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Scott LK-48B

solid state will jump the voltage even more, probably not ideal. 5R4 is a 2 amp heater, close enough to the 1.9 of a 5AR4. More voltage drop by a fair bit too.
 
knockbill said:
Yep,,, the "push em hard" sounds familiar as Fender ran 6V6s to way past design readings,,,, I'm not as used to 6BQ5s tho,,, so variac, ammeter and DBT will be my friends here!!! May have to use a SS rectifier, as the 5R4 may draw too much htr current for the Scott PT with the output tubes included tho...
You were very correct saying kit builds may have never been wired correctly,,,, and the first one I had (WA-P2) wasn't!
Stay tuned we'll see good, bad, or ugly!!!
Click to expand...
One kit I received was a Eico HF-85, The input selector switch, was wired one terminal off, it gave the strangest results! Another was a Scott LC-21? preamp recap someone did, before me, they copied one channel for the other, but that section was supposed to be mirrored, so several connections were backwards, it looked perfect when you saw it. So not only kits can be miswired.
 
gadget73 said:
solid state will jump the voltage even more, probably not ideal. 5R4 is a 2 amp heater, close enough to the 1.9 of a 5AR4. More voltage drop by a fair bit too.
Click to expand...
Yep,,, I realize that,,, its why I went 5R4 in the first place,,,, SS worked good with just teh pre amp section but 6U8s use 6V winding, so they didnt get enough to heat properly, if I dialed down teh variac for the AX7s,,,, so 5R4 works well, now,,,, I ll try it if you think it will work OK but it will be more of a load,,,,
Baby steps,,,, I'm trying to get another truckful of Oak before the storms hit!!!
Got the Oak!!!
 
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s-petersen said:
One kit I received was a Eico HF-85, The input selector switch, was wired one terminal off, it gave the strangest results! Another was a Scott LC-21? preamp recap someone did, before me, they copied one channel for the other, but that section was supposed to be mirrored, so several connections were backwards, it looked perfect when you saw it. So not only kits can be miswired.
Click to expand...
Well this one is wired horribly,,, every time I took one end of a cap or resistor off to replace,,, the other end just came off also,,, not sure what solder was used, but when I reflow em and add some new solder, it flows nice...
 
Finally got back to this guy,,, I have it connected a pair of spkrs to it, and got it connected to a variac and DBT, so it isn't able to run at full power...
Got music thru one side that sounds good,, then swapped teh tubes
L to R and teh other channel played , altho not as well,,, so I tested the tubes and one pair is way mismatched... Its teh side with the replacement transformer, that doesn't sound good,,,, I just checked and resoldered the tube socket connections,, and washed em down with alcohol and cleaner,,, letting it dry for now,,, So the original OPT side sounds good and seems I got the missing and convoluted spkr wiring back OK,,, an the replaced OPT side needs some trouble shooting,,, It could be teh Tx isnt working right, or still some wiring glitches,,,
Some more summer fun!! But its progress to me!!!
 
I got it!!!!!!!!!!
Found a heater wire for one pair of output tubes was never soldered,, it was buried and I missed it Now we know why the other OPT was ruined!!! Odd OPT side is a little less volume but easily tweaked with balance pot,,,
Still on DBT and Variac,,, and needs output coupling caps, and phono stage rebuilt... But I'm gaining on it!!
6BQ5 running at 300VDC a
 

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that would certainly make it unhappy. I guess long term maybe the imbalance opened the transformer?

depending on what tap and what the transformer ratio is you may have slightly different feedback levels channel to channel. that would cause an imbalance.
 
You are probably right,,, I went over most of the solder connections on this,, and I didn't see teh small wire just wrapped around teh bottom of teh socket lug,,, till I looked for it when one channel was intermittent,,, I ran it thru the lug hole and its secure now!!!! Gotta try to find a mate for teh other Scott OPT, since we know it works now,,,, or try the Fishers,,, but I think that will just be opening a can of worms,,, FB, mounting, etc,,,
As always, thanks for your input,,,
 
Maybe Scott, but that's not in my skill set on something this complicated,,, apparently Scott used FB in a lot of stages,,,,
Replacement OPT will fix it tho,,, someone has to have an orphan,,, as I dont want to tear up a complete one,,,,
Tiny turn on the Balance pot and the sides match, even tho the odd OPT is half to 2/3 size of the Scott, and voltage is within one volt of each...
Thanks for the reply
 
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Just ask the moderator to incorporate your posts and answers from this thread into the other thread. Should be Doable.
 
And DONE! Merged Fisher OPT transformer posts into your HH Scott thread!
Enjoy!
 
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