might be R29 based on the schematic. This connects to D9 but no D10? Can you show me where is that located on the board?
Second question, matching transistor on the amplifier Q11, Q12 Q15, Q17 Q16, Q19. Is hfe matching good enough? And what hfe do you suggest?
Attachments
Hi Freddie,
Yes R26 should be R29 as on the schematic. LEDs D10 and D11 are not on the board but with wires extended to be placed somewhere on the front panel. D10 reed shows PS regulator protection triggered, and D11 green means PS regulator works correctly.
Matching power amp transistors:
Q3 with Q4 matched Vbe hfe not so critical just to be in the same class C
Q11 with Q12 matched Vbe hfe not so critical just to be in the same class C
Q2 with Q14, Q6 with Q8, Q5 with Q7 hfe matching.
Rest of BJTs not need matching.
Output MOSFETs needs matching, but usually if from the same batch matching is quite simple.
Damir
Hi Dadod,
Could I eliminate the power amp regulator and use this one instead for speaker protection? Have a hard time fitting all the board in one box. Is there a big difference of using the amp regulator and without?
I haven't finish soldering all components on the amp board. I'd been out of town for a month now traveling from client to client and no time for DIY.
Could I eliminate the power amp regulator and use this one instead for speaker protection? Have a hard time fitting all the board in one box. Is there a big difference of using the amp regulator and without?
I haven't finish soldering all components on the amp board. I'd been out of town for a month now traveling from client to client and no time for DIY.
Hi Dadod,
Could I eliminate the power amp regulator and use this one instead for speaker protection? Have a hard time fitting all the board in one box. Is there a big difference of using the amp regulator and without?
I haven't finish soldering all components on the amp board. I'd been out of town for a month now traveling from client to client and no time for DIY.
Hi Fredy,
Yes, this can replace speaker protection on the PS regulator, but not over current protection.
I need to test this SSR on an amp, for now it passed bench test only.