First One M module's sum bias current range is from 80-360 mA, 280 mA recommended. At this point output mosfets (two pairs) have 220 mA bias current, that sets them to thermal equilibrium - neutral thermal coeficient. Idle power dissipation is therefore 35 W at +/-60 V power supply. Of course module's bias current can be lower to get less idle power dissipation (smaler heatsink) but not below 100 mA if sonics is to be preserved.
C1 chassis uses SK157 heatsink, 0,4 K/W.
C1 chassis uses SK157 heatsink, 0,4 K/W.
0,8 Wrms/8 Ohm in class A, which usually means normal listening conditions, especially at evenings.
These are the last four modules from test series prepared to be send out.
Almost there to accept the orders, if everything as planned, this week we'll start the production, last reels expected to be received shortly and then automated assembly line will be ready to start the step motors.
Please give me few more days as I don't want to get payments before material is ready.
Almost there to accept the orders, if everything as planned, this week we'll start the production, last reels expected to be received shortly and then automated assembly line will be ready to start the step motors.
Please give me few more days as I don't want to get payments before material is ready.
I read about different power supply options here: https://hifiduino.wordpress.com/2014/10/31/first-one-power-supply-selection/
Why is there so much focus on SMPS? What about good old linear PSUs (possibly with ample CRC or CLC filtering)?
Why is there so much focus on SMPS? What about good old linear PSUs (possibly with ample CRC or CLC filtering)?
Concerning idle power dissipation:
- normal bias setting - easily 4 x First One M or 8 x First One S.
- 50% reduced bias setting - up to 8 x First One M or 12 x First One S
I wonder what happened with Pass amp's original electronics you wish to replace or it will be just a copy of Pass chassis?
That much focus on SMPS is because once you hear it, you won't go back, ever. Its input energy storage is easily 50-100 J (310 V on input elco bank) which is served to output capacitors/load at enormous rate, so there is power on demand always present at its output, resulting in better and faster bass response, etc. Also on such small footprint as compact module design and its light-weight you cannot form classic linear power supply, no way. I find unregulated SMPS like SMPS1200 much better since its output duty cycle is fixed 50% at 500 kHz, no matter the Z load present.
You have to try it once.
Thanks. A lot of work to design the latest PCB and I agree, it's very good. Wait a little while when S and L version PCB will be revealed.new low z output OPA's looks good.
Thanks, yes it's hightly inspired from Pass ^^.
I can add two radiator in more inside, 300×160×40. Idea is to put 12 channels, 8 in S and 4 in M. M is for woofers.
With one smps 1200A180 or may be two of them.
What is the reduced bias setting and the consequence?