The 15uH of the tripad plays a roll with a 4 Ohm load.
In practice I can hear up to 13kHz and not above that. And a speaker tent to increase impedance at higher frequencies due the impedance of the voice coil.
So in theory interesting in practise most of us do not hear a thing at those frequencies.
In practice I can hear up to 13kHz and not above that. And a speaker tent to increase impedance at higher frequencies due the impedance of the voice coil.
So in theory interesting in practise most of us do not hear a thing at those frequencies.
I'm 47 and I can hear out to about 15.5kHz, 16kHz if I increase the volume to very high levels, but nothing beyond 16kHz (I'm afraid to turn it any louder for fear of ear damage), but at 15.5kHz I can clearly hear a pure sinewave at nominal volumes. My ears seem to be almost a brick wall filter at 15.5kHz though so I could live with high frequency rolloff above that.
Some claim that you can hear higher frequencies than tests indicate and that it adds something to the music. I disagree. Using a digital brick wall filter at 15kHz and comparing the sound without the filter I hear no difference in music reproduction.
There are a..oles every where David in Winterswijk there are also a lot of them.Helmuth
Your a champion thanks again, the inlaws are always telling me how nice Dutch people are, hmmm, there Dutch
Winterswijk looks like a nice place, at least from google earth it does.
David
That is why that Dutch are moved to Australia people tent to remember the good times and forget the bad so in their mind it was good.
Problem to many people in a to small country.
That's a shame, but be assured there are plenty of a..oles in australia, just more room in between.
Just so I understand correctly before I buy one of these, if the silpad weren't put between the chips and the heatsink, what is the failure mode of the board? Does it shut down on high temperature or does it burn up?
Failure
I haven't read about as many failures lately so they must have fine tuned the placement of the heat sink. When they fail, they burn the output chips. The 4X100 thread has been quiet. Just eyeball to make sure the daughter board looks like it is flat against the heatsink. Not warped.
I haven't read about as many failures lately so they must have fine tuned the placement of the heat sink. When they fail, they burn the output chips. The 4X100 thread has been quiet. Just eyeball to make sure the daughter board looks like it is flat against the heatsink. Not warped.
The datasheet recommends a 15 µH coil in series with the output. That has ~1,88 Ohms at 20 kHz without taking its DC resistance into account. Then there are several capacitors and resistors in parallel to the load. All those components and the speaker itself form a complex voltage divider that will determine the voltage at the speaker terminals.
That will indeed compensate up to the point where the amplifier reaches clipping. If the filter is not adjusted to the load, a flat response after the filter may mean that the response before the filter must rise towards higher frequencies. The headroom will be more limited at the affected frequencies than e.g. in the mids.
A friend of mine claimed that he could not hear anything below 70 Hz which he had tested with his speakers. He was convinced that his speakers could reproduce 70 Hz, because he could see the membranes moving. He was very surprised when I could show him that he could actually hear 16 Hz. His 6 inch short-stroke woofers were simply unable to reproduce anything below 70 Hz loud enough to become audible.
Silpad weren't there I put them there and also Sure shout do that IMO.
The chips have a thermal protection but there are here on the forum who had failure.
That is because every thing has to placed perfect the power chips al shout have the same height and the heat-sink has to fit flat on four chips.
Not a very safe construction this way.
It looks like the solder is going across pins, should it be like that?
What did you clean the flux off with?
I received the Icepower module & it's board has quite a curve in the length, is that normal?
David
You can use spirit / ethyl alcohol instead of thinner too - works like a charm and is better for your health - using an old tooth brush is a good idea too.
Spirit does not dry up as fast as thinner or special cleaning fluid so I use kitchen paper to help with these.
Michael
Hopefully someone can answer this question concerning the Hypex UcD400ST module.
There are two TO-220 case devices on the edge of the board that look like voltage regulators but the caps next to them prevent me from being able to read the part numbers.
They are positioned on the edge of the board such that it looks like they are supposed to be heat sinked.
Do these two parts need to be heat sinked, or just the main aluminum sink that the output transistors are bolted to? And what do they do? Can anyone read the part numbers?
I'm assembling a 5.1 surround amp using 4 UcD400ST and 2 UcD180ST modules. The UcD180ST has no such devices on the edge of its board, but the UcD400ST does, and no instructions I can find on what these are or whether they need to be heat sinked.
Thanks for any advice or info anyone can give me.
I should have this baby assembled this weekend. Once I do I'll have 3 stereo amps that I can sell that this will take the place of. With the entire case acting as a heat sink hopefully the SMPS fans won't kick on.
One of the last sources of noise in my listening room is the transformer in my MOSFET amp. It hums. With the fans gone and using my new SMPS powered UcD180ST amp all I can hear now is the transformer humming away even under no load. That's another huge advantage of the SMPS IMHO: No mechanical hum from 60Hz magnetic fields vibrating the case of the tranny and no 60, 120 or 180Hz hum or buzz in the audio.
Anyway, the heat sink question is of immediate importance since it will dictate the layout of the amp. It's a tight squeeze.
Thanks.
There are two TO-220 case devices on the edge of the board that look like voltage regulators but the caps next to them prevent me from being able to read the part numbers.
They are positioned on the edge of the board such that it looks like they are supposed to be heat sinked.
Do these two parts need to be heat sinked, or just the main aluminum sink that the output transistors are bolted to? And what do they do? Can anyone read the part numbers?
I'm assembling a 5.1 surround amp using 4 UcD400ST and 2 UcD180ST modules. The UcD180ST has no such devices on the edge of its board, but the UcD400ST does, and no instructions I can find on what these are or whether they need to be heat sinked.
Thanks for any advice or info anyone can give me.
I should have this baby assembled this weekend. Once I do I'll have 3 stereo amps that I can sell that this will take the place of. With the entire case acting as a heat sink hopefully the SMPS fans won't kick on.
One of the last sources of noise in my listening room is the transformer in my MOSFET amp. It hums. With the fans gone and using my new SMPS powered UcD180ST amp all I can hear now is the transformer humming away even under no load. That's another huge advantage of the SMPS IMHO: No mechanical hum from 60Hz magnetic fields vibrating the case of the tranny and no 60, 120 or 180Hz hum or buzz in the audio.
Anyway, the heat sink question is of immediate importance since it will dictate the layout of the amp. It's a tight squeeze.
Thanks.
I'm not sure what they are, but they do not need to be heat sinked. In older revisions of the UcD400, these devices were placed differently:
Not much space for heat sinking there. The main T-shaped heat bar should be firmly attached to a good heat sink with a thin layer of thermal paste to ensure the best possible heat transfer, though.
An externally hosted image should be here but it was not working when we last tested it.
Not much space for heat sinking there. The main T-shaped heat bar should be firmly attached to a good heat sink with a thin layer of thermal paste to ensure the best possible heat transfer, though.
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