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Simple SE GU-50

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I am looking at a Tubelab Simple SE.
What I am wondering is if the GU-50 would be a good pentode to choose?
I understand that I would have to wire up the special socket (no biggie).
What I am more concerned about is whether or not the rest of the build would be pretty straight forward like any other pentode?
Also I'd be looking at just Class A mode and am wondering how much power I could expect....Triode? UL? Pentode?....at least 10W??
I know these questions have quite a few answers and I am looking at my first tube power amp.
I have built my tube preamp already, the build went relatively well and I am very happy with the end result.
This PCB looks like a nice "Simple" layout that would be easy to understand.
I think it is a good point to start into my tube amp listening.
 
I am looking at a Tubelab Simple SE.
What I am wondering is if the GU-50 would be a good pentode to choose?
I understand that I would have to wire up the special socket (no biggie).
What I am more concerned about is whether or not the rest of the build would be pretty straight forward like any other pentode?
Also I'd be looking at just Class A mode and am wondering how much power I could expect....Triode? UL? Pentode?....at least 10W??

I'd suggest SE class B :D
 
I have no plans about Denmark yet, but for beginners I would not recommend Gu-50 in pentode because of lethal B+ voltage required for it to breathe free.

Actually that would be down-sizing for me.
I used to repair Color-TV's when it was interesting with tubes in the EHT :D
My first job at all in the biz was maintaining a Gates BC-1T MW-TX with plenty of 833A's where it counts. That was in 1976.

When does a GU-50 start breathing free? At 1KV? And shouldn't it really be driven into grid-current to produce?

rgds,

/tri-comp
 
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@ Wave, I really appreciate your input, it seems that you know a lot about the GU-50.
I am in fact looking at Triode mode for whatever tube that I choose.
I really like the tube socket and possible power output of the GU-50.
The GU-50 also has had quite a few praises for quality and it is nice and cheap.

The Simple SE with GU-50 would run Triode mode I'm mainly wondering about the suitability of this valve in the Simple SE.

Thanks,

Rich
 
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@ Wave, with 450V B+ on the Simple SE GU-50; do you think that is a good application?
What do you suppose I could expect, power wise & quality wise?
I am in the process of building some 96db efficient speakers so I don't need a heap of power.
 
@ Wave, with 450V B+ on the Simple SE GU-50; do you think that is a good application?
What do you suppose I could expect, power wise & quality wise?
I am in the process of building some 96db efficient speakers so I don't need a heap of power.

Do you know how to use plate curves and load lines?

GU50+350v100ma.jpg
 
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@ Wave, with 450V B+ on the Simple SE GU-50; do you think that is a good application?
What do you suppose I could expect, power wise & quality wise?
I am in the process of building some 96db efficient speakers so I don't need a heap of power.
Good morning!
We highly recommend an excellent scheme (personal conception), even if you're new tube amplifiers, making this scheme will give you full satisfaction.
Pentode mode you get up to 18W with low THD, power that will move your 96dB speakers very well.
The scheme is realized in many copies and the results are excellent.
Is relatively small voltage Ua (Ua = 500V), but must be careful, danger is still very high.
You signal the drawings and as 8 ohm load, operating schedule, construction data for OT and supply scheme.
Because floors are pre-outs and attack SRPP, filament power supply must be made as illustrated.
Again, GU50 is a great tube, but it is uglier than the classic series EL ** or KT**.
hoping that I was helpful, thank you for your attention
 

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I prefer when tube works nice even if looks like trashcan, rather than when it looks nice, but works like a trashcan.

However, tastes are different...



Right you say I prefer the tubes (GU50), like everything is a challenge.
GU50 and 6C33C tubes are made ​​to go and play "shoot tank gun" and when MiG (aircraft) is at 10.000Km, so a quiet GU50 function to a good home is very simple ... right?
I made ​​a joke, but honestly I prefer Russian tubes for their robustness, but also its quality in the audio and more.
I believe that a GU50 in a project like the above may work for many years without problems.
 
And for an output stage I would consider grid currents to occur, even if only on peaks, so I personally tend to avoid coupling capacitors to 1'st grids of any output tubes when possible.

When you point at blocking distortion when grid current occurs, the combination of coupling capacitor / high ohm-ish grid leak resistor is more responsible. Replacing the grid resistor by a low DCR grid choke should work OK, also with a coupling capacitor.
Better drive still will be there with an interstage transformer IMO.
 
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My other thought would be to use my Aikido 6CG7 x 6CG7 to drive the GU-50's directly.
This would be wired P2P and I have no problem with that.
As a matter of fact it may simplify my build and save me $45 on a PCB that I can use for parts.
I was thinking maybe 2 Parallel GU-50's for a little more output since I don't need to buy a PCB.
 
No, source follower is better. IMO.

Depends IMHO.
Source follower is the champion in current drive, no question.
With a 1:1 IT the driver tube will be able to deliver higher voltage swings, and current drive will improve with IT step-down (at cost of voltage swing).
It's all a matter of solid engineering; with different approaches equally good results can be obtained IMVHO.
 
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