I'll get back to you guys soon, on how the shield situation goes.
Perhaps something else was at play originally with it that does not exist now, and it was a lingering factor since this wasn't originally true. As I said, my test rig didn't respond to a problem with the resistors inline just in the last day, less any form of shield. You may have solved it.
Perhaps something else was at play originally with it that does not exist now, and it was a lingering factor since this wasn't originally true. As I said, my test rig didn't respond to a problem with the resistors inline just in the last day, less any form of shield. You may have solved it.
Are you saying that you generally believe a fundamental issue is more prevalent than something odd?
Even if that's the case, correcting a fundamental error here still leaves a lot of curiosity about that very drastic changes from resistor types! That may remain a mystery for some time.
For example, let's say the capacitance on the output wires with a shield is causing phase shift. Why is the phase shift so significantly different from type of resistor to type of resistor that's inline from the source? What makes through hole resistors and plastic pots generate something that makes the phase shift increase to a point of clear malfunction?
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What might that have been?
You may be curious about that, but I don't think most here are, because you have not ruled out or corrected fundamental errors. Further, your claim directly contradicts a great deal of experience.
You have not established that it is different.
If you have a clear malfunction then I doubt that the type of resistor is a factor.
Well call it whatever you want, it's clearly audibly so different that someone would think speakers were swapped or something between the volume devices, when there's an issue. It couldn't be more obvious, there's no discrepancy to it occurring. It's not hearing the difference between what resistors sound like, it's hearing their affect on something else. No experience in the world can change that it was occurring. The questions are why and how; but not as important as having it not be a problem.
You have to understand that a lot of initially testing was over a year ago at this point. I've lost track of some things.
You have to understand that a lot of initially testing was over a year ago at this point. I've lost track of some things.
There's nothing to fix. There is no excuse. You're speaking utter nonsense about something you've never seen. I can't fix a correctly wired volume stepped attenuator.
Do you need a refresher or something?
They look like this, all of them,
Unless they're wired for logarithmic .
Lastly I said I'd get back to report about the shield; inconclusive.
You sent us to your gallery and in your gallery you show the wiring you claim to have assembled.
It was/is your gallery post57 IMAG0650 - My Photo Gallery
Your new diagram in post69 is correct. It uses a two wire input circuit and uses a two wire output circuit.
It was/is your gallery post57 IMAG0650 - My Photo Gallery
Your new diagram in post69 is correct. It uses a two wire input circuit and uses a two wire output circuit.
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That's a representation to show you the problem. From what I can tell you're concerned about the ground wire. Well there is no concern, it's wired properly. I didn't draw it in stereo or do it in a form to represent the empirical wires running all over my stereo for obvious reasons. It's entirely unimportant since the issue happens in other stereos.
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As I said, when RF parasitic oscillation may be the cause of a problem there can be little of more importance than details of wiring. We don't want to see a "representation" of something you haven't done; we want to see a picture of what you have done. Ideally, a picture of one which works OK, and a picture of one with the problem. If you were able to judge exactly what is relevant then you would not need our help.
72 posts and still no clear symptoms and no clear picture of what has been done.
72 posts and still no clear symptoms and no clear picture of what has been done.
I see your point, but the volume control was an issue whether I'm changing it at home, or the amplifier is plugged in elsewhere. At no point have I ever wired one differently (nor do I document something I've done dozens of times with 100% success rate). And the problem occurred when I soldered resistors inline between RCA jack and input capacitor as well, showing it wasn't specific to a volume device. It's entirely fruitless to badger me for correctly wired volume devices. Again, the shield may be the crucial factor (that you already came up with), but you and I have to wait to know because it's out of my hands at the moment.
I come here for help as a last alternative. Many long standing members (that post a lot) don't seem to see it's like stepping into an inner circle of antagonists. It isn't because people are straight forward, but the language use still tends to be aggressive with a consistent attitude of assuming to never believe anything anyone says. The stubbornness of repetition that doesn't recontextualize, restate, or give a clue about what the NOP (non-original poster) is looking at for thought directions to explore is exactly what makes a bad teacher. Some might think respect in the by laws is simply not being profane, but in real life that is better tolerated than the level of nepitistic condesention threads often go here.
If I didn't think I could get answers I wouldn't post, but I know many here are smart and experienced. I appreciate the help.
If I didn't think I could get answers I wouldn't post, but I know many here are smart and experienced. I appreciate the help.
Hi,
I've still no idea what is being discussed.
However if you look at the board in the data sheet and
and that Folsom Audio board the grounding arrangements
are very different. The datasheet has a clear common
ground point with separate ground current paths for
signal and power. The signal ground and power ground
are not joined at the chip. The Folsom Audio board is
different and I think just wrong. Separate ground
points for signal and power joined at the chip, no
point having separate pins for that arrangement.
rgds, sreten.
I can't really work out the Folsom Audio board
wiring, but it doesn't look very ideal to me.
I've still no idea what is being discussed.
However if you look at the board in the data sheet and
and that Folsom Audio board the grounding arrangements
are very different. The datasheet has a clear common
ground point with separate ground current paths for
signal and power. The signal ground and power ground
are not joined at the chip. The Folsom Audio board is
different and I think just wrong. Separate ground
points for signal and power joined at the chip, no
point having separate pins for that arrangement.
rgds, sreten.
I can't really work out the Folsom Audio board
wiring, but it doesn't look very ideal to me.
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If you look at the PCB example in the DS, it'll show them tied together. All the boards from China have them tied together.
The reason is the amp won't turn on otherwise. Why the data sheet doesn't cover this? Well, excellent question!!! I have no idea, but I assure you I went nuts trying to figure this one out on an earlier PCB board than the one posted that didn't have the connection made. Even with a brand new chip, I immediately soldered in another. Nothing. Checking voltages, doing the works, and then I noticed the only difference between their PCB and mine was that as far as the schematic would be. I connected the two and got sound.
ANYTHING in-between to reduce noise causes noise. And I suspect it might be related to whatever has occurred that inspired me to post this topic originally. The connection between that, the shield, and types of resistors is complicated if it's what's up. Other's using the amplifier haven't reported anything like this but their amplifiers don't use an arrangement of OSCON with such low ESR/ESL, or a shield. Those are the only two relative factors.
BTW I'd say the Folsom board (mine) is very optimal, actually. That's probably another topic that I'd be happy to PM about, or go on with somewhere else.
If you wanted to replicate my issue.
First I'd try winding a wire around the output wires, and connecting one end to ground. That or using a shielded cable to the output binding posts, with one end connected to ground. And when I say ground I mean circuit, the same as DC in. You CANNOT connect the ground of the shield to the - of the output from chip because it isn't ground at all, it has negative potential since the output is balanced.
Then just try putting resistors inline from the source of different types, or different types of volume attenuators. If 20kohm turns it into bassy mud, the shield is the subject here.
If the shield connected/not connected doesn't affect anything then I'd think switching between an array of OSCON's on copper pours, and some regular electrolytics (1 or 2) with their MUCH higher ESR/ESL.
The KM I wouldn't experiment with, because the occurrence happened with and without it.
For all I know, this could happen to any amplifier with shielded outputs. It's no mystery that problems with oscillations, reactance, capacitance, you name it, on the output of anything is problematic. And because of that, despite my original thinking that the shield was independent of the issue, I tried it anyways because you don't know till you do. DF96 was on this topic, and I assumed if he thinks problem occur from shielded outputs then it'd be worth my time to double check.
Hi,
When will the penny drop ? The only point of having separate
ground pins is not to join them at the chip, see the layout
in the datasheet, which makes perfect sense, they are
joined at the common star point. Chinese boards are mostly
generally me too copycat stuff and they copy wrong stuff.
I doubt the FA board is optimum, don't assume it must be.
rgds, sreten.
When will the penny drop ? The only point of having separate
ground pins is not to join them at the chip, see the layout
in the datasheet, which makes perfect sense, they are
joined at the common star point. Chinese boards are mostly
generally me too copycat stuff and they copy wrong stuff.
I doubt the FA board is optimum, don't assume it must be.
rgds, sreten.
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