Sorry, but the power supply is not my IP to publish. The power supply is by Doug Self and can be found on page 530 of his book "Small Signal Audio Design". I invite you to buy his book. It's a good one!
Supplemental info was included in the zip file that I sent you when you purchased the PCBs
Supplemental info was included in the zip file that I sent you when you purchased the PCBs
Last edited:
I just finished the power supply to this project, and when I test it unloaded i get different readings on the positive and negative rail.
I get +16.56 V DC and -16.91 V DC at the output. If if I measure directly on the secondarys I get 22.15 V AC on both.
Is it normal to have a difference like this on the positive/negative side or should I worry?
Thanks
I get +16.56 V DC and -16.91 V DC at the output. If if I measure directly on the secondarys I get 22.15 V AC on both.
Is it normal to have a difference like this on the positive/negative side or should I worry?
Thanks
No experience with this preamp I'm afraid but generally I would tend to favour a snubber across the secondary as a general purpose 'fix all'. If I were adding something across each diode in the bridge, then again, it would be a snubber of some sort rather than a single cap across each.
Ceramics are OK as long as suitably rated. Transient currents can be large and voltage rise times fast. Foil or mica might be a better bet.
Ceramics are OK as long as suitably rated. Transient currents can be large and voltage rise times fast. Foil or mica might be a better bet.
Doug Self Preamp PCB Kit
Hello all,
I have been inundated with several requests of late for project PCBs. As result I've decided to place one more order for them.
A couple of improvements ...
#1) Per request, the front panel potentiometers have been spread a bit further apart to allow the builder to use a larger knobs.
#2) As before the PCBs are commercial grade double side, plated thru, and tinned. However this time they are cobalt blue in color so as to easily tell this version from the previous. White silkscreen is applied to the top side to aid in parts placement.
#3) The circuit and BOM are identical to previous versions.
#4) The power supply for this project has been improved in that it is now adjustable. Voltages can now be adjusted from +/-9 volts to +/-24 volts and tweaked to track exactly with one another.
// -----------
The PCB kit costs $60 US and amounts to ...
#1) the main PCB (255mm x 155mm)
#2) the 5 x 1 IO board with front panel selector switch and 2 OEM quad RCA phono connector blocks
#3) Power supply PCB (120v but can be modded to 230v)
// -----------
Once I receive your order I will send you a collection of documents that are a pdf the original Linear Audio article (courtesy of Jan Didden and Linear Audio) project schematics, build notes and BOMs.
Please let me know immediately by sending me a private message if you want in on the buy. I will be placing the order April 1st. I expect to ship PCBs within a couple of days of my receipt. That means those that purchase should receive their purchase by April 15th.
Hello all,
I have been inundated with several requests of late for project PCBs. As result I've decided to place one more order for them.
A couple of improvements ...
#1) Per request, the front panel potentiometers have been spread a bit further apart to allow the builder to use a larger knobs.
#2) As before the PCBs are commercial grade double side, plated thru, and tinned. However this time they are cobalt blue in color so as to easily tell this version from the previous. White silkscreen is applied to the top side to aid in parts placement.
#3) The circuit and BOM are identical to previous versions.
#4) The power supply for this project has been improved in that it is now adjustable. Voltages can now be adjusted from +/-9 volts to +/-24 volts and tweaked to track exactly with one another.
// -----------
The PCB kit costs $60 US and amounts to ...
#1) the main PCB (255mm x 155mm)
#2) the 5 x 1 IO board with front panel selector switch and 2 OEM quad RCA phono connector blocks
#3) Power supply PCB (120v but can be modded to 230v)
// -----------
Once I receive your order I will send you a collection of documents that are a pdf the original Linear Audio article (courtesy of Jan Didden and Linear Audio) project schematics, build notes and BOMs.
Please let me know immediately by sending me a private message if you want in on the buy. I will be placing the order April 1st. I expect to ship PCBs within a couple of days of my receipt. That means those that purchase should receive their purchase by April 15th.