DIY 自作派同好同學會 |
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回覆 (251): Back to school - Kent Poon's Prof. course for audiophiles
limage,  
 
here is the link of the new tube sockets i was telling you.  
http://www.partsconnexion.com/econnexion/0209/feb09.html  
under Composite Teflon Tube Sockets  
 
drwkng
09-02-22
23:42:48
回覆 (250): Back to school - Kent Poon's Prof. course for audiophiles
兄弟們,  
 
有時間到呢個 homepage 睇下, Kent Poon 介紹,超過癮!  
 
http://schoeps.de/showroom/
Vash
09-02-21
20:45:55
回覆 (249): Back to school - Kent Poon's Prof. course for audiophiles
See, our famous rcwy and wher ^__^
Vash
09-02-21
20:41:42
回覆 (248): Back to school - Kent Poon's Prof. course for audiophiles
A very nice course and met many many audiophile friends today......
Vash
09-02-21
20:40:58
回覆 (247): DIY 自作派同好同學會
My Latest Double C Core MK2 On Test ~ I am pleased with the changes to the winding specification that I made over the MK1  
 
Photobucket
Tsushima1
09-02-21
01:30:50
回覆 (246): DIY 自作派同好同學會
yes, i have made myself a low-noise buffer using jfet.  
 
mdlover
09-02-20
22:51:42
回覆 (245): DIY 自作派同好同學會
hi albert,  
thank for the link. the input impedance is kind of low. do you use a buffer before that?
drwkng
09-02-20
22:43:25
回覆 (246): DIY 自作派同好同學會
with linear frequency scale,  
 
mdlover
09-02-20
22:36:18
回覆 (245): DIY 自作派同好同學會
this is the noise floor when compared with the internal A/D of my [email protected]  
 
you can see the typical noise spectrum of "deltasigma + noise-shaping",  
 
the red trace is the [email protected] and you know the difference. :-)
mdlover
09-02-20
22:35:24
回覆 (244): DIY 自作派同好同學會
king,  
 
this is the A/D that we have discussed last week.  
 
http://focus.ti.com/docs/toolsw/folders/print/pcm4222evm.html  
 
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=PCM4222EVM-ND  
 
the board is quite nice and it's a 4-layer board. the only drawback is you have to wait after you have placed your order.........  
 
mdlover
09-02-20
22:31:30
回覆 (245): DIY 自作派同好同學會
It depends on which period in history you are looking at. I think Richard the Lionheart is not much better than Adolf Hitler.  
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of course in case like this we use the rule of proximity.
drwkng
09-02-20
22:28:17
回覆 (244): DIY 自作派同好同學會
 
 
 
you got the history wrong  
________________________  
 
It depends on which period in history you are looking at. I think Richard the Lionheart is not much better than Adolf Hitler.  
 
 
cpsjj
09-02-20
22:10:14
回覆 (243): DIY 自作派同好同學會
What Germans? Want me to bring a German amp to counter the evil force?  
 
 
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you got the history wrong. it is te brits against the evil force of german^-^
drwkng
09-02-20
20:01:56
回覆 (246): DIY 自作派同好同學會
sharing this wonderful clip with you, cello performance by Yo Yo Ma playing Astor Piazzolla's Libertango.
http://www.youtube.com/watch?v=z_exd6U1ubY
Welborne
09-02-20
19:59:05
回覆 (245): DIY 自作派同好同學會
guys, almost forgot i have a blog of my own here to share with you. not really about hifi but Argentine Tango, one of my favourite hobbies next to hifi. You can see me dancing (haha) with my partner.  
 
First I love music, then i met hifi, and recently i fell in love with the captivating music from Argentina, and then the dance...
http://tangoromantico.blogspot.com/
Welborne
09-02-20
19:44:32
回覆 (244): DIY 自作派同好同學會
 
 
 
my schulz, when driven by V69a, gives the sound that is simply no joking.....  
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Welborne,  
 
If you reckon the V69a is matching, taking a pair to your place together with the V72 preamp should not be a problem. But I think in your case, just a pair of V73 suffice to take the Brits out. :-)  
 
cpsjj
09-02-20
19:33:07
回覆 (243): DIY 自作派同好同學會
haha, a Klangfilm V69a would be most welcome.  
 
One german guru told me that my schulz, when driven by V69a, gives the sound that is simply no joking.....  
 
anyway, v69a is out of the reach of my pocket at this moment.
Welborne
09-02-20
19:18:46
回覆 (242): DIY 自作派同好同學會
 
 
 
Those are widely available easy to carry and hopefully, good enough to beat the Germans  
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What Germans? Want me to bring a German amp to counter the evil force?  
 
 
 
 
cpsjj
09-02-20
18:56:09
回覆 (241): DIY 自作派同好同學會
hi ginger,  
 
yes WELBORNE is CK reborn ^-^  
 
Yes, i read and saw (photo) so much about your collection , very impressive!!  
 
Yes, i want to visit you, how about next week? PM me
Welborne
09-02-20
18:26:09
回覆 (241): DIY 自作派同好同學會
limage, 話時話,好耐都無攪 P1.7 聚會,夾o岩時間可以試埋這部史上最醜陋既 P1.7…仲要係越砌越覺得佢肉酸至嫳。  
 
~__~
Vash
09-02-20
18:20:11
回覆 (240): DIY 自作派同好同學會
My last pair, includiing a Foundation desginer II were sold to Ginger around 2000 and ended my LS3/5a journey forever though i did get a chance to hear it at different places.  
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I see. You are CK :-)  
WHY not give me a visit these years.  
You are welcome :-)  
 
Gingers
09-02-20
18:08:14
回覆 (238): DIY 自作派同好同學會
easy to carry ??  
 
係咪架?三個 item 都是重量級的呵。  
 
^__^
Vash
09-02-20
18:04:36
回覆 (239): DIY 自作派同好同學會
oh, i suddenly remembered I still have a pair of Rogers Studio one (early xlr input version) somewhere. I think I lent it to a friend. the Rogers Studio One shared the same KEF tweeters as the LS3/5a and same mid-bass cone material.
Welborne
09-02-20
17:23:09
回覆 (238): DIY 自作派同好同學會
drwkng, limage, rcwy,  
 
Welcome your idea of bring ls3/5a. In fact, i was an Ls3/5a owner and collector from around 1990-2000 and at one time I had 4-5 pairs including KEP Piano wood, Spendor early gold badge, rogers black label 15ohm, Harbeth ebony gold mesh, and forgot the other pairs i have had. My last pair, includiing a Foundation desginer II were sold to Ginger around 2000 and ended my LS3/5a journey forever though i did get a chance to hear it at different places. The most recent one was at dd845 a few months ago.  
 
What made me give up LS3/5a? A pair of Diatone P-610ma 6 inch fullrange in orignal bass reflex box, and a pair of Klipsch La Scala that i was attacted to after hearing docjohn's in his place around 2000.  
 
I have not heard LS3/5a driven by Leak 12+ amp though i read so much wonderful stuff about this combo. When I had LS3/5a, i was only using Unision Research Simply 4 el34 pp amp, Audio Research VT-60, Roland Concentra Integrated (the best match i have tried) and a pair of Welborne Labs 300b mono using Eletraprint Ouput trannies. (hence my nick name Welborne today).  
 
So, after nearly 9 years, it would be interesting for me to have a chance to listen to LS3/5a again in a better set up and in an environment with acoustic nature that I am familiar with. Most of the other encounter with ls3/5a in recent years were rather short and brief.  
 
Pleae arrange, I can't wait!!!  
 
^-^
Welborne
09-02-20
17:17:51
回覆 (237): DIY 自作派同好同學會
 
 
Those are widely available  
easy to carry  
and hopefully, good enough to beat the Germans  
 
^_^  
 
limage
09-02-20
16:40:51
回覆 (236): DIY 自作派同好同學會
LS3/5A  
Pass 1.7 pre-amp  
Leak 12.1 and 50+  
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that is the best you muster. i'm so disappointed^-^
drwkng
09-02-20
16:26:31
回覆 (235): DIY 自作派同好同學會
 
 
I am thinking of another interesting party at Welborne's place. We'll gather the best combo we could muster to see if we can beat his Saba array:  
 
LS3/5A  
Pass 1.7 pre-amp  
Leak 12.1 and 50+  
 
What do you say gentlemen?  
 
And of course only if our dear Welborne has absolutely no objection!  
 
 
limage
09-02-20
16:17:50
回覆 (234): DIY 自作派同好同學會
very nice advice from all of you indeed.  
 
I will try as i have a few caps of that value range on hand.  
 
In fact, i have the treble tone control slightly passed the neutral position during most time, as well as the 4uf cap which may prove excessive. I had the saba with 7uf cap (orignally 1uf oil cap on the saba, but they have shifted value to 7uf as measured by my friend) and treble tone control slightly to the right around +1 as I read online reports and measurement that the Eico HF-81 has an early roll off on top and the Stereophile reviewer who praise the eico so much also set the tone control position by ears and not my the indicator on the knob and so did I. Vash seemed to like the tone control up a bit that let more harmonics coming through the tweeter.  
 
I guess all these contributed to the metallic glare that not only annoys Limage but also my girlfriend who made similar comments (women have good ears very often). I will try to change the cap to hear the change.  
 
So the fact may be that Eico hf-81 does not have roll off, and that i don't need 4uf cap neither. May be setting treble tone control to "0" and sticking to 2.2uf strike perfect balance in my diy saba baffle.
Welborne
09-02-20
16:07:54
回覆 (234): DIY 自作派同好同學會
BTW, I trust we all use capacitance meter to make sure caps on both channels are within close tolerance at critical points of the circuit  
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of course we do. there are just too much noise. the SNR is not high righ now.
drwkng
09-02-20
16:04:50
回覆 (233): DIY 自作派同好同學會
 
 
i'm talking about small differences not 2uf vs 4uf scenario. that is just plain silly.  
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I am talking about small difference too! Don't forget my original advice, as a matter of fact, was to ask Welborne to try different caps of the SAME VALUE. It's certainly absurd to have the low pass reset from 125 Hz to 500 Hz.  
 
BTW, I trust we all use capacitance meter to make sure caps on both channels are within close tolerance at critical points of the circuit.  
 
 
limage
09-02-20
15:43:12
回覆 (232): DIY 自作派同好同學會
Different makes do contribute too difference in sound (i.e. frequency response) not because of the make, but because of the accuracy of value. There is a well established mathematical relationship between frequency response and capacitance and this has nothing to do with material or construction per se.  
 
It is easy to be confused and hence myths are generated about the make/brand of caps. Some makes are better simply because they are more accurate than the others. The difference can be great. A good cap has say 5% tolerance, hence a 10u cap can end up 9.5u or 10.5u. A not-so-good cap has 20% tolerance and the same stated value can actually be 8u or 12u. So comparing a good cap and a lesser one being used in the same circuit, the skew in FR does exist and could be audible to sensitive ears for you could be comparing one cap with 9.5u and another one with 12u.  
 
DearAbby
09-02-20
15:00:36
回覆 (231): DIY 自作派同好同學會
I am talking about different makes, of different material and/or construction. Would it make sense then?  
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i don't think so. however it does not mean that different capacitor would not make more difference to the sound than just different roll off points. different cap values might skew the frequency response a bit. i'm talking about small differences not 2uf vs 4uf scenario. that is just plain silly.  
cap has probably the biggest effect on sound than other passive components. capacitance tells a small part of the story. a very small part indeed. so i do agree with your observation but just the explanation is not plausible.
drwkng
09-02-20
14:19:43
回覆 (228): DIY 自作派同好同學會
Dear Welbourne  
Happy to know your work has been completed (at least for the time being, for in my experience it takes weeks to fine-tune a crossover) and demonstrated your work to get feedbacks. From the comments you received no doubt you have done a good job. As I said before, the fun has only just begun. I know I am long winded to say again, voicing the crossover is closer to art than science. At the end, trust your ears in evaluating inputs from all sources.  
 
For the sake of education I find it hard to accept limage's statement that "... Eventually you may perhaps discover that capacitance value may turn out to be the least important part as far as crossover network goes..." Rather I tend to believe the opposite is true. But I am sure limage has good reasons to say that and I certainly would like to learn from him what I dont know.  
 
My view is: capacitance value is THE important part of xo design. Capacitance determines frequency response. The more accurate the better.  
 
The real trouble is how do you know what capacitance value is right? There are two levels: the accuracy of the assigned value (i.e. mathematical accuracy), and secondly the accuracy of the element itself (i.e. manufacturing accuracy).  
 
For mathematical accuracy, there is almost NO WAY you can tell which is the best value. All relevant variables cannot be accurate ascertained: such as coil inductance, capacitance, frequency characteristics, material characteristics etc.  
 
For manufacturing accuracy, there is also no way for the user to determine the value of capacitance and its frequency response characteristics, other than the general characteristics.  
 
At the end, one has to resort to trial and error. This is the art part.  
 
 
DearAbby
09-02-20
12:30:46
回覆 (230): DIY 自作派同好同學會
 
 
I am talking about different makes, of different material and/or construction. Would it make sense then?  
 
 
limage
09-02-20
12:08:13
回覆 (229): DIY 自作派同好同學會
Replacing a 0.022 cap with a 0.018 would move the turnover frequency by a fraction of an octave, but the phase shift may just slip from 60 to 180 degrees. Is it not right?  
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it is not quite possible for a capacitor to have a such phase shift.
drwkng
09-02-20
12:04:18
回覆 (228): DIY 自作派同好同學會
 
 
Yes quite honestly, king.  
 
Replacing a 0.022 cap with a 0.018 would move the turnover frequency by a fraction of an octave, but the phase shift may just slip from 60 to 180 degrees. Is it not right?  
 
 
limage
09-02-20
11:57:56
回覆 (227): DIY 自作派同好同學會
that capacitance value may turn out to be the least important part as far as crossover network goes..........  
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are you sure?
drwkng
09-02-20
11:30:30
回覆 (226): DIY 自作派同好同學會
 
 
Welborne,  
 
When you fiddle around with crossover caps, do try different caps of the same value. Every capacitor has its own pattern of phase shift along the frequency scale, cheap and expensive ones alike, and is definitely having a bearing on the overall integration of your speaker system. I tried no less than 15 different species when I fine tuned my active cross-over years ago.  
 
It's as much good fun as it's educational. Eventually you may perhaps discover that capacitance value may turn out to be the least important part as far as crossover network goes..........  
 
 
 
limage
09-02-20
10:55:38
回覆 (225): DIY 自作派同好同學會
about Limage's comment on Saba's metallic glare, I think it is because I have put in a much larger value cap, 4uf, to replace to old and orignal 1uf which is out of spec anyway. Some preferred 2uf and at most 3uf, and some swear by a much as 6uf. I was listening to 2uf the night before and only switched to 4uf the morning beofore you guys came because I remember Vash likes a bit more harmonics and airiness on the top and so do I. Let me see if i can improve on this. My german friend who is so fond of the saba too also stay with 2.2uf. Perhaps really 4uf is a bit too much.  
 
Welborne
09-02-20
03:32:40
回覆 (224): DIY 自作派同好同學會
oh, i have this unit too in my storage, i had in on loan from a friend who is not intersted in hifi any more, let me dig it out from the pile and try some time.
Welborne
09-02-20
02:00:44