The "Lovely Cube" Headphone Amp (Lehmann Black Cube Linear Clone)
Mar 12, 2014 at 5:26 PM Post #1,126 of 1,624
I never found a reference for that 10.000uF 35V capacitors at the manufacturer. Maybe they are only for OEM or they are fakes. But sincerly, i've takin apart some larger amplifiers for speakers and the largest capacity i found, was 8200uF. Also keep in mind that the elko capacity can rise when you use them below their volt-level after some time.
 
Is the Alps poti well grounded? Can you hear it with your headphones, if you touch the volume knob?
And sorry to ask for it again, but did you measure the dc-offset? :)
 
Mar 15, 2014 at 9:02 AM Post #1,127 of 1,624
Thank´s for you reply, Daniel!
 
My choices were made after reading a lot of tips at forums, like this. And, after my first Lovely Cube clone, that some humming sound in the background and with moderate sound quality (even my modded Project Headbox II at under $200 had a better sound).
So now I decided to build two more of them and go all the way using "the best" components. (I know, there are always something better and sometimes there are preferrables choices).
I´m posting a picture of my first amp.
 
I´m now also thinking of solder the components for the power supply section at the downside at the board, due to the large components (Nichocon KZ Muse 1000uF 50V is really large with an diameter of 18mm!!), and also I think there will be some shielding protection to having the the signal path at the other side of the PCB. I know it sound weird, but this will include having the 10000uF MLytic filtering caps soldered under the PCB.  After everything is soldered and I see the measurements, I will make an aluminium enclosure for it.
 
As for the two10000uF MLytic (replacing the standard 4700uF 35V), I´m not shure if it will be enough if they´re rated at 25V, or if they should be spec´d at 40V? Have measured the voltage for them, and the power supply circuit will give 20V for them. So 25V will be enough at the paper, but I don´t now in the real life if there if some downside, for example bad transients or shorter life span?
 
Also, I´ve seen the BHC ALC10S1080DF from UK, using Slit Foil, will better than Mundorf MLytic? The price is approximately the same. I´ve seen one person claim the 10000 MLytic for his amp sounded slow, but many others say it´s better then Vishay BC, Panasonic TS-HA, Elna LAO and Nichicon KG. Don´t know so much about the BHC. 
 
Daniel; what OpAmp did you use? Did you use Class A for it? I think I´m gonna choose two 3,9kOhm resistors for mine. And did you found any differents in sound swapping OpAmps or resistors for it?
 
 
Best regards: Mikael Markstrom
 

 
Mar 15, 2014 at 9:23 AM Post #1,128 of 1,624
Hello Mikael..
 
I think you went the same way I did..
I'm now improving my version 3, made with the components we both choosed.
I'm now working on the PSU.. I already use one type, just like the one on the link in my previous post.. I'm looking for some other, with better diodes..
 
And, afterwoods, I'll try the balanced way.. I already buyed every component (also the same).. I only still have to order two Talema transformers..
After that, I'll concentrate on the DAC.. Maybe a ES9018 one..
 
About opamp, my choice is based on the OPA2111AM.. It is my favorite..
But I like the LM49720HA too, wich is very close in quality.. Its a mather of taste..
 
Best Regards
 
Daniel
 
Mar 15, 2014 at 9:24 AM Post #1,129 of 1,624
Thank´s for you reply, Daniel!

My choices were made after reading a lot of tips at forums, like this. And, after my first Lovely Cube clone, that some humming sound in the background and with moderate sound quality (even my modded Project Headbox II at under $200 had a better sound).
So now I decided to build two more of them and go all the way using "the best" components. (I know, there are always something better and sometimes there are preferrables choices).
I´m posting a picture of my first amp.

I´m now also thinking of solder the components for the power supply section at the downside at the board, due to the large components (Nichocon KZ Muse 1000uF 50V is really large with an diameter of 18mm!!), and also I think there will be some shielding protection to having the the signal path at the other side of the PCB. I know it sound weird, but this will include having the 10000uF MLytic filtering caps soldered under the PCB.  After everything is soldered and I see the measurements, I will make an aluminium enclosure for it.

As for the two10000uF MLytic (replacing the standard 4700uF 35V), I´m not shure if it will be enough if they´re rated at 25V, or if they should be spec´d at 40V? Have measured the voltage for them, and the power supply circuit will give 20V for them. So 25V will be enough at the paper, but I don´t now in the real life if there if some downside, for example bad transients or shorter life span?

Also, I´ve seen the BHC ALC10S1080DF from UK, using Slit Foil, will better than Mundorf MLytic? The price is approximately the same. I´ve seen one person claim the 10000 MLytic for his amp sounded slow, but many others say it´s better then Vishay BC, Panasonic TS-HA, Elna LAO and Nichicon KG. Don´t know so much about the BHC. 

Daniel; what OpAmp did you use? Did you use Class A for it? I think I´m gonna choose two 3,9kOhm resistors for mine. And did you found any differents in sound swapping OpAmps or resistors for it?

Dude awesome would you mod my Lehmann Clone for money too?
 
Mar 15, 2014 at 12:49 PM Post #1,130 of 1,624
Off course, I can! The problem is that I live in Sweden, and I think the shipment cost will be quite high.
 
However, I´ve bought more components then I need, so I have some extra.
 
Where do you live? I must say if it´s you at the picture, I think you like a famous stand up comedian here in Sweden, called Özz Nujen :)
 
http://www.lifeline.se/wp-content/uploads/2012/02/%C3%96zzN%C3%BBjen3_FotoSannaDahl%C3%A9n_highres.jpg
 
Mar 15, 2014 at 8:45 PM Post #1,131 of 1,624
  Off course, I can! The problem is that I live in Sweden, and I think the shipment cost will be quite high.
 
However, I´ve bought more components then I need, so I have some extra.
 
Where do you live? I must say if it´s you at the picture, I think you like a famous stand up comedian here in Sweden, called Özz Nujen :)
 
http://www.lifeline.se/wp-content/uploads/2012/02/%C3%96zzN%C3%BBjen3_FotoSannaDahl%C3%A9n_highres.jpg


lol.. looks like my uncle... haha
send you a pm thx
 
Mar 16, 2014 at 11:41 AM Post #1,132 of 1,624
Whoaa, now I´ve found something very interesting!!
L3000.gif

 
DT9205A is an multimeter that can also measure capacitors by capacitance (2nf - 200uF/ not sure about up to 2000uF) and measure transistors by hFE.
 
So this little marvelous thing can be just fine for matching those BD139, BD140 and BC550C, BC560C. And the price will only be about $10. You have to pay a LOT more, about $400 for a Fluke, but even soit can not measure hFE!
 
People selling those transistors matched at ebay, will have a lot more payed for them then unmatched.
 
http://www.head-fi.org/t/249447/what-dmm-you-use-to-match-transistors-hfe
 
 
Mikael Markstrom
 
Mar 16, 2014 at 2:36 PM Post #1,133 of 1,624
  Whoaa, now I´ve found something very interesting!!
L3000.gif

 
DT9205A is an multimeter that can also measure capacitors by capacitance (2nf - 200uF/ not sure about up to 2000uF) and measure transistors by hFE.

 
Thank you, i ordered one 2min ago. I own a pretty nice multimeter for capacitors cap., but i was missing the hFE meassure method.

The next clone will be way better, than my first. Maybe the DMM is worth the money, even if it is not super precisely like my 100$ UNI-T device.
 
I think that matched transistors, ressistors and capacitors will deliver more value than "high-end" components. There were some people talking in this thread about the input capacitors and if they are really nessasary because they will allways influence the audio signal. Maybe they are expendable, when there is a optimized circuit. I'm just daydreaming, but the next step would be swapping the nasty OPA for a discrete amp circuit.
 
kind regards
 
Mar 16, 2014 at 6:15 PM Post #1,134 of 1,624
@mikaelmark
Is your offer still valid, you havent replied to my PM yet.. you can conact me via facebook/skype whatever you like
kind regards
 
Mar 29, 2014 at 8:12 AM Post #1,135 of 1,624
Now I´ve contacted the manufacturer CDIL in India, and they can sell 200 pcs BD139-25 and 200 pcs BD140-25. But the shipping cost and bank transfer cost will be quite high. I think those will even be better (higher hFE) than the old Philips/ NXP!
 
I also gonna buy 50 pcs BC550C and 50 pcs BC560C. And I´ve also bought 8 pcs of Intertechnic Audyn True Copper 1,5uF (at least as good as Clarity Cap MR and almost up to Duelund and V-Cap TFTF/ CuTF)
 
As I just also bought hFE -meter, I´m gonna be able to match all of the above 
o2smile.gif

 
So; do someone want any of the above from me? For Lovely Cube, it will use 2 pcs of each.
 
The Audyn True Copper costs about USD 120/ pair.
 
 
Best regards: Mikael Markstrom
 
Mar 29, 2014 at 7:39 PM Post #1,136 of 1,624
You guys with soldering irons make me envious. My standard Lovely Cube, as built by Stephen and Co., is pretty marvelous. I prefer it to my Schiit Lyr with my HD800s. I am arranging to audition the Lehmann Linear and Linear SE, in case anyone is interested in the results... If the clone is this amazing, how will the original sound?
 
Update, FWIW - I heard the Linear and Linear SE, both not much burned-in, up against my Lovely Cube (burned-in). The Linear sounded a bit contained, but pleasant. I preferred the sound of the Lovely Cube with the HD800. The Linear SE sounded nearer to the sound of LC, but took things to another level. I bought it. The sound is superb.
 
Mar 30, 2014 at 5:21 AM Post #1,137 of 1,624
I hav´nt heard the original Lehamann BCL, but the stuff coming with the ebay-clones is not that terrific. But upgrading it is not so difficult and must not be so expensive. For me, I think it will cost about $300-400/ clone - and I´m doing two of them.
 
Stuff I´m using: Audyn True Copper 1,5uF, Mundorf EVO aluminium 2,2uF, FT-1 0,022uF, Styroflex polystyrenes 100pF/ 0,022uF, ST/ CDIL BD139/140-16/25, BC550/560C, , Nover Audio Grade/ Mundorf MLytic 10000uF 35/40V,  Alps RK27 "Blue Velvet", 24 step ladder volume pots, Vishay/ Philips BYV27 rectifier diods, LM317, Fairchild LM337, Wima MKP4 0,15uF, Wima MKP10 0,022uF, PTC, OFC-wires, RCA/ Phono jacks/ plugs, R-Core and other transformer, NE5532 and THS4031/4032 on Brown Dog adapter (should even be better then OPA627).
 
So, as I told in the earlier post; If someone want any of those stuff I´m using, please PM me, as I´ve bought more than I need. 
o2smile.gif

 
The Lehmann Linear SE, with Mundorf caps (M Cap as decoupling caps, it´s jus so so - about the same grade as Wima MKP10 for <$10), better internal wiring cables for the signal etc is a tad better then the standard BCL. Also, the price is about the same as the standard BCL.
 
https://www.lehmannaudio.com/assets/site/home_audio/pre_amps/linear_se/pdf/Lehmann-STEREO-02-2012-ENG.pdf
 
But yes, It should be very interesting to read your experience for the Linear SE to BCL!
 
For myself, I´m using Sennheiser HD600/650/800, Ultimate Ear Triplefi 10 and modded AKGK702. Other amp´s I have is: modded ProJect Headbox II, modded Meier  Corda Swing and Harmony Design Ear 9. Other thing´s I´ve modded is my Arcam CD192 CD-player, Squeezebox 2, Creative X-Fi Elite Pro soundcard, speakers and some DAC´s I´ve built/ modded. (I can sell some of the above, if someone is interested - please PM me!)
 
 
Best regards: Mikael Markstrom
 
Mar 30, 2014 at 7:39 AM Post #1,138 of 1,624
  I hav´nt heard the original Lehamann BCL, but the stuff coming with the ebay-clones is not that terrific. But upgrading it is not so difficult and must not be so expensive. For me, I think it will cost about $300-400/ clone - and I´m doing two of them.
 
Stuff I´m using: Audyn True Copper 1,5uF, Mundorf EVO aluminium 2,2uF, FT-1 0,022uF, Styroflex polystyrenes 100pF/ 0,022uF, ST/ CDIL BD139/140-16/25, BC550/560C, , Nover Audio Grade/ Mundorf MLytic 10000uF 35/40V,  Alps RK27 "Blue Velvet", 24 step ladder volume pots, Vishay/ Philips BYV27 rectifier diods, LM317, Fairchild LM337, Wima MKP4 0,15uF, Wima MKP10 0,022uF, PTC, OFC-wires, RCA/ Phono jacks/ plugs, R-Core and other transformer, NE5532, LM4562 and THS4031/4032 on Brown Dog adapter (should even be better then OPA627).
 
So, as I told in the earlier post; If someone want any of those stuff I´m using, please PM me, as I´ve bought more than I need. 
o2smile.gif

 
The Lehmann Linear SE, with Mundorf caps (M Cap as decoupling caps, it´s jus so so - about the same grade as Wima MKP10 for <$10), better internal wiring cables for the signal etc is a tad better then the standard BCL. Also, the price is about the same as the standard BCL.
 
https://www.lehmannaudio.com/assets/site/home_audio/pre_amps/linear_se/pdf/Lehmann-STEREO-02-2012-ENG.pdf
 
But yes, It should be very interesting to read your experience for the Linear SE to BCL!
 
For myself, I´m using Sennheiser HD600/650/800, Ultimate Ear Triplefi 10 and modded AKGK702. Other amp´s I have is: modded ProJect Headbox II, modded Meier  Corda Swing and Harmony Design Ear 9. Other thing´s I´ve modded is my Arcam CD192 CD-player, Squeezebox 2, Creative X-Fi Elite Pro soundcard, speakers and some DAC´s I´ve built/ modded. (I can sell some of the above, if someone is interested - please PM me!)
 
 
Best regards: Mikael Markstrom

 
Mar 30, 2014 at 1:15 PM Post #1,139 of 1,624
   
And I´ve also bought 8 pcs of Intertechnic Audyn True Copper 1,5uF....
   
The Audyn True Copper costs about USD 120/ pair.

I've paid about 20$ for my Mundorf input capacitors (2,2uf)... but that is insane
popcorn.gif

Looking forward to hear from your results.
 
By the way, i would like to buy a bigger amount of BD140/BD139 transistors from ST MICROELECTRONICS, so are the CDIL / Philips ones so much better?
 
Kind regards
nippon
 
Mar 31, 2014 at 4:02 AM Post #1,140 of 1,624
  I've paid about 20$ for my Mundorf input capacitors (2,2uf)... but that is insane
popcorn.gif

Looking forward to hear from your results.
 
By the way, i would like to buy a bigger amount of BD140/BD139 transistors from ST MICROELECTRONICS, so are the CDIL / Philips ones so much better?
 
Kind regards
nippon


I think you will have difficulties finding genuine Philips transistors.  Most of the one you see on Ebay are fakes from China.  I know first had because I'm living here and see them all the time.
 
I changed capacitors from Wima Mkp 10 to Mundorf ZN capacitors I got on a bargain basement sale.  There was an improvement but I think the power supply is it's weaker point.  The LM317 and LM337 are not the best or quietest regulators available. "They are easy and cheap"  I have a couple of PCB designed by Salas on the diyaudio forumn which are shunt regulators that measure extremely low noise.  I almost have all the parts now.  This will be a lot of work but I think it will make a bigger difference. IMHO!
 

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