As others also found out: GND layout concerning LM2596 makes improvement hard if not impossible. It really is better to get rid of it alltogether. It does not only cause too high ripple but also stray RF. The guy on the french forum has it right. At least that is what I found when measuring the ripple and trying to improve stuff. Many hours could have been saved by directly searching for a LM2596 replacement. Well I posted my findings with the Poiolu module.
You also know about D802 being optimal with "flat" setting (and with SPDIF input, USB input is not as good) and that D802C is worse? I understood a newer revison D802 is being produced but I don't know the differences.
Then you try an Alientek D8 which has its shortcomings and then ....
My findings: any FDA should have good SPDIF and good USB input, the latter preferably asynchronous. Any amplifier should have speaker protection. As far as I am concerned any FDA should be able to play 24/192 and it should have "high bit" volume control as the weakest point is playing at low volume. When giving in to any compromise because of low price then one will meet dissatisfaction.
You also know about D802 being optimal with "flat" setting (and with SPDIF input, USB input is not as good) and that D802C is worse? I understood a newer revison D802 is being produced but I don't know the differences.
Then you try an Alientek D8 which has its shortcomings and then ....
My findings: any FDA should have good SPDIF and good USB input, the latter preferably asynchronous. Any amplifier should have speaker protection. As far as I am concerned any FDA should be able to play 24/192 and it should have "high bit" volume control as the weakest point is playing at low volume. When giving in to any compromise because of low price then one will meet dissatisfaction.
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I have the newer D802 V2 dated 11/11/2017 on the PCB. I wasn't interested in the C model. I am using "flat", no extra bass or treble. I tried "normal" but that doesn't sound normal at all. And there is a "HiFi" mode too but I have no idea if that is a marketing gimmick or not, since I haven't had much time to listen to different eq settings and compare it to something with no eq at all. Does the V1 have that? is it a true HiFi mode? The V2 has a different USB (CM6642), and some changes to layout especially for the regulators, and it has an adjustable Lm2596 instead of fixed 12V, and a few minor changes to caps it seems too. I should have some time tomorrow to go over the D802 more thoroughly - working from home ;-)
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?????????23.62MM ??13.39 ??8.38MM KS090-060A-???
2 yuan crap )) OMG, guys, chinese foolling you like kids.. You need something like this
T94-2??MICROMETALS ?????????? ?24*??12*?8-???
Just $3 difference ))
PS: T94-2 requires 35 turns and only less gauge wire could fit in.
2 yuan crap )) OMG, guys, chinese foolling you like kids.. You need something like this
T94-2??MICROMETALS ?????????? ?24*??12*?8-???
Just $3 difference ))
PS: T94-2 requires 35 turns and only less gauge wire could fit in.
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I think these are the exact ones at RMB1.50. I'm not in the least surprised. China is the most dishonest nation I've ever had the misfortune to deal with. I miss the assumption of fairness and honesty in Europe. Taiwan is significantly kinder than China - I don't know how you cope with the constant dishonesty of life there. Every time i went to China I was super happy when I got to leave. I haven't been back for about a decade but I can't imagine that people there have suddenly grown consciences. ?????????21.1MM??12.07MM?7.11MM KS080-060A-???
Anyway, possible replacements
20mm 22UH 8A 0.8? ?????? ???TDA7498E 160W????-???
and
10UH 15 22UH ??D???????? ??SAGAMI 7G17B?is2092-???
I already have some possible replacements like the latter ones in a parts tray...
Anyway, possible replacements
20mm 22UH 8A 0.8? ?????? ???TDA7498E 160W????-???
and
10UH 15 22UH ??D???????? ??SAGAMI 7G17B?is2092-???
I already have some possible replacements like the latter ones in a parts tray...
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You need 10uH or, Ok, 7uH, 22 is too much. I'm not sure if 2.5RMB for winded coils ok and there is really good-linear #2 material core, rather chinese "analog"(original as you see 6.5RMB for bare core). However, I think it is possible if chinese material #2 is good enough. To make sure I would like to measure THD+N, either buy Micrometals #2 for $1 and wind the coils by yourself.
+1 And the difference in numbers can be so tiny you wonder why... but you don't get what you agreed... and that is usually the source of a problem.
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fooling is profitable only in short terms, if you have a reputation, plans for honest life and respect, you have no reason to deceive anybody. I was shocked, after 10 years in china, I offered some big 100% OEM(they can't use oscilloscope!) my caraudio designs which are very competitive and cost effective and could lift up those silly OEM for completely new level. I showed them one model, they was very happy and asked more models asap. I asked to sign a contract first but they said that can't do that so far because they can't found the factory's stamp to make contract oficial.. After couple monthes I realized that they just had plan to fooling me, and finally they stolen one my model because I was naive and sent them all files needed for production. One my neighbour, american, said - no surprize, if you offer them $10 to start $1,000,000 busines together, you'll see how your "partner" running away with your 10 bucks in 90% cases ))
PS: actually, I'm talking not really about chinese which rather you can find in Taiwan or Hong-Kong, we are talking about "xianbalao", people with broken cultural root. Next time just take a look at how they drive and be sure, everywhere they are the same as on the road )) YouTube
jean-paul, if you need some help to find a respectable supplier in china, try some europian agency like my two english friends established one. They do customers support for free but have money from trusted suppliers. All 3 sides are happy.
PS: actually, I'm talking not really about chinese which rather you can find in Taiwan or Hong-Kong, we are talking about "xianbalao", people with broken cultural root. Next time just take a look at how they drive and be sure, everywhere they are the same as on the road )) YouTube
jean-paul, if you need some help to find a respectable supplier in china, try some europian agency like my two english friends established one. They do customers support for free but have money from trusted suppliers. All 3 sides are happy.
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That is all the necessary info in one sentence
@IVX: I was in China for other stuff but noticed quite fast how things work over there. Anyway, I got to respect clean air, good quality potable tap water and peace and quiet when I came back. I could not live there even if they would pay extremely well.
Exactly how many think about these matters but I saw that in China there are many thinking a bit different.
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Hi
i own the KEFQ100 too. thees are 4ohm speakres as you know.
you really satified with 22µH cores? compared to what coils?
thanks
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I have lots of amps, and several class D and class T to compare. Filters set for 4ohm speakers can sound a little too sharp with Q100 but it does depend on the amp - some Tripaths are a little warmer than some TPA3xxx so... The tweeter is not the sweetest sounding thing I've heard so sharp can sound harsh - the speakers are 4 ohm but in the treble range, which the class D filter affects, the tweeter is around 6 ohm @40KHz and it has a series resistor too so I work at 6 to 7 ohm for the amp. I started off by putting this into Texas Instruments filter design tool to get values/plots and then tried out a couple. For differential AD, 22uH works with between 0.47u and 1u to suit the speaker/taste. For common BD, 22uH with 1 to 1.5uF works for me. People with different hearing sensitivity/range, rooms reflections, DACs, different coil designs, materials, capacitors, etc. will find different filters work for them. Probably 15uH is a better starting point if you want to experiment. Try and see eh. The filter design of the TAS5614 datasheet is hybrid BD designed for 4 ohm - it will create a lift in the high treble which I don't like. However, the V200 has not followed this and seems to have a differential AD with 0.47uF caps and, at the moment, unknown value coils - does anyone know what value they are?
Zaph's test:
Zaph's test:
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Egypt?
CCP made up a lot of history for Han China so it could claim special treatment for the political entity of China as an "ancient" civilisation to compete with Egypt etc - it is old, sure, but not like the CCP claims, and let's face it, its history was broken when the Mongols took over in 13th/14th century. That's been designated as another China dynasty (Yuan) to claim the gazillion years of continuous history bollocks. "We're special so we should get special treatment" stuff. The lies go really really deep, so much so that many people have simple bought into the propaganda without questioning - a lie repeated a thousand times... and if you have been to HK and Taiwan, then you know they have similarities but they are not the same culture. While HK becomes more like China every day, it still prizes fairness and equality, and in the meantime Taiwan becomes ever more different. This is evident in many parts of life from the high quality manufacturing to the kindness of strangers to the increasingly open democratic government. Many of the ICs we rely on are made in Taiwan.
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Do you know what value the inductors are in V200? In the meantime, if you feel like, try to sim the D802 - inductors are 220uH and caps are 1uF - in BD common mode I believe? Your sim is also missing the tweeters series resistor and capacitor in the crossover - 0.68R and 3.9uF IIRC. This is what the TI calculator predicts, and certainly it does not sound like the treble is at all rolled off.
In the meantime, I measured voltages in the D802. The CM6642 is run from the 5V LM317. It is turned off via transistors (Q7 and Q8), that turn on when the USB is connected.
In the meantime, I measured voltages in the D802. The CM6642 is run from the 5V LM317. It is turned off via transistors (Q7 and Q8), that turn on when the USB is connected.
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