I got a built clone that was purchased from AliceMagicBox called the Lovely Cube Premium. I've replaced the opamp with a Burson V5 and it made a noticeable difference, much like changing tubes in a preamp.
My unit is dead silent with HD525 (150 ohm), and some other full sized headphones I've tried. Sound is very nice, to my ears it is natural sounding and the mids is very sweet. Tested out with an AK240 with HD650 in a meet about a year plus ago and the sound was quite remarkable. Definitely scales up well with better sources.
If your builds has buzzes, hums, or other problems then its probably PEBCAK.
Matrix M-Stage amps had originally used the Lehmann topology as well but as they've progressed they've made improvements to it. Newer models now come with several options such as balanced input+outputs, selectable sources, and built in DACs. However the basic topology still remains.
One thing I noticed different between the Matrix unit and the Lehmann clone is the PSU section has 2 trimpots instead of the usual 1. I assume this is because the Matrix allows their builders to use less matched parts so they can adjust both +ve and -ve rails independently, while the Lehmann clone only has 1 so parts selection/matching is more stringent as you can only adjust one rail to match the other fixed output rail. Mine however has no trimpot, which I assume the designer of the clone had sourced matched parts for the power section.
These are the internal pictures of my amp. As far as I'm aware of it is accurate to the Lehmann Black Cube. Also note that it doesn't have the Burson V5 opamp, this is an old photo set.
One thing for sure is I do agree this is a relatively simple amp to build and beginners could try building one as a starter amp. Either this or the clone Beyerdynamic A20.
My unit now has more of a preamp duty as compared to headphone duty, it is paired with my Naim NAP200 power amp clone. The sound is ok, still neutral and sweet, but compared to a NAC52 clone my friend brought over the NAC sounds a lot better with better dynamics and wonderful tone. Just all around better to listen to.
My unit is dead silent with HD525 (150 ohm), and some other full sized headphones I've tried. Sound is very nice, to my ears it is natural sounding and the mids is very sweet. Tested out with an AK240 with HD650 in a meet about a year plus ago and the sound was quite remarkable. Definitely scales up well with better sources.
If your builds has buzzes, hums, or other problems then its probably PEBCAK.
Matrix M-Stage amps had originally used the Lehmann topology as well but as they've progressed they've made improvements to it. Newer models now come with several options such as balanced input+outputs, selectable sources, and built in DACs. However the basic topology still remains.
One thing I noticed different between the Matrix unit and the Lehmann clone is the PSU section has 2 trimpots instead of the usual 1. I assume this is because the Matrix allows their builders to use less matched parts so they can adjust both +ve and -ve rails independently, while the Lehmann clone only has 1 so parts selection/matching is more stringent as you can only adjust one rail to match the other fixed output rail. Mine however has no trimpot, which I assume the designer of the clone had sourced matched parts for the power section.
These are the internal pictures of my amp. As far as I'm aware of it is accurate to the Lehmann Black Cube. Also note that it doesn't have the Burson V5 opamp, this is an old photo set.
One thing for sure is I do agree this is a relatively simple amp to build and beginners could try building one as a starter amp. Either this or the clone Beyerdynamic A20.
My unit now has more of a preamp duty as compared to headphone duty, it is paired with my Naim NAP200 power amp clone. The sound is ok, still neutral and sweet, but compared to a NAC52 clone my friend brought over the NAC sounds a lot better with better dynamics and wonderful tone. Just all around better to listen to.
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Congratulations on your dead silent clone build.
Even though it's blue in color, that's still a different(more recent or updated)board than I used for my build.
The original Lehmann used Wima caps, not the blue Arcotronics and Siemens caps I see in your example.
I'm also surprised that you didn't opt for 1% 10 ohm emitter resistors instead of 5%.
Still a very nice build.
I give up...what is PEBCAK??
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Congratulations on your dead silent clone build.
Even though it's blue in color, that's still a different(more recent or updated)board than I used for my build.
I give up...what is PEBCAK??
I don't think its recent at all. I believe this was made before the eBay kits had flooded the DIY marketplace. Compared side by side it is identical with the insides of the Lehmann BCL except the opamp isn't soldered in.
PEBCAK is
Problem
Exists
Between
Chair
And
Keyboard
(user problem and not the hardware/software
)I think you'll be EXTREMELY lucky if it works after all the time and parts cost you'll have invested.
Better cross your fingers and toes on this one.
No, the clone he built is an older model. He did suggest me to build the newer one that you've linked there.
It's worth the investment, trust me. It pays to choose your other components well too. Mine was already built from here: Lovely Cube Headamp
So they had already chosen the parts well.
Burson already came out with the V6. Or if you feel they're out of your price range still, the V5i is slightly cheaper but in a smaller non-discrete case.
Supreme Sound Opamp V5i – Burson Audio
thanks for the link, gonna take a look,
yeah i already checked the v6- v5i , i m sure they worse the investment but i ll wait till i come a cross a circuit worthy of the upgrade, and maybe i win the lottery till then , lol.
for now i got a Ehna clone board, if i like the sound maybe i try it on that in future.
yeah i already checked the v6- v5i , i m sure they worse the investment but i ll wait till i come a cross a circuit worthy of the upgrade, and maybe i win the lottery till then , lol.
for now i got a Ehna clone board, if i like the sound maybe i try it on that in future.
huh, found some chinese version :
L.K.S Audio Pure Class A Discrete Op Amp
Differential Symmetry Complement Discrete Single OP AMP Class A
Full Discrete Dual Op
L.K.S Audio Pure Class A Discrete Op Amp
Differential Symmetry Complement Discrete Single OP AMP Class A
Full Discrete Dual Op
PEBCAK is
Problem
Exists
Between
Chair
And
Keyboard
(user problem and not the hardware/software
That's really cute and is probably the dumbest use of abbreviated words I've come across before on this site.
Wait...don't tell me...that's a penmarker "original".
I can assure you there's no "user problem" on my end as I've built a total of 2 of these Lehmann clones and they both had hum when the volume was reduced to zero even with only 6dB of gain.
Personally, I wouldn't encourage people to waste their money on any Burson discrete op-amp in hopes that it'll do miracles for the average sound of these Lehmann clones.
When it comes to discrete op-amps and having listened to both personally, the Sparko Labs will easily mop the floor with the Bursons.
Discrete Op Amps - SparkoS Labs Inc.
Combining a dual op-amp(the first achilles heel of these clones) with a discrete diamond buffer and powering it all by cheap and outdated LM3xx regulators is certainly nothing new nor outstanding in terms of sound quality. If this design were so great, more and more commercial manufacturers and DIYers would be using it.
The only reason it's popular is because of the Chinese offering everything in a kit for only $20.
I have plenty of both op-amp and discrete buffer/preamp circuits that I power with the Jung/Didden Super Regulators that are as you call it "dead silent", not to mention how much improved the sound quality is compared the old LM3xx regulators.
What is PEBCAK? Webopedia DefinitionThat's really cute and is probably the dumbest use of abbreviated words I've come across before on this site.
Wait...don't tell me...that's a penmarker "original".
I can assure you there's no "user problem" on my end as I've built a total of 2 of these Lehmann clones and they both had hum when the volume was reduced to zero even with only 6dB of gain.
Send me your mailing address and I'll send my unit to you for testing if you pay the shipping both ways.
I still have the opamp it came with. I've never measured it with the Burson, but so far its been ok on both my Senn HD525 headphones and Rockjaw Kommand IEMs. Some other portable headphones work ok as well.
What kind of danger are we talking here? DC into headphones?
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Lehmann clones are popular and many users are using them with no hum at all.
PS section with LM is not really up to today's standards, but for sure it is not a reason why one can hear hum from these boards.
From four different Chinese boards I had accounted and built these clones, two had problems with hum. Even though parts placement is almost identical, actual PCB detailed design is different - these are dual layers, and on some of these boards bottom and up layers are badly aligned and some ground loops are introduced.
So to avoid hum with Chinese clones of Lehman amp the actual quality of PCB board is important, so choose the right one.
Which one? Don't know, old auctions are gone, new versions appears ...
PS section with LM is not really up to today's standards, but for sure it is not a reason why one can hear hum from these boards.
From four different Chinese boards I had accounted and built these clones, two had problems with hum. Even though parts placement is almost identical, actual PCB detailed design is different - these are dual layers, and on some of these boards bottom and up layers are badly aligned and some ground loops are introduced.
So to avoid hum with Chinese clones of Lehman amp the actual quality of PCB board is important, so choose the right one.
Which one? Don't know, old auctions are gone, new versions appears ...
If that's the case then I'll have to apologize, bad boards are abundant it seems. I'd suggest getting them from the link I posted above. AliceMagicBox made great copies with similar parts to the original. From there on buyers can just swap out with other parts they think could be better.
Back then they sold the kits but from what I see now only finished units.
Back then they sold the kits but from what I see now only finished units.
Thank you for the kind offer penmarker, but personally I wouldn't p_$$ away good, hard-earned money on shipping your above average built Lehmann clone to and from me just to clarify your point of "dead silence".
I'm 100% sure that as soon as I turn on my plasma display along with my EPB fiber optics receiver, they'll be so much hum and other garbage amplified by even your Lehmann build so as to make things unlistenable at lower volume levels.
I don't believe that for one minute having personally built 2 examples that both exhibited hum at lower volume levels.
That's not really much help for newbies who want to build one of these mediocre sounding diamond buffer designs.
. i dont wanna argue with you but just fyi my other lehmann clone works absolutely dead quiet too, no audible hum/noise.
By now we've established that there are bad boards and good boards. I apologize if you take offend with the 'PEBCAK' remark, however there were a lot of problems with amps by experienced builders caused by simple build errors. There is no shame in backtracking and finding out small errors.
My point still remains, the amp topology is silent - as it should be. The build is not "above average", this should be the standard quality of a build. You should know by now that proper components = standard build. I did not use expensive gold foil caps, nuvotem trannys, or expensive 'lytics. All are bog standard proper parts.
To be perfectly honest, even though I've tried a lot of amps I've only had owned this one. I'm currently building a Dynahi since they've updated the board with available non obsolete parts. Once its done I believe it will sound better than the Lehmann clone, I will be disappointed if it didn't because of the parts cost alone.