It's working very well! You were right, with a load voltage is easy to adjust and stays constant.
My transformer gives me 37V unloaded and I adjusted the capacitance multiplier output to 35V. When a load is connected the transformer will give less voltage, it's rated 25Vac when full loaded at 6A per secundary. So, will the cap voltage tracks the transf voltage, that is, when the input voltage decresses one volt will the output also decrease 1V (so the 2V voltage drop remains constant) or it will stay at 35V even if the input is 36 or 35?
What fuse rating should I use?
thanks!
My transformer gives me 37V unloaded and I adjusted the capacitance multiplier output to 35V. When a load is connected the transformer will give less voltage, it's rated 25Vac when full loaded at 6A per secundary. So, will the cap voltage tracks the transf voltage, that is, when the input voltage decresses one volt will the output also decrease 1V (so the 2V voltage drop remains constant) or it will stay at 35V even if the input is 36 or 35?
What fuse rating should I use?
thanks!
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Thanks for the feedback.
When the transformer voltage sags under high load the output will follow, though relatively slowly. That's the beauty of the CM supply, it gives most of the benefits of regulation without being a regulator.
For a pair of VSSA or similar, 6-8A for the fuses will be fine.
When the transformer voltage sags under high load the output will follow, though relatively slowly. That's the beauty of the CM supply, it gives most of the benefits of regulation without being a regulator.
For a pair of VSSA or similar, 6-8A for the fuses will be fine.
Ok 
Have My PS board.. completed?
(under ordered a few wee caps so had to substitute from on hand, same values tho)
Couple of small questions:
What size Fuses ? (240va 28 v Torroid) ooops just read the above: 6-8 amps then ??
Is there a diagram for connections to the myriad wire attachment points?
Not wiilling to simply guess , hope and risk...at this point
Thanks
Have My PS board.. completed?(under ordered a few wee caps so had to substitute from on hand, same values tho)
Couple of small questions:
What size Fuses ? (240va 28 v Torroid) ooops just read the above: 6-8 amps then ??
Is there a diagram for connections to the myriad wire attachment points?
Not wiilling to simply guess , hope and risk...at this point
Thanks
Attachments
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Hi Bare,
The connections should be pretty straightforward. Hardest part will be proper phasing of a dual secondary transformer. As I recall you got an Antek that has dual secondaries and should also have colour coded leads and a connection diagram, so it should be straight forward compared to some.
The end with the pass MOSFETs has three sets of euroblock connectors (spades could be used there if desired). Two sets are labeled as +V GND -V, and are meant to power the amplifiers. The three GND connections in the middle are just for added flexibility in how you return things to the PSU, some have very specific ideas on that.
The input side has two euroblocks (or again spades could be used) labeled +V GND, or -V GND. They can be used to feed DC out to something else that doesn't need to pass through the capacitance multiplier, or alternatively, they can be used to feed the circuit from off-board dual rectifiers. Once again some added flexibility.
The main AC inputs are set-up to accommodate either dual secondaries or a centre-tapped secondary.
For a centre-tapped secondary the connections are AC1A-CT-AC2B.
For dual secondary the connections are AC1A-AC1B and AC2A-AC2B, with the 'phase dots' (same colour leads) located at AC1A and AC2A. The CT connection can be again used as an auxillary ground point.
For your specific transformer brand, if I recall you bought one from Antek:
AC1A - Green lead from either secondary
AC1B - Blue from the same secondary as AC1A
AC2A - Green lead from the other secondary
AC2B - Blue from the same secondary as AC2A
The connections should be pretty straightforward. Hardest part will be proper phasing of a dual secondary transformer. As I recall you got an Antek that has dual secondaries and should also have colour coded leads and a connection diagram, so it should be straight forward compared to some.
The end with the pass MOSFETs has three sets of euroblock connectors (spades could be used there if desired). Two sets are labeled as +V GND -V, and are meant to power the amplifiers. The three GND connections in the middle are just for added flexibility in how you return things to the PSU, some have very specific ideas on that.
The input side has two euroblocks (or again spades could be used) labeled +V GND, or -V GND. They can be used to feed DC out to something else that doesn't need to pass through the capacitance multiplier, or alternatively, they can be used to feed the circuit from off-board dual rectifiers. Once again some added flexibility.
The main AC inputs are set-up to accommodate either dual secondaries or a centre-tapped secondary.
For a centre-tapped secondary the connections are AC1A-CT-AC2B.
For dual secondary the connections are AC1A-AC1B and AC2A-AC2B, with the 'phase dots' (same colour leads) located at AC1A and AC2A. The CT connection can be again used as an auxillary ground point.
For your specific transformer brand, if I recall you bought one from Antek:
AC1A - Green lead from either secondary
AC1B - Blue from the same secondary as AC1A
AC2A - Green lead from the other secondary
AC2B - Blue from the same secondary as AC2A
Hi Bare,
Yes the primaries are connected in parallel for our region in the world, ~115VAC mains @ 60Hz. Red to red and black to black.
The purple shield wire should be connected to the main chassis ground, right where you should have a bonded mains ground wire to the chassis. I usually use a longish brass bolt and put the mains ground connection at the bottom with appropriate washers and a nut. Anything else that should go to the 'protected earth' gets connected on top of that. Quick diagram attached.
Yes the primaries are connected in parallel for our region in the world, ~115VAC mains @ 60Hz. Red to red and black to black.
The purple shield wire should be connected to the main chassis ground, right where you should have a bonded mains ground wire to the chassis. I usually use a longish brass bolt and put the mains ground connection at the bottom with appropriate washers and a nut. Anything else that should go to the 'protected earth' gets connected on top of that. Quick diagram attached.
Attachments
Is the purple wire the interwinding screen?
The screen's purpose is to conduct interference to "Earth".
This is done by inserting a low impedance connection from the internal screen to the Chassis and then capacitive coupling from the Chassis to "Earth" (that big round ball that we all sit on while listening to out music).
For a low impedance connection, the wire link should be short. If the wire link is long then it will have higher impedance due to inductance of the longer wire.
Take the screen connection direct to Chassis at the point that the screen wire exists the transformer insulation.
If one does not do this, then the HF and VHF and UHF components of the interference will see a high impedance connection to Earth.
The screen's purpose is to conduct interference to "Earth".
This is done by inserting a low impedance connection from the internal screen to the Chassis and then capacitive coupling from the Chassis to "Earth" (that big round ball that we all sit on while listening to out music).
For a low impedance connection, the wire link should be short. If the wire link is long then it will have higher impedance due to inductance of the longer wire.
Take the screen connection direct to Chassis at the point that the screen wire exists the transformer insulation.
If one does not do this, then the HF and VHF and UHF components of the interference will see a high impedance connection to Earth.
Gentlemen, I have equipped the Nelson Pass ACA#1 - PCBs of my current 4-channel ACA - build, being used for the high- and middle tones of an active speaker-project,
with onboard Jason's CAP-multiplier (image1).
I have adjusted the ACAs (using a 4x20VAC/300VA custom wound torroid - image2)) to an operating voltage of 24.5VDC and an ACA "bias voltage" of 12VDC.
I am measuring an incredibly low ripple of <2mVAC (image 3) on the output voltage.
In my eyes (ears): Jason's CAP-multiplier (which is even adjustable within a small range) is a real gem, and you will get hooked on the ACA's sound.
Why should you ever go for any other PSU, giving you a "small" (about 1.4A) current?
Best regards - Rudi_Ratlos
with onboard Jason's CAP-multiplier (image1).
I have adjusted the ACAs (using a 4x20VAC/300VA custom wound torroid - image2)) to an operating voltage of 24.5VDC and an ACA "bias voltage" of 12VDC.
I am measuring an incredibly low ripple of <2mVAC (image 3) on the output voltage.
In my eyes (ears): Jason's CAP-multiplier (which is even adjustable within a small range) is a real gem, and you will get hooked on the ACA's sound.
Why should you ever go for any other PSU, giving you a "small" (about 1.4A) current?
Best regards - Rudi_Ratlos
Attachments
Rudi
How do you think the CAP-multiplier would work with the FC-100 amp - somthing worth trying?
Jason, do you have any boards left for sale?
Thanks
How do you think the CAP-multiplier would work with the FC-100 amp - somthing worth trying?
Jason, do you have any boards left for sale?
Thanks
Hi marcus1,
Sorry to say I do not have any boards left. The files have been downloaded a fair number of times; maybe someone else had some made?
I think the supply can be used with any amplifier that falls into the mid-range power level that might benefit from a quiet supply. Always worth a shot.
Jason, Marcus1: Roender's FC-100 is a very powerful amplifier with 3 TO-264 output transistors (NJL0281 / NJL0302) on each power-rail.
Moreover: the FC-100 design distinguishes very precisely between frontend- and backend power-supply. For example: Roender developped a very precise shunt regulator to drive the frontend of the FC-100.
In contrast the backend power-supply is simple: rectifier diodes and reservoir caps.
I myself would not use Jason's cap-multiplier to power the FC-100.
A lot of other "smaller" amplifiers (like the standard SYMASYM or the ClassA ACA#1 f.e.) would/do benefit from Jason's CAP-multiplier though.
I have done a layout for Jason's PSU and ordered a couple of PCBs (together with a dual LT1763-based PSU on the same PCB - I will cut the PCB).
The PCB's sizes are:85x50mm (Jason's PSU) and 90x50mm (the LT1763 PSU).
The PCBs will arrive in 2-3 weeks.
I can offer you one (more?) of these PCBs.
Best regards - Rudi_Ratlos
Moreover: the FC-100 design distinguishes very precisely between frontend- and backend power-supply. For example: Roender developped a very precise shunt regulator to drive the frontend of the FC-100.
In contrast the backend power-supply is simple: rectifier diodes and reservoir caps.
I myself would not use Jason's cap-multiplier to power the FC-100.
A lot of other "smaller" amplifiers (like the standard SYMASYM or the ClassA ACA#1 f.e.) would/do benefit from Jason's CAP-multiplier though.
I have done a layout for Jason's PSU and ordered a couple of PCBs (together with a dual LT1763-based PSU on the same PCB - I will cut the PCB).
The PCB's sizes are:85x50mm (Jason's PSU) and 90x50mm (the LT1763 PSU).
The PCBs will arrive in 2-3 weeks.
I can offer you one (more?) of these PCBs.
Best regards - Rudi_Ratlos
Attachments
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You could use a cap multiplier to provide a cleaner supply to the front end of the Roender amplifier.
I would not use any form of multiplier/regulator to supply the "power" end of the Roender. As from Rudi, a simple rectifier/smoother is sufficient.
i just realized i have using tip142/147 without pinout change from your original pcb from the first page, meant for mosfets. and the circuit has been working fine, sounds great. what's been happening here?
the voltage can be adjusted, the darlingtons are lukewarm to the touch. tip142 in the positive rail. i just dropped it in the mosfet slot without bending legs or even thinking about it...
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