https://elprojects.wordpress.com/2014/01/13/soft-start-circuit/
I have used this circuit with success
A link to A40 schematic and pcb pleaseI can confirm ....... Have built A40 already,very nice and powerful .
Best regards,Alex
A link to A40 schematic and pcb please
Download the attached spreadsheet, and search the "A40" tab on the bottom: http://www.diyaudio.com/forums/solid-state/292226-directory-apex-audio-amplifiers-5.html#post4751139
You may also see: http://www.diyaudio.com/forums/solid-state/292226-directory-apex-audio-amplifiers.html
A link to A40 schematic and pcb please
Hi Thimios,
The Schematic is in post #4026.
The board layout that Alex posted is in post #4037.
Attachments
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It looks to me that the T5A and the 47r, 20W are chosen to suit a 1kVA transformer.
I would use a lower resistance than 47r for a 1000VA to 1200VA, maybe 20r to 30r.
Or changing to a lower fuse for a 220/240Vac, 500VA (T2A), 750VA (T3.1A), 900VA (T4A).
If this is scaled to 110/120Vac duty then halving all the resistor values would be about right.
Maybe need to increase the value of 220uF to get the delay you require.
And double the value of the fuse.
I would use a lower resistance than 47r for a 1000VA to 1200VA, maybe 20r to 30r.
Or changing to a lower fuse for a 220/240Vac, 500VA (T2A), 750VA (T3.1A), 900VA (T4A).
If this is scaled to 110/120Vac duty then halving all the resistor values would be about right.
Maybe need to increase the value of 220uF to get the delay you require.
And double the value of the fuse.
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I have no history with this long thread as I have been making class A amps on Pass forum. However I will be trying an iteration of LX521 speakers, only with sealed monopole bass and I am wondering if it is possible to improve on the Emotiva XPA-5 amp with a DIY amp.
I have a few of the new output devices: MJL4281A (NPN) and MJL4302A (PNP) lying around.
>>Any of the designs here making use of these and with a good performance both down low and high up?? (since my mids will still be driven by classA monoblocks)
If not I can probably make Rod Elliot's P3A. on a second thought I could probably even make a pcb to switch between the P3A and one of Mile's designs (AX? or?) to make a comparison if the circuit was reasonable close; maybe only a difference in the output stage?
any thoughts on this challenge?
I have a few of the new output devices: MJL4281A (NPN) and MJL4302A (PNP) lying around.
>>Any of the designs here making use of these and with a good performance both down low and high up?? (since my mids will still be driven by classA monoblocks
)If not I can probably make Rod Elliot's P3A. on a second thought I could probably even make a pcb to switch between the P3A and one of Mile's designs (AX? or?) to make a comparison if the circuit was reasonable close; maybe only a difference in the output stage?
any thoughts on this challenge?
