B6 voltage too high on Paraglow II PSU update
- Thread starter KGW
- Start date
Are you going to keep the 5965?
On the Smash-up schematic:
37R4 R1 becomes 90.9R
44K/4W becomes 330K/3W (Vishay PR-03)
49R9 R1 becomes 177R
100K R2 becomes 300K/3W (Vishay PR-03)
147K R4 becomes 330K/3W (Vishay PR-03)
0.1uF/400V Cc becomes 0.1uF/630V
Add one 33K 1/4W resistor to Y+/Y- on B side
Add one 10,000uF/6.3V cap to Y+/Y- on B side
Add one 300K/2W resistor between OB and -Reg
To add bias adjustments, you would populate a TL431, 4.99K resistor, and 10K trim pot on the unused regulator section of the Smash-up.
The new board wires in like the Tucker board, but you don't need that resistor between the power supply and the board, just connect it directly to the high voltage supply.
You'll have to work off the schematic of the Smash-up and the tube datasheets to get it wired in.
-PB
On the Smash-up schematic:
37R4 R1 becomes 90.9R
44K/4W becomes 330K/3W (Vishay PR-03)
49R9 R1 becomes 177R
100K R2 becomes 300K/3W (Vishay PR-03)
147K R4 becomes 330K/3W (Vishay PR-03)
0.1uF/400V Cc becomes 0.1uF/630V
Add one 33K 1/4W resistor to Y+/Y- on B side
Add one 10,000uF/6.3V cap to Y+/Y- on B side
Add one 300K/2W resistor between OB and -Reg
To add bias adjustments, you would populate a TL431, 4.99K resistor, and 10K trim pot on the unused regulator section of the Smash-up.
The new board wires in like the Tucker board, but you don't need that resistor between the power supply and the board, just connect it directly to the high voltage supply.
You'll have to work off the schematic of the Smash-up and the tube datasheets to get it wired in.
-PB
You'd need to go back to 5965s. The Smash-up would come with a 6SN7 you don't need, but they do sometimes come in handy 
Yes, the 15/5W resistor goes away.
Yes, the 15/5W resistor goes away.
That is what I would use for 5665s. To be totally honest, this kind of work can be unforgiving of any mistakes, and is certainly something I could pop in for you if you sent these in for repairs.
Otherwise, there's no manual for this. If you asked nicely (and ultimately order the Smash-up upgrade to use for parts), Doc B. may be OK with me sending you the Paramount soft start retrofit manual. That would be about 90% of the instructions you would need, though it's for a slightly different amp with a 5670 and not a 5965.
Otherwise, there's no manual for this. If you asked nicely (and ultimately order the Smash-up upgrade to use for parts), Doc B. may be OK with me sending you the Paramount soft start retrofit manual. That would be about 90% of the instructions you would need, though it's for a slightly different amp with a 5670 and not a 5965.
I mean, it won't really matter all that much to me one way or the other. For the cathode bias resistors in the standard Paraglow, I have a ton of 2K/25W tubular resistors, and I use one of those and another 1.2K 10W resistor in series with that.
I also somewhat frequently just rebuild these on 8x10 chassis plates. This gives me room for a really beefy 3K/50W tubular resistor that runs nice and cool.
In either case, I do enjoy refurbishing the old kits.
I also somewhat frequently just rebuild these on 8x10 chassis plates. This gives me room for a really beefy 3K/50W tubular resistor that runs nice and cool.
In either case, I do enjoy refurbishing the old kits.
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KGW
New member
Hi Paul,
I got the smash kit in the mail today. I guess I will order the new giant resistors and the resistors for the smash kit.
I think I will try to get the amps working without the smash kit. If I get stuck on the smash kit installation, could I get the amps to you to do that part?
cheers,
Kevin
I got the smash kit in the mail today. I guess I will order the new giant resistors and the resistors for the smash kit.
I think I will try to get the amps working without the smash kit. If I get stuck on the smash kit installation, could I get the amps to you to do that part?
cheers,
Kevin
Sure thing!
Ohm's Law tells us that power is current squared time resistance. Current is 0.060A.
KGW
New member
Update. I have updated the PSU on both Paraglow IIs. I also replaced the big resistors on the 2A3 tubes. B6 is still around 260VDC instead of 215VDC.
So I guess I will send or deliver the amps to you to do the smash upgrade and get the amps dialed in. I found the 5965 tubes that came with the kits. So I'll get those to you as well.
Please let me know the arrangements.
thanks,
Kevin
So I guess I will send or deliver the amps to you to do the smash upgrade and get the amps dialed in. I found the 5965 tubes that came with the kits. So I'll get those to you as well.
Please let me know the arrangements.
thanks,
Kevin
Attachments
Did you try rolling in a fresh pair of driver tubes? I think those Tucker boards used the 6N1P right? Those aren't exactly the longest lived tube in the world, and when they get flat, that plate voltage will start drifting up.
Otherwise, you can just order the flat rate repair service for two amps, and that will take care of what you need done. It may take a little while for the boxes to go out and come back to me, so toss a note in one of the boxes that's just a print out of this thread and I'll remember what to do.
-PB
Otherwise, you can just order the flat rate repair service for two amps, and that will take care of what you need done. It may take a little while for the boxes to go out and come back to me, so toss a note in one of the boxes that's just a print out of this thread and I'll remember what to do.
-PB
