Yes, 3U is fine, but, if you can go with the 400mm (depth) then do so.
I run mine in a 3U/300mm and its right at Fabs target temp.
Unfortunately, Hifi2000 is closed until Sept. 1.
Cheers,
Greg
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Hello Eric
My USSA-5 is in a box 3U - 300mm and no particular problem of heat for 1.1A on the mosfets, the temperature of the heatsinks does not exceed 47 ° with an ambient temperature not exceeding 25 °. The only problem with a model 3U - 30mm is the space available inside for the power supply which is quite limited and a model 3U - 400mm would be more suitable.
😉
Attachments
My SA2015 (Class AB) in a 400mm 3U.
I will never use this for a class A.🙂
At least in Greece.....
I will never use this for a class A.🙂
At least in Greece.....
Attachments
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It depends on the quality of the resistors you have. First drift of nominal value is based on temperature of the resistor and its Temperature Coefficient of Resistance. The TCR of the part number indicated in BOM is 100ppm (or lower).
Lower power resistor means higher temperature in operation. Therefore, you must at least verify the TCR of your 0,25W resistors. The most critical resistors (0,5W ones) in that regard are the M3/M4 at source and the "low" feed-back resistors (75 ohms for USSA-3). In USSA-3 this feed-back resistors value of 15 ohms is even more critical. As for the effect on sound it has not been evaluated but if you want optimised results do not deviate from BOM parts characteristics...
Metal film vs carbon material has been found to have different sonic signature by peoples. I do not have much experience in that regards but technically metal film is good for me.
Fab
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PS I was eyeing this one:
High Precision Aluminum Chassis Power Amplifier Enclosure DIY Case with VU Meter 358962407116 | eBay
Although this one is lovely:
Imitate BOLDER style percision work CNC power amplifier aluminum chassis box | eBay
High Precision Aluminum Chassis Power Amplifier Enclosure DIY Case with VU Meter 358962407116 | eBay
Although this one is lovely:
Imitate BOLDER style percision work CNC power amplifier aluminum chassis box | eBay
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To give you an idea my USSA-5 with 25Wrms full class A (into 8 ohms) has about 300mm x 140mm x 40mm heatsinks (standard vertical fins) for about a little less than 50C (20C ambient).
Smaller heatsink will allow less bias thus less power in class A for the same temperature.
Fab
Smaller heatsink will allow less bias thus less power in class A for the same temperature.
Fab
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They do. You'll have to fill out some fields for customs-purposes during the ordering process, but nothing difficult there. If you want to you could send me a PM and we could do a "mini-gb" for the USSA-parts 😉.
Looking forward for your next review Mr. Ggetsoff.
Fabs 1/10pcb sale /built amp goal. a for lower (feedback/noise) selling pcb no reason but for feedback of built amp A wild estimate ~> or ~<
TBA.
Enjoy your amps & music.
Fabs 1/10pcb sale /built amp goal. a for lower (feedback/noise) selling pcb no reason but for feedback of built amp A wild estimate ~> or ~<
TBA.
Enjoy your amps & music.
Hi Tonza75
Since you have the pcbs, Mosfet transistors and complete build manual have you started your build and if so what step # are you?
Fab
Since you have the pcbs, Mosfet transistors and complete build manual have you started your build and if so what step # are you?
Fab
Build manual#Fabient1 ¬∨∧∨¬ x.x.A
‘Better’ and
‘worse’ are qualifications that
do not have a place here;
On page xxx Programming Logics: Essays in Memory of Harald Ganzinger
‘Better’ and
‘worse’ are qualifications that
do not have a place here;
On page xxx Programming Logics: Essays in Memory of Harald Ganzinger
