That amp was a 100TH CCS loaded driving a even bigger 304TL ... dismantled after a week or so, it was way too hot. Your amp will need a ton of transformers ... I assume you are aware you need DC on filaments (current sources there too). Enjoy!
The dropping R before the CCS can be anything > 1k
The dropping R before the CCS can be anything > 1k
Wow!😀
A power radio station converted to audio reprodution!
MIne will do two monoblock with all rod coleman filament supply (six x-formers), separated six B+ lines (other six irons) and two transformers for all grid bias.
Plus the B+ filter chokes ( four) for 845 and will put in gyrator choke on 811-10 and 10y.
A lot of work ad fun next days for me!🙂
A power radio station converted to audio reprodution!
MIne will do two monoblock with all rod coleman filament supply (six x-formers), separated six B+ lines (other six irons) and two transformers for all grid bias.
Plus the B+ filter chokes ( four) for 845 and will put in gyrator choke on 811-10 and 10y.
A lot of work ad fun next days for me!🙂
planned two big mono, three floor construction with supply and ampli togheter. Any issue for that ?
I have my 801 dc-coupled to 75TL (4 cabinets ... 100+kg of iron) that I have not used in quite a while. Currently running a 801A amp (just that tube and a step-up transformer) and a still-to-be-completed 6CG7 dc-coupled to VT52 (it is a two differential stages amp) and a Pass F4. I need to work more on my DACs and preamp this winter.
I use CCS almost everywhere now.
I use CCS almost everywhere now.
Current is set via the trimmer P100 (and P200), you cannot set voltage in CCS mode that will depend upon the tube bias. You can set voltage in gyrator mode by trimmer P101* (and P201*) ... se schematics at post 153.
Thank you Luca.
So if I set fixed negative grid voltage and set a target current by ccs trimmer I will have the working-point voltage on plate.
Le t me now If I am right.
Have you used the gyrator mode ? what difference have you found with ccs?
Anto
Yes, you are correct. Actually I trim the CCS current to hit the desired plate voltage as my amps are DC coupled (and fixed bias at cathode).
So far, I never used the PCB as gyrator
So far, I never used the PCB as gyrator
...and in yours what power value you have selected ?😉
Gluca I have another question : how much voltage I will add at B+ input ccs for an adequate headroom? If I have a plate voltage of 650 V 100 V added would be right?😕
Ciao,
Anto
B+ on the plate of the tube plus half the swing you need at the grid of following stage plus headroom
example
650V at the plate
200Vpp to swing the grid of final tube at full power
30V headroom
required voltage at CCS is 650+200/2+30=780V
sum the voltage drop across the resistor to that number
example
650V at the plate
200Vpp to swing the grid of final tube at full power
30V headroom
required voltage at CCS is 650+200/2+30=780V
sum the voltage drop across the resistor to that number
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