Wow! That is a very professional and good looking board! Mind to share some more with us? Is it an all ground-plane design?
I like the aluminum bars, which make you able to lay the board flat on the panel
With kind regards,
Bas
Hi Bas,
Thankyou. I had posted about these amps back in 2008 when I was in the process of finishing them.
A friend of mine did all of the CAD work while I did the mechanical planning. They do not have a ground plane but rather the Negative supply covers alot of the bottom while the positive supply covers a lot of the top. Where possible it has grounding of course. A few local friends helped me out with the machine work.
The red board is a swappable active crossover. I have two versions, a 12db\octave and a 24db\octave. Both are linkwitz-riley type.
The servos are nice, I wish I had used one on the single LM3886 as well to keep offset low.
The one thing I do kind of wish I did differently was I used X7R ceramics for my input coupling caps. I've never noticed a problem but I know there could be one under certain conditions. I suppose if it really bothers me, at one point I could just jumper the pads and use an inline film cap. Luckily I used C0G type ceramics in the crossover and everything else is DC coupled so the input coupling cap is the only problem child.
If you want to know more, please feel free to contact me via PM.
Thankyou. I had posted about these amps back in 2008 when I was in the process of finishing them.
A friend of mine did all of the CAD work while I did the mechanical planning. They do not have a ground plane but rather the Negative supply covers alot of the bottom while the positive supply covers a lot of the top. Where possible it has grounding of course. A few local friends helped me out with the machine work.
The red board is a swappable active crossover. I have two versions, a 12db\octave and a 24db\octave. Both are linkwitz-riley type.
The servos are nice, I wish I had used one on the single LM3886 as well to keep offset low.
The one thing I do kind of wish I did differently was I used X7R ceramics for my input coupling caps. I've never noticed a problem but I know there could be one under certain conditions. I suppose if it really bothers me, at one point I could just jumper the pads and use an inline film cap. Luckily I used C0G type ceramics in the crossover and everything else is DC coupled so the input coupling cap is the only problem child.
If you want to know more, please feel free to contact me via PM.
12db/octave crossover.
first power up. nothing burnt up I was happy The amp boards have spots for RCA jacks for both the single lm3886 and the BPA200 section so they can be used without a crossover.
original powered advent amplifier. this is what I replaced. It was 80W x2.
250W worth of biamped LM3886 power
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
first power up. nothing burnt up I was happy
The amp boards have spots for RCA jacks for both the single lm3886 and the BPA200 section so they can be used without a crossover.An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
original powered advent amplifier. this is what I replaced. It was 80W x2.
An externally hosted image should be here but it was not working when we last tested it.
250W worth of biamped LM3886 power
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
Thanks a lot for sharing. Amazing project, you must be very proud and happy!
My below remarks are of course subjective, but just to share.
1: Why not considering to use DC servo's at the input stage of the crossovers? I know forum member Infinia won't be agree with me, since he hate servo's
but in my active speaker project we did test with multiple people between different capacitors, no capacitor and DC servo's. Eventually we went with the DC servo. The conclusion was, that any type of capacitor degraded the performance, the difference between no cap's and DC servo's on the outputs of the crossover was inaudible.2: I would suggest to use SMD film caps in your crossover instead of ceramics. Makes a world of difference in sound quality.
With kind regards,
Bas
Last edited:
HI Bas,
With all due respect, I doubt SMD film caps would outperform 5% C0G ceramics. C0G ceramics are very stable capacitors that produce very little distortion and work very very well in filters. They also are very reliable and long lasting. These caps will probably still test within spec 50 years from now. Unfortunately I won't
In regards to the DC servos at the input of the crossover I was very new to this at the time and didn't think of that perhaps on the next project.
With all due respect, I doubt SMD film caps would outperform 5% C0G ceramics. C0G ceramics are very stable capacitors that produce very little distortion and work very very well in filters. They also are very reliable and long lasting. These caps will probably still test within spec 50 years from now. Unfortunately I won't
In regards to the DC servos at the input of the crossover I was very new to this at the time and didn't think of that
perhaps on the next project.
Last edited:
HI Bas,
With all due respect, I doubt SMD film caps would outperform 5% C0G ceramics. C0G ceramics are very stable capacitors that produce very little distortion and work very very well in filters. They also are very reliable and long lasting. These caps will probably still test within spec 50 years from now. Unfortunately I won't
In regards to the DC servos at the input of the crossover I was very new to this at the time and didn't think of that
Dear Tube,
It is very subjective and nothing technical related. Heck I never performed any measurements on Ceramics Vs. Film
. It was just when I started to listen to active crossover, and played with different capacitors, I preferred the sound of Film caps. With kind regards,
Bas
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.