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回覆 (74): noble iron
as i said freqency response is a minimum. these exotic materials are supposed to excel in detail retrieval.
drwkng
12-07-19
17:02:06
回覆 (73): noble iron
Thanks Dr. Its the consistence that brought us the big surprise. Still, just that for such higher price product, I do expect a better curve down at the lower end.
bobui
12-07-19
16:59:40
回覆 (72): noble iron
I don't think fequency response is really teh forte of these exotic material. it is ashamed that they can't even get this right.
drwkng
12-07-19
16:54:07
回覆 (71): noble iron
Below is the Frequency response curve from a Sowter SE12 cow. It has a 1.75k relative load. suitable for tw0 300B  
 
Look closly, the dipping end on the right high frequency point scaled at 120Khz. Not 20Khz in the AN. And the lower frequency extension goes all the way down to 10Hz almost flat. What you are seeing is a transformer with fairly flat from 20Hz to 20Khz. And when measure max power ouptut the cow can handle. Some brands cheat by measuring at mid or higher frequency. Best to reflect the power handling when measure at lower frequency because thats we your power requirement comes in. Sowter measure it at 20Hz, 30Watts. Its has a primary inductance of 28 henry.  
 
 
And Sowter acheived all these figures using only M6 iron which is a very good quality grade grain oriented silicon core but cannot be regarded as exotic materials.  
 
bobui
12-07-19
16:45:30
回覆 (70): noble iron
Shouldn't they have a better tolerance & quality built?  
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The answer is Yes. Only it doesnt apply to AN.
bobui
12-07-19
12:32:49
回覆 (69): noble iron
Custom made are made to order, & they ask for more. Shouldn't they have a better tolerance & quality built?
Derek2A3
12-07-19
11:54:59
回覆 (68): noble iron
Most importantly, these HK$150,000 cows don't even come with a name plate saying they are AN and/or silver wired (just like a Rolex without that crown logo)!  
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to be fair, custom made trans do always come with name plate. my winder electraprint does not have them as well. but then they only cost a fraction of that.
drwkng
12-07-19
11:44:07
回覆 (66): noble iron
The DCR figures confirm that the windings are OK. Obviously the air gabs were not properly adjusted.
ThomasC2
12-07-19
11:28:32
回覆 (65): noble iron
This is of course not satisfactory, not to say outstanding. Primary inductance at 1KHz of one of them is 3.69H while the other is 4.99. This is quite low for a 2.7K SE opt by general standard and probably explains the early roll off at the low end.  
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多謝你的分析報告! 嘩,咁貴cow, 有無QC架。定係多左D圈,定winding 打錯X。不過無所謂啦,D Hardcore Audionote fans 鍾意未得囉! 我都係用番D正正經經無花巧M6鐵心,14組分叉 Winding既Sowter好囉! 要買快手啦,Sowter真係就黎唔做啦!
bobui
12-07-19
09:30:43
回覆 (64): noble iron
silver wire double C 50% nickle steel core  
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對牛正牌有銀用, 物料盲目追求者的當頭棒喝! Thomas 好嘢, 踢爆佢!
Derek2A3
12-07-19
01:21:41
回覆 (72): noble iron
why it is called noble iron not sucker iron?
drwkng
12-07-18
23:57:19
回覆 (71): noble iron
and their model number.
ThomasC2
12-07-18
23:54:04
回覆 (70): noble iron
Inductance and DCR.
ThomasC2
12-07-18
23:52:26
回覆 (69): noble iron
Frequency response curve
ThomasC2
12-07-18
23:49:11
回覆 (68): noble iron
The equipments used.
ThomasC2
12-07-18
23:47:20
回覆 (67): noble iron
Too bad that no photo can be shown.  
 
Two other pairs of OPTs which cost far less than 10% of these noble irons were compared. These AN's sounded detailed and lively (or you may say bright and harsh to the ears). The cheapies all sounded obviously more musical.  
 
These noble irons have been measured professionally and the figures basically concurred with our hearing. On the low end, they started to roll off at 200Hz. This is of course not satisfactory, not to say outstanding. Primary inductance at 1KHz of one of them is 3.69H while the other is 4.99. This is quite low for a 2.7K SE opt by general standard and probably explains the early roll off at the low end. The signficant difference in the primary inductance of the two transformers in a pair certainly is again unacceptable expecially for something which are supposed to be the best money can buy.  
 
Most importantly, these HK$150,000 cows don't even come with a name plate saying they are AN and/or silver wired (just like a Rolex without that crown logo)!  
 
ThomasC2
12-07-18
23:45:27
回覆 (66): noble iron
once more or will try again later.
ThomasC2
12-07-18
22:23:31
回覆 (65): noble iron
..
ThomasC2
12-07-18
22:17:55
回覆 (64): noble iron
try again
http://desmond.imageshack.us/Himg256/scaled.php?server=256&filename=img154x.jpg&res=landing
ThomasC2
12-07-18
22:14:54
回覆 (63): noble iron
Had the privilege of auditioning these pair of silver wire double C 50% nickle steel core output transformer. Priced at Sterling Pound 6000 EACH + another 72 Pounds for the copper caps.  
 
[URL=http://imageshack.us/photo/my-images/256/img154x.jpg/]
ThomasC2
12-07-18
22:13:16
回覆 (62): Chemistry!!!!
icefox and highhands,  
 
The Leak 3090 is the late upgraded version of the 2075. Much the same other than the tweeter replaced by a ribbion and additional L-pads for the upper cabinet three units. A very very nice modern sounding speaking that also very power hungry.  
 
I had a go with a SE PX25 amp wating just to hear how vocal sound. And guess what happened. The PX25 cathode cuurent meter was shaking like hell soon i had the volume up even at 9am.
bobui
12-07-05
13:30:29
回覆 (61): Chemistry!!!!
bobui, for you.
http://www.audionet.com.tw/doc/view/sn/5013
icefox
12-07-05
12:34:12
回覆 (61): AVO Valve tester
Limage,  
 
Much appreciated for your insight and advice on the AVO tester. Plenty for me to learn and it's such a luxury to have a mentor.  
 
Thanks a lot,  
Bobui
bobui
12-07-02
14:43:48
回覆 (60): Chemistry!!!!
Awful awfully awful interviewer. Peter was kind of OK! You can ALMOST tell he is quite knowledgable! His DSP concept is more than 15 years behind folks, Meridian!
bobui
12-06-30
19:45:20
回覆 (59): Chemistry!!!!
icefox
12-06-30
08:12:19
回覆 (58): Chemistry!!!!
bobui, you should give him a buzz,  
 
icefox
12-06-30
08:05:11
回覆 (57): Chemistry!!!!
笨吾係,亂狗咁黎嫁!!  
icefox
12-06-29
21:42:18
回覆 (56): Chemistry!!!!
Monster looking  
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Its call Leak+puppy7
bobui
12-06-29
15:46:33
回覆 (55): Chemistry!!!!
bobui, I'm impressed with the chemistry of your DIY amp with this monster looking speaker........... cool banana!!!!  
 
icefox
12-06-29
15:33:27
回覆 (54): Ribbon Cable
Fellow electronics pro,  
 
I wonder if you guys know the proper trade name for this cable? I wonder if any of those usual outfits like RS, Diikey, Mouser, Farnell may offer this cable in length.  
 
Thus far, I found one source that offer this cable in unit of 3" each....... @@
icefox
12-06-25
09:40:48
回覆 (53): Handheld Flat / Ribbon Cable Cutter
Gents,  
 
I probably made a mistake, instead of flat cable cutter, I am indeed requiring a flat cable stripper.  
 
I need to make open the ends of a flat cable for soldering onto a PCB.  
 
If you have one that I can borrow, it would be very helpful. The flat cable i am dealing with is 15 ways, roughly 39mm in width.  
 
Thx.
icefox
12-06-08
08:58:02
回覆 (52): Handheld Flat / Ribbon Cable Cutter
Hi fellow hi-hands, I wonder if you would have access to (though your profession) a handheld Flat / Ribbon cable cutter that I could borrow for some work?  
 
Cutter like these,  
 
1. http://hongkong01.rs-online.com/web/p/cable-cutters/4153811/  
2. http://hongkong01.rs-online.com/web/p/cable-cutters/0359548/  
http://hongkong01.rs-online.com/web/p/cable-cutters/4153811/
icefox
12-06-08
00:26:57
回覆 (51): Naughty but Nice - The AVO
vintage equipments need calibration  
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First of all, I am reading the AVO manual on calibration already. Then, as fox suggested, Limage AVO is in healthy condition, you know, master reference. So if after i got mine and running. I can record some testing results and hand deliver to Limage to make comparsion.  
bobui
12-06-05
12:22:17
回覆 (50): Naughty but Nice - The AVO
TV7? No way ah, love to hear an owner's comment, that's a toy only, entry level tool, or in simple terms, better than none. I think ice do make a point, those antique or vintage equipments need calibration, otherwise how on earth you know they are telling you the correct figures.
Derek2A3
12-06-05
12:03:41
回覆 (49): Naughty but Nice - The AVO
I think your biggest nightmare is going to be on how to certified or calibrate your ancient AVO to ensure that is indeed up to spec for the measuring jobs. .......... nightmare man! I have 200% confidence on Limage that his AVO is nicely maintain at tip top condition.  
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Danke Danke! Thats what friends lor!  
 
There is a hidden agenda I like to disclose and its time to do so. The truth is, I need to sell some of my valve collections on bay watch. Its getting to a point where i would soon need to sleep on top of my boxes of valves or if not, under lor. I have been more greedy than I can chew!  
 
And no one in this plant would take seriously on the measurement/photos from my home made tester even if i am so willing to fix it and polish it, right? The option is either an AVO or TV7, right?  
 
 
 
bobui
12-06-05
11:00:50
回覆 (48): Naughty but Nice - The AVO
You should at least make an effort seeing Limage first for an audition of his Big Snake Peeing system and ask for a tutorial session on AVO. Then you should have a good idea on what is GOOD SOUND and what is a SOUND VALVE TESTER.........  
 
I think your biggest nightmare is going to be on how to certified or calibrate your ancient AVO to ensure that is indeed up to spec for the measuring jobs. .......... nightmare man! I have 200% confidence on Limage that his AVO is nicely maintain at tip top condition.  
 
 
icefox
12-06-05
10:17:23
回覆 (48): Naughty but Nice - The AVO
Don't worry, if it's not good enough, just sell it. After all it's an AVO!
Derek2A3
12-06-05
09:58:13
回覆 (47): Naughty but Nice - The AVO
Mine is MK4, so I have more luck.  
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Lots of reading and head scratching coming for me. Right now, I have absolutely zero idea of the trouble I am about to get into. And I think I need luck, plenty of it please!  
 
Oh, come on. This Brits made AVO cant be worst than the little monster I created myself.  
 
 
http://www.duncanamps.com/technical/ct160.html
bobui
12-06-05
09:29:43
回覆 (46): Naughty but Nice - The AVO
 
to share tips on the AVO and how to maintain it in top form.  
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feed it to victoria harbour.LOR!  
 
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Mine is MK4, so I have more luck.
dkyyu
12-06-04
23:35:40
回覆 (50): Naughty but Nice - The AVO
Apprentice bobui lor! Mine is the smaller CT160.
bobui
12-06-04
21:29:14