audio-talk

Yeah, the docs could certainly be clearer.

But most connector docs aren't exactly straightforward I've found. The RS website is the best search engine I found, at least you can search for poles and voltage. Mouser for instance is all about the insert type.

Interesting perspective Nick, thanks. Not sure it makes things any clearer in my mind but it should be reassuring to some extent. I've found these connectors at CPC which look about the best option I reckon: Socket (£5.76) https://cpc.farnell.com/mbs-connect/sp2112-s9-1c/circular-panel-socket-9-pole...

Thanks Nick, that's good - 450VAC is much easier to source than 800VAC

I still need to source an adequate connector. Most give an AC rating rather than DC. Is is reasonable to convert an AC rating to give a DC rating? And if so the internet tells me VDC = VAC / (root 2). I thought it was VDC = VAC / (2 x root 2) - not something I want to get wrong!

Second draft, minus the transformer. I should probably add a fast blow fuse though.
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I remember now why I thought a PCB tx was a good idea - 2x12V secondaries chassis mount EI transformers are quite scarce. Farnell have one, Mouser none, Digikey one but it's a special order. Unless I'm looking in the wrong places.

Thanks. I don't have to use a PCB mount tx, I just thought it was neater. I'll think a bit more.

First draft of the raw PS PCB for the TubeCAD MC Pre. . TubeCAD MC Pre PS screenshot.png . The transformer shown above is bigger than the actual size as I bodged an existing footprint for the Vigortronix 2x12V 6VA PCB tx I intend to use but I haven't changed the 3D model. I want to check the actual ...

Ah right, I see. I'm drafting a PCB for a PCB mount transformer, Quasi, rectifiers and filter. I thought I'd put a ground plane under the transformer to connect to the joins of the two pairs of snubbers, rather than solder wires in the middle of the board. I figure the ground plane should be fairly ...

I've used Hirschmann G30 series in the past - very good, locking (bolt through the middle) and a very reasonable price: https://www.tme.eu/gb/katalog/g-connectors_112982/?params=2:all;416:1450310_manufacturer:hirschmann;connector-series:g They look like they're only 4 way, unfortunately I need 9 po...

Morgan Jones wrote: ↑Thu Sep 12, 2024 1:26 pm Add 10n polyester from each end of each secondary directly to chassis. That will become a 5nF slugger/injection capacitor, so use that in the Quasimodo test.

Why polyester? Instinctively I'd look at polypropylene (audiofoolery?) but it's obviously not the best dielectric in this case.

Fair point. A lot of connector info isn't very specific I've found. I've spent years looking, on and off, for a reasonable price connector for valve projects but just never found suitable. Even the expensive mil spec stuff at Mouser et al isn't straightforward - got to work out the pin configuration...

I'd never considered using D connectors and just the thought makes me a little nervous! But this is the datasheet for the very first D connector I came across - 500V and 5A. So definitely worth pursuing. https://acrobat.adobe.com/id/urn:aaid:sc:EU:c02518eb-bad9-4199-bf1b-0dbeab0e4f8b For screening b...

What could possibly go wrong? :-D I'll go back and read what Morgan wrote. As the currents are so small (2mA per channel for the Boozehound and 24mA per channel for the Tubecad IIRC, will have to look at LTSpice again to remind myself) is it worth thinking about a shunt reg? I've never used a TL431 ...

Rather than let all this scary stuff put me off an umbilical I'm reminding myself I'm building this for me only and don't need to worry about harming anyone else :-) (my better half won't go anywhere near stuff I build, a very healthy attitude!) Back to the jfet MC pre(s) for a moment. I built two -...