diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Chip Amps (http://www.diyaudio.com/forums/chip-amps/)
-   -   "Yuanjing" Gainclone 3886 - eBay amazing value ? (http://www.diyaudio.com/forums/chip-amps/142923-yuanjing-gainclone-3886-ebay-amazing-value.html)

gainphile 25th April 2009 06:47 AM

"Yuanjing" Gainclone 3886 - eBay amazing value ?
 
The plan is to power my 10-drivers OB using multi-channel gainclone. Was ready to build the usual point-to-point 3875 until I spotted this on EBay.


http://www.kcheungshop.com/iwannebuy..._2x_68w_04.jpg

Price is amazing, which comes to about A$12/channel (!). Very tidy. What I am not sure though is the additional op-amp which I believe can be easily bypassed. The other thing, I haven't heard 3888 compared to 3875. I have lived with my 3875 and never had the need to tweak or lust any other amp since day-1.

Any advise?

Nuuk 25th April 2009 07:30 AM

Quote:

Any advise?
At that price? Yes, buy one and listen! ;)

planet10 25th April 2009 07:37 AM

Can you give us an auction URL?

dave

postpunk 25th April 2009 08:42 AM

I've got one of those. It produces a terrible hissing noise, and it hums. I think that the Wimas are all fake, they look like they've been sanded. The chips looks strange too, thinner leggs than normal and the packages are not equaly thick. They too look like they've been sanded off... I would not recommend that crap to anyone.

gainphile 25th April 2009 08:47 AM

The link is here:

http://cgi.ebay.com.au/ws/eBayISAPI....m=330324271515

Thanks for the warning. As nuuk said I may just try one.

Hiss would most likely due to the op-amp, this can be bypassed. Hum is more serious and difficult to fix as this is due to trace/grounding design.

I'm not sure what you meant by "sanded". Do you mean they try to sand off the "LM3886" marking ? Any possibility to post a close-up pic?

THanks.

postpunk 25th April 2009 08:51 AM

The cases are scratchy and a bit disformed. They don't look the same between the two of them. I shall see if I can take a few pics.

postpunk 25th April 2009 09:54 AM

The pics didn't turn out well, too blurry. You can't see anything. But the chips look like they didn't break out clean from the mold. Jagged edges. I have never seen such rough finished casings on any original lm3886. They just have to be fakes.

Edit: Here one can at least see the strange looking corner of one chip..
http://img12.imageshack.us/img12/809...e017ofn.th.jpg
http://img12.imageshack.us/img12/6968/picturehtu.th.jpg

postpunk 25th April 2009 10:28 AM

I just saw that my chips and the chips on the amp pcb in the ebay auction have got the same batch numbers: JM23AJ. What are the chances of that. I bought mine off a guy in Hamburg. Fakes, anyone?

gainphile 25th April 2009 10:55 AM

Very dodgey indeed :eek:

Thanks for sharing that. It does seem too good to be true!

SimonKit 25th April 2009 12:13 PM

I bought a similar cheap amp as experiment:
http://alturl.com/g7wp
Sound is OK however not really satisfying. So I replaced the Wima input capacitor with ERO MKT 1822 4,7 uF and now the sound is good. However my Peter Daniel LM3875 premium amp with BG capacitors still sounds better.


All times are GMT. The time now is 02:43 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2