mouz

I've got one that's not in SG but it's recommended to me by a friend who's teaching electronics in a school here.

http://ourpcb.com/

This one's in Malaysia but not too sure if the price's reasonable

http://www.custompcb.com/index.html

wah, you really getting into one project after another huh? Actually, same goes for me, next up after mini3 is SOHA than Millett hybrid. hee hee

Thanks Heady, I'll go check out the multimeter. This hobby's getting expensive....

Mouz, sorry brother, your DMM got no capacitance measurement.

hmm.. looks like i need to in a better one soon. Got that for $10 cos i was thinking I won't get serious into this. So you got any recommendations? Fluke 73 series? Saw some 2nd ones on sale . Sorry ar, i still very new into these things so need to ask noobie qns like this haha!

I've just solder the opamp so your usual way is the one at amb.org or by measuring the opamp pin to pad reading?

yup, opamp pin to pad.

wat reading did u get when u measure using the usual way, from the pin to pad? reflowing the solder on those 2 points might help

Use the capacitance setting to measure caps. Can't use DCV to measure capacitance. At least not as I know it.

Thanks for the tip, pardon me but what do you set to to measure capacitance? ohm, VDC, etc?

I'm using the multimeter below btw.

I'm using a different method, I added a tiny ball of lead to the pads, heat the pad up to absorb the ball so more solder ends up on the pad, place the opamp in place, keep it in place with a pair of tweezers and than use the iron to press the pins down one by one. No problem with the continuity though. Not confident with the flooding method as I'm afraid of creating a short between the pins.

BTW, I desoldered C5+ and C5-, not sure how to test if it's faulty or not but when I set it to DCV 200mv, one measures 190+mv and the other measures 10+mv. Does this mean the cap is faulty?

這是ㄧ款全新規劃的耳機擴大機套件，使用真空管(6922/6DJ8)放大，輔以OP做Buffer輸出，可推動各式耳機，體積小巧，並採Adapter供電，攜帶方便。

製作簡單，更適合初學者製作。

本套件包含所有零配件，但不包含機箱，真空管採用6922-EH，本版本不含Adapter，請自行選用穩壓相關套件，輸出規格為12VDC / 650mA以上即可適用。

本套件亦可當成前級使用。

套件內容:

1. 6922-EH X 1

2. PCB X 1

3. 電阻包 X 1

4. 電容包 X 1

5. 相關零組件包 X 1

6. 零件表 X 1

7. 電路圖 X 1

Let me try and translate ar... Do correct if I'm wrong, haha!

This is a new headphone amplifier, uses 6922/6DJ8 tube for amplification, something about using OP for buffer output, able to drive various headphones, small in size, uses power adaptor, portable. Easy to construct and is suitable of beginners.

Package does not include casing, comes with 6922-eh tube, no adaptor included. Please choose a 12VDC / 650mA DC adaptor for power. Can also be used as a preamp.

6922-EH x 1

PCB x 1

Potentiometer x 1

Capacitor package x 1

Package of other accessories x 1

Parts list x 1

schematic x 1

Thanks for the tips heady, think this will come in pretty handy on builds that uses transformers in the future.

So in the Canare cable I suppose it uses the foil for RFI. Wonder what it uses for EMI shielding, grounding the drain wire to signal ground?

Looks like a pretty good cable with foil shield to stop EMI, RFI. That's going on my list of DIY materials, thanks for sharing this

Say, do you think lining aluminium foil (those found at the supermarket) inside the case will help shield out EMI RFI?

Thanks Guys! Gives me an alternative to buying hammond casings

BTW, is that interconnect made from cat5 network cable?

Nice work, any idea where i can get those casings?

knew this was gonna leak sooner or later....

Yah, did my best to get as much off as possible. Gonna try Heady's mod, seems like a much better one than just stuffing the sponge in

Eh nice mod! Bookmarked!

You got anymore ?

Feels the same actually, the foam just fills in the gap between the tube section and the rest of the tip.

Now I figured out why Jaben sells one year supply of foam tips, the set of super complys I bought lasted me barely one month and it was starting to tear. So I figured might as well make good use of it and stuffed the foam into the original silicon tips that came with my IEM. Beats replacing foam tips every month if you asked me...

Results...

Good: Better bass and treble (probably due to the foam minimising vibrations in the tube section of the tip), improved sealing out of ambient noise and the durablility of silicon tips.

Bad: sealing out of ambient noise still not as good as foam tips.

Same here but based on tangent's site, I guess decreasing the resistance on the output resistors might help to drive your headphones a bit better? AMB's initial checks on DC offset recommends 5mw but cmoy recommends 20mw but both are different amps, maybe can work around that area...

Hi guys, left 3 more guys to collect

demonicangelz

aegisoframe

kahchun

Heady, still quite new to this stuff, dt150 is 250ohms, is that considered high impedance and is the reason why it doesn't drive properly?

Mouz,

By tmr you mean Tues evening abt 6.10 - 6.20pm? Should be ok. Give me an sms when you arrive. Will PM you my mobile number in case you haven't got it already. Thanks,

 

heady

Yup see u tomorrow

Thanks for the offer heady, think I ll try it on my own first lah, I'll give u a call when i surrender. Anyway, I went thru the headwize forums, seems those readings of shorts and back to zero are normal, so gonna go ahead wif the rest first.

http://headwize.com/ubb/showpost.php?fnum=...d=65823&fpage=6

BTW, u free tomorrow night for collection? I can meet u up at Simei MRT behind the station gates around 610-620 as always.

Ok heady, its urs than

How's ur mini3 coming along? I'm still stuck at looking for shorts, so irritating, it just flashed a few ohms n goes to zero everytime i checked. Can't see the short anywhere. BTW, any of you guys got any spares for the cap below for sale (C8, C7 positions)?

multilayer ceramic X7R capacitor 0.1µF 50V

Sorry guys, made a mistake, its actually one xtra set left. Forgot to take one set for myself. Priority will be given to grp buy participants first.

K lah, adn6244, u got 2 sets than. 2 more extra, anyone wants?