digi01

sorry,have to write in simplicity chinese again 我用来调整放大器的耳机有三个.包括低阻抗的HD495,CD3000和高阻抗的K141M.这些耳机都是非常有个性而且很难伺候的.这个机器虽然很小,但输出的电流很实在.我用DISCO里面经常放的舞曲做测试,低音的控制力很好.高阻抗的k141m,在音量电位器开到11点钟的位置就进入满功率状态了. eaton buffer 的缺点是声音比较干，没有一点优雅的味道,基本是不作修饰的把信号放大.后来我在推动级的op上作了一些补偿,芯片也换成口碑不错的ad823.原来使用过ne5532,发现声音有点浑浊. 输出晶体管也用了比较好的B647/D667(120V1A0.9W),声音比较人性化一点.

This amp is again an opamp + discrete design. However, the design is slightly different from afterburner’s amp. The idea of the discrete output is from EATON amp. you can find some detail here: http://headwize.com/projects/showfile.php?file=eaton_prj.htm this is a europe diyer work: http://www.justchords.com/docs/eaton.html With slight modification, the amp uses AD823 opamp to drive a pair of matched B647/D667 audio grade transistors, running in AB mode. Input stage using ERO caps and dale resistors; Elna 220uF BP non-polar caps are used as output; PSU with Telecom. Grade Siemens Caps and FC; Alps potentiometer; Gold plated RCA jack, and pre-out ( can serve as dedicated preamp.the amp voltage gain setting in 11) as requested. in fact,the amp style can drive a wide range of headphones with different impedance.it certainly can drive HD650, it can even drive AKG K1000 with PSU upgrade.

Goondu, YGPM

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another mini amp,for dennis

enjoys BTW,The amp only RUN-IN 2 hour,you listen to some time more, sound will graceful a little. Help me to take several pictures if having time.

wonderful,have you modify the power supply parts?only add schottky diodes?

Wonderful! I m looking forward to hear your commend.

The amp is built using original parts as recommend by David Lin. It uses metal film resistors,philips 1uf/63v film caps for input and dc server. A dual opamp AD823 for input gain stage and a TL072 for server.the ouput stage is based on a couple of solid state 2sd882/2sb772,it is seting in class A/B mode.the amp can output 5W rms power pre channel. the amp price is S$160 + S$40 shipping. = S$200 To upgrade its performance,you can choose the uparade packages that I offer. here is lc-king forum: http://www.firestone.idv.tw/cgi-bin/produc...vcategory_id=1# Upgrade packages: 1. 2 x opa637 + adapter S$60 2. 2 x opa627BP + adapter S$40 3. opa2604 for DC Servo S$8 4. 2 x Solen 5.0uF at PSU ( greatly improve the highs and soundstage) S$10 5. 2 x balckgate 100uF , power cap for opamp S$10 6. All elna cerafine caps replacement in PSU S$30 7. alps blue upgrade S$10 8. speaker driving capability. include: speaker out jack higher VA transformer(shipping fee will vary due to heavier transformer used) S$30 Freebies ( upon request) 9. upgrade to DC King 10.upgrade to 10W capability.

the board size is as same as a 9v battery,it is still in progress.I will cut no used space when finished.

the switch for power on/off.the amp is not finished yet.for some reasons,I like opa2604...a little sweet.

I use a couple of ERO caps,dale and philips resistors.opa2604.alps#16 pot.

ALPS volume pot and power switch,ero 0.47uf/100vMKT input caps.opa2604 plug in dip8 socket. the board size is 70mm x 33mm. edit:part list and add 2 pic.

wow,cool machine! excellent photography I am a camera fans too digi

sorry N@Z,I have sent the amp to Afterburner,no chance take photo of the back of the board. here is my old A47 amp in 1999. top view: soldering: digi

thank you Afterburner :") I will send out the amp weekend enjoys

top pic:

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the main PCB board size is 134mm x 120mm,psu board size is 134mm x 47mm.including the transformer and AC socket,VOL pot rooms.I think the minimum size of case is 160mm x 180mm,height 100mm(tube inside building).

Yes,a littel expensive.but top grade the case size is 240x380x130mm,the thickness of the front board is 4mm,all aluminium.

those are all manufacture OEM case,for audio diy used.

Hi Mackie,bpribadi The unit i mean is one set of kit, with things you need to make a Morgan Jones Amp exclusive of tubes,transformer and case.as for part list, you can refer to my ealier post in this thread. I can provide tubes and transformer and case, but shipping cost is not worth. about the case,I find one here.size is 240x380x130mm,aluminium.53S$.

bpribadi,great drawing.I will try work on Visio too

I will let go a unit for you all to tryout..introductory price... S$130 plus air shipping.. pls PM me . first come first serve

mukegile,thank you supply the info The purpose of the standard kit is making a tube headphone amp at a reasonable cost.it will be a pleasure progress. The kit is designed to be upgradable.so it can use diode rectification to lower the cost.or use tube rectification which will improve the sound.. yes, you can replace the resistor with choke.. which makes CLC filter.