After some months working quite hard on them (specially for the metal hardware), my Aleph X's are both up and running.
Voltage at the fets: Between 17.5v and 18v
bias: 7,2A
AC Gain: 54%
Number of fets: 8
The DC offset between the outputs is between 18 and 25 mV and the absolute DC offset 350mV after two hours of use. The temperature is fine: after two hours, I still can touch them with the hands without problems.
The sound is really amazing. They are driving a pair of B&W 803 and the preamp is an Aleph P1.7
Xavier
Voltage at the fets: Between 17.5v and 18v
bias: 7,2A
AC Gain: 54%
Number of fets: 8
The DC offset between the outputs is between 18 and 25 mV and the absolute DC offset 350mV after two hours of use. The temperature is fine: after two hours, I still can touch them with the hands without problems.
The sound is really amazing. They are driving a pair of B&W 803 and the preamp is an Aleph P1.7
Xavier
Attachments
I bought them in a local hardware store. They are supposed to be use for making glass tables or shelves.
The width of the square tubes is 25mm and you can get the tubes cut at any lenght. They have several different edge connectors (3 or 4), feets, etc.
The structure can be mounted without any screw.
The width of the square tubes is 25mm and you can get the tubes cut at any lenght. They have several different edge connectors (3 or 4), feets, etc.
The structure can be mounted without any screw.
Hi!
i noticed that you used mills resistors...isn't it?
Another thing.....on your picture i can see just a part of your loudspeakers...are your speakers B&W?! they really look like!
I don't know if oyu gave the necessary time to the amp to burn in all the new components.....how does it sound like so far?
What stereo parts do you have?...cables...source....speakers....?
Best,
Stefano.
i noticed that you used mills resistors...isn't it?
Another thing.....on your picture i can see just a part of your loudspeakers...are your speakers B&W?! they really look like!
I don't know if oyu gave the necessary time to the amp to burn in all the new components.....how does it sound like so far?
What stereo parts do you have?...cables...source....speakers....?
Best,
Stefano.
Bravo Xavier.
with 18 V rail voltage Which is the maximum voltage swing at +- ouput connector on your aleph-x before (voltage) clipping?
Wichi value of McMillian resistor have you use?(4.7k?)
Thanks Paolo
x Beppe: about the pcb http://www.diyaudio.com/wiki/index.php?page=Aleph-X+Compact+PCB
Ciao Paolo
with 18 V rail voltage Which is the maximum voltage swing at +- ouput connector on your aleph-x before (voltage) clipping?
Wichi value of McMillian resistor have you use?(4.7k?)
Thanks Paolo
x Beppe: about the pcb http://www.diyaudio.com/wiki/index.php?page=Aleph-X+Compact+PCB
Ciao Paolo
sinuko said:
Grazie Mille, Paolo!
Mmmmm.... the GB was 2 years old
at that time I did know nothing about Mr. Pass and this forum! Stefanoo said:
Yep Stefano, in Italy we like the beautiful things!
The Pass projects are a very elegant way to approach audio electronics! How do not love them?!
Nice to meet on this forum
Thank you guys! And, specially thanks to Grey and Nelson. It is a great design!
Let me try to answer some of your comments and give some more details:
The heatsinks are Fischer SK157 0,22ºC/W. Their size is 300x200x83mm.
The PCBs come from Carondimonio. Sinosuko is right, that link points the GB that I joined quite late.
Regarding the psu, I am using one transformer Amplimo 2x15v 625VA for each channel. CRC for filtering, using 4 100mF capacitors, i.e. a total of 400mF per channel.
I am using 8 IRFP044 per channel and the value for the source resistors is 0.27R (yes, they are Mills). The McMillan resistors are 4.75k, R1/R45 68R and I am not using caps at the input.
Regarding clipping, this measurement is still pending. However, I would say that the voltage at the fets is not as high as 18v, is more between 17.6 and 17.7v.
My initial impression on the sound is very positive. The sound is really good. Bass is tight and controlled, the midrange is sweet and extremely transparent. The highs are a little brighter than my tube amplifier but less than commercial transistor amplifiers.
Xavier
Let me try to answer some of your comments and give some more details:
The heatsinks are Fischer SK157 0,22ºC/W. Their size is 300x200x83mm.
The PCBs come from Carondimonio. Sinosuko is right, that link points the GB that I joined quite late.
Regarding the psu, I am using one transformer Amplimo 2x15v 625VA for each channel. CRC for filtering, using 4 100mF capacitors, i.e. a total of 400mF per channel.
I am using 8 IRFP044 per channel and the value for the source resistors is 0.27R (yes, they are Mills). The McMillan resistors are 4.75k, R1/R45 68R and I am not using caps at the input.
Regarding clipping, this measurement is still pending. However, I would say that the voltage at the fets is not as high as 18v, is more between 17.6 and 17.7v.
My initial impression on the sound is very positive. The sound is really good. Bass is tight and controlled, the midrange is sweet and extremely transparent. The highs are a little brighter than my tube amplifier but less than commercial transistor amplifiers.
Xavier
Great work! It is good to see more people complete the Aleph-x sucessfully
What type of tube amplifier are you comparing it to?
Does the absolute DC offset stay fairly steady at 350mV? or does it drift slightly?
Also, can you notice any hum at your speakers? I am going through final tweaks on my pair and have a faint hum at the speaker still, however I still plan to eliminate it completely (and post some pictures) when I get some free time. It is definatley a slow process
Jeff
What type of tube amplifier are you comparing it to?
Does the absolute DC offset stay fairly steady at 350mV? or does it drift slightly?
Also, can you notice any hum at your speakers? I am going through final tweaks on my pair and have a faint hum at the speaker still, however I still plan to eliminate it completely (and post some pictures) when I get some free time. It is definatley a slow process
Jeff
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