Wavebourn said:
I speak Russian.
...................
why I'm not surprised.............?
😉
late for edit 😉
anyway-hy I'm asking for that file is because i have one priboj in my shop waiting for fix (first), then major redo (second)..........knowing me-that second will be first probably 😉
so-I'm just chasing "second opinions"......already downloaded schmtc from Jogi's
funny-even if I repaired fair number of Russian gadgets (does "Lorta" usilitel (cyrilic) ring a bell? ) ,once I even own russian CRO,and now just RLC meter......I never get used to russian way of drawing schematics........probably just matter of habit 😉
so-druzja Lisovskiy....I'll be grateful if you translate that russian text...........
anyway-hy I'm asking for that file is because i have one priboj in my shop waiting for fix (first), then major redo (second)..........knowing me-that second will be first probably 😉
so-I'm just chasing "second opinions"......already downloaded schmtc from Jogi's
funny-even if I repaired fair number of Russian gadgets (does "Lorta" usilitel (cyrilic) ring a bell? ) ,once I even own russian CRO,and now just RLC meter......I never get used to russian way of drawing schematics........probably just matter of habit 😉
so-druzja Lisovskiy....I'll be grateful if you translate that russian text...........
Zen Mod said:
so-druzja Lisovskiy....I'll be grateful if you translate that russian text...........
1. Druzja means many friends. I am one.

2. Which text?
gorgon53 said:no screengrid resistors either...not good
In triode connection?
I have an opposite opinion.
gorgon53 said:no, not triode, pentode, paralelled
I thought you mean Priboj they are speaking about:
An externally hosted image should be here but it was not working when we last tested it.
It uses paralleled 6R3S-1 double ray tetrodes in triode connection developed especially for audio output stages.
Ok, here's the complete article on Priboi mod in Russian. If you Welbourne, could be helpful with some notes we would all be happy. What is important for DIYers is how to fix the transformer to get two separate windings for each of the amps - quasi monoblock.
PRIBOI MOD
I read in AudioXpress about increasing Pout from 6L6 and 807 by having the screen grids at 80V higher than the anode. The tubes were good enough to take it.
PRIBOI MOD
I read in AudioXpress about increasing Pout from 6L6 and 807 by having the screen grids at 80V higher than the anode. The tubes were good enough to take it.
Wavebourn said:
1. Druzja means many friends. I am one.
2. Which text?
..........
1. <cyrilic> izvinite,tovaris.... 😉 <cyrilic>
2. as I see -you can find it few posts above .........so ,there is no need that I repeat link
TIA
soundbrigade said:Ok, here's the complete article on Priboi mod in Russian. If you Welbourne, could be helpful with some notes we would all be happy. What is important for DIYers is how to fix the transformer to get two separate windings for each of the amps - quasi monoblock.
PRIBOI MOD
I read in AudioXpress about increasing Pout from 6L6 and 807 by having the screen grids at 80V higher than the anode. The tubes were good enough to take it.

regarding increasing Pout- who cares for it,especially if is possible toob eating........
soundbrigade said:Ok, here's the complete article on Priboi mod in Russian. If you Welbourne, could be helpful with some notes we would all be happy. What is important for DIYers is how to fix the transformer to get two separate windings for each of the amps - quasi monoblock.
PRIBOI MOD
In my mind the article is very weak and I disagree with many statements of the author.
Do you want me to transtale it as is, or may I comment it for you?
I read in AudioXpress about increasing Pout from 6L6 and 807 by having the screen grids at 80V higher than the anode. The tubes were good enough to take it.
Even if it increases output power twice it is not so significantly audible to spend tubes linke matches. I prefer to parallel tubes instead.
Sorry Marrio2005, is it off-topic. Your topic about perfect GU-50 tubes that I love and use turned to question about Russian Priboy amp and it's modifications. People asking me to translate the article about modification of the amp that uses 6R3S-1 tubes that according to my opinion are worse tham GU-50. Do you want me to answer, or should we start a new Priboj topic?
Yes, better to avoid any vodo-tricks, better to use paralelled tubes, or speakers (increaseasing radiaton-area has the most advantages)
I have both the original article on Priboi and a shortened version in Swedish (my translation), so I don't need a translation.
However Zen-Mod was interested in a translation som Gospodin Welbourne or Gospodin Soundbrigade may give him the necessary points in the article off the list (PM).
Yepp the 6R3S is a tube wellknown for it's poor quality (very unreliable mehanically), so lets stick to the GU50! 😉
I've had my EC52/GU50 singing for some time and I am very happy. Sad the EC52 is such an odd tube, but isn't that half of the fun - to use odd looking tubes.
Next project would possible be a GU50PP., though I have some 6L6 (Russian brands) that would give some power to me. But anyway can anyone a rough idea how such an amp would look like, or could I use an outline for EL34 or 6550/KT88 with slight modifications?
However Zen-Mod was interested in a translation som Gospodin Welbourne or Gospodin Soundbrigade may give him the necessary points in the article off the list (PM).
Yepp the 6R3S is a tube wellknown for it's poor quality (very unreliable mehanically), so lets stick to the GU50! 😉
I've had my EC52/GU50 singing for some time and I am very happy. Sad the EC52 is such an odd tube, but isn't that half of the fun - to use odd looking tubes.
Next project would possible be a GU50PP., though I have some 6L6 (Russian brands) that would give some power to me. But anyway can anyone a rough idea how such an amp would look like, or could I use an outline for EL34 or 6550/KT88 with slight modifications?
Helo i'm new here and ned some help. I have 30 of GU-50 tubes and i wont to make a amplifier . Can somebody help me whitch is the best working and give me amp schematic and transformator schematic . Have a nice day. Simon
Wavebourn said:
Ok, let's call Tubelab on the stage now, to open both tubes and measure/compare internals. 😀
I've compared "externals" for myself, GU-50 sounds much tastier, is more powerful (however, I am comparing now 2 nearly identical amps, with 4x6L6 vs 2xGU-50, though 6L6 and KT88 are a bit different, but they are very similar).
Military ray pentodes won against guitar ray tetrodes.![]()
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If you will recall: some time ago I XRay'd both those types.
GU-50 and Chinese 6L6 internal through shots from many
angles. Thread might still exist around here somewhere, if
you care to dig up those photos.
I think GU-50 was a true Pentode, not a ray type. Observed no
alignment of grid and screen. Perhaps this gives GU-50 lower
capacitance for RF? And can abuse G1=G2 drive if everything
holds true according to Telefunken's original LS-50 spec.
Beam tubes (except maybe space charge types) are never
characterized for G1=G2. The G2 screen directly in the focus,
rather than hiding in the shadow of G1. Formula for disaster!
i am reading this threat with great intrest , i want to put a gu50 in triode
with a 6n1p ev as as driver ,the amp is now working with el34 in triode
and i want to convert the el34 stage in a gu 50 stage for some more power
anybody a idea about a good working schematic??
grtz ko
with a 6n1p ev as as driver ,the amp is now working with el34 in triode
and i want to convert the el34 stage in a gu 50 stage for some more power
anybody a idea about a good working schematic??
grtz ko
Thanks for your comment,
Actually i dont use that 250V Zener ,only for protect 2 grid from
high voltage in case 275V or more.
Andreas , can you suggested capacitor value ,I can test.
I test russian triode 6N8S and have good result
If somebody need Transformers I have some excellent SE transformers in this range for 45 Euros . pair 90 euros about 115$
2K5/8R 140mA 25W
weight 4.5 kg or 9.9 lbs
Freqency response: 10Hz-45KHz (-3db)
EI-core 108 Waasner M 111-35 N
Toroidal power transformer 300W sec 320V.07A : 6.3V5A :6.3V5A :40V 0.6A for 35 EURO or 44$
Regards
mario
as for the capacitor value you could use a .22uf cap. it cuts off at around 15 hz
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