UCD-D類後級工作坊實况 (Day1+2)

want to upgrade the UCD 400 onboard cap to Blackgate, 470u/100v, how is the pricing?

Hi Admin, if I find myself interested in the UCD400 module after I finish the introductory PCB course, could I order the parts via you later at the same price?

Kelvin1728, sure, pls contact me when we see on this Thur to confirm the details

見到大家玩得咁開心, 我都想黎

I found Blackgate price: 470u/100v, STD series, @HKD 270. HK Bush

I got this case from HK bush, HKD 700, and they have a smaller one, HKD 600.

I saw the power amp of Nuforce(Class D)at BO Acoustic is very small, why UCD 180(also Class D) need big transformer and big condenser?

gogogjump, it is the difference of switching power supply and linear power supply. UCD can also use switching power supply as well.

Is there any differ for the sound quality? Compare with linear and switching power supply.

Good switching mode power supply is hard to make as there will be lots of EMI affect the amplifier section.

It is just similar to your PC sound output, no matter how good is your sound card, there will be some interference from the PC's power supply and circuit.

However, technology is advancing and we can see some better products in the market which has the quality comparable with linear power supply.

Due to time shortage, the theory session was skipped. Is it possible to forward the powerpoint slides of the theory session that KK has prepared to us? I do like to know more on this.

TWM,

Sure, we'll send you the files

我也想要一份powerpoint.
我因為太忙的關係,還未有時間細聽它,反而我的朋友急不及待把它取去試聽.他現有的器材是DIY 的convergent SL-1前級, goldmund后級及屏風speaker.接上class-D後級的結果非常理想,與他的goldmund比較也差不了多少!在沒有任何補品的情況下也有這樣效果!所以我在想如果加了補品就更加不得了!
現有問題請教:
在UcD板上的電容是否用作提供電源給OP amp?如換了blackgate會否好得多,效果明顥嗎?(由於還未看過powerpoint,現只是假設輸入訊號先過OP amp作傳統放大,才再做modulation)
另關於8支電源電容:由於輸出的管只須做開關動作,相對而言,對電源質素的要求是否比傳統A類或AB類amp低?(是否換了好的電容分別也不大)
在堂上KK Sir提過OP amp可upgrade,有進一步的資料嗎?
現在的效果已非常好,多謝William與KK Sir!但欲望無止境,好似吸毒一樣...

Dear folks

this is the circuitry of UcD 180 from Jan Peter of Hypex.  I thought the capacitor you are talking is C7 &C8.

Happy listening

http://www.diyaudio.com/forums/showthread.php?s=ccff42f8bead2471198dd575335315bf&threadid=38199[/img][/url]

Sunsvc,
But I am using UcD400. It is 470U/100V, big differ from UcD180. Can you tell me where to download the circuit?
Thanks a lot.

Leo

You may follow the link above and ask Jan-Peter, he looks very helpful.

By the way, the thread also contains a lot of discussion on the upgrade.

Good Luck!

Pls also email me the powerpoint.

Please send the powerpoint to me also.

Thomas

Hi Leo,

I am helping you to get the recommendation from Hypex regarding the cap upgrade inside the module

Hi Godwin & Thomas,

information has been emailed to you

thanks william and sunsvc!
william: would you please also send me the powerpoint?

Leo, you are welcome, information has been sent to you.

William, i have not received it; maybe something wrong with my server. can you send it again to lleung@grove.com.hk or the hififever account? thanks.

Hi Leo,

Sent to you again using hififever account. pls check

William, I got it. Thanks

William, sorry to trouble you again... do you have the "2nd week" powerpoint?

Yes, "2nd week" powerpoint X2. What you send to us is the procedure of assembly. What we want is the circuit theory of the UcD or Class D amp. If I am not mistaking, KK has prepared it and showed 1-2 slides of it to us in the class.

BY the way, any news on replacing the input buffer to AD Op Amp?

Leo, this is the must do mod.

By the way, the following is quote from a guy name matjans
Quote:  on the ucd180 (rev 1.00) the input caps are c7 and c8, on the ucd400 thay are indeed c23 and c24

When replacing the input caps, you can use high quality non-polar (bipolar) electrolytics like black gate N, NX or, better still, use high quality film caps. These tend to be much larger than electrolytics but they sound better. If you want to use these, remove the old input caps, bridge them with a small piece of wire and put the input caps between the rca/xlr sockets and the modules. As these are non-polar, direction (??) is not important  unquote

Leo & TWM, I'll send you the session of the slides asap

Leo, for the cap replacement, the engineer from Hypex also recommend 220uf/100V "136" type from BC components. Blackgate is also fine but he feel a little bit too soft. You may have a try and compare.

guys, I will try my blackgate 470u. if i feel it is too soft then i will try some other, maybe jensen. will update all of you. for the +/-12V stuff or op amp, i will wait...

Leo, look forward to your upgrade result

Hi everybody, KK is finalizing the slides, you may also review the following information first

D類放大器走向成熟
http://www1.ti.com.cn/customer/article/2004/01/0115_03.asp

D類設計提升音訊放大器的效率
http://www.ti.com.tw/articles/detail.asp?sno=49&catalog=10

the improvement is not that high; i will roll it back and use the 470u (Blackgate) to try the aux +-12V power.

See the UcD 400 with Blackgate, the improvement is not that good so i roll it back, attached pix FYI only.
William, can you post more detail regarding the aux power? (model number of the IC, circuit...)

forgot to attach the pix...

Leo,

http://www.hypex.nl/docs/UcD400AUX.pdf

Tell you how to use dedicated +/- 12V power for the input buffer

My 2nd UCD400, with speaker protection. Use Jensen 10, 000uf x 4 per channel.
Sound is good! More musical.

勁!! 我們有一份現成的12v穩壓, 可以用在opamp, 有興趣嗎?

yes, i have. I will call you later today.