Sorry if this question does not belong in this thread ... but I would like to build the Pearl 3 and I want to make sure that I purchase all the necessary parts. From what I can tell if I purchase the DIY kit from DIY Audio Store ($150) and I purchase the Modushop kit "Wayne's Pearl III Chassis Kit" (230 Euros), that is all I need. Is that correct? Thanks, Ed
^ No. The build document (the .pdf in post 1) provides a list of all the other necessary (and optional) components.
@EGlaser I am going through the BOM and buying all the same stuff today and had the same questions. Most of the part numbers are in the BOM in the directions.
1. You need to head over to DigiKey and Mouser and purchase quite a few things to finish the power supply and case.
-From Mouser I got this stuff: RCA connectors, XLR connectors, Ground Post, AC plug, Caps for C1-C11, Resisters for R3-11, LEDs for D3-5, rectifier for D1, 2, and 6 ~ $115 at mouser
-From DigiKey I got: U2 (if XLR), Transformer (on backorder right now, shipping August) Fuses, 2 and 3 slot terminal blocks, cable gland, IEC fuse holder, and switch ~$65 at Digikey
2. You will need wire/cable for internal power, umbilical cord, and signal wires. I picked up some Mogami from Performance Audio. ~$20
3. You will need M3 5mm standoffs with screws and nuts ~$10 at Amazon
4. Stuff for ground wires however you want to hook them up including misc screws, star washers etc.
5. Sandpaper to scratch the paint off the case panels to connect them all together electrically
I will still need to order some 16 gauge wire from Amazon for the power box, some spade connectors and spade terminals for the board, probably use some old Cat 6 wire to extend the LEDs out to the front of the case, random shrink wrap, electrical tape, solder, soldering iron, crimp fittings etc.
This might not be everything, but this will get you started for sure. I up to about $575 of stuff right now (including the diyAudiostore kit and the Modushop case). I'm thinking I will need a few more things once I get into it.
1. You need to head over to DigiKey and Mouser and purchase quite a few things to finish the power supply and case.
-From Mouser I got this stuff: RCA connectors, XLR connectors, Ground Post, AC plug, Caps for C1-C11, Resisters for R3-11, LEDs for D3-5, rectifier for D1, 2, and 6 ~ $115 at mouser
-From DigiKey I got: U2 (if XLR), Transformer (on backorder right now, shipping August) Fuses, 2 and 3 slot terminal blocks, cable gland, IEC fuse holder, and switch ~$65 at Digikey
2. You will need wire/cable for internal power, umbilical cord, and signal wires. I picked up some Mogami from Performance Audio. ~$20
3. You will need M3 5mm standoffs with screws and nuts ~$10 at Amazon
4. Stuff for ground wires however you want to hook them up including misc screws, star washers etc.
5. Sandpaper to scratch the paint off the case panels to connect them all together electrically
I will still need to order some 16 gauge wire from Amazon for the power box, some spade connectors and spade terminals for the board, probably use some old Cat 6 wire to extend the LEDs out to the front of the case, random shrink wrap, electrical tape, solder, soldering iron, crimp fittings etc.
This might not be everything, but this will get you started for sure. I up to about $575 of stuff right now (including the diyAudiostore kit and the Modushop case). I'm thinking I will need a few more things once I get into it.
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Have now got one channel working fine. The channel with the intermittent LED, however, is not working. The red LED comes on but goes off again and even when it's on there's no sound. I'm scratching my head to work out where the issue is. In addition to the basic tests in the build guide are them some further diagnostics I can perform? I have the functioning board to compare with. The channel that works sounds great so am keen to fix the one that's not working! Is it possible that it's the LED that's actually faulty?
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Update on diagnostics - I've painstakingly been through the malfunctioning board to test all continuity between the joints and components. Every thing is fine except R19 on the bad board is measuring 750R on the meter not 1K. This is despite the banding being correct on the component. I have also performed some diagnostics with power on and compared the values on boath boards. It seems there are some discrepancies on Q5, Q7 and Q8. Please see the image attached. If anyone has any clues as to the issue it would be most appreciated. The board that's functioning sound sgreat and I'm keen to get both channels humming....
Some of your measurements are not clear. For instance, the output of U1B is -8 volts, but R25, which is physically connected to U1B output, is not the same. Yet Q7 E is -8 volts, did you mean Q7 B? There are not that many components around Q7, D1 and Q6. Double check the pin orientation, resistor values and solder connections.
For the output circuit to be working properly the output of U1B should be around+0.95 volts and the other side of D1 should be -.95 volts. If you measure across D1 you should see about 1.9 volts. My pearl 3 was +.93v and -.93v and across D1 was 1.84v
The other issue you are having is with capacitor multiplier Q8 and should be resolved. Check R19 and R20. A simple voltage divider. Is R20 possibly 1K?
For the output circuit to be working properly the output of U1B should be around+0.95 volts and the other side of D1 should be -.95 volts. If you measure across D1 you should see about 1.9 volts. My pearl 3 was +.93v and -.93v and across D1 was 1.84v
The other issue you are having is with capacitor multiplier Q8 and should be resolved. Check R19 and R20. A simple voltage divider. Is R20 possibly 1K?