No, they seem to hold up fine, but we see it as too much excitement for
consumers to be playing with, just like plugging and unplugging inputs
with the amplifiers running.
Some time ago I was wondering what the heck was wrong as suddenly one of my channels didn't bias up enough anymore (post #5677).
Well.. it turned out that it was my bad all along... While soldering the SS back I hadn't checked the proper hight with the PCB raisers - that having the impact of forcing a couple of the SS legs to bend and finaly crack. But as they didn't fall apart, they still worked but not biasing properly. Now fixed and biasing proparly again.
Just though I'd share this if someone else would happen to bump i a similar problem.
Thanks Generg for pointing that out. =)
Well.. it turned out that it was my bad all along... While soldering the SS back I hadn't checked the proper hight with the PCB raisers - that having the impact of forcing a couple of the SS legs to bend and finaly crack. But as they didn't fall apart, they still worked but not biasing properly. Now fixed and biasing proparly again.
Just though I'd share this if someone else would happen to bump i a similar problem.
Thanks Generg for pointing that out. =)
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This post goes along with my post #5798 regarding power supply parts.
This is for those that don't want to build a discrete bridge rectifier.
The following could be a good solution. There are also higher and lower rated parts.
VBE26-06NO7
IXYS
http://www.mouser.com/ds/2/205/l361-79647.pdf
This is for those that don't want to build a discrete bridge rectifier.
The following could be a good solution. There are also higher and lower rated parts.
VBE26-06NO7
IXYS
http://www.mouser.com/ds/2/205/l361-79647.pdf
Noob question, please bear with me...building one of these beauties and I'm stuck at the heat sinks. Conrad didn't answer my inquiry so I'm back to HeatsinkUSA and their 10.080" device. Talked to someone there and they recommended I inquire here regarding what is needed. I read that 30% headroom is desired; will that be achieved using SS 125s on say 7" height 10.080" wide cuts? I've seen the math and this doesn't appear to come anywhere near the .21 or so rating I've seen spoken of as needed. I wanted to do a low-profile build but I'm good going towards the cubic if it has to happen. Thank you for bearing with me on what must be the umpteenth repeat of a RTFM question. (I've read a great deal of this thread and I've seen one member with two channels of SS on a single 10.080 X 12", I believe, and they say "no problem" yet the math isn't adding up to what is said to be needed...argh.)
The answer most often given is "you can never have too much heat sinking".
I suppose there's some relief in calculating exactly what you need, but some brute force and over-engineering helps as well. I'm sure there are people here that can tell you exactly what size to buy, but there are other variables like chassis/case ventilation, room placement (sun light), placement in rack or proximity to other gear (above amp), where you live and how warm does the room get, Will it be near an AC vent or some external fan, etc.
The difference in cost between a 7" and 9" x 10.80 HS is $15. Throwing money at a problem is not always efficient, but it kind of is with heat sink sizes choices, when bigger is more better.
I suppose there's some relief in calculating exactly what you need, but some brute force and over-engineering helps as well. I'm sure there are people here that can tell you exactly what size to buy, but there are other variables like chassis/case ventilation, room placement (sun light), placement in rack or proximity to other gear (above amp), where you live and how warm does the room get, Will it be near an AC vent or some external fan, etc.
The difference in cost between a 7" and 9" x 10.80 HS is $15. Throwing money at a problem is not always efficient, but it kind of is with heat sink sizes choices, when bigger is more better.
A Standard F5 does what power disipation at the output? Don't put any more power disipating devices on the H.S.! 1.3A x 23.5V???
I tested a 10.08 section 8" high in open air with 4 power transisters fed with a current source. it was 55 Degrees C at 85 watts! Your 65 watt F5 will do fine at stock bias! Even better at 1.6-1.7A bias!
How much burning amp do you want?
I tested a 10.08 section 8" high in open air with 4 power transisters fed with a current source. it was 55 Degrees C at 85 watts! Your 65 watt F5 will do fine at stock bias! Even better at 1.6-1.7A bias!
How much burning amp do you want?
Tape,
If you do this in 3 sections, you should have a plate that joins all three heat sinks as one. Heat spreader?
Take the 5U chassis heat sink as an example. 15.7 x 8.25 x 1.5=194.5 inches cubed. We know that the 5U can dissipate enough heat for one 50w F5T v2 channel.
For the HS USA- 13.8 x 2.5 x 7= 241.5 inches cubed. Number of fins is important, but should be close. This is a rough estimate. It's really about the surface area.
Can you see what I'm getting at?
Another thing that's important is that black anodized heat sinks dissipate heat better than natural aluminum heat sinks. It's a factor.
If you do this in 3 sections, you should have a plate that joins all three heat sinks as one. Heat spreader?
Take the 5U chassis heat sink as an example. 15.7 x 8.25 x 1.5=194.5 inches cubed. We know that the 5U can dissipate enough heat for one 50w F5T v2 channel.
For the HS USA- 13.8 x 2.5 x 7= 241.5 inches cubed. Number of fins is important, but should be close. This is a rough estimate. It's really about the surface area.
Can you see what I'm getting at?
Another thing that's important is that black anodized heat sinks dissipate heat better than natural aluminum heat sinks. It's a factor.
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The finger to the wind, rule of thumb that seems to work is 4"x6" worth of finned heatsink per device, minimum.
More is always better.
Also very important is breathing room for the amp, at least 1" clear below the heatsinks and 2" above, again, more is better. (The distance gives a chance for air to move due to natural convection.)
7" x 10" should be fine for 2 devices. What's the ambient temp of the room, is it air conditioned?
More is always better.
Also very important is breathing room for the amp, at least 1" clear below the heatsinks and 2" above, again, more is better. (The distance gives a chance for air to move due to natural convection.)
7" x 10" should be fine for 2 devices. What's the ambient temp of the room, is it air conditioned?
The black finish gets you maybe 10% more, but a fan is much better, maybe 200-300%, depending on how it's done.
Impingement cooling, blowing the air into the fins (fan parallel to the base plate) and having it come out of both sides, is best.
You can run many fans on half voltage or so, making them much more quiet. Or, get a "hi-fi" fan, designed to be quiet.
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Thank you very much everyone. The person at HSUSA said that by their calculator, the 10" piece wouldn't get to .21 even at great lengths. I'm severely right-brained but I can parse the math used to determine the measurement when going horizontally versus vertically, but these anamolies forced me to ask those already knowledgeable. Thanks. I've got notes on the F6 build from this thread including that 10" experiment with all four devices, and info on sinks from other threads (I did search, but that alone does not promise understanding). Yes, I'd be happy going 15" deep with the 4.6" serrated, set up correctly as indicated in one of the replies...perhaps 6" high? The site says:
"C/W/3": approximately 1.4 Weight per Inch"
So three of them, linked, means .466 dissipation, at a one inch height (um, or slightly better as they say 3"..). Adding height removes less heat than side-by-side, so how hight would three 4.6"-ers need to be...6"? Random guess. The 10" device says it's .8 per 3" of height, in comparison. Must be conservative figures.
I'm in a small room but the amp will have plenty of space for cooling. No air conditioner, Southern California. Definitely have a fan in the room...
I greatly appreciate the hand-holding. Soon there will be beautiful music.
"C/W/3": approximately 1.4 Weight per Inch"
So three of them, linked, means .466 dissipation, at a one inch height (um, or slightly better as they say 3"..). Adding height removes less heat than side-by-side, so how hight would three 4.6"-ers need to be...6"? Random guess. The 10" device says it's .8 per 3" of height, in comparison. Must be conservative figures.
I'm in a small room but the amp will have plenty of space for cooling. No air conditioner, Southern California. Definitely have a fan in the room...
I greatly appreciate the hand-holding. Soon there will be beautiful music.
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A Standard F5 does what power disipation at the output? Don't put any more power disipating devices on the H.S.! 1.3A x 23.5V???
I tested a 10.08 section 8" high in open air with 4 power transisters fed with a current source. it was 55 Degrees C at 85 watts! Your 65 watt F5 will do fine at stock bias! Even better at 1.6-1.7A bias!
How much burning amp do you want?
That's the kicker. It implies that two 10.08" X 4" sections will make a perfectly fine stereo amp with plenty of temperature headroom. Cheers!
Tape Echo, I did a build using 2 per channel of those 10.08" HeatsinkUSA cut down to total 18" long by 6" high. Look at Aleph J Illustrated Build Guide at post #801 to see pics. If you want I will email you the pdf drawings. HeatsinkUSA had the machine work done locally for me. Going wider helps more than going taller, but "you cannot have too much heatsink". I have it on 1.375" tall feet. An Aleph J at 1.2 amps/device is more heat than the F6 will put out, so you should be in real good shape. BTW, I am thinking of lowering my bias a little to run a little cooler and still sound good.
Thank you both: 10.08 X 18" per channel, finally makes sense! I would very much appreciate the plans to generate a pair.
http://www.diyaudio.com/forums/pass-labs/241729-aleph-j-illustrated-build-guide-81.html
Great build by the way! The creativity and individual spin everyone puts on their work around here is inspiring and boggling!
http://www.diyaudio.com/forums/pass-labs/241729-aleph-j-illustrated-build-guide-81.html
Great build by the way! The creativity and individual spin everyone puts on their work around here is inspiring and boggling!
Does having a mechanical component in an amp affect the sound quality at all?
I don't know. I've never used a fan in an amp. Would you use regulated power for the fan?
There are some computer fans that spec at -60db. I put in a 4-5" (Zalman fan) in a music server with good results.
Thanks,
vince
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I would say it says an 8" length of 10.08"is fine for 1 ch. And I wrote it! It does imply you would also be good enough with a 6" length/ch.