I convert my smd version in more through all version for part stock reason....
Will send to board house certainly begin of november
Marc
Will send to board house certainly begin of november
Marc
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nice, but i think you should check your cap dia with whats available. honestly, i cant make out the dia from pictures...obviously, 100uF63V cant be of same dia as 470uF/100V 🙂 unless you plan to use some specific caps that you have in mind...
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First Quasi works..... offset stable, bias is good (after changing R13 back to 820R).
However I used parts that I have so will need to make an order and change a few things.
didn't have the right comp caps so used closest value. Also used KSA1220A for the buffer and inverter.
and .47R source resistors.
Scope says it works🙂
will try on speakers soon.....
thanks for the board files and all the Information here.
However I used parts that I have so will need to make an order and change a few things.
didn't have the right comp caps so used closest value. Also used KSA1220A for the buffer and inverter.
and .47R source resistors.
Scope says it works🙂
will try on speakers soon.....
thanks for the board files and all the Information here.
Attachments
Nice layout, Phunk. Come to that, your logo is very nice too - not to mention your moniker......
I love seeing a AB push pull amp with Goliath facing across the arena at David - it really is absurdly bizarre!
Now, to figure out keeping the quasi output always on, how to do it?
Cheers,
Hugh
I love seeing a AB push pull amp with Goliath facing across the arena at David - it really is absurdly bizarre!
Now, to figure out keeping the quasi output always on, how to do it?
Cheers,
Hugh
post1564.
Phunk, have you swapped R1 & R2?
I suggest you move the Signal Return pin to next to the Signal Input pin. Just widen the Sig Gnd track a bit to get a fit.
And move C11 & C13. At present the ground trace between the caps is very long. If you move these caps up to the top of the PCB you can shorten the ground trace gap between them very considerably. I'd guess the new length will be ~40% of existing. That's a big decrease in impedance (inductance).
Phunk, have you swapped R1 & R2?
I suggest you move the Signal Return pin to next to the Signal Input pin. Just widen the Sig Gnd track a bit to get a fit.
And move C11 & C13. At present the ground trace between the caps is very long. If you move these caps up to the top of the PCB you can shorten the ground trace gap between them very considerably. I'd guess the new length will be ~40% of existing. That's a big decrease in impedance (inductance).
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Very nice looking layout. I like the BD139 on top of MOSFET without any flying leads. Under hung stacking. Cool.
meanman:-Thanks.I like it too!
prasi:-Thanks.That`s a good catch.I have rectified the situation.12mm diameter cap in now.That should be ok,I think?...that`s me being a little bit lazy.Can just check my catalogues later.
AKSA:-Thanks very much.The moniker comes from being the life of the party in my young days.It is shortened from "uncle funk":-i`ve changed it to "unkel phunk",and "phunk" stuck to this day.
The logo is from my first try which was a little bit too "busy" for my liking.Found a couple of threads on the forum with regard to Sprint and just started implementing.
Yes,I had to start laughing when i saw what was looking back at me.
AndrewT:-Thanks for noticing.Will have a look at R1&R2 when i get home.I may have swapped them around inadvertently.
C11&C13-I have looked at the gap and it kind of bothered me.Thanks for clarifying the issue.I will make the changes to the caps with respect to the ground gap.
Sgnd&Input:-Will put them closer together.
xrk971:-Thanks man.Love the energy with which you tackle new projects.
As said before,a second set of eyes does help.I`ll wait a day or two before i post the amended layout.
Thanks
phunk
prasi:-Thanks.That`s a good catch.I have rectified the situation.12mm diameter cap in now.That should be ok,I think?...that`s me being a little bit lazy.Can just check my catalogues later.
AKSA:-Thanks very much.The moniker comes from being the life of the party in my young days.It is shortened from "uncle funk":-i`ve changed it to "unkel phunk",and "phunk" stuck to this day.
The logo is from my first try which was a little bit too "busy" for my liking.Found a couple of threads on the forum with regard to Sprint and just started implementing.
Yes,I had to start laughing when i saw what was looking back at me.
AndrewT:-Thanks for noticing.Will have a look at R1&R2 when i get home.I may have swapped them around inadvertently.
C11&C13-I have looked at the gap and it kind of bothered me.Thanks for clarifying the issue.I will make the changes to the caps with respect to the ground gap.
Sgnd&Input:-Will put them closer together.
xrk971:-Thanks man.Love the energy with which you tackle new projects.
As said before,a second set of eyes does help.I`ll wait a day or two before i post the amended layout.
Thanks
phunk
Hi,
I plan on building the Quasi very soon, can someone verify if the heatsink I plan to use are appropriate. I would use 1 per channel without forced cooling. (see link below)
My own Quasi will be powered at +/- 40Vdc with a load of 4 ohm.
My friend's Quasi will be powered at +/- 28Vdc with a load of 8 ohm.
We are each making our own enclosure both our heatsinks will be located inside the enclosure with ventilation opening below and above each heatsink.
I usually build class A power amp (biggest power consumption at idle) so heatsink sizing is quite easy, how do you go along sizong one for AB ?
Aluminum Heatsink Cooling Fin 150mmx60mmx25mm for Power Amplifier CP | eBay
p.s. I do not know this seller, this is just the heatsink size I intend to buy.
Thanks a lot,
Eric
I plan on building the Quasi very soon, can someone verify if the heatsink I plan to use are appropriate. I would use 1 per channel without forced cooling. (see link below)
My own Quasi will be powered at +/- 40Vdc with a load of 4 ohm.
My friend's Quasi will be powered at +/- 28Vdc with a load of 8 ohm.
We are each making our own enclosure both our heatsinks will be located inside the enclosure with ventilation opening below and above each heatsink.
I usually build class A power amp (biggest power consumption at idle) so heatsink sizing is quite easy, how do you go along sizong one for AB ?
Aluminum Heatsink Cooling Fin 150mmx60mmx25mm for Power Amplifier CP | eBay
p.s. I do not know this seller, this is just the heatsink size I intend to buy.
Thanks a lot,
Eric
I used a 4" section of this per channel:
5.375" - HeatsinkUSA
More then adequate and not too expensive. Not sure if shipping to Canada is a deal breaker.
5.375" - HeatsinkUSA
More then adequate and not too expensive. Not sure if shipping to Canada is a deal breaker.
Eric,
I have used that very same heat sink on 8 of my class AB amps in the 50w range. It's on the smaller side but should work fine but make sure it has enough ventilation. I would recommend placing it outside if possible. I personally like the Pentium CPU heatsinks that I have been using better as the aluminum base is much thicker. They cost about the same.
The one recommended by Evanc is much better of course.
I have used that very same heat sink on 8 of my class AB amps in the 50w range. It's on the smaller side but should work fine but make sure it has enough ventilation. I would recommend placing it outside if possible. I personally like the Pentium CPU heatsinks that I have been using better as the aluminum base is much thicker. They cost about the same.
The one recommended by Evanc is much better of course.
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Thanks guys,
Price for heatsinks on ebay sky rocket above 150mm x XYZmm so I'll use 2 of them per channel (side by side) and use a thick 1/4" aluminum piece (300mm x 60mm) to mechanically hold them together.
p.s. I'll probably cut 2 inches to get a length of 10 inches.
BR,
Eric
Price for heatsinks on ebay sky rocket above 150mm x XYZmm so I'll use 2 of them per channel (side by side) and use a thick 1/4" aluminum piece (300mm x 60mm) to mechanically hold them together.
p.s. I'll probably cut 2 inches to get a length of 10 inches.
BR,
Eric
Q4 is heat absorber while Q3 produce heat. in my opinion Q3 must be mount direck to heatsink not in the plastic body of power transistor which is also heat producer. Nice Layout 😉
regards,
dacz
Dear Mr Thiago,
Thank you so much.
Your sprint layout lib is very nice. Can you share them?
Best regards,
ThaiKy
I don't recommend your proposed solution.
Use a thicker backplate heatsink that is capable of spreading the heat out to the most remote fins.
If he connects the sinks together with a 1/4" thick plate I would think that should work as a heat spreader.
I have used this heatsink before. Just one will work without any need for spreader plate or secondary heatsink. It's just on the thin side but works well enough for a 50w class amp.