The "Lovely Cube" Headphone Amp (Lehmann Black Cube Linear Clone)

[reiserFS]

I might fit this baby inside a Hifi2000 Slim case, probably going to look sleek.

 

[InFn-0]

this might be a very stupid question, but does the seller provide the on/off button near power in thing? or will i have to source it from elsewhere? Im talking about the one in the picture below

 

[francisdemarte]

 
No, but I believe that comes with the case which I did not order. The board itself came with a pair of really nice quality RCA jacks.
 
That thing is called and "IEC power jack", this particular one has a fuse and a power button built in. You can order them online or just rip them out of some old piece of electronics equipment.
 
New pictures, I've decided the case I was using was too big and heavy. re-cased it in a $5 project box from Radio Shack. Now I have shorter cable runs with silver teflon cables.
 

 

 
The brass knob is from Head Fi'er Vilts.

 

[francisdemarte]

Stumbled on more technical info for the Lovely Cube.
 

 

 

 
 
BOM:
 
 
The Kit Parts List :
[size=medium]

Parts	Parts no. on PCB (not on Schematic)	Qty
Resistor	VISHAY DALE
100R 1/4W	R305、307、314	8
10K 1/4W	R101、201	5
15K 1/4W	R313	3
1K1 1/4W	R306、308	6
1K5 1/4W	R106、108、206、208	10
2K2 1/4W	R103、204	5
3R3 1/4W	R301-304	10
47R 1/4W	R105、107、109、205、207、209	15
4K7 1/4W	R102、202、311、312	10
680R 1/4W	R104、203	5
10R 1W	R110、111、210、211 (Panasonic / Taiwan Resistor) * note 1	10
47R 1W	R309、310、315、316 (R309 & 310 : 3W OHMITE -USA / DRALORIC) * note 1	10
Capacitor
250V/1.5u	C101、201 (Simens) * note 1	2
63V/0.022	C102、202、315、316 (SPRAGUE 223 / ERO 223) * note 1	4
250V/0.1u	C301-304 (BC / ERO) * note 1	4
63V/0.15u/154	C307-312 (Simens / ERO) * note 1	6
63V/100P	C317、318 (Philips Tin Foil) * note 1	2
63V/102/1n/1000P	C319	1
35V/470uf	C103、104、203、204、313、314 (Philips BC / ELNA RE3 25V) * note 1	6
50V/4700uf	C305、306 (ELNA) * note 1	2
	* note 1 : Brand /Model depends on stock availability , or same grade
Transistor / Diode
BC560（TO-92）	Q101、201	2
BC550（TO-92）	Q102、202	2
BD140（TO126）	Q103、203	2
BD139（TO126）	Q104、204	2
LM317（TO-220）	Q301	1
LM337（TO-220）	Q302	1
BYV27-200 (Diode)	D301-304	4
LED	L301、302 3mm	2
LED	L303 (Blue) 3mm	1
IC / OPAMP
OPA2134UA	SOIC to DIP8	1
Others
2 Way dB Switch/Selector	SW101、201	2
Fuse (PPTC) 72V 0.9A	F201、202	2
PCB	Gold Plate	1
Heat Sink TO-220	Large for Rectifier /Small for BD139/140	6
TO-220 Silica Set	Sheet+Plastic Ring+Screw	6
6.35mm Headphone Jack	NEUTRIK	2
5.0mm Connection Block 3PIN	for AC Input	1
VR 50K*2	ALPS-27 (Half Round Shaft)	1
DIP-8P Socket	Nextron	1
RCA Socket	One Red, One Black	2
Transformer ( Optional)	Input : 220V (Red - Red)   Output : 2x15V 30VA (Blue - Blue , Black - Black)	Optional

[/size]  

 

[kboe]

Sweet option for the money, not to mention the ability to put it in any case one desires!

 

[purrin]

francisdemarte: Have you direct-coupled the inputs yet (removed caps)? Also do you think you will replace the diodes D301-D304 with HEXFREDs or other soft-recovery diodes?

 

[francisdemarte]

 
Quote:

francisdemarte: Have you direct-coupled the inputs yet (removed caps)? Also do you think you will replace the diodes D301-D304 with HEXFREDs or other soft-recovery diodes?

Nope haven't done it yet. I'm leaving for vacation and my wedding Thursday and I'll get to it when I get back.
 
I've always been dissuaded from using high speed soft recovery diodes/FREDs/Schottkys as I've been told they make very little to no audible difference over a traditional one. Do you have any experiences to the contrary?
 
The next major mod I think I'll make is to replace the RK27 with a DACT or the Twisted Pear Joshua Tree  attenuator and a nicer wood case over the $7 Rat Shack one I'm using now.
 
 
 
 
 
 

 

[aspenx]

After much consideration, I've finally placed an order over the weekend.
 
I have no DIY experience at all so I'm hoping it wouldn't be too tough.
 
Should I be looking for RCA jacks, some jumpers (if so, what types?) and a power cord now?
 
I got the whole package with a nice-looking Talema transformer by the way.

 

[francisdemarte]

You'll do fine, just take your time.
 
I recommend you start a thread on the DIY forum. If you get stuck you can ask for help there or in this thread.
 
Post lots of pictures!

 

[DaEMoNteNTAcLe]

i believe he provides the RCA jacks as well..

 

[aspenx]

Alright. I'll make a thread if I do need more help with the DIY.
 
I'm getting fidgety already (it's still not here!) and had forgotten that it's supposed to come with the jacks. While waiting, I did realise that the old iron is busted, the only solder I could find at home is too thick and a lot of equipment that I thought I had are missing. Going to have to do more shopping.
 
Hmm, I'll be sure to post pics alright. Heh. What with nobody else doing so. We need more pics and feedback!
 
And oh, congratulations on your wedding Francis!

 

[francisdemarte]

They send by regular post so it took a week and a half for mine to arrive and clear US customs.
 
You'll need:
 
* basic soldering iron and if you feel like it accessories like a stand and a sponge (I like Weller)
* Electrical grade solder
* Flux (I like the paste type that comes in a tube or jar, and a toothpick to spread it)
* 22-26 gauge wires of your choice 
* A nice pair of wire strippers that can handle small 22-26 gauge wire
* small screwdrivers 
* heat shrink tubing (They provide a couple of pieces in your order but its nice to have extra of various sizes)
* lighter to small torch for the heat shrink tubes
 
Not necessary for this project but nice to have is a digital multimeter if you want to do more DIY projects in the future. 
 
Tanget has some nice video tutorials on soldering: http://www.tangentsoft.com/elec/movies/
 
PS: Thanks for the wedding wishes I take off for Costa Rica tomorrow! 
PPS: Really nice to see all the Audio Technica woodie fans.

 

[aspenx]

Stephen, the seller, says it should take 4-6 days to reach me (Singapore) after he mails it later today.

 
Thanks for the comprehensive list! Do you think I should get wires too while I'm at it? How about a "3rd helping hand"? I came across tangent's site after following a link on the STEPS regulator here and I've been glued to it ever since (the "luxury" of unemployment). Great material and I'm already thinking of assembling the YJPS out of curiousity. haha
 
Have a great wedding and come back to enjoy your AT woodies soon!

 

[aspenx]

Okay. It arrived on Monday. Very nicely packaged and bubble wrapped.
 
After practising my soldering first, blowing a fuse (a spare one was provided! phew) and fumbling around, I managed to get it up and running with the seller's patient assistance through email.
 
I read that the BCL sounds best at the highest gain setting, so I'm using that with W1000X. The headamp is basically noise-free for my listening and pretty transparent in my opinion. I'm actually sad that my source (Musiland Monitor 02 USD) is not that fabulous. Regardless, soundstage and bass are noticeably much better.
 
It really brought a old CD player that I dug up back to life though. And here it is, the full package with the top removed:
 

 
I noticed that there isn't a clear image of the opamp used in the output stage so...

 
It's a BBOPA 2134UA. Burr Brown?
 
Anyways, it was a great first experience with DIY. Seller provided basically everything to complete the amp. Very good workmanship, parts and service for the price point, in my newbie opinion.

 

[komebudu]

Aspenx,
 
Very nice photos....  nice job.