Nice build. The mounting plate (s) caught my eye. Could you share some more pictures?
That is luscious!!! I'm sure it sounds great, but I also love the way it looks.
smd version of high quality MM phono preamp https://www.patreon.com/posts/nabiraem-po-su-v-72330414 and https://www.diyaudio.com/community/threads/nick-sukhov-su-xxi-mm-phono-stage-85-dba-sn-ratio.387375/
Showing a high-end headphone amplifier I designed. I am planning to release this as a DIY project on the forum in the next few months. That will include a full schematic, BOM, gerber files for PCBs, CAD files for a chassis, build instructions, measurements, etc. This is an expensive project, probably the cost of parts is something like $1.5K given it makes heavy use of Lundahl inductors and a high-quality chassis, but the sound is excellent (in my opinion) and it is very easy to build for someone with a little experience. I can build this amplifier from scratch in 6 hours. There will likely be some forthcoming reviews by some dudes on Head-Fi forum, the first one is on a road trip for demoing purposes. The amplifier was recently featured at the ZMF Headphones table at CanJam SoCal, feedback was very positive.
Here is a general schematic.
Input stage is choke loaded parallel-section 6SL7, cathode biased with Jupiter Cosmos bypass caps. Input stage is capacitor-coupled via Jupiter copper foil film caps to a triode-strapped pentode output stage. The output stage is a transformer-coupled cathode follower, biasing is done by the DCR of the OPT primary winding and some added series resistance. There is no bypass capacitance required in the output stage, which results in excellent clarity, staging, airiness, and dynamics. All voltage gain is done by the choke-loaded 6SL7, it swings over 300Vpk-pk. Each output tube has its own heater winding referenced to its cathode to avoid violating Vhk at peak output swing. Potentiometer cannot exceed 25K given the high Cmiller of the parallel 6SL7. The power supply is a split rail CLCRCRC, it is tube rectified, no semiconductors in this build.
Input tube is mandatory 6SL7 pair
Rectifier are 5V / 2A types - 5AR4, 5V4, 5R4, 5Y3 (although care must be taken with 5Y3 not to overspec DC current)
Output tube are various power pentodes - EL34, KT77, KT88, 6550, 6V6, 6L6, EL37, and many more.
Distortion is very low at normal listening volumes, bandwidth is down < 1dB at 20Hz and 20kHz. There is an ELMA output switch to change for high Z (150ohms and up) and low Z (32-150ohms) headphones. Output impedance on the high Z setting with EL34 outputs is ~17ohms. Output Z on the low Z setting with EL34 outputs is ~5ohms. Output power is around 2W into 32ohms on low Z, 2W into 150ohms on high Z. I will post real measurements when the thread is made.
Pictures of the completed amplifier.
The circuit.
Think people will be interested in building my headphone amplifier? We will see!
Here is a general schematic.
Input stage is choke loaded parallel-section 6SL7, cathode biased with Jupiter Cosmos bypass caps. Input stage is capacitor-coupled via Jupiter copper foil film caps to a triode-strapped pentode output stage. The output stage is a transformer-coupled cathode follower, biasing is done by the DCR of the OPT primary winding and some added series resistance. There is no bypass capacitance required in the output stage, which results in excellent clarity, staging, airiness, and dynamics. All voltage gain is done by the choke-loaded 6SL7, it swings over 300Vpk-pk. Each output tube has its own heater winding referenced to its cathode to avoid violating Vhk at peak output swing. Potentiometer cannot exceed 25K given the high Cmiller of the parallel 6SL7. The power supply is a split rail CLCRCRC, it is tube rectified, no semiconductors in this build.
Input tube is mandatory 6SL7 pair
Rectifier are 5V / 2A types - 5AR4, 5V4, 5R4, 5Y3 (although care must be taken with 5Y3 not to overspec DC current)
Output tube are various power pentodes - EL34, KT77, KT88, 6550, 6V6, 6L6, EL37, and many more.
Distortion is very low at normal listening volumes, bandwidth is down < 1dB at 20Hz and 20kHz. There is an ELMA output switch to change for high Z (150ohms and up) and low Z (32-150ohms) headphones. Output impedance on the high Z setting with EL34 outputs is ~17ohms. Output Z on the low Z setting with EL34 outputs is ~5ohms. Output power is around 2W into 32ohms on low Z, 2W into 150ohms on high Z. I will post real measurements when the thread is made.
Pictures of the completed amplifier.
The circuit.
Think people will be interested in building my headphone amplifier? We will see!
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I'll also add, and maybe I should have said this from the get go, that this is not targeted toward super experienced DIYers. This is a simple circuit, obviously, and a high priority was placed on the ease of being able to build it and with little risk of parts failure. It is meant to be buildable by someone with little-to-no DIY experience. And I am not making money, I am going to post it all for free.
Sorry Ian, I will consult you next time before posting to ensure I am using the correct nomenclature.
All I was doing was asking for clarification. I see the term high end used all the time as if it has some specific meaning but it appears it just means high cost.
Cheers
Ian
I used what I felt were high quality parts in this build and I consider that an attribute of an audio component being categorized as high end. I paid more to use high quality parts, so by default it is also high cost. Of course what qualifies as a high quality part is open to debate.
It IS a very nice job with (as far as I can correctly interpret those pictures) quality components.
For me, high end means also very good measuring characteristics of the design. And these did not accompany the pictures.
But I am feeling a bit unpleasant with the content Ian's first response. Was that really necessary?
For me, high end means also very good measuring characteristics of the design. And these did not accompany the pictures.
But I am feeling a bit unpleasant with the content Ian's first response. Was that really necessary?
It is not clear to me how you see quality just by LOOKing. Quality is not a thing it is a property of something.
I don't. I can see a lot of expensive components. ELMA switches for instance - we used those at Neve in recording consoles back in the 70s and they were chosen for their demonstrable reliability in an 24/7 operational situation. In fact most of the components and controls were chosen principally for their quality of reliability.
No doubt about that