Anyone know the specs on the transformer in the boomer base amps? I'm fixing one for my buddy and the transformer is smoked. I plan on having epd build it but I can't find the specs on it anywhere.
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Kriss boomer transformer specs.
- Thread starter 419_boston
- Start date
A Kris 600SSB (1 tube driving 3) I recently repaired uses a part number 93P-11. I am pretty sure this is a Stancor part but was never able to find the specs on it despite searching catalogs from the 60's and 70's.
Maybe EPD can do something with that part number.
Good Luck!
73's
David
Maybe EPD can do something with that part number.
Good Luck!
73's
David
You'll need 6.3 Volts at 10 Amps for the heaters.
The B+ winding needs to be center tapped. This is to provide a B+ voltage for the driver that is half what the finals get. Running the driver tube from half-B+ voltage allowed them to directly ground the grids on the driver tube, skipping the expense of adding fixed negative bias voltage. The driver tube would overheat running from the full B+ voltage unless it had 8 or more Volts negative bias on the control grid.
You have some leeway on the B+ winding. A 550-Volt rating gets you just under 800 Volts DC from the rectifier bridge. A 700-Volt winding pushes this up to roughly 1000 Volts DC. The current rating for the B+ winding should be no less than 500 mA. The higher this rating, the longer you can key it before the transformer overheats.
Oh, and every Stancor catalog part number I can find begins with a letter, not a number.
Biggest headache with a custom replacement will be the overhead clearance. Too tall and the cabinet won't fit.
73
The B+ winding needs to be center tapped. This is to provide a B+ voltage for the driver that is half what the finals get. Running the driver tube from half-B+ voltage allowed them to directly ground the grids on the driver tube, skipping the expense of adding fixed negative bias voltage. The driver tube would overheat running from the full B+ voltage unless it had 8 or more Volts negative bias on the control grid.
You have some leeway on the B+ winding. A 550-Volt rating gets you just under 800 Volts DC from the rectifier bridge. A 700-Volt winding pushes this up to roughly 1000 Volts DC. The current rating for the B+ winding should be no less than 500 mA. The higher this rating, the longer you can key it before the transformer overheats.
Oh, and every Stancor catalog part number I can find begins with a letter, not a number.
Biggest headache with a custom replacement will be the overhead clearance. Too tall and the cabinet won't fit.
73
This is not the best picture of the transformer from the Kris I rehabbed several months ago but the only one I have showing more than the "Owners Manual" part number.
Nomad,
I don't remember ever searching for the "1402004" number on the transformer. I was just curious about the specs not trying to replace this one.
Perhaps someone can decipher the correct transformer from the additional numbers visible in the below photo.
And a photo of the underside of the transformer for reference.
419_boston,
Good luck!
73's
David
Nomad,
I don't remember ever searching for the "1402004" number on the transformer. I was just curious about the specs not trying to replace this one.
Perhaps someone can decipher the correct transformer from the additional numbers visible in the below photo.
And a photo of the underside of the transformer for reference.
419_boston,
Good luck!
73's
David
The straight Kriss Boomer schematic is here: http://www.cbtricks.com/Amp/kris/boomer/graphics/boomer_om.pdf
Says it only has two 6JU6 tubes at 1.6 amps each on the filaments and no drivers or center tapped transformer. They do make other models though, so be certain the name matches the schematic.
Says it only has two 6JU6 tubes at 1.6 amps each on the filaments and no drivers or center tapped transformer. They do make other models though, so be certain the name matches the schematic.
This is the 1 driving 2. Right now it buzzes and pulls the rear of the case towards the transformer so I figured its cooked haha the guy has brand new tubes so I'm trying to help him out to get it fixed. The schematic didnt list any values on the transformer itself tho.
Thanks man
Chris
First test for a transformer showing signs of overload is to unhook at least one wire of each winding. If it still hums with all the loads unhooked from it, that transformer is bad.
If it behaves itself with the loads unhooked, the fault (faults?) are downstream from the transformer's secondary windings.
Oh, and the 6.3-Volt heater winding for a new transformer won't need to be more than 5 Amps for three of those tubes.
73
If it behaves itself with the loads unhooked, the fault (faults?) are downstream from the transformer's secondary windings.
Oh, and the 6.3-Volt heater winding for a new transformer won't need to be more than 5 Amps for three of those tubes.
73
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The guy gave up on it.. I told him it wouldnt be worth the money going to sell the tubes and do somthing with the box. I'm gonna build him a power supply with switchers so we can do a 1x4 or somthing of the sorts. Thanks for the help guys..oh it was a mach 3+3.
Chris
Chris