I was told it's the quality control mark like in my country "MSZ" + grades, but I might be able to ask someone from Russia (or somebody here in the forum can answer this question too, for 100% sure).
Back to the tubes, I managed to find a 6N6P-I datasheet and compared to 6N6P the "I" types can be put 1:1 into most of the 6N6P circuits (including mine) so my original question got answered.
Back to the tubes, I managed to find a 6N6P-I datasheet and compared to 6N6P the "I" types can be put 1:1 into most of the 6N6P circuits (including mine) so my original question got answered.
Yes agreed, someone here will know.
If I recall, the number inside the shape, be it diamond, triangle or Pentagon, that determines which grouping (military/aerospace, etc
I didnt intend to divert this thread, it is good that you have confidence in either version
If I recall, the number inside the shape, be it diamond, triangle or Pentagon, that determines which grouping (military/aerospace, etc
I didnt intend to divert this thread, it is good that you have confidence in either version
Hmm that's interesting. According to Lampizator site ... scroll down / search for "OTK":
click
OTK
Otbor tiehneecheskovo kachiestva - quality controll level - they used the stamp OTK followed by a number. The lower number the better. The zero is if I am not mistaken the best. Zero was strictly military; one - also military but not for nukes, and so on. I would like to read more about this aspect one day.
Just don't forget that in the Soviet times for producing a faulty tube the worker could face 10 years in siberian labour camp in minus 50 degrees without gloves. These times were not funny at all.
click
OTK
Otbor tiehneecheskovo kachiestva - quality controll level - they used the stamp OTK followed by a number. The lower number the better. The zero is if I am not mistaken the best. Zero was strictly military; one - also military but not for nukes, and so on. I would like to read more about this aspect one day.
Just don't forget that in the Soviet times for producing a faulty tube the worker could face 10 years in siberian labour camp in minus 50 degrees without gloves. These times were not funny at all.
That's BS. Or, if you will, "urban legend" completely divorced from reality.
Even the abbreviation itself is expanded incorrectly.
And that is correct.
I just made this EXACTLY, with 6N1P / 6N6P tubes, AC heating and the prototype just sounds wonderful. I can highly recommend this clever, simple design, it's sooo detailing, with so nice warm mids, strong controlled clean bass, huuuge dynamics, I was really astonished. And this is only the prototype, in a paper shoe box lol. Chassis is on its way, shielded toroid already here, what else is needed ? Maybe a little play around the output capacitor, but with a standard 10-yrs-old Daewoo electrolytic + 3.9uF new film combination it sounded still fantastic, can't wait to try something more sophisticated here (e.g. paper/oil, Mundorf, etc).
Well, the prototype.. here you are 😀
The little girl (not sure why I think it's female). 😀
2 days old. Couple more days left 'til final goodbye, dismantling and trying it done well & properly in the final home, a nice metal case.
For now.. laughing is allowed
But hey - it sounds already great.Trying my two ECC99 tubes soon to check any differences between those and the 6N6Ps.
Enjoy
but the cardboard, I like it (futur fire ?). Yes, box it !
do these tubes need matching ? Is that a simple project but the high voltage, for someone who populated some pcbs already ?
do these tubes need matching ? Is that a simple project but the high voltage, for someone who populated some pcbs already ?
Some say it needs matching, I don't see or hear any difference, I have 4x 6N6Ps and 4x 6N1Ps, I just took 2-2 from both types and used them, that's it.
Cardboard is not fireproof, however the socket heat doesn't even color it, so absolutely fine. (No, NO. Don't try it.. I took the risk but I cannot give such an advice to others).
My main concern is now what kind of quality parts to use in the final version. Toroid is excellent, a very high grade one. And the ALPS pot is great too I think.
Now it has cheap (but at least) new electrolytic caps, some film caps and cheap metal resistors.
Any advice maybe ? What kind of resistors would you recommend ? (Which would need to be placed elsewhere probably, due to socket heat - metal resistors are immune to heat, but others aren't).
Cardboard is not fireproof, however the socket heat doesn't even color it, so absolutely fine. (No, NO. Don't try it.. I took the risk but I cannot give such an advice to others).
My main concern is now what kind of quality parts to use in the final version. Toroid is excellent, a very high grade one. And the ALPS pot is great too I think.
Now it has cheap (but at least) new electrolytic caps, some film caps and cheap metal resistors.
Any advice maybe ? What kind of resistors would you recommend ? (Which would need to be placed elsewhere probably, due to socket heat - metal resistors are immune to heat, but others aren't).
I stay tuned , I have a hate love relation with tubes : always wanted some but always avoided because theory, fear, price, elitism side - they shine like diamonds and you wish they were here-
Nice man. Ya, I made an error. The one I posted is single ended and can swing about 20mA. You can swap the 6N1P for a 6DJ8 or 6AQ8 or 6N23P etc without changes if you're into that, too.
Thank you.. 20ma and still enough for a 95 dB-ish headphone - at least for me it has the power, punch.. great stuff.
Btw boxing it properly: do you prefer (would you keep) this 'open wiring' (don't know how you call it in English) or would you opt for a PCB ? (Noise, etc).
Btw boxing it properly: do you prefer (would you keep) this 'open wiring' (don't know how you call it in English) or would you opt for a PCB ? (Noise, etc).
Same here, but I'm leaning towards tubes now, hearing this.. I had such a huge smile on my face.. instruments now sound like instruments.. no minuscule THD can provide this; at least what I've heard 'til now measure probably far better than this one here - all were like 'hmm, nice, nice, okay, that's it'.
But this is a completely different animal. These tubes instantly dropped me into a medium sized room and instruments just play floating in the air, it's aaaaaaah.
I think the thing with tubes is like with women: boob size doesn't matter, overall enjoyment does. As simple as f.c.u.k. 😀
Nice job! Are you using this with your Cooler Master MH751 headset? Have you tried it with any different headphones?
Yes, the MH751 (which is a Takstar Pro 82 with closed bass). No more headsets tried yet but I'm going to put this into the case asap, have a properly built device and then listen to it again.
I've already talked to some friends, one has a Takstar Pro 80, the other a Massdrop AKG based something.. the third a HD650 .. if interested I can keep you updated.
They will definitely sound all different but not sure if I can conclude ANY interpretable results with these regarding sonic character of my amp if I haven't got used to these animals at all, so I will still be able to tell only how my headphones sound because I know it's sound character with some different amps. Or I'll ask them for a honest review. 😱
What I'm interested more in will be the play around the output caps, 470uF electrolytics (+film on it). Now that I moved this cap to be a PSU cap joining the other 470uF can and replaced the output cap with 3x100uF (+film) the amp lost something from the vitality and dynamics on the bottom end. Still very detailing on the top but the lower section is a bit smoother, doesn't have that 'merciless' bite and punch I liked before. Not sure if it's a reason of having 300uF here or just because the 3x 100uF electrolytics are a different and newer brand but I've ordered the very exact types and will try the block with 5 caps at 500uF (that should be pretty close to 470uF). If it doesn't deliver what I experienced with the big old cap I'll swap them back. And haven't tried a Mundorf or Jantzen here yet.
This can be a long journey I think, just to check some caps but I hope the best to find one final solution pretty soon, with a little bit of luck.
Nevertheless I'm still VERY satisfied with the overall sound.
With such a fine detailing capability this doesn't apply to my FLAC files anymore.
This little toy does one important thing also very well: converting any kind of 'hiss' into analog 'fluidness' like many triodes out there. Highs are gleaming/shining like never before and the whole frequency band is very even to my ears. Everything lost the harshness while details are kept. I'm really not interested in THD-s if that's the price for a fantastic listening experience.. not gonna have this checked by Audiosciencereview (although I have a big respect to Amir). 😀
But it's demanding on source side. A forgiving circuitry with a not-so-forgiving sound on weak material (I mean mastering).
Fun fact 1) already blown the fuse (1A, slow). Touched my PC's metal parts on the back with the jack plug's tip while searching blindly for the right hole. Fuse replaced, works like a charm. I'm still alive lol.
Fun fact 2) tube sockets Nr. 9 (screen) aren't connected to ground. Yet. 😀 This is something which isn't on the schematics but definitely helps for even better triode separation within one tube. Not a big deal seemingly..
I've already talked to some friends, one has a Takstar Pro 80, the other a Massdrop AKG based something.. the third a HD650 .. if interested I can keep you updated.
They will definitely sound all different but not sure if I can conclude ANY interpretable results with these regarding sonic character of my amp if I haven't got used to these animals at all, so I will still be able to tell only how my headphones sound because I know it's sound character with some different amps. Or I'll ask them for a honest review. 😱
What I'm interested more in will be the play around the output caps, 470uF electrolytics (+film on it). Now that I moved this cap to be a PSU cap joining the other 470uF can and replaced the output cap with 3x100uF (+film) the amp lost something from the vitality and dynamics on the bottom end. Still very detailing on the top but the lower section is a bit smoother, doesn't have that 'merciless' bite and punch I liked before. Not sure if it's a reason of having 300uF here or just because the 3x 100uF electrolytics are a different and newer brand but I've ordered the very exact types and will try the block with 5 caps at 500uF (that should be pretty close to 470uF). If it doesn't deliver what I experienced with the big old cap I'll swap them back. And haven't tried a Mundorf or Jantzen here yet.
This can be a long journey I think, just to check some caps but I hope the best to find one final solution pretty soon, with a little bit of luck.
Nevertheless I'm still VERY satisfied with the overall sound.
With such a fine detailing capability this doesn't apply to my FLAC files anymore.
This little toy does one important thing also very well: converting any kind of 'hiss' into analog 'fluidness' like many triodes out there. Highs are gleaming/shining like never before and the whole frequency band is very even to my ears. Everything lost the harshness while details are kept. I'm really not interested in THD-s if that's the price for a fantastic listening experience.. not gonna have this checked by Audiosciencereview (although I have a big respect to Amir). 😀
But it's demanding on source side. A forgiving circuitry with a not-so-forgiving sound on weak material (I mean mastering).
Fun fact 1) already blown the fuse (1A, slow). Touched my PC's metal parts on the back with the jack plug's tip while searching blindly for the right hole. Fuse replaced, works like a charm. I'm still alive lol.
Fun fact 2) tube sockets Nr. 9 (screen) aren't connected to ground. Yet. 😀 This is something which isn't on the schematics but definitely helps for even better triode separation within one tube. Not a big deal seemingly..
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It's definitely the 300uF vs 470uF regarding the low end.
300uF and 26R = fc = 20.404 Hz
470uF and 26R = fc = 13.024 Hz
If I were you (using 26R headphones) I'd use 3300uF.
3300uf and 26R = fc = 1.854 Hz
I like Kemet
ALS70A332KF350 KEMET | Mouser Canada
Right now, I'm using 560uF 350V Panasonic electrolytic caps I got as surplus. I can't even remember if I bypassed them with 0.22 film or not. Sounds great to me though. I have a pair of 47u film caps I'll use on a dedicated HP build for my 470R Audio Technica R70x phones one day - 560u is overkill for 470R. Still, I'd prefer 100u.
47uf and 470R = fc = 7.204 Hz
100uf and 470R = fc = 3.386 Hz
560uf and 470R = fc = 0.604 Hz
Also if you want more single ended current from this design, put two 6N6P in parallel and drop the cathode resistor from 100R to 50R. Theoretically, this will double the current and quadruple the power out.
26R and 20mA = 10mW
26R and 40mA = 40mW
470R and 40mA = 750mW
As you see, the design works best with higher Z phones 🙂
300uF and 26R = fc = 20.404 Hz
470uF and 26R = fc = 13.024 Hz
If I were you (using 26R headphones) I'd use 3300uF.
3300uf and 26R = fc = 1.854 Hz
I like Kemet
ALS70A332KF350 KEMET | Mouser Canada
Right now, I'm using 560uF 350V Panasonic electrolytic caps I got as surplus. I can't even remember if I bypassed them with 0.22 film or not. Sounds great to me though. I have a pair of 47u film caps I'll use on a dedicated HP build for my 470R Audio Technica R70x phones one day - 560u is overkill for 470R. Still, I'd prefer 100u.
47uf and 470R = fc = 7.204 Hz
100uf and 470R = fc = 3.386 Hz
560uf and 470R = fc = 0.604 Hz
Also if you want more single ended current from this design, put two 6N6P in parallel and drop the cathode resistor from 100R to 50R. Theoretically, this will double the current and quadruple the power out.
26R and 20mA = 10mW
26R and 40mA = 40mW
470R and 40mA = 750mW
As you see, the design works best with higher Z phones 🙂
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