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Old 18th February 2013, 10:13 AM   #301
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Don't use any.
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Old 18th February 2013, 05:42 PM   #302
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I bypass them with modified Wima .33 polyprops (steel leads dremeled off and 6N copper leads installed and then marked for outside foil orientation and installed with the outside foil going to the output....pics on my website) and install WA-Quantum chips on them. Sounds like $100 fully burned in Teflons.....maybe better. You also want to remove the 50K resistor to ground after the cap. You don't need it and they sound bad. You don't want the bypass caps dangling in the air....they should be mounted with a little Amazing Goop. Double stick tape sounds really bad!
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Old 19th February 2013, 12:52 AM   #303
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Quote:
Originally Posted by Ric Schultz View Post
I bypass them with modified Wima .33 polyprops (steel leads dremeled off and 6N copper leads installed and then marked for outside foil orientation and installed with the outside foil going to the output....pics on my website) and install WA-Quantum chips on them. Sounds like $100 fully burned in Teflons.....maybe better. You also want to remove the 50K resistor to ground after the cap. You don't need it and they sound bad. You don't want the bypass caps dangling in the air....they should be mounted with a little Amazing Goop. Double stick tape sounds really bad!
I'm finding more and more caps are coming with steel leads .

I was recently doing a Dumble ODS guitar amp clone, trying to replicate the
original caps used, the newer caps of exactly same brand / number / type
all had steel leads. Had to do the same, snip snip - damn frustrating.

If you need a cap in the signal path and need a perfect reference, insert a
Duelund VSF, that will tell you what it should sound like. Then try to find
something that comes closest to them. They are pretty much as good as it
gets - but too expensive.

But as Joe states, better off ditching them altogether if possible.
Nothing like nothing



Z
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Old 21st February 2013, 09:28 AM   #304
mvc is offline mvc  United Kingdom
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OK, so a direct output cap replacement is problematic. I like to keep things simple, but I cannot remove them, sadly.

I'm currently trying out some fancy regulators in a preamp. I might want to try them in the 105 too, but I had some difficulty identifying the regulators used in there. I could see a pair of LM316/317 and I assume these are used for the output stages, ot not? There's another pair at the end, in huge heat sinks, and a single one in the middle. The middle one could be the supply for the Sabre, or not?

Has anyone of you managed to identify these other regulators, and do you happen to know what feeds what? And then, obviously, the question is which ones would be the best candidates for upgrade. I'd guess the DAC regulation, but the professional modders don't seem to do that one, or do they?
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Old 26th February 2013, 06:57 AM   #305
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Interesting. Got the cheaper BDP-103 on my bench.

The Mainboard is the same of course, but the DAC/Analog board is based on CS4382A DAC. On all eight channels, the outputs from the DAC goes through electrolytic capacitors. This is before 5532 opamps. There is a 2.5V offset there. There is 10mV offset on the inputs of the opamp (checked L and R) and 20mV on the output and... another electro cap before RCAs.

Oh well.

I am connecting 1:1 transformer across the two phases - no DC will go through the two transformers I'll be using - and should get about 2.3V outputs. These voltage DACs have fairly low output Z (unlike Sabre) and perfect for 1:1 transformers. Disconnect RCA from board and wire the secondary there.

Cheers, Joe
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Old 9th March 2013, 04:26 AM   #306
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Hi Guys

Just thought I'd post the photo below. Maybe some of you (Rick?) have noticed the slightly 'scrambled' way the phases/layout is arranged - the DACs outputs are paralleled and doubled up on the unbalanced stereo and are only single on the balanced. The fourth is of course for the headphone section.

Peculiarly, the unbalanced Stereo, the I/V converter resistors are not the same on both phases: 1K2 and 530R - so about 2:1 - asymmetrical. This gets summed of coursed and would be similar output level identical 865R ((1200+530)/2=865).

This explains the 2 x 1K8 (very similar to 1200+530) I/V resistors on the balanced (XLR) gives almost the same output per phase.

So note in the picture below that two Reds are paralleled up, as are the two Blues - this applies to both channels.

Cheers, Joe
Attached Images
File Type: jpg Img_3772.jpg (150.1 KB, 355 views)
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Old 9th March 2013, 08:26 AM   #307
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May I add a correction, I dumped outputs into 3R3 and got 863mV (RMS) on both.

Also the gain resistor I use in my post DAC circuit that controls gain, needs to be doubled to get same output approx.

This means there are no paralleled phases at all. I have added two phases together in the photo in #306.

So where in the Oppo 95 where I had four parallel phases, in the Oppo 105 that is reduced to two in my case/upgrade. There is a third phase for the headphones, that leaves one phase unused. Not sure what they have done with it, is it open circuit or grounded? Haven't traced that yet.

Cheers, Joe
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Old 16th March 2013, 09:37 AM   #308
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Has anyone looked for ground loops designed into the circuit board traces of the 105?
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Old 16th March 2013, 05:59 PM   #309
Coris is offline Coris  Norway
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Quote:
Originally Posted by inline_phil View Post
Has anyone looked for ground loops designed into the circuit board traces of the 105?
Not yet as I know... Have you more infos about or is an only question?

Last edited by Coris; 16th March 2013 at 06:08 PM.
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Old 16th March 2013, 06:28 PM   #310
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Only a question. I just got mine yesterday and from my experience with other circuit boards of this type there are usually ground loops everywhere. For some reason, few people who layout PC boards understand the huge impact of ground loops on the sound of an audio component.

Does anyone have a hi-res image of the trace side of the circuit boards? I would be willing to give it a go. I want to wait for a few weeks before I take mine apart.
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