[T.IIZUKA]

Quote:

What do you guys think of the "economy edition"
 
http://cgi.ebay.com/LOVELY-CUBE-Headphone-Amplifier-KIT-Economy-Edition-/200541739530?pt=LH_DefaultDomain_0&hash=item2eb1381a0a
 
its not the same board and no opamp but other than that its the same right?
 
looks like a good soldering project for me.

lower grade capacitors and resistors.
Lovely Cube is being used more difficult to obtain parts.
 
I think kit is $89 deal.
(Deal of the Finished Board $99 more.)

 

[ViciousXUSMC]

Ahh with lower grade parts I would not be interested.  Plus only $10 for a finished board is a deal compared to the $89.00 kit.  Most people that do DIY for you charge way more than $10 for the labor.

 

[DaEMoNteNTAcLe]

after some brief tweaking...
i end up changing from opa627 to lme49860na biased with 7.5kOhm.
gain set to 20.
i noticed that changing gain changes the sound quite a bit after biasing.
im also using dual ground wire with both shield grounded at one end.. but havent finalized yet.. improves a bit of clarity, but also seemed to sound messy. will be tweaking more later after some burnin..
 
currently only prefer using 627 unbiased.. but imho its too messy and lack depth. -_-
biased have too much pounding bass and too dry on the vocals. seems like going below 3mA also isnt a good idea with 627, not clean sounding enough.
dunno if i should go for 1361.. cant find 1364 where im staying now.

 

[francisdemarte]

 
Did some minor tweaks. Removed the output caps and moved those darn gain switches to the top of the board. I don't understand why there are two of them. Why would anyone want to have 2 difference gain settings on the left and right channels...going to replace them with 1 switch.
 
Coming up: Ordering another board a going balanced!

 

[ninjikiran]

The rare chance one of your ears is damaged greatly Though I doubt that was the reason why.
 
The real reason might just be the way the circuit is designed.
Quote:

 
Did some minor tweaks. Removed the output caps and moved those darn gain switches to the top of the board. I don't understand why there are two of them. Why would anyone want to have 2 difference gain settings on the left and right channels...going to replace them with 1 switch.
 
Coming up: Ordering another board a going balanced!

 

[VictoriaGuy]

Just a general FYI-
I ordered a Lovely Cube from Stephen a month ago. It arrived here in BC (Canada) yesterday, right on schedule.
Very high quality assembly- everything fits perfectly, very neat wiring, nice touches like locking lacquer on board mounting screws, the switch access holes in the underside are properly located and finished, etc.
It definitely doesn't have any DIY flavour at all!
Sounds good as well.
I'm happy.
Total price including shipping was $231 Cdn.
The support and communications from Stephen are first-class. There was a minor problem (wrong IEC cord) and Stephen replied via email almost immediately. Within a couple of hours I had a small refund back in my PayPal account. You really cannot ask for more that that!
 
Cheers
John

 

[T.IIZUKA]

Today's Lovely.
 

 
 
Heat capacitor. Plans to measure heat.
3-Terminal regulator's Heatsink touch with the capacitor. This seems to be the cause.
 

 

[stau]

hi
 
I use OPA2134 original again - bigger room / stage little bass

opa267 was somehow more bass but less room / stage

 

[T.IIZUKA]

 
 
Quote:

Heat capacitor. Plans to measure heat.
3-Terminal regulator's Heatsink touch with the capacitor. This seems to be the cause.
 

 
 
Mr. Stephen did the answer to my question.
Made a great page.
 
http://www.alicemagicbox.com/lasercollection/lovelycubesecretofheat.html

 

[stau]

super  !!! thanks for link

 

[francisdemarte]

 
Thanks for the link! I think that will put a lot of people's minds at ease.

 

[SP Wild]

I've built up two of these silicon chip headphone amplifier boards and I own a Lehmann Black cube Linear.  The circuits have the same topology,  opamp input, same transistors for current gain and voltage regulation 
(317/337)on a separate board.  The only major difference I can see is that the BCL has no feedback going back into the opamps and the silicon chip one does.
 

 
I could not get the silicon chip board to equal the BCL in technicalities...there was always something that constrained the transparency and speed of the silicon chip boards - I removed the zobel network, the output inductors, replaced the diodes for ultra fast ones in the psu board, uprated all electrolytics to lower esr and higher capacity units...I got more detail out of it than the BCL...but still something was smothering the sound.
 
Until I removed the input capacitor...that finally unleashed the silicon chip board to be as fast as the BCL amp...but the modified silicon chip board has lower sub bass extension and extra lower midrange detail because of this.  The kit cost Aus $37 for the amp board and $20 for the PSU board from Altronics or Jaycar in Australia ...all you need then is a toroidal for your country's AC voltage.  I will modify the second board and balance both boards.
 
I thought I would post this up on this thread being an owner of the original $1000 BCL and this board sharing an almost identical topology.

 

[aspenx]

I've built up two of these silicon chip headphone amplifier boards ...

I don't think I follow you. Could you post a link to the board you're talking about? Is this your personal implementation?

 

[SP Wild]

Quote:

Quote:

I've built up two of these silicon chip headphone amplifier boards ...

I don't think I follow you. Could you post a link to the board you're talking about? Is this your personal implementation?

http://www.altronics.com.au/index.asp?area=item&id=K5503
 
Link to the amplifier kit from Altronics Australia - actually only $34 with the bits included
 
http://www.altronics.com.au/index.asp?area=item&id=K5501
 
The accompanying PSU board for $20
 
By not installing some of the components that come with the kit...I guarantee it will meet the objective performance of the BCL.  Fitting higher capacity low esr capacitors will get more subbass extension and subjectively surpasses the BCL performance.  The caveat being you need to make sure that your source has very little DC offset, as the key for me was eliminating the input capacitor.  I goes to show that the BCL is a highly tuned device as it does what it does whilst being strangled by an input capacitor.  (I will not mod the $1K + BCL...but rather sell it)
 

 

[francisdemarte]

I've read quite a few positive reviews of this amp over at Rockgrotto. Seems like a good deal for a basic amp kit.
 
Though the Lovely Cube seems to have an edge parts wise. For a bit more money you get bigger caps, a decent volume pot, selectable gain, and a beefier power supply that is integrated into the board. 
 
Might pick a board up to experiment with!