Here’s a link to the video introduction to the Kx2-Amp
I’ve put a link in the first post as well.
A quick reminder: the Kx2 is designed to drive efficient speakers (so 92 dB or higher) OR more normal efficiency speakers in smaller spaces. The peak class A power is 28W per channel.
I’ve put a link in the first post as well.
A quick reminder: the Kx2 is designed to drive efficient speakers (so 92 dB or higher) OR more normal efficiency speakers in smaller spaces. The peak class A power is 28W per channel.
...and a very good amp it is too. [Mine is driving a pair of 87Db speakers in a room approx 30'x15-17'x10' and which is acoustically quite dead. Unless attempting to play arena level
rock or full orchestral this amp is just about managing its location. But the imaging and speed of smaller scale Classical and Jazz is so amazing that I am hanging on in from a speedy
decision on changing speakers or amp.....that room is too big - and acoustically dead. I aim using the KX after Bonsai's line pre, and also have the
Phono pre - as yet waiting for my front end problems to be resolved. (I also have a very early version of Bonsai's NX amp which I like a lot) An X-Altra Mini Preamp is used with
these amps.
😀
rock or full orchestral this amp is just about managing its location. But the imaging and speed of smaller scale Classical and Jazz is so amazing that I am hanging on in from a speedy
decision on changing speakers or amp.....that room is too big - and acoustically dead. I aim using the KX after Bonsai's line pre, and also have the
Phono pre - as yet waiting for my front end problems to be resolved. (I also have a very early version of Bonsai's NX amp which I like a lot) An X-Altra Mini Preamp is used with
these amps.
😀
hello,
I am thinking about building one kx2 in 2025. This will be my first amplifier build, but I feel I am able to build it.
Right now, I am trying to estimate what should chassis and transformer I should buy.
From what I read here and there, an audio grade Toroidy, 400 VA and 2 x 22V secondaries would do a nice job, is this correct ?
About the chassis, it seems to be all about heatsink dimensions. I plan to use the amplifier in class A (in winter 😀), so I need 0.3̊ C/Watt per channel heatsink.
At modushop.pl, this leads to 4U chassis : https://www.modushop.pl/radiator-300x165mm-3pd04300.html .
But earlier in the thread, oloppolo says he uses a 3U chassis which heatsinks are rated 0.4°C/W and Bonsai says it's ok.
So, is 0.4 is enough ?
thanks and merry christmas,
Luc
I am thinking about building one kx2 in 2025. This will be my first amplifier build, but I feel I am able to build it.
Right now, I am trying to estimate what should chassis and transformer I should buy.
From what I read here and there, an audio grade Toroidy, 400 VA and 2 x 22V secondaries would do a nice job, is this correct ?
About the chassis, it seems to be all about heatsink dimensions. I plan to use the amplifier in class A (in winter 😀), so I need 0.3̊ C/Watt per channel heatsink.
At modushop.pl, this leads to 4U chassis : https://www.modushop.pl/radiator-300x165mm-3pd04300.html .
But earlier in the thread, oloppolo says he uses a 3U chassis which heatsinks are rated 0.4°C/W and Bonsai says it's ok.
So, is 0.4 is enough ?
thanks and merry christmas,
Luc
Hello Luc
I’m glad you are interested in building the kx2.
1. The Toroidy transformers are good. 300VA will be ample for the kx2
2. For a housing for this amp, a 4U by 250mm deep Mini Dissipante will work well. I have the drilling drawing for this and can send it later this week if you go that route. 0.4C/watt is ok
Any other questions, let me know.
I’m glad you are interested in building the kx2.
1. The Toroidy transformers are good. 300VA will be ample for the kx2
2. For a housing for this amp, a 4U by 250mm deep Mini Dissipante will work well. I have the drilling drawing for this and can send it later this week if you go that route. 0.4C/watt is ok
Any other questions, let me know.
Hello Bonsai
thanks ! I guess you talk about the 3U by 250mm case ? There is no 4U by 250 on their websites.
The drilling drawing will be useful, for sure ! But I am not in hurry at all. I will take the time to try to understand the whole schematic before the build and it will take some time.
Regarding the drilling and taping, I would like to avoid taking the risk to ruin the heat sinks. I never taped holes and everybody seems to agree that this is a hard part in the build.
I see two options : asking Moduloshop to do it for me or drilling (not taping) holes just to screw aluminum bars which I will tap. This solution would be more mistake friendly as I could retry more easily if I fail.
About the heat sink specs : I tried to estimate the value by myself by applying the formula "thermal resistance = (Junction T° - Ambient T°)/dissipated power", but I failed to find the proper values.
How do you calculate this ?
thanks ! I guess you talk about the 3U by 250mm case ? There is no 4U by 250 on their websites.
The drilling drawing will be useful, for sure ! But I am not in hurry at all. I will take the time to try to understand the whole schematic before the build and it will take some time.
Regarding the drilling and taping, I would like to avoid taking the risk to ruin the heat sinks. I never taped holes and everybody seems to agree that this is a hard part in the build.
I see two options : asking Moduloshop to do it for me or drilling (not taping) holes just to screw aluminum bars which I will tap. This solution would be more mistake friendly as I could retry more easily if I fail.
About the heat sink specs : I tried to estimate the value by myself by applying the formula "thermal resistance = (Junction T° - Ambient T°)/dissipated power", but I failed to find the proper values.
How do you calculate this ?
I have added to the first post the Modushop Mini Dissipante 4U x 300mm chassis drillings in fpd format. The drillings will take the sx, nx, kx2 and forthcoming nx2 amplifiers. Any questions, just let me know!
thank you Bonsai for the drilling files and happy new year ! I will come back later with questions 🙂
Hi Andrew,
I have a pair of Amiga's loudspeakers 84dB (Paul Carmody's). Which of your amp projects would you suggest to drive them?
Hi, the kx2 is designed for driving high efficiency speakers in normal listening spaces, or more normal efficiency ones (like the ones you mention) in small spaces. To play it safe, I’d suggest you build an nx-Amp. I have a new nx2 coming in the next few months if you are ok to wait.