You can try this address in France. They have the box (but some models are out of stock curently).
http://www.stquentin.net/coffret/coffretgalaxy.php
Web site is **** but they are serious.
http://www.stquentin.net/coffret/coffretgalaxy.php
Web site is **** but they are serious.
Inside width is given on their website, and it's about 31cmx28cm on my case (which is the largest they do).
The top and bottom are *steel* and the sides are alu. There are no instructions, but it's mostly obvious how to fit them together, except that I have some longish steel coloured screws that don't seem to fit anywhere ... (anyone got any ideas?)
You can get some low profile 200Va transformers from LCAudio. I built a Zappulse with two of these in one 40mm high case, and I guess it sounds OK.
Photos here:
http://wildgooses.com/downloads/amp4.jpg
I can't help wondering if 400Va isn't enough for these modules anyway... (running at 63V). With the UCD I am going to just get an 80mm case and go with the 1Kva tranny... (unless someone has a reason not to?)
The top and bottom are *steel* and the sides are alu. There are no instructions, but it's mostly obvious how to fit them together, except that I have some longish steel coloured screws that don't seem to fit anywhere ... (anyone got any ideas?)
You can get some low profile 200Va transformers from LCAudio. I built a Zappulse with two of these in one 40mm high case, and I guess it sounds OK.
Photos here:
http://wildgooses.com/downloads/amp4.jpg
I can't help wondering if 400Va isn't enough for these modules anyway... (running at 63V). With the UCD I am going to just get an 80mm case and go with the 1Kva tranny... (unless someone has a reason not to?)
Hifi chassis
Try www.audiokit.it, though it looks like that the cases there are either 19" rack series or the one like the Galaxies (which are nice btw.).
It seems we have now a Class-D forum
.
Try www.audiokit.it, though it looks like that the cases there are either 19" rack series or the one like the Galaxies (which are nice btw.).
It seems we have now a Class-D forum
.
stef1777 said:
For AudioKit, you should add the VAT and the shipping cost to compare.
For the French supplier, I don't know the shipping cost.
Yes, so for a GX288 it is EUR 26.40 at AudioKit and EUR 55 at the French site. Shipping should be about the same. Pretty clear pricing difference...
Maximum load R?
UcDs have a 2nd order lowpass filter at the output, series L and parallel C to the load. A no-load condition means we're essentially dealing with a series LC circuit, which with an applied signal near the resonant frequency tends to build up higher voltages on the components.
Bruno, is there a maximum Rout specification for the UcDs?
Thanks,
Francois.
UcDs have a 2nd order lowpass filter at the output, series L and parallel C to the load. A no-load condition means we're essentially dealing with a series LC circuit, which with an applied signal near the resonant frequency tends to build up higher voltages on the components.
Bruno, is there a maximum Rout specification for the UcDs?
Thanks,
Francois.
DIY_Peter said:
Found this supplier of 17" cabinet. Realy nice but they are located in New Zealand.
http://www.designbuildlisten.com/
134€ with shipment cost for a complete box.
Re: Maximum load R?
The somewhat curious result of this is that when you run the amplifier without load and watch the pwm duty cycle while doing a frequency sweep, the modulation effectively drops to near zero at the resonance frequency, precisely because the filter is undamped and produces voltage gain. At the same time, the output of the filter will be a nice constant voltage.
The UcD data sheet (which admittedly is not always easy to track down on JP's web site) shows a graph of frequency response at loads of 3ohm, 6ohm and No Load At All. The physical resonance frequency of the filter is 35kHz. As you can see, the UcD control circuit simply takes the filter's own frequency response out of the equation.
No other commercially available class D amp does this. Other amplifiers either
1. ignore the problem, making feeble attempts to mollycoddle it by setting the corner frequency very high.
2. same as 1. but add a zobel network
3. have some of the feedback from the output filter, reducing but not eliminating the problem. Normally a zobel network is added to such designs to insure stability under no-load conditions.
This effect is absent on UcD. The feedback takes off at the output. Even at the resonant frequency, the output voltage is fully controlled (Zout=0.1ohm at 35kHz).DSP_Geek said:
The somewhat curious result of this is that when you run the amplifier without load and watch the pwm duty cycle while doing a frequency sweep, the modulation effectively drops to near zero at the resonance frequency, precisely because the filter is undamped and produces voltage gain. At the same time, the output of the filter will be a nice constant voltage.
The UcD data sheet (which admittedly is not always easy to track down on JP's web site) shows a graph of frequency response at loads of 3ohm, 6ohm and No Load At All. The physical resonance frequency of the filter is 35kHz. As you can see, the UcD control circuit simply takes the filter's own frequency response out of the equation.
No other commercially available class D amp does this. Other amplifiers either
1. ignore the problem, making feeble attempts to mollycoddle it by setting the corner frequency very high.
2. same as 1. but add a zobel network
3. have some of the feedback from the output filter, reducing but not eliminating the problem. Normally a zobel network is added to such designs to insure stability under no-load conditions.
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