For right - handed mode you will need higher B+ and paralleled tubes, to use 3.5K transformer.
Of course, left handed, 400V, and 3.5K
Now you see from your load line what kind of drive you need on the 1'st grid. Time to think about adequate driver.
Absolutely right. Gu-50 tubes are nice for P-P. In pentode, 800V-900V B+, 8K load. For SE they are good for experimenting and learning things, no more. Or, need to be used in A2 in left handed mode, or in right handed mode, or in pentode mode, but always with good negative feedback.
Hello
My advise to you (if it count) try to put something together for test purpose.
You already has the transformers.
Do some test so you can see if it worth to work around these GU50 tube..
When I get my OP transformers (I buy min 3K even I use 2 GU50 paralleled) I do some test if I do not like the result probably I will change the power tube to 300B or so.
I read different opinion about these power tube some say only for PP.
Other say he built both SE & PP and only he like the SE.
Luckily these tube and sockets are not expensive. So if I have to change the power tube to 300B I don't lose $$$..
Right now I don't know if there is other power tube to get out enough power just the 300B.
All do that tube is not cheap but more popular (probably not accidentally) more info available on the net (schematic etc)
What I want to say you can design a perfect circuit around these GU50 but if you do not like the sound (result) on the end waste of time.
Greetings Gabor
My advise to you (if it count) try to put something together for test purpose.
You already has the transformers.
Do some test so you can see if it worth to work around these GU50 tube..
When I get my OP transformers (I buy min 3K even I use 2 GU50 paralleled) I do some test if I do not like the result probably I will change the power tube to 300B or so.
I read different opinion about these power tube some say only for PP.
Other say he built both SE & PP and only he like the SE.
Luckily these tube and sockets are not expensive. So if I have to change the power tube to 300B I don't lose $$$..
Right now I don't know if there is other power tube to get out enough power just the 300B.
All do that tube is not cheap but more popular (probably not accidentally) more info available on the net (schematic etc)
What I want to say you can design a perfect circuit around these GU50 but if you do not like the sound (result) on the end waste of time.
Greetings Gabor
So far I only have built a GU50 SE, but am in the mechanical and thinking phase of a PP amp. In the SE the sheer power and solid performance of the GU50 has made me a big convert.
My PP will be quite unconventional but I'll post progress - I'm hoping it will be something special though, as it will almost be like two SE circuits back to back, driven from a beam deflection tube phase splitter.
QUOTE=Globulator
So far I only have built a GU50 SE, but am in the mechanical and thinking phase of a PP amp. In the SE the sheer power and solid performance of the GU50 has made me a big convert.
Hello
So in one word are you satisfied with the result as a SE amp??
Do it worth to play with these power tube. To me these will be a amp to get some experience to build a GM70 SE amplifier. But if I spend $$$ on the irons, choke, tubes etc I do not want to waste all that investment. I think that way must have a back up plan. In these case a 300B so I do not waste all my investment.
It uses similar OP tranny same power supp...
Greetings Gabor
So far I only have built a GU50 SE, but am in the mechanical and thinking phase of a PP amp. In the SE the sheer power and solid performance of the GU50 has made me a big convert.
Hello
So in one word are you satisfied with the result as a SE amp??
Do it worth to play with these power tube. To me these will be a amp to get some experience to build a GM70 SE amplifier. But if I spend $$$ on the irons, choke, tubes etc I do not want to waste all that investment. I think that way must have a back up plan. In these case a 300B so I do not waste all my investment.
It uses similar OP tranny same power supp...
Greetings Gabor
No, I did not. I was aiming at GU-50 SE, tried many variants on paper, and decided to go by different road for SE. 4P1L tubes are cheap and very linear in triode more, they are very consistent and easy to parallel, and transformers with around 1K primary are cheaper and easier to get of nice quality. Gu-50 tubes are nice for PP, much better than 6L6 variants.
6N6P = 6Н6П Cyrillic. But that schematic was just a preliminary draft, it may contain some errors. Needs breadboarding.
No, I did not. I was aiming at GU-50 SE, tried many variants on paper, and decided to go by different road for SE. 4P1L tubes are cheap and very linear in triode more, they are very consistent and easy to parallel, and transformers with around 1K primary are cheaper and easier to get of nice quality. Gu-50 tubes are nice for PP, much better than 6L6 variants.[/QUOTE]
Hello Wavebourn
If I knew these at least a year earlier probably I do not invest into these amp.
Even now good to know because I wanted to buy more 8PC G50 tubes.
I know the price not a big deal but with shipping, import duty.
Now I test these tube but I go with 1 power tube per channel.
If I like her I keep it, if not I use the transformers for a 300B amp.
I don't know those Chinese 300B or other cheaper type like JJ etc if it worth to invest in them.
Again these to me a amplifier to get back a bit into the tube world.
My plan to put together a SE GM70 tube amp.
Greetings Gabor
Hello Wavebourn
If I knew these at least a year earlier probably I do not invest into these amp.
Even now good to know because I wanted to buy more 8PC G50 tubes.
I know the price not a big deal but with shipping, import duty.
Now I test these tube but I go with 1 power tube per channel.
If I like her I keep it, if not I use the transformers for a 300B amp.
I don't know those Chinese 300B or other cheaper type like JJ etc if it worth to invest in them.
Again these to me a amplifier to get back a bit into the tube world.
My plan to put together a SE GM70 tube amp.
Greetings Gabor
Thanks for the head up. Lucky I have lots of 6H6n, ah....I can play around with this tube. You asked I have to work out a driver. What I have in mind is I'll try to work out something with your preliminary draft. I'll try front end 1/2 6H6n to drive 1/2 6H6n. I therefore just have one tube to drive the GU50. I have a pair of hammond 1640SE 1.2k so I could try PSE too. Will post that for your comment/ correction.
Quickie22 made SE on Gu-50 and likes it a lot, you may send him PM asking to chime in and answer practical questions.
Just got Albertli's pm.... Yup, the GU50 make good amps, even in triode SE mode.....gasp.
Operating points as described by Wavebourn. However, I have converted my system. Currently I have revised my circuit and it is now a 6E5P driving the GU-50 in pentode mode with local feedback. (plate to plate)
I think you can work out the loadlines for 6E5P and GU-50.
Operating points as described by Wavebourn. However, I have converted my system. Currently I have revised my circuit and it is now a 6E5P driving the GU-50 in pentode mode with local feedback. (plate to plate)
I think you can work out the loadlines for 6E5P and GU-50.
Yes I can confirm the GU50 totally rocks as an SE tube. I use mine in Pentode mode on 430V with (lots of) feedback from the anode to the driver stage (a 6N2P SRPP stage, no other FB).
I found it was the best combination to get an effortless dynamic sound. Plus the tube quality is supreme and they all cost peanuts
Hello
Thank quikie, and Globulator! That give me some confidence to must build and test these tube.
I will go with one tube. If I can get 7-8W that is more than enough to me.
I used to listening a Philips 2W SE tube amp (it was upgraded or rebuilt) for Jazz, folk, Gospel it was great.
I had problem only with Classical.
Globulator if you would be so kind to share your schematic...
Thank you.
Quikie which schematic U using now. I also want to drive it with 6E5P around 430V anode voltage..
Greetings Gabor
Several company build commercial amp with GU50 power tubes bot SE and PP to, hard to believe if bad they can sell them. Some of them cost $$$$..
Thank quikie, and Globulator! That give me some confidence to must build and test these tube.
I will go with one tube. If I can get 7-8W that is more than enough to me.
I used to listening a Philips 2W SE tube amp (it was upgraded or rebuilt) for Jazz, folk, Gospel it was great.
I had problem only with Classical.
Globulator if you would be so kind to share your schematic...
Thank you.
Quikie which schematic U using now. I also want to drive it with 6E5P around 430V anode voltage..
Greetings Gabor
Several company build commercial amp with GU50 power tubes bot SE and PP to, hard to believe if bad they can sell them. Some of them cost $$$$..
I built several prototypes of PP amps with GU-50 outputs. I like them a lot. You can't get such quality of sound from 6L6-like tubes, like KT-??, 807, etc... However, it is not the best tube for SE, but compared to 807 in SE it is much better.
An externally hosted image should be here but it was not working when we last tested it.
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