Being one of the best sounding headphone amp in the world, Lehmann BLC is a pricy unit (about 860 € new). I owned this amp back in 2015. and sold it 2 yrs later. I regret this decision, so decided to build myself a new one, with original components, not this cheap Lovely Cube rubbish.
It took me about a year to build it, and it turned out this DIY journey wasn't cheap at all. Looking for original components took some time, and when shipping was added to price, the price raised to level of used original Lehmann BCL :(
But it looks nice, and sounds like original:
Few words and pictures about building process. The bare PCB was ordered form ebay. This one has 4x normal copper thickness (which can't be bad :). All other parts was ordered strictly original: Vishay/BC components caps, Phillips and Fairchild transistors, Nippon Chemi, Wima and Epcos caps, precision metal film resistors, Burr Brown OPA2134 op-apm. For example only Alps potentiometer cost 15 €:
My addition here is relay switch. When power if OFF input signal is directed to other pair of RCA connectors. When power is turned ON small signal relays redirect input signal into the amplifier, leaving other pair of RCA's floating. I found this very practical for switching between headphones and power amplifier which drives speakers:
This small additional BCBs are fully made on CNC ruter. I'm attaching manufacturing files for it at the end of post:
Since aluminium enclosure is closed only on bottom, mounting everything inside was a bit challenging. All holes must be drilled precisely, for which I used templates.
The enclosure is connected to mains ground, as well as amplifiers ground (not directly but via cap+resistor). Hums due to noise pichup and ground loops are in this way eliminated.
All in all it's a beautifully looking and sounding amp.
Schematics, drawings, Eagle CAD and CAM files can be found here.
It took me about a year to build it, and it turned out this DIY journey wasn't cheap at all. Looking for original components took some time, and when shipping was added to price, the price raised to level of used original Lehmann BCL :(
But it looks nice, and sounds like original:
Few words and pictures about building process. The bare PCB was ordered form ebay. This one has 4x normal copper thickness (which can't be bad :). All other parts was ordered strictly original: Vishay/BC components caps, Phillips and Fairchild transistors, Nippon Chemi, Wima and Epcos caps, precision metal film resistors, Burr Brown OPA2134 op-apm. For example only Alps potentiometer cost 15 €:
My addition here is relay switch. When power if OFF input signal is directed to other pair of RCA connectors. When power is turned ON small signal relays redirect input signal into the amplifier, leaving other pair of RCA's floating. I found this very practical for switching between headphones and power amplifier which drives speakers:
All in all it's a beautifully looking and sounding amp.
Schematics, drawings, Eagle CAD and CAM files can be found here.
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