richie00boy said:
You will not get the double power at 2 Ohm, the modules deliver a max current of 20A. So with 40V peak you hit the 20A in 2 Ohm, this means you can get upto 400W exactly in 2 Ohm. This gives your 50V powersupply a little bit of margin since the peak output voltage the amp has te deliver in 2 Ohm is 10V less than the rail voltage. Even with losses in the power supply and amp, you maybe able to reach maximum power in 2 Ohm with a 50V supply.
Best regards
Gertjan
So, bottom line, all things considered perfect (max. rail voltage etc)
Power output on the UcD400 should be:
200W in 8 ohms
400W in 4 ohms
400W in all resistances lower than this?
Thanks for your input.
PS. Got my UcD400 1.1 modules yesterday, made a quick test on a 54V/-54V source in an old amp.
Worked out nicely, but had some signal ground loop problems somehow, so I had 50hz humming
- only tested on an old 8 ohm minispeaker, so no listening results yet...
I didn't happen when I disconnected the female mini-jack I used to test the signal in, so it must be in there somewhere.
Oh well, now I know what to do
Builld the damn thing like I should!
BTW, is 16 gauge cable good for rail power from/to the UcD or is this not adequate for the possible 20A over 60V?
Thanks
Power output on the UcD400 should be:
200W in 8 ohms
400W in 4 ohms
400W in all resistances lower than this?
Thanks for your input.
PS. Got my UcD400 1.1 modules yesterday, made a quick test on a 54V/-54V source in an old amp.
Worked out nicely, but had some signal ground loop problems somehow, so I had 50hz humming
- only tested on an old 8 ohm minispeaker, so no listening results yet...I didn't happen when I disconnected the female mini-jack I used to test the signal in, so it must be in there somewhere.
Oh well, now I know what to do
Builld the damn thing like I should!BTW, is 16 gauge cable good for rail power from/to the UcD or is this not adequate for the possible 20A over 60V?
Thanks
Just came back from a single channel test with an UcD400 module...
Used my old Yamaha as transformer/power supply - this is doing 54v/-54v with 28800uF caps present.
Only tested 1 channel and used an old tapedeck as attentuator
Didn't have extra cooling for the modules so had to limit myself to 60 seconds tests.
I had tried the other module before to test the setup into an old 8 ohm speaker, it worked, ok...
But now there was a Nautilus 804 at the other end of the module... turned on without the tapedeck, hiss is almost non-existant? No hiss at all, just a veeery distant 50hz hum due to my testing setup (not nice at all)
With my cd player connected, lots of 50hz hum, but I had "mass circles" of well over 2 meters cable, took care of that and 50hz hum was gone, on with the test...
first impression with a St. Germain track:
- One speaker playing at low volume, where is that bass coming from? Is my sub on? No? Only one word for it: Authority.
Bass & midrange sounded like my speaker just became bigger. Turned volume up a little, authority remained, it's like the speaker is ruled with an iron fist. Voices were great even with a single speaker. Could here some samples St. Germain used that sounded good in the past, now they were obviously samples, could hear the noise present in the single sample, wow.
2nd 60 sec test: Treble... very messy at first, became better in minutes, must be "burn-in" or heating up of circuitry I guess
Staging & stuff, couldn't test, was driving single channel, but I went wow a few times, never believed there could be so much difference in amplifiers, especially at this price point.
This test will make me go further, I'm building the amp!
Hope to report later!
Used my old Yamaha as transformer/power supply - this is doing 54v/-54v with 28800uF caps present.
Only tested 1 channel and used an old tapedeck as attentuator
Didn't have extra cooling for the modules so had to limit myself to 60 seconds tests.
I had tried the other module before to test the setup into an old 8 ohm speaker, it worked, ok...
But now there was a Nautilus 804 at the other end of the module... turned on without the tapedeck, hiss is almost non-existant? No hiss at all, just a veeery distant 50hz hum due to my testing setup (not nice at all)
With my cd player connected, lots of 50hz hum, but I had "mass circles" of well over 2 meters cable, took care of that and 50hz hum was gone, on with the test...
first impression with a St. Germain track:
- One speaker playing at low volume, where is that bass coming from? Is my sub on? No? Only one word for it: Authority. Bass & midrange sounded like my speaker just became bigger. Turned volume up a little, authority remained, it's like the speaker is ruled with an iron fist. Voices were great even with a single speaker. Could here some samples St. Germain used that sounded good in the past, now they were obviously samples, could hear the noise present in the single sample, wow.
2nd 60 sec test: Treble... very messy at first, became better in minutes, must be "burn-in" or heating up of circuitry I guess
Staging & stuff, couldn't test, was driving single channel, but I went wow a few times, never believed there could be so much difference in amplifiers, especially at this price point.
This test will make me go further, I'm building the amp!
Hope to report later!
Jan-Peter,
First I was thinking, no way, this is the Audiophile placebo effect...
Then my girlfriend yelled out, she's sitting in the computer room, but somehow it's a kind of basstrap, the bass from the living room is amplified in there.
She yelled at me why I turned up the bass so much....
I'm trying to keep a neutral point of view, but these first 2 minutes of testing kind of caught me off guard, UcD seems to be amazing (let's hope it's the same in treble & presence)
Thanks for a great amp! If you ever build a "deluxe" version (high quality regardless of cost) let me know... and please build it so we just have to plug in the 6 connectors
Just put my DSP-A2 back on the N804's... where's my beautiful low end?
Yves
First I was thinking, no way, this is the Audiophile placebo effect...
Then my girlfriend yelled out, she's sitting in the computer room, but somehow it's a kind of basstrap, the bass from the living room is amplified in there.
She yelled at me why I turned up the bass so much....
I'm trying to keep a neutral point of view, but these first 2 minutes of testing kind of caught me off guard, UcD seems to be amazing (let's hope it's the same in treble & presence)
Thanks for a great amp! If you ever build a "deluxe" version (high quality regardless of cost) let me know... and please build it so we just have to plug in the 6 connectors
Just put my DSP-A2 back on the N804's... where's my beautiful low end?
Yves
ClassD, I'm a very patient man, being a network engineer and all
I even took a lot of time setting these tests up... checking again & again, following the cable runs, checking if everything is tight, multimeter present...
Jan-Peter, this was a impression based on 2 minutes, no judgement yet - nobody should take these comments as truth, it's my very, *very* limited opinion.
I'm sure the treble will be fine.
I even took a lot of time setting these tests up... checking again & again, following the cable runs, checking if everything is tight, multimeter present...
Jan-Peter, this was a impression based on 2 minutes, no judgement yet
- nobody should take these comments as truth, it's my very, *very* limited opinion.I'm sure the treble will be fine.
Yeah,
Allow me to guess what happened though.
"At first, you said "I know I really shouldn't run it with no extra cooling, but just ten seconds, 10 quick seconds ... can't hurt"
Then you said:
"Wow, did I hear that right? can't be. Hmm, can't really tell in 10 seconds..... 20 seconds, I bet it can handle 20 seconds"
Now you're up to 60 seconds Hope you had a fan around at least. New toy syndrom!
Allow me to guess what happened though.
"At first, you said "I know I really shouldn't run it with no extra cooling, but just ten seconds, 10 quick seconds ... can't hurt"
Then you said:
"Wow, did I hear that right? can't be. Hmm, can't really tell in 10 seconds..... 20 seconds, I bet it can handle 20 seconds"
Now you're up to 60 seconds
Hope you had a fan around at least. New toy syndrom!
Yves Smolders said:Just came back from a single channel test with an UcD400 module...
Used my old Yamaha as transformer/power supply - this is doing 54v/-54v with 28800uF caps present.
Only tested 1 channel and used an old tapedeck as attentuator
Didn't have extra cooling for the modules so had to limit myself to 60 seconds tests.
I had tried the other module before to test the setup into an old 8 ohm speaker, it worked, ok...
But now there was a Nautilus 804 at the other end of the module... turned on without the tapedeck, hiss is almost non-existant? No hiss at all, just a veeery distant 50hz hum due to my testing setup (not nice at all)
With my cd player connected, lots of 50hz hum, but I had "mass circles" of well over 2 meters cable, took care of that and 50hz hum was gone, on with the test...
first impression with a St. Germain track:
Bass & midrange sounded like my speaker just became bigger. Turned volume up a little, authority remained, it's like the speaker is ruled with an iron fist. Voices were great even with a single speaker. Could here some samples St. Germain used that sounded good in the past, now they were obviously samples, could hear the noise present in the single sample, wow.
2nd 60 sec test: Treble... very messy at first, became better in minutes, must be "burn-in" or heating up of circuitry I guess
Staging & stuff, couldn't test, was driving single channel, but I went wow a few times, never believed there could be so much difference in amplifiers, especially at this price point.
This test will make me go further, I'm building the amp!
Hope to report later!
Congratulations, you have discovered the magic of Class D. You will be surprised even more when you go to stereo. Soundstaging is also much better with a good class D amp.
Have fun
Gertjan
Is this enough cooling for 2 Ucd400's? It's an old alu heatsink for Pentium IV.
Would it work if I mount the Ucd400's on the side of the fins like in the picture, or would the "massive" side be better?
I've read to mount the modules vertical with the T shape towards the floor, but how can you gain anything from a heatsink this way?
Thanks for the help...
Yves
Would it work if I mount the Ucd400's on the side of the fins like in the picture, or would the "massive" side be better?
I've read to mount the modules vertical with the T shape towards the floor, but how can you gain anything from a heatsink this way?
Thanks for the help...
Yves
Attachments
There is some very exact notes from Bruno I think on heat sink sizes somewhere in this or the 180 thread.
However, that heatsink looks way more than needed, but you would have to make sure heat transfer from one to the other was adequate.
Personally I have mine screwed to the sides of one of those audiokit2000 case wall and the alu wall barely gets warm to the touch.
In contrast I have an almost identical amp using a pair of Zappulse 2.2SE board and the side of the amp is quite hot to the touch...
Basically screw the heatsink to a lump of alu about the size of an A5 sheet and it should be plenty. Sides of the case or the bottom of the case (if it's alu) should be more than enough.
The only thing which gets hot on mine is the output coil and so you should mount the board so there is some airflow around that bit of the board, ie make sure there are air holes above and below the board.
However, that heatsink looks way more than needed, but you would have to make sure heat transfer from one to the other was adequate.
Personally I have mine screwed to the sides of one of those audiokit2000 case wall and the alu wall barely gets warm to the touch.
In contrast I have an almost identical amp using a pair of Zappulse 2.2SE board and the side of the amp is quite hot to the touch...
Basically screw the heatsink to a lump of alu about the size of an A5 sheet and it should be plenty. Sides of the case or the bottom of the case (if it's alu) should be more than enough.
The only thing which gets hot on mine is the output coil and so you should mount the board so there is some airflow around that bit of the board, ie make sure there are air holes above and below the board.
Thanks.
Another question... is it bad to connect the signal in mass and power mass together? This is only for testing in an integrated amp - I've measured AC and DC between the power supply mass and the ground of the pre-out on the receiver and it's 0.
I'm still in test phase here, so this will not be permanent.
Another question... is it bad to connect the signal in mass and power mass together? This is only for testing in an integrated amp - I've measured AC and DC between the power supply mass and the ground of the pre-out on the receiver and it's 0.
I'm still in test phase here, so this will not be permanent.
power supply
I had a peek inside a DS 4.0 module. I was especially interested in the transformer used to power the UcD module inside which is supposed to be the same as the UcD 400. A 46V 3A transformer is used. This means that a 300VA 42V (42V to be on the safe side...) transformer will be enough to drive the UcD almost 100%. Is that correct or should I use a transformer with a higher VA rating? (500VA?)
Jan
I had a peek inside a DS 4.0 module. I was especially interested in the transformer used to power the UcD module inside which is supposed to be the same as the UcD 400. A 46V 3A transformer is used. This means that a 300VA 42V (42V to be on the safe side...) transformer will be enough to drive the UcD almost 100%. Is that correct or should I use a transformer with a higher VA rating? (500VA?)
Jan
Leeuwarden,
The DS4.0 subwoofer amplifier is indeed based on the UcD400. However we use in the DS4.0 a seperate 12V winding on the transformer to create the voltage for the driversection of the powerfets. So for this reason we have here used the save maximum voltage.
Why do you wants to drive the UcD400 module to the maximum, do you have to feed a special lamp. And you need the maximum light?
There is no sonic difference between "listening" to a 300VA or 500VA transformer...........
You better use a good audio grade electrolytic capacitors (BHC Slitfolis) and a good layout to have the lowest hum. This give you more sonic pleasure.
Jan-Peter
The DS4.0 subwoofer amplifier is indeed based on the UcD400. However we use in the DS4.0 a seperate 12V winding on the transformer to create the voltage for the driversection of the powerfets. So for this reason we have here used the save maximum voltage.
Why do you wants to drive the UcD400 module to the maximum, do you have to feed a special lamp. And you need the maximum light?
There is no sonic difference between "listening" to a 300VA or 500VA transformer...........
You better use a good audio grade electrolytic capacitors (BHC Slitfolis) and a good layout to have the lowest hum. This give you more sonic pleasure.
Jan-Peter