Tom, here are some AC-AC wall warts offered for sale at Jameco's store in Belmont California, and also on their website. You could try a test order from their web store to discover whether they'll ship all over North America; perhaps try Mexico or Canada or Barbados. Another way to find AC-AC warts is to search eBay and AliExpress and Alibaba for "CCTV transformers" ; apparently a big piece of the closed circuit TV hardware market is standardized on 24VAC power input, through barrel jack connectors.
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Interesting. I wonder why the distributors turned me down then. I did look at Jameco back then. Maybe the requirements have been relaxed. I just had a quick peek at Digikey. They now have plenty of Triad brand wall warts now in the AC/AC power supplies section. Go figure.
No doubt you can get wall warts from China. At the time I was needing some, I tracked down the Chinese manufacturer Schiit uses for their wall warts. The wall warts were stupid cheap. Like a few bucks each kinda cheap. The only snag was that the minimum order quantity was 250 and that was more warts that I wanted to store in my garage, especially since I'd need at least four different ones to cover the four major plug types.
Tom
No doubt you can get wall warts from China. At the time I was needing some, I tracked down the Chinese manufacturer Schiit uses for their wall warts. The wall warts were stupid cheap. Like a few bucks each kinda cheap. The only snag was that the minimum order quantity was 250 and that was more warts that I wanted to store in my garage, especially since I'd need at least four different ones to cover the four major plug types.
Tom
Hello Jan,
Where would I find a schematic and/or gerbers for this regulator. I saw nothing in the GB thread.
I'd love to see what it is all about.
Many thanks,
Steve
The reason the Preamp Power Supply is ±12 V and not the more common ±15 V is that the RECOM switching brick are available in ±15 V and ±24 V output with nothing in between. The two LDOs on the board require some voltage across them to regulate. They're very low noise, so that was a tradeoff that I was willing to make. For the vast majority of audio circuits ±12 V vs ±15 V makes no practical difference.
The other reason for ±12 V is that it allows the Preamp Power Supply to be used to power the input buffer of a Hypex NC500 and Purifi 1ET400A amp.
Tom
The other reason for ±12 V is that it allows the Preamp Power Supply to be used to power the input buffer of a Hypex NC500 and Purifi 1ET400A amp.
Tom
Thanks Tom and Jim.
I have two Preamp Power Supply (s) one for a HP22 in a Hammond enclosure. The other is for swapping in and out of what ever experiment is on the bench top, including the Pearl 3.
The Preamp Power Supply may be part of a P3 one box solution.
Thanks DT
I have two Preamp Power Supply (s) one for a HP22 in a Hammond enclosure. The other is for swapping in and out of what ever experiment is on the bench top, including the Pearl 3.
The Preamp Power Supply may be part of a P3 one box solution.
Thanks DT
Take the right and left channel boards and power them with two different supplies. Use one channel of your cartridge, or a low level feed from another music source.
Feed the outputs into a differential amplifier. Play some music and observe the difference on a 'scope.
For the gold standard, one of the power supplies can use Jan's Super Regulator set to 18V. The LM7815/7915 will actually add noise in this case! The method was suggested to me by "the editor" when we did the great power supply bake-off for LinearAudio (but we just did an exhaustive listening test).
Feed the outputs into a differential amplifier. Play some music and observe the difference on a 'scope.
For the gold standard, one of the power supplies can use Jan's Super Regulator set to 18V. The LM7815/7915 will actually add noise in this case! The method was suggested to me by "the editor" when we did the great power supply bake-off for LinearAudio (but we just did an exhaustive listening test).
Steve, ask Patrick. It may be that he provides a schematic with the unit.
I received fully assembled boards; they're tiny, only a little bit larger than the 78xx/79xx series and have the same pinout, with the a copper plane at the back for connection to a heat sink if required.
Jan
Thank you Jan. I was asking about the schematic because I have no idea what type of regulator it is. I guess I can check with Patrick unless you know what flavor regular this is. Thanks.
This is a screen shot of the AP500 screen; the P3 input breadboard with the ZTX NPN transistors, without the jfets (1k resistor in their place).
Two 12volt gel cells are in series, to KA7815 regulator to the P3 input breadboard.
The breadboard is in a 8 X 8 X 4 J box bonded to the analyzer ground.
The cookie tin still has cookies in it.
At this point batteries are looking good. I suspect that the jfets and more so the cartridge will dominate the noise.
Thank DT
Two 12volt gel cells are in series, to KA7815 regulator to the P3 input breadboard.
The breadboard is in a 8 X 8 X 4 J box bonded to the analyzer ground.
The cookie tin still has cookies in it.
At this point batteries are looking good. I suspect that the jfets and more so the cartridge will dominate the noise.
Thank DT
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I’ve got the ESP-05 power supply for the ESP-06 preamp kit but a bit confused about what power source is ideal.
The choices are:
- 16V AC 1A wall wart,
- 15 VA transformer 0-15V
- 30VA transformer 0-15-30V
- 30VA transformer 0-15V x2 separate windings
What’s not clear is whether the wall wart or single winding transformer still supports +/- 15V outputs as needed by the ESP06
Split the supply, it is easy to do, just put two caps in series across supply, conect ends to 0-30, the joint of the caps is ground.
That gives you the 15-0-15 you need.
That gives you the 15-0-15 you need.
I have a power supply board, the question I am asking is which of the options above are preferred for the power source.
@Kevviek , I use the 1/2 bridge with a 15V AC 1.5A wall wart for my phono pre. 1.5A is probably overkill but what I had.
This scheme works very well for a pre amp and keeps any magnetic fields outside the chassis and away from the circuit.
The link supplied above to the Elliot PS board is what wouls be cheapest and easiset for you in Oz.
I use a 1.5x the bulk capiticance that Rod uses. Also overkill but it works well.
You might also consider wrapping the AC line with a ferrite sleeve before entering the chassis.
This scheme works very well for a pre amp and keeps any magnetic fields outside the chassis and away from the circuit.
The link supplied above to the Elliot PS board is what wouls be cheapest and easiset for you in Oz.
I use a 1.5x the bulk capiticance that Rod uses. Also overkill but it works well.
You might also consider wrapping the AC line with a ferrite sleeve before entering the chassis.
For a completely overbuilt option with adjustability, one could combine the MW +/- 15VDC unit(s) MJ mentioned and add Tombo's R25 regulated power supply boards that include filtering. I have two of those MW units powering a WBA2018 with subjective silent background (no extra filtering).
Edit: I may have misspoke. Tombo's R25 may only be for AC in. So like MJ said, use the amyalice filters with the MW +/-15VDC unit.
Edit: I may have misspoke. Tombo's R25 may only be for AC in. So like MJ said, use the amyalice filters with the MW +/-15VDC unit.
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