[Danielsc]

Hy..
Ok..
I will then put some posts..
Trying to be interesting for everybody..
 
Regards.
 

 

[Danielsc]

Quote:

 
Someone was kind enough to provide a link to this amp on ebay in the Matrix M-Stage thread. I thought I would be a great amp around 1/2 the price of the M-Stage and an easy DIY project to pass the time.
 
 


EDIT 04/13/2011: You can now buy the Lovely Cube Premium fully assembled.

For details: http://www.alicemagicbox.com/lasercollection/lovelycubepremium.html




Hardware  
 
The "Lovely Cube" is sold on ebay by Laser Collection. It runs about $100 shipped for a fully populated board, a pair of nice quality RCA jacks, some heat shrink, a few SIP connectors for the inputs, and a couple of LED's.
 
The vendor also sells the rest of the components you need to complete the amp: 220v transformer and case as well as unpopulated boards.
 
The Lovely Cube is an exact copy of the Lehmann BCL where the Matrix M-Stage is a slightly altered version. Here's some pictures I borrowed from the ebay auction:
 
 
 

Bottom of the board with the Gain adjustment DIP switches.
 
 

 
Alps volume pot
 


Swappable opamps. I switched the SOP + adapter for the DIP8 version of the OPA2134 I had laying around.
 
 

 

 
The amp arrived via normal HK Post about 2 weeks after I ordered it. All components look to be name brand and high quality.
 
Be aware that it came with no instructions of any sort, so you'll have to be a little familiar with DIY. In the picture above I've labeled all the wiring points for everyone's reference. 
 
On the far left is the primary input, grounds in the center and signals are the outer connectors.
The center 3 connection points output 15V DC. It is used in the USB version of the Lehmann BCL to power the DAC and USB ports. Pretty nice addition since you can use it with a voltage regulator to power a DIY DAC.
 
Next to that is the 2nd inputs, I believe these are muted if you plug a headphone into the 2nd headphone jack. I did not connect this in my installation.
 
Lastly the power input with convenient screw terminals. The amp has an internal PSU so all you need to provide is a 15V AC transformer.
 
Here's a internal picture of a real Lehmann to get an idea of how things look wired up.
 
 

 
 
Sound
 
Going to reserve this space for further impressions. My current install in a old external CD-Rom chassis powered by the DY-1 power supply that came with the Head Direct EF-5 amp set at 16V AC.
 
I have a minor grounding issue since my case does not have a faceplate. I hear buzzing on my low Z phones when I touch the volume pot, I think I need to ground it to the case. I'll update this section once I get a new case or get this issue resolved.
 
Edit 07/07/2010: Buzz is now gone. I had to ground the Alps pot to the star ground in my case. The amp is now totally silent with no music playing and the volume turned all the way up with my 42 Ohm ATH-W1000X's.
 
 
Initial Impressions
 
I'm not the best amp reviewer here but the review of the Matrix M-Stage's sound signature all applies here. This is a fantastic amp for the price! Fast, dynamic, and works well with all my headphones.
 
Currently I have mine set at gain 0 and it really brings my ATH-W1000X to life. The bass goes low and hits effortlessly and the mids, while still forward are smooth. The HD650 also sounds great at gain 0!
 
 
Initial Conclusion
 
This is a steal at around $100 shipped for a finished board. If you have a little DIY experience or want to get your feet wet without the complexities of putting together an entire amp this is a great start!
 

Mods

Thanks to JiggaD369 for compiling a list of mods mention in this thread!

http://www.head-fi.org/t/501046/the-lovely-cube-headphone-amp-lehmann-black-cube-linear-clone/915#post_7966068

I basically went through the entire thread about three times in order to condense all of the info. This is basically my first complete DIY modding project and mostly out of curiosity. It was painful but worth it IMO!

Below are the mods with Newark/Farnell part numbers (otherwise noted):


PSU:
Replaced the two 4700uf caps with United KMH caps (16M6799).
Replaced the ADJ caps with Sprague10uf tantalums (30C8841).
Replaced the R2 resistors with zener diodes as per BlaBla method (18C6023).
Replaced the regulators with Fairchild (58K8936/58K8937).
Replaced the four transistor 470uf caps with Panasonic FC (80K8337).

Signal Path:
Bypassed input caps with 6N copper wire.
Replaced the stock opamp with OPA2111KP.
Replaced the two opamp supply caps with Silmic II's.
Replaced the two small 0.022uf caps bypassing the Silmics with Philips (.027uf) Polystyrene caps. (Ebay)
Replaced the output 10 ohm resistors with Allen Bradley 1W carbon resistors (Ebay).
Replaced the 100pf caps with LCR Polystyrene caps (64K0006)
 

 
Thread Highlights & Updates
 
Edit 07/07/2010: Upped the gain to 10, which gives the HD650's a bit more oomph while still leaving some headroom for the W1000X's. 
 
Edit 08/31/2010: The ebay seller now as an official site for the Lovely Cube: http://www.alicemagicbox.com/lasercollection/lovelycube.html
 
Edit 09/24/2010: Sunneebear creates the first balanced Lovely Cube Amp! http://www.head-fi.org/forum/thread/501046/first-impressions-lovely-cube-semi-diy-amp-lehmann-black-cube-linear-clone/75#post_6948982
 
Edit 10/01/2010: Comparison between Lovely Cube and Matrix M-Stage with the HE-5: http://www.head-fi.org/forum/thread/501046/first-impressions-lovely-cube-semi-diy-amp-lehmann-black-cube-linear-clone/105#post_6964362
 
Edit 10/13/2010: ebay seller now has OPA627AU and Class A adapters available. Nichicon KG Gold Tune 4700uF 50V replaces the Elna for Audio 4700uF 35V caps on new units. Some pictures by aspenx http://www.head-fi.org/forum/thread/501046/first-impressions-lovely-cube-semi-diy-amp-lehmann-black-cube-linear-clone/105#post_6990039
 
Edit 11/14/2010: Removed output caps replaced with solid core wire, opens up sound stage a bit and increases treble extension. 
 
Edit 11/29/2010: Is your Lovely Cube case feeling very warm? Relax, it's suppose to be that way: http://www.alicemagicbox.com/lasercollection/lovelycubesecretofheat.html

 
I made almost every mod that are described here..
I did not Bypass the input caps but used MKP Mcaps.. I use 6N wire for the kabling to the RCA sockets.
But, about the OPA, I choosed the OPA2111AM.. I tried the KP model, but was disapointed by it.. But, this is probably a personal taste..

 

[Chodi]

I was actually thinking of ordering one of these Lovely Cube premium version but when I went to his web site today to get a quote I found that none of the contact links are working? I was unable to leave a request for quote? Is he out of business? Then I looked on Ebay and I find that the finished Lovely Cube is not there (at least not today). I will try to send him a note later through his Ebay site as he has a few items listed but this is not encouraging.

 

[Dillweed]

I just e-mailed him yesterday about a question I had for the pre-assembled Premium I bought from him back around Christmas of 2011, and he got back to me within the day. You might want to try just e-mailing him if you haven't already. I don't know if he's still making these or not since I didn't ask, but he's still reachable in any case.

 

[Danielsc]

Hello StaxPatrick. I'm very interested in this project, with the power supply apart. I just wanted to know what was then needed to disable, on the amp PCB? Upto wich part? Do you have some pictures to show, already? And what are the results of modding it this way? Regards.

 

[linhhonlangdu]

 Hi guys, I have just made a Lovely Cube. I am trying IC OPA627AO but not sure about its quality. Would you please give me some recomendations? Thank you.

 

[Danielsc]

Hello..
Good evening from Belgium..
There are some posts about the different OPA's, in the first pages, I think.
Changing an OPA is the easiest way to change the sound of your amp..
But be sure that you are the only one to know wich will fit the best to you. It is only a mather of personnal taste.
Basic OPA will probably not be the end choices. They are cheap, they work, and that's all.
I like the détails and airy sound.. So, my choice went to the OPA2111AM. Very clear, very detailled, and a very wide soundstage.
Just after this, I would choose the LME49720HA.. I did not try yet, the Dual LME49710HA, but I heard very good feedback from it.
I got the dual OPA627AP, but it is not very precise in the deep bass.. It has very good mids, but not enough clarity in treble and low basses..
These are only some I tryed.. There are lots more.. If you can affoard, try Discrete OPA..
But, be sure the only one who gets the best answer is yourself..
Regards.
Daniel

 

[linhhonlangdu]

My lovely cube has some problems.There are hum sound when the volumn is up to more than 30% loud.Does anyone know the reason and resolution for this problem?

 

[Danielsc]

Hello.
Did you make some mods on your LC?
Or is this hum present since you got it?
 
Regards

 

[linhhonlangdu]

 I got the "hum" sound right after i made my LC ( I haven't moderate it). When the volume is over 50%, the "hum" sound appear (Even if there is no input signal).

 

[nippon]

Hi,
a few questions:
 
Have you connected the Alps poti to GND/Case?
How big is your DC offset?
What headphones do you use while the "hum" appears?
High sensitive phones will make the hum audible, try to keep in mind that every amp hums, just with a different intensity.
 
For example: On my LC clone i can't use the AKG450 or the Audio Technica ATH-M50, but AKG K601 and DT 770 (250ohm) are nearly silent.
But my Clone works no longer in class A mode. If you are willing to modify you LC with a soldering iron i can give you some tips, just let me know (if you can read german i can send you a link to my "how to fix/build an LC clone" thread)
 
regards,
nippon

 

[Danielsc]

Hello, Nippon..
 
Greatings from Belgium.
You can always send the link, even in german.. It can always be interesting, even if sometimes, Google traduction have to help .
 
Regards.

Daniel

 

[nippon]

Well, here is the link. May google be with you
 
http://www.hifi-forum.de/viewthread-71-10591.html

 

[HumanSaurusRex]

Can someone please do a little comparison between the lovely cube and other DIY amps like the O2?
I need a new DAC/amp combo and can't decide whether to go O2/ODAC, Magni/Modi, pupDAC/Lovely Cube, ...
 
 
 
Thanks for your advice!

 

[linhhonlangdu]

  Hi,
a few questions:
 
Have you connected the Alps poti to GND/Case?
How big is your DC offset?
What headphones do you use while the "hum" appears?
High sensitive phones will make the hum audible, try to keep in mind that every amp hums, just with a different intensity.
 

 
Hi everyone
I have read your link with the help of google and I think my problem lies in the quality of the components, but I'm not sure
I have connected the Alps poti to GND/Case,it was better but still not completely discharged hum
I used the ATH AD900 while the "hum" appears, I tried with the others, but all are the same
Finally, I don't know the concept of "DC offset", can u guide me ?
Thanks