Hi
Possibly Oliver is the one to help here, but I have ordered an optical vol control and wondered if the 100K pot listed on the BOM is OK to use with the DCB1?
Is it possible to use a 50K pot as I have a couple of these?
Thanks
Possibly Oliver is the one to help here, but I have ordered an optical vol control and wondered if the 100K pot listed on the BOM is OK to use with the DCB1?
Is it possible to use a 50K pot as I have a couple of these?
Thanks
Argh! I'm still waiting for digikey to ship my parts order for the "blue edition" dcb1 buffer.
Just one quick question;
I hope the BC517-ND is an ok substitute for the BC517-G.
(They didn't carry any "g"s.)
Just one quick question;
I hope the BC517-ND is an ok substitute for the BC517-G.
(They didn't carry any "g"s.)
Let's say, hypothetically speaking, that I wanted to go for the gold and hit the 2A sweet spot. How big a PS would I need? I'm guessing new diodes of course. 12W resistor should still work, right?
I mean this is just hypothetical. I'd be crazy to even try it... 😀
Merlin:
Maybe stronger in mW? As long as it is an NPN Darlington, I would not worry. And it is.
Maybe stronger in mW? As long as it is an NPN Darlington, I would not worry. And it is.
''Stage 3 = circa 2A. 40W dissipation per rail. F5 size sinks & Tx. 1R 12W''.
Ok, so something like this should work, yeah?
All the mechanical work is done! 😛
Internal overview
The front panel
The rear panel
The PSU section
The input and volume control & power switch section
The DCB1 blue edition closer look
Now it´s time for wiring!
An externally hosted image should be here but it was not working when we last tested it.
Internal overview
- 1st 65VA Transformer, double shielded with two power lines (Optical Volume Control & input switch) - upper left side
- +/- Power Supply (27.000µF for OVC & 10.800µF for input switch)
- 6 to 1 input switch
- 1st +5V shunt reg for OVC
- 2nd +5V shunt reg for input switch
- Optical Volume Control pcb
- Power Switch pcb (includes a solid state relays with no wear). The front switch must only handle +12V
- DCB1 blue edition pcb
- 2nd 65VA Transformer double shielded for the DCB1 blue edition
An externally hosted image should be here but it was not working when we last tested it.
The front panel
An externally hosted image should be here but it was not working when we last tested it.
The rear panel
An externally hosted image should be here but it was not working when we last tested it.
The PSU section
An externally hosted image should be here but it was not working when we last tested it.
The input and volume control & power switch section
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The DCB1 blue edition closer look
Now it´s time for wiring!
Yippee, I got my parts in from digikey finally.
I'll have to figure out where to get some heatsinks (if I crank up the current...)
I'll have to figure out where to get some heatsinks (if I crank up the current...)
Connections, solder joints, bad relay, bad pot, burned audio fets. PSU is common so if one channel works, PSU works.
No pot in this one yet. Just testing to make sure it is working.
Relay clicks, so I assume it is working. Unless I should be looking at voltage then only voltage I'm gettting is 0.63v(pin1) and 11.72v (pin10)
how to tell if audio fets are burned with dmm? is it similar to checking for B-E voltages. Or do I have to remove and test with my tester.
I will check solder joints and reflow.
Relay clicks, so I assume it is working. Unless I should be looking at voltage then only voltage I'm gettting is 0.63v(pin1) and 11.72v (pin10)
how to tell if audio fets are burned with dmm? is it similar to checking for B-E voltages. Or do I have to remove and test with my tester.
I will check solder joints and reflow.
Check voltage on all 2sk170's in DCB1 section, across pins 1 and 3.
Should have 9-10v. Measure DCoffset at output points, and play signal through and look for AC signal on output points.
Should have 9-10v. Measure DCoffset at output points, and play signal through and look for AC signal on output points.
Alreadychecked voltages across 1-3 and getting around 9v. DCoffst is .003/.007. I will check for AC now
Thanks
Thanks
Hi; I've got a couple of quick questions regarding the blue edition pcb board.
The .22u/100uf caps in the middle - what up with that? Is it two caps ( 1x .22uf and 1x 100uf) or something else?
I've noticed two resistors just before v+ / v- out (labelled '1') - are these on the BOM?
Thanks,
JG
The .22u/100uf caps in the middle - what up with that? Is it two caps ( 1x .22uf and 1x 100uf) or something else?
I've noticed two resistors just before v+ / v- out (labelled '1') - are these on the BOM?
Thanks,
JG
That´s the PSU module from my Reference DAC project that feed the +5V Salas shunts.
Play a CD and use your AC set DVM. Should be able to show something when there is signal. Even better if you got a low steady sine wave from a test CD or a computer file, easier to catch by most. Say 100Hz 0dB. Keep the black probe hooked to ground and poke around with the red. Is it going in to the board at all on the problematic channel? Does it pass the input 220R? does it exit the output 220R? If it makes it till there, does it pass the relay? It may click, but does it receive signal, and does it achieve contact? If its on the output, is it on the other end of the output cable? A joint, a burned part, a sticky contact, a problematic cable?
Having DC offset, says its alive, your signal stops somewhere.