Thanks for the feedback. Your scope screenshots of the squarewave looked pretty good - there was overshoot? Did not look that visible from what I saw. Anyhow, glad you have time to listen to them. What speakers are they driving?
It really fits on 2 inches square? Amazing...
Didn't Mr. Mile suggest you could set the bias at only 70mA?
Have you tried it at that level?
If I can leave the heatsink(s) off the BD139/140, that would simplify the build even more.
Tomorrow I will unbolt the VAS heatsink and see how hot they get.
The overshoot is no big deal. It just looks like a high pass tone control is added. The highs and mids are sweet and the bass is to die for. I have been a VSSA fan but I think I like this one better.
I fit both channels on a 2-3/4" x 4" board and that includes the area beneath the outputs.
It sounds just fine on 70mA. I actually set it at 70mA with +-36V rails. Then I bumped it up to +-42V rails because someone had asked about higher rails. That raised the current to 100mA. Even at that they are fine on the smallish heatsink I have clamped to it. That heatsink is only 8" x 1-3/4" with 1-1/2" fins. Handles it fine.
Today I was listening to it through my test speakers which are JBL 4311.
Attachments
Hi
I'm unable to open any of your attached file for some reason.
I have WinRAR 64bite version..
Does anyone has the same issue?
Thanks 🙂
Greetings
zipped and in excel 97-2003 for the ods file as posted by Ben. hope this solves all problems🙂. better to open it with default winzip!
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Hi
I could open these one
I would love to get your layout, silkscreen
Are U using Sprint because I own that and I can open Sprint files to
To be honest I'm confused usually I'm able to open the layout and silkscreen from zipped to. Is these your layout, I mean your design?
First time I got these problem
Thank you any way
Greetings
STMicroelectronics.
I used to use Onsemi but I ran out. These have about the same hFe and seem to give the same results.
Thank you for the reply, Terry.
I bet you go through quite a bit of solder looking at the bottom of your board.🙂
I'm going to have some boards manufactured using the earlier Sprint file you posted where the 139/140s are at the rear of the board, instead of near the middle like on the board you've shown here.
Things are a little too crowded for my liking on the 5cm x 5cm boards someone posted, so I'll stick with my 55mm x 62mm boards.
If you are using that layout then the VAS is not an issue because you can just attach the to the main heatsink since they are all in line with each other.
Hi,
Layout of 50mmx50mm size is done by Sonal Kunal and he has posted sprint file in http://www.diyaudio.com/forums/soli...imate-fidelity-amplifier-649.html#post4635579 no. 6484 (only correction in decoupling cap orientation[ 2 nos. of 47uF to be reversed] on positive rail, other than that, its been tested by Terry-no problems). I only posted gerbers as it was requested by a member.
Hope its clear now.
reg
prasi
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Thanks for the Gerbers - those allowed me to directly upload the design to a fab house and order boards. Just waiting for them to come in now. It's amazing how inexpensive it is to get prototype boards made at 10 for $10 (5cm x 5cm).
Nice design - what is the advantage of this circuit vs previous ones, or to the FX-8 I am about to build? Is this another 100w design or can handle more with four output transistors?
Are bias or offset trim pots needed?
Adventage of AX10 and AX11TEF there is no bias transistor, no need to set bias, only drivers and output transistors is on heatsink.
WOW! Seems like Mr. Mile turns out new designs faster than most folks can build them.🙂
Yep. He has posted another new amp in his other MOSFET thread. Thats 2 new amps in a day!.😀😀