It looks like a HiFi2000 manufactured case. See their e-commerce website: modu
The model is Galaxy Maggiorato (2U) GX 283 or GX288 std version with 3 mm thick alu front panel and mild steel top and bottom panels (also available with 10mm thick alu front panel silver or black and 2mm thick alu top and bottom panels).
RichLund used the alu sides the other way round: the brushed surfaces should be external.
Hi Merlin
The case I used above is the Galaxy Maggiorato GX388 330 x 280 mm with iron covers. The Alu covers look nicer and more expensive but are recommended if you are thinking of heat sinking to the case.
It is 2U - 80mm high.
modushop.biz
There is a 2U rack mounted range for the pesante and slim line models. If you look under spare parts you can order 10mm fronts or alu covers etc.
Massimo - you can use the sides either way round depending how you want the side channel configuration. There are grooves (channels) cut into the sides to allow for various PCB or mounting options. I chose the side with the least grooves on the outside.
The case I used above is the Galaxy Maggiorato GX388 330 x 280 mm with iron covers. The Alu covers look nicer and more expensive but are recommended if you are thinking of heat sinking to the case.
It is 2U - 80mm high.
modushop.biz
There is a 2U rack mounted range for the pesante and slim line models. If you look under spare parts you can order 10mm fronts or alu covers etc.
Massimo - you can use the sides either way round depending how you want the side channel configuration. There are grooves (channels) cut into the sides to allow for various PCB or mounting options. I chose the side with the least grooves on the outside.
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Of course you can, but they look nicer from the brushed side
Moreover, the two grooves on the (supposed to be) inner side hold M3 bolts, while the other grooves don't. This might be useful to quickly fix some L shaped bars for boards or heatsinking TO220 semis without dirilling holes.
I got my isolation pads between my heatsinks and mosfets.
I've checked the test points and get +9.33v/-9.33v
and +9.25/-9.25v on the other unit. So, I believe everything looks a-ok.
Just a couple of questions;
Now that the mosfets are isolated from the heatsinks, I can secure them to the case, right?
What should I do with a/c ground?
I've checked the test points and get +9.33v/-9.33v
and +9.25/-9.25v on the other unit. So, I believe everything looks a-ok.
Just a couple of questions;
Now that the mosfets are isolated from the heatsinks, I can secure them to the case, right?
What should I do with a/c ground?
You can drill holes to the sinks and pass bolts to the chassis, or use long Mosfet bolt and extra nuts to secure to both sink and chassis as a system with a single bolt. If you will get any hum, tie a cable from middle point Tx connector to chassis. That is chassis earthing the main PSU return node. You should also tie the mains earth prong at a near point to IEC inlet to chassis anyway for safety. Maybe with a short cable to a ring fastened on one of the IEC female plug's fixing bolts.
470 Ohm resistors
Hi:
I am in the process of rounding up parts for a Mesmerize board. The BOM I found says that the 4x470R resistors ought to be carbon film rather than metal film. Can anyone explain this preference? Is there a technical reason why those resistors ought to be noisier, lower precision, or have a worse TCR than the other resistors?
Also, I seem to remember reading something about this in another thread, but can't find it now: has anyone tried using something like buried-zener voltage references instead of strings of LED's? Wouldn't those be quieter, more accurate, better matched, etc? Could they be a drop-in replacement at the current levels used here? Just thinking out loud...
Thanks for any insights.
Hi:
I am in the process of rounding up parts for a Mesmerize board. The BOM I found says that the 4x470R resistors ought to be carbon film rather than metal film. Can anyone explain this preference? Is there a technical reason why those resistors ought to be noisier, lower precision, or have a worse TCR than the other resistors?
Also, I seem to remember reading something about this in another thread, but can't find it now: has anyone tried using something like buried-zener voltage references instead of strings of LED's? Wouldn't those be quieter, more accurate, better matched, etc? Could they be a drop-in replacement at the current levels used here? Just thinking out loud...
Thanks for any insights.
Those resistors are gate stoppers. Small enough and of other function than to inflict all those inferiorities you mentioned, but non inductive, which is the major parameter we seek in a stopper. Its almost academic in DCB1's case though because there is plenty of phase margin in the regs to use even the likes of Dale RN60 if you may.
Since you imply LM329 I suppose, those are almost single vendor today and $10 on Ebay to be recommended. If you have them try them. Leds can even superceed them for nVrtHz and harmonic noise when fed from a matching impedance Jfet mind you. Matching for voltage between polarities you will never achieve by the way without a certain mod, because I have already undermined it for total symmetry by design. Only in a Blue Hypno.
Since you imply LM329 I suppose, those are almost single vendor today and $10 on Ebay to be recommended. If you have them try them. Leds can even superceed them for nVrtHz and harmonic noise when fed from a matching impedance Jfet mind you. Matching for voltage between polarities you will never achieve by the way without a certain mod, because I have already undermined it for total symmetry by design. Only in a Blue Hypno.
100uF caps
Hi, another question (sorry to be a pest). The spaces on the board for the 100uF caps in the PS (around the LED's and on the regulator output) have 5mm spacing and 10mm diameter. You can get a pretty big capacitance value in that location, as much as 1000uF @ 25V, and easily 470uF in a high-quality cap. Is there any advantage, or disadvantage, in using values larger than 100uF for those locations?
Thanks.
Hi, another question (sorry to be a pest). The spaces on the board for the 100uF caps in the PS (around the LED's and on the regulator output) have 5mm spacing and 10mm diameter. You can get a pretty big capacitance value in that location, as much as 1000uF @ 25V, and easily 470uF in a high-quality cap. Is there any advantage, or disadvantage, in using values larger than 100uF for those locations?
Thanks.
Since you imply LM329 I suppose, those are almost single vendor today and $10 on Ebay to be recommended. If you have them try them. Leds can even superceed them for nVrtHz and harmonic noise when fed from a matching impedance Jfet mind you. Matching for voltage between polarities you will never achieve by the way without a certain mod, because I have already undermined it for total symmetry by design. Only in a Blue Hypno.
LM329 are less than $2aud at farnell/element14 and they have plenty. so whoever is charging 10 on ebay is a crook.
there are better lower noise references available from linear tech at MUCH tighter tolerance than LM329's 5% if you wanna take it to another level, but these ARE a bit pricey in the higher levels
for carbon comp I would recommend AMR, which are new stock high grade carbon comp and are one of my faves. little pricey, but all decent carbon comps are these days and at least these are potted in an anodized black alloy case and with gold plated OCC leads.
How about LT1029? Digikey have the CZ part (5V, 1% tolerance, tempco 34ppm/C) for C$3.38, and the ACZ part (5V, 0.2%, 20ppm/C, up to 10mA) for C$5.45; those prices are for singles. Like most things these days, it's hard to find much through-hole. If you want to work with surface-mount parts you can get a LT1634ACS8-5, 5V, .05% tolerance, 10ppm tempco, 30mA for C$10.22. Noise for the LT1634 is 35uV P-P; the LT1029 datasheet doesn't have a noise figure.
And yeah, Digikey have the LM329 for $1.34.