And a varistor too.
In other forums, months ago, I wrote:
Star ground
[URL]http://maty.galeon.com/WP-imagenes/hard/ATL-PSD-08-maty-edition-inside.jpg[/URL]
[IMG] [URL]http://maty.galeon.com/WP-imagenes/hard/ATL-PSD-08-maty-edition-inside-3.jpg[/URL]
In other forums, months ago, I wrote:
Star ground
[URL]http://maty.galeon.com/WP-imagenes/hard/ATL-PSD-08-maty-edition-inside.jpg[/URL]
[IMG] [URL]http://maty.galeon.com/WP-imagenes/hard/ATL-PSD-08-maty-edition-inside-3.jpg[/URL]
I swapped out my input caps (10uF Silmic II and Panasonic 3.3uF 250v MKT) for a Jantzen 5.6uF 400v MKP. And changed the source resistors to metal thin film 1%. It measures the same as before. Listening to it now, I think the sparkle of the highs is better. It’s subtle but there is a difference.
Attachments
![URL]](/community/proxy.php?image=http%3A%2F%2F%5BURL%5Dhttps%3A%2F%2Fi11.servimg.com%2Fu%2Ff11%2F18%2F52%2F85%2F08%2F2017-013.jpg%5B%2FURL%5D&hash=98f10cbd184f0970226720b6a7e71732)
Haha, maybe so, but these were a gift from a friend. 😉
Also, at $5.42 not pricey enough to be boutique.
Jantzen Audio 5.6uF 400V Crosscap Capacitor
Also, at $5.42 not pricey enough to be boutique.
Jantzen Audio 5.6uF 400V Crosscap Capacitor
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The Mundorf caps have been my second experience with boutique. The first, a very cheap and NOS 10nF 650V styroflex (polystyrene) capacitors to bypass the tweeter cap of my KEF Q100 coaxial speakers. And I liked them so much that I decided not to change the original (yellow) for a Jantzen (red).
Tony Gee's Capacitor page updated..
![URL]](/community/proxy.php?image=http%3A%2F%2F%5BURL%5Dhttp%3A%2F%2Fmaty.galeon.com%2FWP-imagenes%2Fkef-q100%2FKEF-Q100-crossover-styroflex-bypass.jpg%5B%2FURL%5D&hash=837220c6fd301a49f9d93e2dfcbf8ef1)
Tony Gee's Capacitor page updated..
Audyn Cap Q4 4.7uF 400V MKP Metalized Polypropylene Foil Crossover Capacitor
I would try these caps, those are on sale now
I would try these caps, those are on sale now
By the way, polystyrene has problems with Tª > 70 ºC (descompose). Phono, preamps, DACs, low power Class AB amps and speaker filters only. Or buffer with Class D (Nord, Hypex NC500).
NEVER inside class A amplifier.
NEVER inside class A amplifier.
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X, How about Jupiter paper wax capacitors😀😀 and qualify for boutique man..just a bit of fun...I could build 4-5 amps easily for the price of a single cap.
Hi Irribeo,
So far, the cpu coolers have no problem controlling the heat at 22vdc. Although, I will be increasing to about 25-26vdc when my transformer arrives. The fans I’m using have a speed control and they are at the lowest/quietest speed.
The amplifier is performing very nicely. I’m using speakers on the bench that are not an easy load (4 ohm, low 80’s sensitivity) to an uncomfortable listening level. So, this amp will have no problem “rocking” with 8ohm, 95db and up speakers.
Attachments
Brilliant, Vunce,
You have marvellous cooling, too. Solid heatsinks, do you cool best with the fins vertical? I assume no fan on them when installed in the case?
Yes, 4R is not the forte for the ALPHA 20. It's a 8R amp. Theoretically you could double the current by halving the Pass CCS sense resistor - no other changes - and it might be OK with those large heatsinks to cope with the heat too.
Congratulations!!
HD
You have marvellous cooling, too. Solid heatsinks, do you cool best with the fins vertical? I assume no fan on them when installed in the case?
Yes, 4R is not the forte for the ALPHA 20. It's a 8R amp. Theoretically you could double the current by halving the Pass CCS sense resistor - no other changes - and it might be OK with those large heatsinks to cope with the heat too.
Congratulations!!
HD
Thank you Hugh🙂
Your encouragement reinforces my will to put my best efforts into these ALPHA projects.
Cheers,
Vunce
Your encouragement reinforces my will to put my best efforts into these ALPHA projects.
Cheers,
Vunce
Hi X,
My trafo and caps arrived today, I can finish the Juma/Prasi capMx and send some real power to the ALPHA 😀
My trafo and caps arrived today, I can finish the Juma/Prasi capMx and send some real power to the ALPHA 😀
Vunce, what voltage did you settle on for your transformer assuming a 4V loss from the CapMx? Or am I not doing my math correctly? I read through the Easy Peasy CapMx thread quick but it was a little hard for me to follow.
Also got my boards! These are beautiful pieces of work. Thanks again Hugh, X, and JPS for this great amplifier. What a team!
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Hi danielrev,
I estimate your heatsink around 0.30C/watt.
With the dissipation of both outputs using 24V rails I estimate each module will create around 75W.
This would increase the heatsink assuming even heat distribution along the heatsink to be 75 x 0.3 = 22.5C.
I assume that inside ambient temperatures in Java would be around 28C. So final temperature would be 50.5C, 22.5C over ambient.
This is acceptable. It will be quite hot but modern mosfets will withstand this temperature for about twenty years.
Go for it - but you will need TWO heatsinks, one for each module.
Cheers,
HD
I estimate your heatsink around 0.30C/watt.
With the dissipation of both outputs using 24V rails I estimate each module will create around 75W.
This would increase the heatsink assuming even heat distribution along the heatsink to be 75 x 0.3 = 22.5C.
I assume that inside ambient temperatures in Java would be around 28C. So final temperature would be 50.5C, 22.5C over ambient.
This is acceptable. It will be quite hot but modern mosfets will withstand this temperature for about twenty years.
Go for it - but you will need TWO heatsinks, one for each module.
Cheers,
HD
Hi Hugh thanks for the explanation ,i would try using w/o fan first . if there is no thermal problem i would be happy .
im tempting to build this amp cause no unobtanium jfet and the rest of component i have on my bin .
its recommended to make just single sided board ?