DIY 自作派同好同學會 |
<   >   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
 
*** ﹝請按主旨作出回應﹞ ***
主旨寄件者更新日期
回覆 (535): 220 VAC input step up to 235 VAC / 50w mini CHOKE device
Vash,  
 
Thanks for your advice last time, when I change the loading resistor to 150 ohm and change the value of output cap. The body is back! Total balance become more well.  
 
 
Cheers  
Sing
TaiMonSing
09-05-03
15:08:31
回覆 (534): 220 VAC input step up to 235 VAC / 50w mini CHOKE device
"鬼" 斧神工再現!勁!  
 
Vash
09-05-03
14:09:37
回覆 (533): 220 VAC input step up to 235 VAC / 50w mini CHOKE device
220 VAC input step up to 235 VAC / 50w mini CHOKE device
ghost
09-05-03
12:12:16
回覆 (532): 220 VAC input step up to 235 VAC / 50w mini CHOKE device
Hello limage 師傅  
 
220 VAC input step up to 235 VAC / 50w mini CHOKE device  
 
昨日終於完工,因我部前級電源只有 220v 設定,我用這隻 CHOKE device 供 235v 給我部前級前作前後比較效果如下:  
 
高段稍 +1%, 細緻 +2%. 中段深度稍好,整體性都 OK 唯一係 150Hz 至 300Hz 稍薄 dd. 但低段控制力與場面感染力又好番 d 喎!  
 
因 235v 供電入我部前級是高于它的正常運作標準所以不能作準.可能畀落係部 230v 設定 0既前級效果就捷言不同. ( 造個220 VAC 升壓設備唔難.但要造個用後聲效討好人就非常難 )  
ghost
09-05-03
12:10:48
回覆 (531): DIY 自作派同好同學會
嘩!又一重本製作啊!  
 
Vash
09-05-03
04:02:43
回覆 (530): DIY 自作派同好同學會
內部搭棚照
laipanda
09-05-03
01:35:17
回覆 (529): DIY 自作派同好同學會
laipanda
09-05-03
01:27:58
回覆 (528): DIY 自作派同好同學會
剛完成300B膽後級完成照片.
http://i104.photobucket.com/albums/m194/laipanda/DP300BF1-ZIP.jpg
laipanda
09-05-03
01:26:45
回覆 (527): DIY 自作派同好同學會
Vash Hing ,,,,又做邊部.........?  
 
Ivan SiuFu..... May be the wire need a little bit run in..... Now it is ok except that the Bass is a little bit lower when compared to the old house, Need some fine tuning....  
 
accphoto
09-04-30
13:22:52
回覆 (526): DIY 自作派同好同學會
是否你講的神物? (PCB 特敏福- Telfon)。
jcml
09-04-30
11:31:19
回覆 (525): DIY 自作派同好同學會
這種靚板是小弟第二次近距離欣賞,第一次是 GT 既 27G。
Vash
09-04-30
10:54:27
回覆 (524): DIY 自作派同好同學會
These set of PCB came from from another DIY enthusiast , 泰哥。
Vash
09-04-30
10:52:08
回覆 (523): DIY 自作派同好同學會
 
 
Anthony,  
 
Every room has its bearing on the sound. I guess you may need some more time before your ears are able to adapt themselves.  
 
The bad news is, if the sound is horrible from the start, you cannot really expect a 180 degree turnaround in due course. Chances are that you may need to experiment with other speaker placements.  
 
>_<  
 
 
limage
09-04-30
10:47:24
回覆 (522): DIY 自作派同好同學會
>>>.....頭一個鐘係唔聽得...  
 
Yr new place needed to warm-up ? BTW., any foto of your new setup/environment ?  
 
^__^  
Vash
09-04-30
02:53:01
回覆 (521): DIY 自作派同好同學會
好辛苦....今日終於開番聲.....頭一個鐘係唔聽得...  
accphoto
09-04-30
00:06:46
回覆 (520): DIY 自作派同好同學會
There is a very long thread on diyaudio. You can also put in a anemophic lens to get wide field!
ackcheng
09-04-28
22:41:19
回覆 (519): DIY 自作派同好同學會
Just found this DIY project very attractive, anybody have an intention to try it ?  
 
^__^
http://item.taobao.com/auction/item_detail-0db2-c45a2de40fb38cc89859f936c419ac7e.jhtml?cm_cat=50018908#
Vash
09-04-28
14:51:13
回覆 (518): DIY 自作派同好同學會
>>>No! i'm just expressing my personal preference^-^  
 
Then I prefer to be 27 rather than 17, I want larger and larger !! And G for others.......bigger and bigger......
Vash
09-04-24
15:52:56
回覆 (517): DIY 自作派同好同學會
Are you suggesting that there will be a 27G coming up?  
--------------  
No! i'm just expressing my personal preference^-^
drwkng
09-04-24
15:29:35
回覆 (516): DIY 自作派同好同學會
 
 
 
but i prefer G over D wor  
_________________________  
 
Are you suggesting that there will be a 27G coming up?  
 
 
 
cpsjj
09-04-24
15:18:51
回覆 (515): DIY 自作派同好同學會
ha..ha... but the sound is not better than 27D thru'......  
------------  
but i prefer G over D wor!
drwkng
09-04-24
15:15:50
回覆 (520): DIY 自作派同好同學會
I guess it is constant load at high temperature that causes the fatigue.  
--------  
this should be called creep deformation. i think.  
 
 
how about thermal stress. every time the amp is on, the brass ring experiences thermal deformation and expand. however the steel pin which has low thermal conductivity will deformation less. so the load on the brass ring should at least cycle during every power on and down cycle. how significant it is? i don't know.
drwkng
09-04-24
15:12:47
回覆 (519): DIY 自作派同好同學會
 
 
I guess it is constant load at high temperature that causes the fatigue.  
 
There is a huge difference in sound between contact and tight contact. The sockets were good for a little over 2 years and thereafter I have to tighten the grip (quite strenuously and with a special tool I have made for the purpose) every two weeks. The metal seems to lose its gripping tension quite quickly now than it used to be before.  
 
 
limage
09-04-24
14:42:38
回覆 (518): DIY 自作派同好同學會
 
 
 
the initial gripping power is weaker and there is no way by which you can tighten the grip when it gets loose over time. This is the one I am now using and I suspect the alloy used is too thin for the job and metal fatigue seems quite evident after 2 years  
____________________________________________________________________________________________  
 
limage,  
 
I wonder how many times you have subjected the metal strips to cyclical load over the years to cause metal fatigue. It is true that low cycle fatigue may occur due to excessive strain in the metal but is it not true that the less grip power of the metal strip, the less it will be susceptible to plastic deformation. As long as it provides a great enough surface for electrical contact, why do you worry about its gripping power if the contact is not subject to any mechanical force during the course?  
 
 
 
 
 
 
cpsjj
09-04-24
13:39:01
回覆 (518): DIY 自作派同好同學會
 
Multiple contacts:  
 
 
limage
09-04-24
12:50:26
回覆 (517): DIY 自作派同好同學會
 
 
The other one looks like a cup and upon close examination, there are actually four spots of contact around the circumference of the pin, a state slightly better than the biting teeth in terms of contact area. However, the initial gripping power is weaker and there is no way by which you can tighten the grip when it gets loose over time. This is the one I am now using and I suspect the alloy used is too thin for the job and metal fatigue seems quite evident after 2 years.  
 
limage
09-04-24
12:49:36
回覆 (516): DIY 自作派同好同學會
 
2 contact points:  
 
limage
09-04-24
12:48:26
回覆 (515): DIY 自作派同好同學會
 
 
I am now working again on tube sockets which regrettably I find none on the market satisfactory. Many manufacturers pay attention only to the material used for the base and very few truly get down to the actual working part of the socket whose purpose is to maintain tight contact with each pin to ensure perfect voltage, current or signal transfer. For those who can, like the CMC (which I used before), they usually cannot stand the heat or high temperature that the gripping power quickly degenerates after a couple of months.  
 
I am specifically concerned with the gripping power on individual pins and for this purpose I have dissembled two major types to examine their characteristics. One works like a jaw with two teeth biting on both sides of the pin, but as the picture below shows, there are only two tiny points of contact and when dirt or dust accumulates over time, these tiny contacts would hardly be satisfactory, without constant cleaning and tightening, in the long run.  
 
limage
09-04-24
12:47:30
回覆 (514): DIY 自作派同好同學會
ha..ha... but the sound is not better than 27D thru'......  
 
^_~
Vash
09-04-24
11:41:23
回覆 (513): DIY 自作派同好同學會
李老師有 27D,今云我有前輩譚孝文於昨日帶來的 17G,即 17 枝膽既 GG。  
--------------  
vash,  
do you know that G is bigger than D even 27 is larger than 17^-^
drwkng
09-04-24
10:54:17
回覆 (516): DIY 自作派同好同學會
Vash Gor,  
 
招呼不周,還請見諒,找日再到你到請教請教!!  
 
Sing
TaiMonSing
09-04-24
08:03:10
回覆 (515): DIY 自作派同好同學會
Vash
09-04-24
06:46:54
回覆 (514): DIY 自作派同好同學會
之後聯同 Ken1967 夜闖 Taimonsing 師兄的聽氣浮直臂既黑膠,一屋優皮天地既擺設最o岩我!
Vash
09-04-24
06:46:21
回覆 (514): DIY 自作派同好同學會
效果?與家中的一部廠 kit 比較緊係天與地既分別啦!
Vash
09-04-24
06:43:02
回覆 (513): DIY 自作派同好同學會
先看圖,這部 17 G 用左右獨立膽整流及穩壓(每邊 7 技),燈絲乃共用同一個 module。
Vash
09-04-24
06:41:51
回覆 (512): DIY 自作派同好同學會
李老師有 27D,今云我有前輩譚孝文於昨日帶來的 17G,即 17 枝膽既 GG。
Vash
09-04-24
06:41:15
回覆 (511): DIY 自作派同好同學會
Here's the review of AW's preamp
http://www.positive-feedback.com/Issue26/preamps.htm
F2aYeung
09-04-22
22:43:47
回覆 (510): DIY 自作派同好同學會
Is you design the same using SCF type?  
---------  
you mean SLCF? No. my design is different. in this regard i don't quite agree with him. there are many ways to skin a cat. his is only one of them^-^
drwkng
09-04-22
20:51:53
回覆 (509): DIY 自作派同好同學會
drwkng hing,  
 
Is you design the same using SCF type?
ackcheng
09-04-22
20:20:04
回覆 (508): DIY 自作派同好同學會
 
 
Vash,  
 
Thanks for the link. I have extracted the key elements that I think every DIYer should always bear in mind when he sets about to construct his own amp:  
 
 
 
* Utilise differential operation (an optimised form of ‘balanced’) to ensure absolute internal stability and freedom from noise  
* Achieve very low distortion from correct design of the circuits themselves, without the crutch of negative feedback  
* Use no loop negative feedback—as this destroys transient purity and paints over any inherent circuit problems  
* Allow extremely wide bandwidths— at least a decade higher & lower than that of the signal to be handled.  
* Create the gain needed in as few a number of stages as possible—aka the KISS principle  
* Use constant current operation to ensure that large, fast signal swings don’t even momentarily unbalance the circuits  
* Make the power supply and all support circuitry hugely capable—well beyond what’s normal or expected  
* Operate all the electronic components–especially the tubes–way inside their ratings to ensure reliability, stability and long life.  
 
 
 
The discussion on SE operation is particularly interesting and it serves as the best counterpoint to the overwhelming popularity of SE circuits lately.  
 
limage
09-04-22
09:49:45