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Dr Tony Balls wrote: ↑

Wed Apr 24, 2024 7:25 am

Hard to say. Those F&Ts are 38mm long, and the board you bought is 45 with the turrets set in a bit....it'll be a tight fit for sure but you may be able to elevate the caps above the turrets if there's not enough clearance.

I did think that was what was probably gonna have to happen.

Or there's this one that's the same sort of style you usually use with the double tabs.

*EDIT: actually, screw it. I've ordered one of those instead. It's a little cheaper and looks to be a bit more spacious. Not a lot, but an extra 10mm would be nice and I like to silicone down the big caps

I do have a few of these I can use too, it it makes laying things out more convenient...



I was going to use one near the PT to do the centre tap, and maybe ground the resistor from the bias pot. But I have at least 1 spare

JSett wrote: ↑

Wed Apr 24, 2024 8:13 am

I do have a few of these I can use too, it it makes laying things out more convenient...



I was going to use one near the PT to do the centre tap, and maybe ground the resistor from the bias pot. But I have at least 1 spare

This PT has no center (centre) tap, the reference to ground will be created with a bridge rectifier. So you wont need a terminal strip there. Could to know that you have them, though, and can always use them for caps that dont fit, screen grids, etc. This will all click into place a bit when I get a layout worked up.

Dr Tony Balls wrote: ↑

Wed Apr 24, 2024 8:24 am

This PT has no center (centre) tap, the reference to ground will be created with a bridge rectifier. So you wont need a terminal strip there. Could to know that you have them, though, and can always use them for caps that dont fit, screen grids, etc. This will all click into place a bit when I get a layout worked up.

Ahh, okay. I knew there was no centre (center) tap and assumed I'd have to do a virtual one with two 100r to ground like I did on my amp build back in 2022. Is there a bias tap on the PT or is that done with circuit trickery too? I couldn't see one but the cables are messy AF in there

I just looked and I have 1x 5 way (1 to ground) and 3x 3 way (1 to ground) of those mini terminal strips to play with. One will be nice on the 1k5 resistors coming from the power tube pins 5 before they go to the master volume for extra stability. I can do that myself though, no need to include on a drawing.

Easy part is done. To note:

1) no center tap on the PT secondary. ground reference is achieved through bridge rectifier.
2) no center tap on the PT filament secondary. ground reference is achieved through R30 & R31.
3) brown utility tap used for bias voltage.
4) master volume is dual gang.

Dr Tony Balls wrote: ↑

Wed Apr 24, 2024 9:10 am

Easy part is done. To note:

1) no center tap on the PT secondary. ground reference is achieved through bridge rectifier.
2) no center tap on the PT filament secondary. ground reference is achieved through R30 & R31.
3) brown utility tap used for bias voltage.
4) master volume is dual gang.

Cheers Tony, that is great. I'm trying to read it and check what I know vs my parts list.

Is C7 supposed to be 0.001uF or should it be 0.01uF?

JSett wrote: ↑

Wed Apr 24, 2024 9:55 am

Is C7 supposed to be 0.001uF or should it be 0.01uF?

You're correct, that should be 0.01uF

Here's a rev 2.0:

Dr Tony Balls wrote: ↑

Wed Apr 24, 2024 9:56 am

JSett wrote: ↑

Wed Apr 24, 2024 9:55 am

Is C7 supposed to be 0.001uF or should it be 0.01uF?

You're correct, that should be 0.01uF

Whoop! I'm learning

Oh also all resistors are 1/2W unless noted.

Dr Tony Balls wrote: ↑

Wed Apr 24, 2024 10:01 am

Oh also all resistors are 1/2W unless noted.

Yeah, I gathered as much. I've got a lot here but all 1w so I've ordered what I need in the same wattage for now so they're mostly the same size visually.

Knowing what I know of schematics (very little) it is still starting to make sense. I can see each section now and know what it does - to a point. Translating it into a 3D layout and subsequent building is where I fall short

Here's my high tech parts list ...



I went with 1N5408 1000v Rectifiers

JSett wrote: ↑

Wed Apr 24, 2024 10:24 am

I've got a lot here but all 1w

1w is FINE, just maybe a little bigger.

JSett wrote: ↑

Wed Apr 24, 2024 10:27 am

Here's my high tech parts list ...

You're gonna need FIVE diodes. Make em 1N5408s.

Dr Tony Balls wrote: ↑

Wed Apr 24, 2024 10:29 am

You're gonna need FIVE diodes. Make em 1N5408s.

That's handy, I just ordered 5 more - and 1N5408 as well. Pretty sure I have some in the drawer somewhere too but they're small and I can't see them

I only just spotted the one in the bias circuit too. Sneaky little begger

For anyone else following, I've made a parts list:



The 'Ordered From' is obviously for my reference. You can buy from wherever.

Damn now I want to do a custom Hotrod amp