Well Electrix, I am glad you asked....
Again, my ultra efficient wife, knowing how precious I am about such matters as tubes, decided to pack them in the "SAFE BOX' which consequently got sent to Poland, (to add context she is Polish, it was not a random insidious attack by her to counter my love for all things audio and some way redress the balance of my neglect as perceived by her)
Why would she pack them away... we moved house, reluctantly from my side, apparently living in a field away from everyone is not a way to live, I would argue the contrary.
There were a lot of boxes sent, and as efficient as she is, she had neglected to create an itinerary for all of the boxes and mark them accordingly, so I figured that perhaps acquiring new tubes may be a solution, plus the excitement of using different tubes did attract me to the prospect.
Kiitos
Again, my ultra efficient wife, knowing how precious I am about such matters as tubes, decided to pack them in the "SAFE BOX' which consequently got sent to Poland, (to add context she is Polish, it was not a random insidious attack by her to counter my love for all things audio and some way redress the balance of my neglect as perceived by her)
Why would she pack them away... we moved house, reluctantly from my side, apparently living in a field away from everyone is not a way to live, I would argue the contrary.
There were a lot of boxes sent, and as efficient as she is, she had neglected to create an itinerary for all of the boxes and mark them accordingly, so I figured that perhaps acquiring new tubes may be a solution, plus the excitement of using different tubes did attract me to the prospect.
Kiitos
The important thing here is the grid to cathode voltage, that determines the current. Can you say anything on that?
That -75, is that connected to the bottom cathodes or what? I don't see the difference between bottom and top, is it just the physical location in the chassis?
Jan
Jan,
I love your conclusion, however, I have the manual, it clearly states 6080, plus, I also listed all of my tubes, I am odd like that, they were GEC 6080 tubes.
There is a difference in the top and bottom, the bottom have a hook up to the circuit on the bottom right providing -75VDC to each channel, the top have a hook up to the circuit at the very top, with the grey cap, providing +85VDC.
I have had it running now with no load and no source, and it has not peeped!
Even turned it on and off several times to see if we can get some inrush from a dodgy cap, nothing...
I have some other speakers, maybe I try them to see if the speakers are to blame, I have woven cable, I will try some other cable, it tests fine, but you never know!
I love your conclusion, however, I have the manual, it clearly states 6080, plus, I also listed all of my tubes, I am odd like that, they were GEC 6080 tubes.
There is a difference in the top and bottom, the bottom have a hook up to the circuit on the bottom right providing -75VDC to each channel, the top have a hook up to the circuit at the very top, with the grey cap, providing +85VDC.
I have had it running now with no load and no source, and it has not peeped!
Even turned it on and off several times to see if we can get some inrush from a dodgy cap, nothing...
I have some other speakers, maybe I try them to see if the speakers are to blame, I have woven cable, I will try some other cable, it tests fine, but you never know!
G1 and G2 are tied together on both top and bottom, K1 and K2 of the top go to the + of the capacitor which goes to the speaker terminal for the top tubes, bottom tubes, K1 and K2 are tied to GND.
Voltage on both top and bottom are -78VDC taken as G on positive lead.
I will come back with voltages when loaded with 8ohm speaker
Voltage on both top and bottom are -78VDC taken as G on positive lead.
I will come back with voltages when loaded with 8ohm speaker
Please realize that this is an almost content-free post. What is 'top', what is 'bottom'. A tube has a handful of terminals and it makes a whole world of difference which terminal is connected to which.
A schematic drawing from your inspection/measurement would help a lot.
Jan
Jan,
I will put something together for you, however I am slowly getting over this whole journey.
Maybe I should accept the demise of this beast and let it go to the gods of unfinished projects and repairs.
As far as speakers go, I have a collection of 4/8/16ohm speakers that I should otherwise throw away, but just cannot, and a distinct lack of any resistors at home, so the speakers will make a sacrifice to the gods and 'lets see what happens if'
Kiitos
I will put something together for you, however I am slowly getting over this whole journey.
Maybe I should accept the demise of this beast and let it go to the gods of unfinished projects and repairs.
As far as speakers go, I have a collection of 4/8/16ohm speakers that I should otherwise throw away, but just cannot, and a distinct lack of any resistors at home, so the speakers will make a sacrifice to the gods and 'lets see what happens if'
Kiitos
So a push pull with the triodes for each tube simply paralleled as the grids are tied.
The top cathode connects to the bar that then comes down to be bottom set. The big cap sits on this bar and is bypassed by another cap.
The bottom cathode then goes off back to the PSU.
If the amp is running 160 top and -75 bottom that’s not particularly even so I would expect that linking car from to top bottom is going to have some +V on it. Just put a voltmeter on the output lug of the speaker to see if there’s any voltage offset.
Also I would check the current .. only thing that would be used between no connection and connection are the output (and bypass) caps.
The top cathode connects to the bar that then comes down to be bottom set. The big cap sits on this bar and is bypassed by another cap.
The bottom cathode then goes off back to the PSU.
If the amp is running 160 top and -75 bottom that’s not particularly even so I would expect that linking car from to top bottom is going to have some +V on it. Just put a voltmeter on the output lug of the speaker to see if there’s any voltage offset.
Also I would check the current .. only thing that would be used between no connection and connection are the output (and bypass) caps.
Noooo! That would be very unsatisfactory! If you give up now it will haunt you for years to come ;-)
Jan
Updated number a lot…
So it is now playing 2 cellos for the last 40 minutes on some old *** French speakers with different speaker cable and no explosions yet!
8ohm speakers and different cable?!?
As I am typing this I am semi expecting a bang… nothing yet.
It is definitely PP by the way probably should have mentioned that from the start.
Kiitos
So it is now playing 2 cellos for the last 40 minutes on some old *** French speakers with different speaker cable and no explosions yet!
8ohm speakers and different cable?!?
As I am typing this I am semi expecting a bang… nothing yet.
It is definitely PP by the way probably should have mentioned that from the start.
Kiitos
The resolution is not quite good enough to see if there’s a resistor between the common phase bar and each grid. Although the bottom left looks like there is.
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