I use these too - but the cost + freight cost makes it very expensive unless you are buying other parts at the same time.Jay wrote: ↑Mon Nov 11, 2024 9:26 amIt will work provided amp rating is sufficient and you only need to switch between two options. Also, it can get knocked out of position...StrummersOfThunder wrote: ↑Mon Nov 11, 2024 8:22 am Would this be over kill ratings wise for an output impedance switch ?
https://surplustronics.co.nz/products/6 ... SVR4TXp3Xx
The other local option :
https://oamarucomputers.co.nz/product/s ... le-switch/
Or are the 250v 2A mini toggles from Jay car ok ?
A better choice is this:
https://www.amplifiedparts.com/products ... position-0
6g2 Brownface Princeton build
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Re: 6g2 Brownface Princeton build
Whakanuia o mea kei a koe
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Re: 6g2 Brownface Princeton build
So, the speaker current is AC, not DC. But you can get an idea of the current & voltage handling required (the DC formula you've used gets you in the ballpark) then choose a switch with "better" (say double) ratings for current & voltage. Also consider the mechanical rigidity of the switch because it WILL get knocked! If it was a 100W amp I'd do the AC calcs or choose a switch/impedance selector that someone like Amplified parts sell.Jay wrote: ↑Mon Nov 11, 2024 9:33 amFor DC the formulea are correct. It will work for your scenario.StrummersOfThunder wrote: ↑Mon Nov 11, 2024 9:23 amIs this correct:
15w OT -> V = √PR
For an 8 ohm speaker V =√15x8 = 11v Current would be -> I=V/R = 11/8 = 1.4. for a 4ohm speaker 2.75 for a 16ohm speaker 0.7A
I was going to do 8/16 impedence switching
So the mini toggle should be ok?
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Re: 6g2 Brownface Princeton build
How would the formulae look for AC?Jay wrote: ↑Mon Nov 11, 2024 9:33 amFor DC the formulea are correct. It will work for your scenario.StrummersOfThunder wrote: ↑Mon Nov 11, 2024 9:23 amIs this correct:
15w OT -> V = √PR
For an 8 ohm speaker V =√15x8 = 11v Current would be -> I=V/R = 11/8 = 1.4. for a 4ohm speaker 2.75 for a 16ohm speaker 0.7A
I was going to do 8/16 impedence switching
So the mini toggle should be ok?
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Re: 6g2 Brownface Princeton build
Complicated!StrummersOfThunder wrote: ↑Mon Nov 11, 2024 9:45 amHow would the formulae look for AC?Jay wrote: ↑Mon Nov 11, 2024 9:33 amFor DC the formulea are correct. It will work for your scenario.StrummersOfThunder wrote: ↑Mon Nov 11, 2024 9:23 am
Is this correct:
15w OT -> V = √PR
For an 8 ohm speaker V =√15x8 = 11v Current would be -> I=V/R = 11/8 = 1.4. for a 4ohm speaker 2.75 for a 16ohm speaker 0.7A
I was going to do 8/16 impedence switching
So the mini toggle should be ok?
Whakanuia o mea kei a koe
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Re: 6g2 Brownface Princeton build
Under board wiring done and board installed.
Starting the off board wiring
Starting the off board wiring
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Re: 6g2 Brownface Princeton build
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Re: 6g2 Brownface Princeton build
Hopefully it doesnt smell the same when I fire it up !Jay wrote: ↑Mon Nov 11, 2024 7:46 pm I see you caps are roasted by my local cafe
https://sozocoffee.co.nz/
Did you make yourself a current limiter or use a Variac ?
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Re: 6g2 Brownface Princeton build
I use a poor man's 240VAC lightbulbStrummersOfThunder wrote: ↑Mon Nov 11, 2024 7:51 pmHopefully it doesnt smell the same when I fire it up !Jay wrote: ↑Mon Nov 11, 2024 7:46 pm I see you caps are roasted by my local cafe
https://sozocoffee.co.nz/
Did you make yourself a current limiter or use a Variac ?
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Re: 6g2 Brownface Princeton build
Care to post a diagram of it ?Jay wrote: ↑Mon Nov 11, 2024 8:06 pmI use a poor man's 240VAC lightbulbStrummersOfThunder wrote: ↑Mon Nov 11, 2024 7:51 pmHopefully it doesnt smell the same when I fire it up !Jay wrote: ↑Mon Nov 11, 2024 7:46 pm I see you caps are roasted by my local cafe
https://sozocoffee.co.nz/
Did you make yourself a current limiter or use a Variac ?
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Re: 6g2 Brownface Princeton build
It's just a bayonet fitting in series with the PT primary causing a voltage drop and a visual way of seeing what is going on. Too bright under no load and without valves is no good
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Re: 6g2 Brownface Princeton build
Bit more progress last night.
All thats left now is to install the filter caps ( when they arrive) , heater filaments and OT.
All thats left now is to install the filter caps ( when they arrive) , heater filaments and OT.
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