There was a question about the mother board :
Interest for XEN Headphone Amplifier Motherboard
https://www.diyaudio.com/forums/att...phone-amplifier-motherboard-xen-hpa-mb-v2-png
https://www.diyaudio.com/forums/att...conductance-amplifier-180715-sl-trans-top-jpg
The original GB was for 2mm boards, 35µm with blue resist.
They are unaffordable now because of all the surcharges.
If (all of) you must have (min. 5), we can offer them for 20€ in 1.6mm thickness, 35µm, blue resist.
It will be extra work for us, because they need to be shipped in a box to avoid damage.
And then postage is likely to go up also.
My suggestion is to build as is first, listen, and then decide whether you still want a dual-mono build.
Patrick
Interest for XEN Headphone Amplifier Motherboard
https://www.diyaudio.com/forums/att...phone-amplifier-motherboard-xen-hpa-mb-v2-png
https://www.diyaudio.com/forums/att...conductance-amplifier-180715-sl-trans-top-jpg
The original GB was for 2mm boards, 35µm with blue resist.
They are unaffordable now because of all the surcharges.
If (all of) you must have (min. 5), we can offer them for 20€ in 1.6mm thickness, 35µm, blue resist.
It will be extra work for us, because they need to be shipped in a box to avoid damage.
And then postage is likely to go up also.
My suggestion is to build as is first, listen, and then decide whether you still want a dual-mono build.
Patrick
I know, some stuff relevant to the XELF crosses over into this thread.
Just interested in XELF (to start with)
A quick update.
We have got all your contact info.
Still waiting for PCBs.
Once they are ready, one of us will contact you to ask for payment.
We'll then ship to you by air mail with tracking.
We ship FOB at our cost, and are not responsible for any posting losses.
If you wish to have extra insurance, we'll have to pass on the extra charge to you.
The PCBs will most likely be shipped from the EU.
You'll get documentation by email after you confirm here that the PCBs have arrived.
Thanks for the patience,
Patrick
We have got all your contact info.
Still waiting for PCBs.
Once they are ready, one of us will contact you to ask for payment.
We'll then ship to you by air mail with tracking.
We ship FOB at our cost, and are not responsible for any posting losses.
If you wish to have extra insurance, we'll have to pass on the extra charge to you.
The PCBs will most likely be shipped from the EU.
You'll get documentation by email after you confirm here that the PCBs have arrived.
Thanks for the patience,
Patrick
Another UTHAiM is making music and finally finished.
It has been playing music for quite a while, but finishing the build took much longer than anticipated...
partly due to the restrictions that came with the pandemic, partly due to looking for other things.
The build kind of inverts the usual idea of a case with having the heatsinks inboard, forming a nice heat chimney
and separating the case in two channels. It has the recommended psu with even more capacitance and custom
wound toroids with a piggy back arrangement of the rectifier boards.
The amplifier boards are biased a bit higher and are fed by about +- 21V.
As can be seen the case is a real heavyweight with a custom made front and two additional sides made from
hardwood like modelling foam.
Signal routing is as short as possible on the input side and goes to the LEMO connector down the middle of the
chimney. The amplifier is as quiet as it can get.
It has been playing music for quite a while, but finishing the build took much longer than anticipated...
partly due to the restrictions that came with the pandemic, partly due to looking for other things.
The build kind of inverts the usual idea of a case with having the heatsinks inboard, forming a nice heat chimney
and separating the case in two channels. It has the recommended psu with even more capacitance and custom
wound toroids with a piggy back arrangement of the rectifier boards.
The amplifier boards are biased a bit higher and are fed by about +- 21V.
As can be seen the case is a real heavyweight with a custom made front and two additional sides made from
hardwood like modelling foam.
Signal routing is as short as possible on the input side and goes to the LEMO connector down the middle of the
chimney. The amplifier is as quiet as it can get.
Attachments
Gosh! Stixx is the king!
Mine builds will never look like this.
It is interesting to see Stixx'es internal sink size!
Mine has also an internal one but much smaller. I use BJT current mirrors, hence I decided to use 4V lower voltage, which results in some <2W per channel lower dissipation, but a longer listening session proves to be hot.
Mine builds will never look like this.
It is interesting to see Stixx'es internal sink size!
Mine has also an internal one but much smaller. I use BJT current mirrors, hence I decided to use 4V lower voltage, which results in some <2W per channel lower dissipation, but a longer listening session proves to be hot.
Most top-of-the-line over-ear headphones are specified for 200mW max.
At 32ohm, this will mean approximately 125mA current consumption.
Even for a non-push-pull amp, 200mA bias is more than sufficient.
With 24V rails, this means 10W dissipation per channel.
Assume a heatsink temperature of 25°C above ambient, a heatsink of < 2.5°C/W would meet the requirements.
An example is Fischer SK42 :
https://www.fischerelektronik.de/web_fischer/en_GB/heatsinks/A01/Standard%20extruded%20heatsinks/$catalogue/fischerData/PG/SK42/search.xhtml
For a single heatsink accommodating both channels, take a look at Fischer 502 :
https://www.fischerelektronik.de/web_fischer/en_GB/heatsinks/A01/Standard%20extruded%20heatsinks/$catalogue/fischerData/PG/SK502/search.xhtml
Cheers,
Patrick
At 32ohm, this will mean approximately 125mA current consumption.
Even for a non-push-pull amp, 200mA bias is more than sufficient.
With 24V rails, this means 10W dissipation per channel.
Assume a heatsink temperature of 25°C above ambient, a heatsink of < 2.5°C/W would meet the requirements.
An example is Fischer SK42 :
https://www.fischerelektronik.de/web_fischer/en_GB/heatsinks/A01/Standard%20extruded%20heatsinks/$catalogue/fischerData/PG/SK42/search.xhtml
For a single heatsink accommodating both channels, take a look at Fischer 502 :
https://www.fischerelektronik.de/web_fischer/en_GB/heatsinks/A01/Standard%20extruded%20heatsinks/$catalogue/fischerData/PG/SK502/search.xhtml
Cheers,
Patrick