If you remove the ground leg from the SPDT switch, the ACA mini's power consumption will still fall to zero, but the power draw will fall more slowly. Without that ground, the discharge path for capacitor C5 becomes (R4 series R0). When the voltage on C5 falls below about 6 volts {~ approx. 2 * Vth_Q4}, DC power draw from the V+ supply will hit zero.
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text in article (post #3) sez - Switch - SPDT (single pole double throw) - Digikey EG2355-ND
there are 3 contacts/pads there
so, FE JFets either having gate potential grounded ( nonoperational/stdby) or elevated to approx. U/2 (operational)
so, any form of single pole double throw switch will be adequate
there are 3 contacts/pads there
so, FE JFets either having gate potential grounded ( nonoperational/stdby) or elevated to approx. U/2 (operational)
so, any form of single pole double throw switch will be adequate
I can't answer as to what switch to use, but this may shed some light on what the switch does.
I can also tell you that when flipping the switch to “off” position while using a lab supply, the circuit is still drawing current as witnessed by the meters.
This is correct according to the BOM of the original article shown in post #1 of this thread...Part # EG2355-ND is an SP-DT On-On switch.
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Got my mini back in system this week. Amazing little thing. Took the Aleph 30 out for summer time.
Hard to believe what it can do to a pair of 3 way speakers....8" in 25L sealed and then OB mid and hi. 5 watts powering 8 drivers .(Dipole hi) And we watched the 'new' Top Gun last night so it was playing hard and it sounded mighty.
Powered from a MW 24v...took the fan and lid off, and also power via a Mark Johnson SMPS filter.
Hard to believe what it can do to a pair of 3 way speakers....8" in 25L sealed and then OB mid and hi. 5 watts powering 8 drivers .(Dipole hi) And we watched the 'new' Top Gun last night so it was playing hard and it sounded mighty.
Powered from a MW 24v...took the fan and lid off, and also power via a Mark Johnson SMPS filter.
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Beautiful!! Great size and form factor if you or your customers ever decide to perform experiments, plugging (N > 1) of the filters in series for more, More, MORE filtering.
Is the value of C2,C3 critical?
The original article says 15kuF, the BOM on the store says 10kuF.
I have some 15kuF 35v caps lying around.
The original article says 15kuF, the BOM on the store says 10kuF.
I have some 15kuF 35v caps lying around.
Oh happy Day
My first complete build swings and sings so much
THANK YOU NELSON AND EVERYBODY FOR THEIR NICE CONTRIBUTION!
Good times with ACA mini
Eric
My first complete build swings and sings so much
THANK YOU NELSON AND EVERYBODY FOR THEIR NICE CONTRIBUTION!
Good times with ACA mini
Eric
maybe 🙂
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Thank you for your remark and question and sorry for not cleaning the furniture before taking a photo.
The heatsinks get at 27° (C) ambient on the top about 44-46° and near the FET ~55° after 2 hrs (measured at the outer side). The heatsinks are stacked (a little larger ones than the originals). I‘ll do another one with the original heatsinks once. The plate on the top is quite heavy and will get warm too.
The heatsinks get at 27° (C) ambient on the top about 44-46° and near the FET ~55° after 2 hrs (measured at the outer side). The heatsinks are stacked (a little larger ones than the originals). I‘ll do another one with the original heatsinks once. The plate on the top is quite heavy and will get warm too.
Thank you, the goal was to substitute my direct heated PP amp and to enjoy the music also in summertime. The proportion probably must change to meet the other devices. I wished to meet the design of the CD-player… but the plate, where the line is, it’s a little high ;-)