DC offset has to be measured with input shorted to GND, otherwise it is a result of source's DC offset or input bias current voltage drop on input resistance.
Just measured my demo First One running all day, 1,5 mV on one and 2,1 mV on another channel.
ok input is open for now.
i connect the oscilloscope and it,s very clean.
i wonder how big heatsink i need for two channels.
one will drive the midrange and the other the tweeter.
drivers are 8 ohms 89 db.
i connect the oscilloscope and it,s very clean.
i wonder how big heatsink i need for two channels.
one will drive the midrange and the other the tweeter.
drivers are 8 ohms 89 db.
As we don't want to have more than 45 C in idle, please use heatsink having thermal coeficient of 0,5K/W or less for each channel.
First One module has 35 W idle power dissipation when supplied from +/-63 V PSU.
First One module has 35 W idle power dissipation when supplied from +/-63 V PSU.
Heatsink split
Hi LC,
I suppose the heatsink being split into 2 equal pieces for each channel won´t create any thermal issues, as I assume FO must be somehow similar to VSSA (i.e no thermal compensation necessary). The two parts are joined so they share the same temperature for sure in the central area.
Can you please confirm this is correct? Have you any other objection against this kind of mounting? The case I picked up has this construction detail that I noticed only today 😱
Thanks!
Hi LC,
I suppose the heatsink being split into 2 equal pieces for each channel won´t create any thermal issues, as I assume FO must be somehow similar to VSSA (i.e no thermal compensation necessary). The two parts are joined so they share the same temperature for sure in the central area.
Can you please confirm this is correct? Have you any other objection against this kind of mounting? The case I picked up has this construction detail that I noticed only today 😱
Thanks!
Attachments
The most important is mechanical rigidity, so no movement between two heatsinks is possible. No thermal issue estimated for your solution. 😉
Otherwise, mount module exactly in the centre, aligned in a way that the output transistors will be located at the bottom of the common heatsink, so all the heat generated would be located as low as possible. Use thin TO-264 mica & grease.
Otherwise, mount module exactly in the centre, aligned in a way that the output transistors will be located at the bottom of the common heatsink, so all the heat generated would be located as low as possible. Use thin TO-264 mica & grease.
You sould add thermal paste between the two heatsinks before assembling them to ensure a good thermal contact and no air between them.
I did that with the heatsinks of my F5, only one little minus: every time I move the F5 I have some thermal paste on my hands 🙂
You can use acetone to clean the overflows onto the surfaces after the heatsinks are assembled: It works very well.
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Stereo amp with SMPS1200A400, dual?
yeap stereo with dual smps1200a400.
the amp outperfomed easily hypex ucd and coldamp sonora,
it did outperformed bryston 4bst too.
about nc400 i have test it but only from memory definitely f.o have bigger sound.
it doesn,t have the brutal punch of nc400 but it sounds with fuller body
especially at low volume.
i can,t say from memory which one is smoother and more detailed but
f.o is for sure among the best.
p.s.it,s not even burned in.
Would a single SMPS1200A400 set to 49v be suitable for a bridged FO monoblock?
Any idea how the voltage presets on the SMPS differ? Just resistor values?
Any idea how the voltage presets on the SMPS differ? Just resistor values?