My buddy is in the music instrument amp repair business and hes been around for a good number of years and has quite a bit of Russian surplus PIO caps and iron kicking around. I do believe he did say he had a 7H 1A choke or could get one... i know it was one of the 2 🙂
as far as the transformers i will be going with Hammond and they did say they can custom wind me something for like a $30 setup fee.
Was thinking 400-0-400 @1A or 1.5A should be plenty, but not sure how many tube rectifiers can handle this amount of current :/
as far as the transformers i will be going with Hammond and they did say they can custom wind me something for like a $30 setup fee.
Was thinking 400-0-400 @1A or 1.5A should be plenty, but not sure how many tube rectifiers can handle this amount of current :/
Power Supply schematic...
Still trying to find a working PP Quad Schematic that i can replace the KT88s with KT120 with minimal mods.
An externally hosted image should be here but it was not working when we last tested it.
Still trying to find a working PP Quad Schematic that i can replace the KT88s with KT120 with minimal mods.
SW3 and SW3 control are voltage select switches.
SW3 allows control 300 or 400 VAC, SW4 is for screen voltage select at 100 or 200 VAC. SW5 is for floating the ground of the powersupply
SW3 allows control 300 or 400 VAC, SW4 is for screen voltage select at 100 or 200 VAC. SW5 is for floating the ground of the powersupply
There is the potential for a lot of energy to be in the transformer at the time of some switching operations - overvoltage spiking on the windings can be managed by MOVs or capacitors to divert high dV/dt and high V levels.
Were you planning on any NTC or inrush management, or fusing?
If switch 3 is double pole then you may want to check its working voltage level to earth, and between poles.
Was your plan with the standby switch to have screens powered but not B+ ?
You've got a lot of discrete pre-load resistors - is there a reason for so many?
Ciao, Tim
Were you planning on any NTC or inrush management, or fusing?
If switch 3 is double pole then you may want to check its working voltage level to earth, and between poles.
Was your plan with the standby switch to have screens powered but not B+ ?
You've got a lot of discrete pre-load resistors - is there a reason for so many?
Ciao, Tim
On Standby the high voltage transformer are off and only the heater transformer are on allowing the 866's to come up to working temperature as they require up to 30 seconds to allow mercury to become vapor before they can be blasted with HV.
The resistors are in place to discharge the caps and not to allow a static charge build up in the caps.
The switches will most likely will be replaced by relays and when standby will be triggered a 5V remote will also trigger the each mono block to warm up the tubes.
Either way...
The main transformers HV transformers will be 0-100-200-300-400 @ 1A
Since they will be custom run from either Hammond or Mercury Magnetics...
I been tinkering with the idea of adding in more taps just in case i decide to use this power supply in other builds...
In that case it will be 0-50-100-150-200-250-300-350-400-450 still at 1A
Now just gonna have to find a 4 pin ( 2 HV + GND + Remote ) connector that will withstand 1KV @ 0.5A :s
The resistors are in place to discharge the caps and not to allow a static charge build up in the caps.
The switches will most likely will be replaced by relays and when standby will be triggered a 5V remote will also trigger the each mono block to warm up the tubes.
Either way...
The main transformers HV transformers will be 0-100-200-300-400 @ 1A
Since they will be custom run from either Hammond or Mercury Magnetics...
I been tinkering with the idea of adding in more taps just in case i decide to use this power supply in other builds...
In that case it will be 0-50-100-150-200-250-300-350-400-450 still at 1A
Now just gonna have to find a 4 pin ( 2 HV + GND + Remote ) connector that will withstand 1KV @ 0.5A :s
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This is just a partial mock up as there are a few elements left off and its still in design phase as untill i have the iron, chassis and caps its still just a concept...
However...
The schematic was "lifted" from HERE and it is working order as seen HERE but as can be seen is in a similar application.
However...
The schematic was "lifted" from HERE and it is working order as seen HERE but as can be seen is in a similar application.
This might be option #2..
However...
this would almost double the component count on the screen voltage circuit, however will give me a more flexible way to keep voltage in check if i do use both taps.
An externally hosted image should be here but it was not working when we last tested it.
However...
this would almost double the component count on the screen voltage circuit, however will give me a more flexible way to keep voltage in check if i do use both taps.
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