Wow, getting a bit more complex then I'd like
On second thoughts, is there any reason I couldn't just place a passive filter between the sub out and the sub once I've measured how low my bookshelves go?
This is really good stuff, can you please elaborate more with pictures or diagrams? I have this amp labeled "Trible" too and the freq doesn't move worth beans. Did they just mis-wire it?
Aye. Funny to me how this dcbias stuff supports superiority of tantalum's alongside aluminium's, yet so many dismiss their use anywhere, except to weigh the bin down. They're as good as oscons!!! lol...
I mentioned larger than spec voltage as that is one of my starting points of selection, as is having larger physical size for capacitance (reason I detest smd).
Of course many other factors are considered, I think I mentioned swamped in cap spec😱 sheets...
Yes, but you can get less capacitance at a given voltage from higher rated voltage due to bias (Dependsing on ceramics).
So starting from higher voltage is not always best.
Beside this, the larger the size, the larger usually the microphonics (due to piezoelectric effects).
So starting from higher voltage is not always best.
Beside this, the larger the size, the larger usually the microphonics (due to piezoelectric effects).
Hi xrk971!
I have not enough technical knowledge and instruments to answer Your question. The text what I quoted you can find here:
Opinions regarding Ebay YuanJing 2.1 amplifier board. Anybody tried it? - Page 2
I tuned my 2.1 system pretty empirically (by ears). The open baffle cabinet is rather simple to easy modification.
New 2.1 board on ebay:
TPA3116 High Power 2 1 HiFi Digital Subwoofer Amplifier Verst Board 2X50W 100W | eBay
In description found:
Advantages:
- Left and right channel full-range output, Can drive a 3-16 ohm speakers In the condition of rated voltage 24V,a very wide range
- The subwoofer channel at rated voltage 24V state can drive 2-16 ohm subwoofer, unique
- Bass cutoff frequency independent regulation 20HZ-20KHZ adjustable
- Independently adjustable subwoofer gain
Regards
egra
Attachments
The most elegant implementation is the "adaptor" as You can see on the attached image. IMHO.
PS: I ordered similar board last week, I'm curious about the result with red WIMA's.
Regards
egra
Attachments
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Next you'll be telling me the world is actually round, and not flat. Despite what I see before me! 😉 lol.
My methods aren't "technically accurate" but they work. As I mentioned in another post, "research, absorb, decifer, judgement, decide"... All leads to personal choice, and preference. Not all one and the same.
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The following link may help anyone that both mine, and drmod posts have confused.....
Temp and voltage variation of ceramic caps, or why your 4.7-uF part becomes 0.33 uF | EDN
As I said drmod, and in true Yoda style.... "piles of cap spec sheets do I go through".
Although my method of choosing larger physical size per capacitance isn't from this info, it seems to agree somewhat.
And as a very highly respected audio manufacturer and Polish electrical engineer discovered, voltage is pretty irrelevant except for meeting minimum requirements.
A good general rule is cap V should meet voltage before cap+voltage after cap+voltage losses within cap " connection". Pretty much same as using tantalum's.... Must be 2Xrequired voltage, but should add 50% of V as tantalum's capable of losing large Voltage!!!
I do like the theory of DC bias in capacitors, as it argues against miniturisation of passive components!!! 😀
Temp and voltage variation of ceramic caps, or why your 4.7-uF part becomes 0.33 uF | EDN
As I said drmod, and in true Yoda style.... "piles of cap spec sheets do I go through".
Although my method of choosing larger physical size per capacitance isn't from this info, it seems to agree somewhat.
And as a very highly respected audio manufacturer and Polish electrical engineer discovered, voltage is pretty irrelevant except for meeting minimum requirements.
A good general rule is cap V should meet voltage before cap+voltage after cap+voltage losses within cap " connection". Pretty much same as using tantalum's.... Must be 2Xrequired voltage, but should add 50% of V as tantalum's capable of losing large Voltage!!!
I do like the theory of DC bias in capacitors, as it argues against miniturisation of passive components!!! 😀
Elegant yes but adds a part you have to build/buy? Just bend the pins and keep the signal path simple. If too short, solder on extension pins from discarded pin clippings.
Yep. Voltage ratings on a MLCC mean "above this value, dielectric breakdown is possible" and nothing else.
My Wiener card has two 4.7uF/50V X7R decoupling caps handling TPA decoupling, they're 1210 package and close to 3mm tall. Capacitance for those is still above 4uF with 24V bias.
I can also buy a 10uF/50V X5R cap in a 1.6mm high 1206 for far less money. You'd think that since I'm only running the part at half its voltage rating and it's got twice as many uF's to start with, it should work just as well, right? 😉
I just bent the damn legs🙂 Everything came out allright. Can't judge the sound yet, because im having so e oroblems with volume pot. It is an Alps 50k -http://www.aliexpress.com/item/NEW-1pcs-Japan-ALPS-Volume-control-27-type-potentiometer-Dual-50K-Round-shaft/1858501633.html
Dont know if it's authentic, but it costed almost as much as the amp😛
What is bothering me is the hum i'm getting with it. No matter which poin I try to properly ground, when my hand approaches the pot, I get a buzzing sound.
Connections i made (the pot has 1 2 3 labeled on its side):
1 all the grounds together. From raspberrypi to leftand right and then to the amp.
2 inputs. Raspi's left and tight
3 to the amp
Possibility of sth wrong? Maybe something else i should check out ?
Before this board I had a yired which had no grounding issues (if this is what's happening) and was silent like a grave.
Dont know if it's authentic, but it costed almost as much as the amp😛
What is bothering me is the hum i'm getting with it. No matter which poin I try to properly ground, when my hand approaches the pot, I get a buzzing sound.
Connections i made (the pot has 1 2 3 labeled on its side):
1 all the grounds together. From raspberrypi to leftand right and then to the amp.
2 inputs. Raspi's left and tight
3 to the amp
Possibility of sth wrong? Maybe something else i should check out ?
Before this board I had a yired which had no grounding issues (if this is what's happening) and was silent like a grave.
Nope. Smaller package with different dialectic. Wouldn't matter if max V is same. The V rating here is irrelevant as twice needed i.e V before + V after.
Decoupling slightly different in V requirement of cap than bypass, but using same rule neither improves, nor degrades.
With mlcc there is also question of how many layers in any given cap. More layers in same size cap means thinner dialectic between each layer.
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That obviously applies to monolithic more than multilayer.
I would personally always chose the monolithic of any given value of cap, rather than multilayer of same value. My choice is down to dialectic thickness. Usually, creating a larger size cap for given value.
The other advantage of monolithic is smaller total surface area of dialectic/dialectic coating. =internal capacitance rather than =surface capacitance.
Very similar improvement that we would see between solid resistors compared to film/wirewounds. Solid = less surface area. And solids =less inductance etc. =my use of Allen Bradley or Arcol solid carbon composites.
But, as before, I push the right to personal preference. Nobody has to agree, nobody has to disagree.
I would personally always chose the monolithic of any given value of cap, rather than multilayer of same value. My choice is down to dialectic thickness. Usually, creating a larger size cap for given value.
The other advantage of monolithic is smaller total surface area of dialectic/dialectic coating. =internal capacitance rather than =surface capacitance.
Very similar improvement that we would see between solid resistors compared to film/wirewounds. Solid = less surface area. And solids =less inductance etc. =my use of Allen Bradley or Arcol solid carbon composites.
But, as before, I push the right to personal preference. Nobody has to agree, nobody has to disagree.
Update: big red caps seem to be causing some problems. When i touch them, the buz gets worse. Plus, sound quality isnt quite what I expected. The yired was much better. Unless it gets better with use...
That happens to my YJ blue/black (copy) when go near the blue input caps, but when I bypass those caps with others to test, the buzzing and noise disappears.
Mine can't be the cap connections as my way of bypassing to test is by soldering to the bottom of the input cap pins (haven't removed them as yet because waiting for replacements). So I presume my issue is the caps themselves..... Maybe same with yours.
Update2: Turning off my TV seems to cure quite a bit of this noise. (if the tv is off touching the big red does nothing), the board is picking up crap from "thin air" I guess. Even with the tv and fish tank pump off, the amp is still to loud. Louder than dead quiet red board, anyway. Is there a way of finding the cure now? Or should I just enclose it in an earthed metal enclosure?
Can't wait to figure out this noise, as this amp, modded as it is, sound A LOT better than the red one. But only when it's working at least partially properly.
Another problem: sounds like popping and crashing when playing just a bit louder, but still not loud. I'm feeding it 14V DC.
Can't wait to figure out this noise, as this amp, modded as it is, sound A LOT better than the red one. But only when it's working at least partially properly.
Another problem: sounds like popping and crashing when playing just a bit louder, but still not loud. I'm feeding it 14V DC.
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