Hi Steve,
Try here Lee's (Thomo) site for the opamps and caps as well as some other goodies you might fancy trying!
Definately a seperate regulator on the 5v feed to the analogue DAC. Even better a low noise reg! If you fancy going that far let i'll post instruction!
Also, read rays mod list in the 1st post. Although it starts as a component replacement list, there are some details for other mods at the end of the doc (heaphone bypass, mute disable etc)
Ian
Try here Lee's (Thomo) site for the opamps and caps as well as some other goodies you might fancy trying!
Definately a seperate regulator on the 5v feed to the analogue DAC. Even better a low noise reg! If you fancy going that far let i'll post instruction!
Also, read rays mod list in the 1st post. Although it starts as a component replacement list, there are some details for other mods at the end of the doc (heaphone bypass, mute disable etc)
Ian
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Dammit... was testing the new lm317/337 regulators yesterday.
At some moment, I was soldering a wire to the Vin on the main PCB (where the 79xx used to be) and... bam! spark!... must have been some leftover current somewhere.
Didnt have time to check out whether there was any damage... how severe could it be?
At some moment, I was soldering a wire to the Vin on the main PCB (where the 79xx used to be) and... bam! spark!... must have been some leftover current somewhere.
Didnt have time to check out whether there was any damage... how severe could it be?
Thanks, I like it when things look nice and neat
I ordered a small batch of just 10 pcs. at The PCBShop.com. There are no startup or tooling costs. The PCB's are made in a print-pooling system, where small batches are clustered with 'the big guys', so costs are relatively low. Took them less than 10 days to deliver them
.And for those who are interested: Partsconnexion has a 20% off (almost) everything sale. They carry a good inventory of BG's...
Regards,
Ray
Steve, I'd pop the original regs back and check for correct voltage/operation.
where exactly did the spark come from?
Thanks for the info Ray
Ray,
I took out the old regs so I had 3 empty holes, and was soldering a wire (unconnected on the other side) to the Vin (coming from the transformer) hole. The spark happened as I approached Vin with my soldering iron, and might have been caused by:
VIn - Soldering iron
VIn - Soldering Iron - Ground
VIn - Soldering Iron - VOut
At the time the board was out of the chassis/frame, so there was no ground really.
I took out the old regs so I had 3 empty holes, and was soldering a wire (unconnected on the other side) to the Vin (coming from the transformer) hole. The spark happened as I approached Vin with my soldering iron, and might have been caused by:
VIn - Soldering iron
VIn - Soldering Iron - Ground
VIn - Soldering Iron - VOut
At the time the board was out of the chassis/frame, so there was no ground really.
Probably a capacitor discharge Vin <> GND. The main smoothing caps cannot release their charge if the regulators are out, so there is a remaining energy in the caps, even if the PCB is disconnected for some time. Check with a voltmeter and discharge with a 100R resistor.
Like Ian says, put the original ones back in, to make sure nothing's damaged. Otherwise you'll be solving two problems at once if one of your regs doesn't work.
Regards,
Ray
Like Ian says, put the original ones back in, to make sure nothing's damaged. Otherwise you'll be solving two problems at once if one of your regs doesn't work.
Regards,
Ray
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It's alive! .... Alive!
At least when using the old regs. After I discovered it's still alive, I put in the lm317/337 and alas, that didn't work (disc spins, just no sound at all, no errors)...
Output voltages of the lm317/377 were 11.9V and 10,9V (which is a bit odd, but could be measurement error due to my testing setup).
At least when using the old regs. After I discovered it's still alive, I put in the lm317/337 and alas, that didn't work (disc spins, just no sound at all, no errors)...
Output voltages of the lm317/377 were 11.9V and 10,9V (which is a bit odd, but could be measurement error due to my testing setup).
The only rails that those regs are supplying are the +/-12v to the HDAM and opamps (thats why everything else will work but you're getting no sound).
I would run 3 wires Make sure you have the pin config correct for the - reg
See Audio Upgrades - Voltage Regulators. The pin out is half way down the page.
I would run 3 wires Make sure you have the pin config correct for the - reg
See Audio Upgrades - Voltage Regulators. The pin out is half way down the page.
3 wires, what do you mean? I used 3 wires for testing as you said.
Connected Vin and Ground to the Reg, and Vout and Ground to the multimeter.
Very likely I busted the PCB traces and metal around the holes since I soldered and desoldered a couple of times (desoldering the old ones,testing new ones, putting back old ones to see if the machine still works, desoldering, putting in the new ones etc etc). So I will probably need to hard-wire the broken connections to the next point (e.g. Vin to the Vout of the nearest elco)
Connected Vin and Ground to the Reg, and Vout and Ground to the multimeter.
Very likely I busted the PCB traces and metal around the holes since I soldered and desoldered a couple of times (desoldering the old ones,testing new ones, putting back old ones to see if the machine still works, desoldering, putting in the new ones etc etc). So I will probably need to hard-wire the broken connections to the next point (e.g. Vin to the Vout of the nearest elco)
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It's possible the regulator doesn't work correctly when you test it on the bench without any load. Try connecting a small cap (10...47u) between the reg's output and ground, and make sure the minimum load current is 10mA. This can be met by placing a 1k resistor across the cap.
Regards,
Ray
Regards,
Ray
Thanks, it looks so much cooler than a home-made PCB, with solder mask and silk screen
I'm thinking about rebuilding the one in my SA8400
Finally this forum accepts larger image sizes
Ray,
Those boards look really nice.
However, the lack of having one last year made me learn how to design one, and taught me a new skill.
But with you now having those nice boards more people can easily make up a DOS, which everyone should have in their players!
The DOS is still the single biggest improvement I have ever made in audio.
Steve
