It could be the divider for the DC coupling
If this was to flash over then it would stuff the tube...
Regards
M. Gregg
If this was to flash over then it would stuff the tube...
Regards
M. Gregg
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I´ve split it and soldered wires so i can run it disassembled.
Didn´t have a neon so stuck in a zener instead.
Checked the tubes one 6j5 dead one bad.
Didn´t check them since they were NIB NOS Brimar just stuck them in.
Time for a new trip to storage and some non "drive by engineering" check recheck doublecheck then fireup.
Didn´t have a neon so stuck in a zener instead.
Checked the tubes one 6j5 dead one bad.
Didn´t check them since they were NIB NOS Brimar just stuck them in.
Time for a new trip to storage and some non "drive by engineering" check recheck doublecheck then fireup.
A standard diode would be better 1N4007 has been used in the past..
1n4148..etc
Regards
M. Gregg
Just for interest..
I wonder if this could be your oscillator conduction in both directions with a zener?
I wonder if this could be your oscillator conduction in both directions with a zener?
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Express trip to storage.
Soon to be tested !
I guess these have a series resistor 110v...no resistor required just straight from grid to cathode. 🙂
They will come on for about 5-10 seconds then as the tubes warm up they go off...
Regards
M. Gregg
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Just for reflection,
I have found that I tend to run the amp many hours at a time..
I don't even think about the tube offset or the bias... (never enters my thoughts)
I never even think of it as OTL...
Just switch on and play..I find I tend to head straight to the amp and power on as soon as I come home.
It’s on mainly on one heater for 4-6 hrs a day..Most days..
Strange....most amps I have bought or built tend to get switched off after a time..not this one..when I go to turn it off I don't want to..normally under pressure for someone to go and do something..YMMV 🙂
Regards
M. Gregg
I have found that I tend to run the amp many hours at a time..
I don't even think about the tube offset or the bias... (never enters my thoughts)
I never even think of it as OTL...
Just switch on and play..I find I tend to head straight to the amp and power on as soon as I come home.
It’s on mainly on one heater for 4-6 hrs a day..Most days..
Strange....most amps I have bought or built tend to get switched off after a time..not this one..when I go to turn it off I don't want to..normally under pressure for someone to go and do something..YMMV 🙂
Regards
M. Gregg
My stash of 6j5Gs are out only ones i found is "no glows"
No nice CC so far but i´ll dig around a bit more.
Neons didn´t make any magic.
That pesty oscillation is probably related to the cheapskate resistors.
No nice CC so far but i´ll dig around a bit more.
Neons didn´t make any magic.
That pesty oscillation is probably related to the cheapskate resistors.
Do you have a plan of action?
Just out of curiosity what was it like when you had music playing....don't know how long for?
Regards
M. Gregg
Just out of curiosity what was it like when you had music playing....don't know how long for?
Regards
M. Gregg
I had a little PSU hum otherwise the short impression was very promising.
I´ll get it going sooner or probably as it looks later.
Time for resistor ripout
I´ll get it going sooner or probably as it looks later.
Time for resistor ripout
I use my amp for hours at a time..
So I guess if you get it right....
I have used 1 watt 500V rated resistors in all signal places..
2 Watt 500V in the PI....
12W wire wound across the supply PSU caps and a 300 ohm 12 W in series with the CT of the power Tx..
Regards
M. Gregg
So I guess if you get it right....
I have used 1 watt 500V rated resistors in all signal places..
2 Watt 500V in the PI....
12W wire wound across the supply PSU caps and a 300 ohm 12 W in series with the CT of the power Tx..
Regards
M. Gregg
LOL,
I will look forward to a you tube video....and the ticker tape + flags... LOL
I have a few things I want to try, however I like to listen to it and can't pull it to bits at the moment...Perhaps I should think of a mark 2 and then I can keep using this one.. 🙂
Regards
M. Gregg
I will look forward to a you tube video....and the ticker tape + flags... LOL
I have a few things I want to try, however I like to listen to it and can't pull it to bits at the moment...Perhaps I should think of a mark 2 and then I can keep using this one.. 🙂
Regards
M. Gregg
FINALLY
A BEAUTY IN ACTION
It is alive and playing music for more than 5 sec at a time.
Now its time to let the tubes settle.
A BEAUTY IN ACTION
It is alive and playing music for more than 5 sec at a time.
Now its time to let the tubes settle.
Volume halfway up the chitter chatter starts .
A quick check on the HP 3582A/339A wasn´t to breathtaking either.
I didn´t come close to your readings before THD skyrocketed.
My tubes probably needs a burnin period before measuring again so i´ll leave it on repeat and forget about the electric bill for a while.
A quick check on the HP 3582A/339A wasn´t to breathtaking either.
I didn´t come close to your readings before THD skyrocketed.
My tubes probably needs a burnin period before measuring again so i´ll leave it on repeat and forget about the electric bill for a while.
Resistor failure probably to low voltage rating.
It´s starting to come alive, sounds better for every minute.
Can´t turn it all the way up starts distorting badly at 75%.
I´ll let run at 50% for a burnin period before starting to measure which stage is doing what.
Have start figuring out a way to trick it into playing a little louder .
It´s starting to come alive, sounds better for every minute.
Can´t turn it all the way up starts distorting badly at 75%.
I´ll let run at 50% for a burnin period before starting to measure which stage is doing what.
Have start figuring out a way to trick it into playing a little louder .
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