When we're waiting for guests, the kid is sleeping, all cooking is done what then do the husband ?🙂 changing cathode res to 180ohm and got 0,43/0,45mA 😀
Gain is high!! Scary dynamics now... Almost to much in your face. But clean yet smooth. Wife says; "sound is so clear"
You gotta be a bit crazy about this hobby when your doing that + writing here today😀
Ok over n out😎😀
Gain is high!! Scary dynamics now... Almost to much in your face. But clean yet smooth. Wife says; "sound is so clear"
You gotta be a bit crazy about this hobby when your doing that + writing here today😀
Ok over n out😎😀
Woo hoo! you finally are waking the tubes up from their slumber.
That is fantastic. The best part is that with good quality and proper values their is little need for tone control...at least that is my experience.
That is fantastic. The best part is that with good quality and proper values their is little need for tone control...at least that is my experience.
Yeah i sure do 🙂
So you think i should stop here or go down more so i came over or on to 5mA? I think 120-150ohm then i'm there.
Also i guy locally sells chokes, it's 10H but dcr is higher, 270ohm /90mA. Its very cheap (brand Triad) 20 bucks. Or should i order overseas?
Have no clue why it have to around 100ohms....? Just because res is that? Can we really trust this design i'm thinking?
And is it possible to burn of some gain using 100k as leakres instead of 1M i have now? Seems that gain is so high compared now with original 10k
So you think i should stop here or go down more so i came over or on to 5mA? I think 120-150ohm then i'm there.
Also i guy locally sells chokes, it's 10H but dcr is higher, 270ohm /90mA. Its very cheap (brand Triad) 20 bucks. Or should i order overseas?
Have no clue why it have to around 100ohms....? Just because res is that? Can we really trust this design i'm thinking?
And is it possible to burn of some gain using 100k as leakres instead of 1M i have now? Seems that gain is so high compared now with original 10k
That choke will work great.
For gain you really don't have a lot of options. the gain of your tubes is 36 which is pretty high. With the circuit functioning properly your simple option is to swap tubes to a lower gain tube like 6n6p or 6cg7 which will work with your current setup of 250r on the cathode. these have a gain of 20 which might work better.
I would not advise running the circuit sub optimal to reduce gain.
You are not running capacitors on the cathodes of the bottom sections are you?
For gain you really don't have a lot of options. the gain of your tubes is 36 which is pretty high. With the circuit functioning properly your simple option is to swap tubes to a lower gain tube like 6n6p or 6cg7 which will work with your current setup of 250r on the cathode. these have a gain of 20 which might work better.
I would not advise running the circuit sub optimal to reduce gain.
You are not running capacitors on the cathodes of the bottom sections are you?
Sub optimal? I don't understand?
No there is no caps on cathode. Is it better or? I see design have the resistor bypassed by a cap. Don't know why though.
No there is no caps on cathode. Is it better or? I see design have the resistor bypassed by a cap. Don't know why though.
I don't think there is minimum for choke, just maximum current.
Bypassing the cathode resistor with a capacitor on the bottom triode will increase gain a little...but since your circuit does not use one then that is not an option.
What I mean by sub optimal is that you finally have the tubes operating as intended in the srpp circuit. If the gain is too high then you should use different tubes with lower gain.
I am not sure lowering the leak resistors will reduce your gain and might have a negative effect on the circuit. Having said that it only costs you time now to experiment so go for it.
Bypassing the cathode resistor with a capacitor on the bottom triode will increase gain a little...but since your circuit does not use one then that is not an option.
What I mean by sub optimal is that you finally have the tubes operating as intended in the srpp circuit. If the gain is too high then you should use different tubes with lower gain.
I am not sure lowering the leak resistors will reduce your gain and might have a negative effect on the circuit. Having said that it only costs you time now to experiment so go for it.
The first cap a film? How big? Before the choke? You mean last one a bit bigger like 100uf?
Ok i understand. Have a bunch of 1uf /ero mkt1813 /250V that just collects dust.
Maybe 3x1uf parallel or something could work then.
Maybe 3x1uf parallel or something could work then.
Today i got my choke. Just installed it but not listened yet. Also changed cathode resistors to 150ohms.
Also a bunch of MKPs for PSU came in from Germany. Not installed yet.
Strange this, get a reading of 0,46 vs 0,50v but how do i calculate mA of that? Cus when i do it i get a lower value then with 180ohm ??? 😕
Like i said, mathematics is NOT my strong side😀
Also a bunch of MKPs for PSU came in from Germany. Not installed yet.
Strange this, get a reading of 0,46 vs 0,50v but how do i calculate mA of that? Cus when i do it i get a lower value then with 180ohm ??? 😕
Like i said, mathematics is NOT my strong side😀
hmmm it sounds nice with a choke.. more separation, details and openness in midrange. Like it. Good upgrade and cheap price.
BUT now i have some kind of "hizz" in tweeter i've not heard before. Annoying.
So now there is first (little) hum and then this hizz high up in freq!? Don't understand? everything is same as before.
BUT now i have some kind of "hizz" in tweeter i've not heard before. Annoying.
So now there is first (little) hum and then this hizz high up in freq!? Don't understand? everything is same as before.
What is your b+ now? You might need to adjust that 5k resistor a little to increase b+.
You are dropping voltage as you run more current through the tubes and your choke is 270 ohm versus the 100 ohm resistor you had there before.
Your new psu caps will have an effect too.
You are dropping voltage as you run more current through the tubes and your choke is 270 ohm versus the 100 ohm resistor you had there before.
Your new psu caps will have an effect too.
Yes, i forgot to measure B+ 😱 It's 154V now 
You mean the 10K between caps? What voltage do you think is good? I have some 2,2K and 5,1K in my box i can test
You mean the 10K between caps? What voltage do you think is good? I have some 2,2K and 5,1K in my box i can test
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I put 5,1K and voltage went up to 176V. The hizz is little bit better but not much. Just darker sounding. Lower freq??
Also, measure the volage drop across the choke AND the next dropping resistor and calculate the total mA current there.
Then compare to the calculated mA across each cathode resistor - they should be close.
Then compare to the calculated mA across each cathode resistor - they should be close.
Like 1V or so across choke/2,2k?
Just to be sure, same setting as measuring cathode res?
Does this make any sense; i keep lowering dropping res till i can get 0,75v (over cathode) then it should be 5mA over cathode with existing 150ohm res. Just an own calculation hehe😉
Ok but i will do as you said but it have to be tomorrow. Thx!
Just to be sure, same setting as measuring cathode res?
Does this make any sense; i keep lowering dropping res till i can get 0,75v (over cathode) then it should be 5mA over cathode with existing 150ohm res. Just an own calculation hehe😉
Ok but i will do as you said but it have to be tomorrow. Thx!
Actually come to think of it just measure across the dropping resistor, not the choke.
Be careful not to run the tubes too hot, seems that you had it running nicely with the 180 ohm resistor.
I wouldnt tackle tweaking the PSU until you get the B+, cathode currents, and sound where you are happy with it. Then do the capacitor swap on the PSU.
Be careful not to run the tubes too hot, seems that you had it running nicely with the 180 ohm resistor.
I wouldnt tackle tweaking the PSU until you get the B+, cathode currents, and sound where you are happy with it. Then do the capacitor swap on the PSU.
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