Thank you nomiconxp
Hello
I'll wait to see all the schematic. So these does not use inter stage transformer?
OT transformer if is great quality how you wrote it would be worth to order from a guy who is familiar with these amp.
I know the shipping is not cheap but we can use surface mail for shipping..
I know Edcore sell transformers and it possible to order spec type to. I want something better.
Hashimoto's not bad but a bit pricy..
Still better to get from someone who built these amp!
Thank you one more time.
Greetings Gabor🙂
Hello
I'll wait to see all the schematic. So these does not use inter stage transformer?
OT transformer if is great quality how you wrote it would be worth to order from a guy who is familiar with these amp.
I know the shipping is not cheap but we can use surface mail for shipping..
I know Edcore sell transformers and it possible to order spec type to. I want something better.
Hashimoto's not bad but a bit pricy..
Still better to get from someone who built these amp!
Thank you one more time.
Greetings Gabor🙂
I don't know which one you are referring to.
This is an alternate version where the GU-50 is configured as a Right-handed triode requiring positive grid voltage. I have not built it and do not know the power output.
Yes, you are right that I built the one with many MOSFETS. But the MOSFETS are all mostly in the power regulator section, not the amp section. I built my power supply with split power supply and CLC smoothing, and eliminated the voltage regulator stages. 🙂 Also replaced the gyrator section with a resistive plate load due to lack of time to make a gyrator. So basically, mine has got NO MOSFETS 🙂.
By the way, if you want to build GM-70, be aware that you will need higher voltage specification parts, eg high quality high voltage chokes, capacitors and output transformers even though running at 900V, which will cost a lot. These are the reasons that still holding me back from building a similar amp. But whichever amp you choose, you can be sure it will sound good.
BTW, it seems the graphite plate GM-70 are not as good as the copper plate... some say "metallic", some say "nasal" sounding for the graphite plates. I don't know because I do not have any experience. Maybe nomix can offer his thoughts as he has experience in the GM-70.
This is an alternate version where the GU-50 is configured as a Right-handed triode requiring positive grid voltage. I have not built it and do not know the power output.
Yes, you are right that I built the one with many MOSFETS. But the MOSFETS are all mostly in the power regulator section, not the amp section. I built my power supply with split power supply and CLC smoothing, and eliminated the voltage regulator stages. 🙂 Also replaced the gyrator section with a resistive plate load due to lack of time to make a gyrator. So basically, mine has got NO MOSFETS 🙂.
By the way, if you want to build GM-70, be aware that you will need higher voltage specification parts, eg high quality high voltage chokes, capacitors and output transformers even though running at 900V, which will cost a lot. These are the reasons that still holding me back from building a similar amp. But whichever amp you choose, you can be sure it will sound good.
BTW, it seems the graphite plate GM-70 are not as good as the copper plate... some say "metallic", some say "nasal" sounding for the graphite plates. I don't know because I do not have any experience. Maybe nomix can offer his thoughts as he has experience in the GM-70.
I would like to know his contact and order these transformers too. 🙂
These would be perfect for the GM70. Thanks nomix.
graphite plate sounds very nice!! i am very happy with it!!
I don't believe some people say about the sound that is a bit metallic...
In my opinion the sound is very nice. the low are good the mid and the high!!
i hear very balanced sound!!
I believe i must give credit to the D3A!! very nice tube!!
About the copper plate i don't know much... me i never tried it...
three times the price of the graphite plate!! 🙁
So i don't know much about it other than what i read in the web..
Some say that the copper plate is weaker in the low's..... not good bass!!
about the output transformers i will contact my friend! i believe he will gladly help you!! 🙂
Their small company is founded by three people.. their dad an old guy that knows everything!!
his brother that he is a teacher in the university in electronics! and more in the transformers... 🙂 i went there. and the other brother (my friend) that his is an electronic engineer in the military!!!
I don't believe some people say about the sound that is a bit metallic...
In my opinion the sound is very nice. the low are good the mid and the high!!
i hear very balanced sound!!
I believe i must give credit to the D3A!! very nice tube!!
About the copper plate i don't know much... me i never tried it...
three times the price of the graphite plate!! 🙁
So i don't know much about it other than what i read in the web..
Some say that the copper plate is weaker in the low's..... not good bass!!
about the output transformers i will contact my friend! i believe he will gladly help you!! 🙂
Their small company is founded by three people.. their dad an old guy that knows everything!!
his brother that he is a teacher in the university in electronics! and more in the transformers... 🙂 i went there. and the other brother (my friend) that his is an electronic engineer in the military!!!
Hello quikie22
Yes I know the parts cost much more because the high voltage.
For PS we can use 600VAC oil capacitors , Russian PIO or teflon capacitors are great, some of them 1000V but it they can take even more.
There is a Bulgarian guy on Ebay, he sell 400V teflon caps and he tested them up to 1000V..
On the transformers I interested to!
I read one guy who built his GM70 with graphite plate type of tubes, after he purchased cooper plate tubes and he doesn't like it all.
The mids was better but very weak bass, so He tried to modified the amp but on the and He decided better to stick with the graphite plate version.
Aldo we can get the cooper plate about $100/PC.
That price still OK.
Do you know the life time both of these tubes GU50 & GM70??
Thanks 🙂
Greetings gabor
Yes I know the parts cost much more because the high voltage.
For PS we can use 600VAC oil capacitors , Russian PIO or teflon capacitors are great, some of them 1000V but it they can take even more.
There is a Bulgarian guy on Ebay, he sell 400V teflon caps and he tested them up to 1000V..
On the transformers I interested to!
I read one guy who built his GM70 with graphite plate type of tubes, after he purchased cooper plate tubes and he doesn't like it all.
The mids was better but very weak bass, so He tried to modified the amp but on the and He decided better to stick with the graphite plate version.
Aldo we can get the cooper plate about $100/PC.
That price still OK.
Do you know the life time both of these tubes GU50 & GM70??
Thanks 🙂
Greetings gabor
because i am an electronic engineer too they are helping me to make transformers!! all types power! tube output! they are very good guys!! yesterday i winded two output transformers!!!
For my 6SN7GTB, 12GN7A headphone amplifier!! great results!! 🙂
For my 6SN7GTB, 12GN7A headphone amplifier!! great results!! 🙂
thanx nomix, but one thing i am worried about is the shipping..
how much will it cost to ship halfway round the world? 😱
how much will it cost to ship halfway round the world? 😱
I don't understand what you mean. You've attached one of versions to your own message. That means you could see it, save it, attach, and post here.
I don't think it is a good idea for a novice to start playing with high voltages, even if you don't have children you can kill yourself. Gu-50 requires 300-400V in left handed triode mode, it is already dangerous. In right handed triode, or pentode, it requires 600-900 Volt, it is killing voltage.
I would recommend you to stay away from it.
The Master has spoken.
I agree with you fully Anatoliy... those voltages can kill 😱😱
I am glad I took your advice on the SE GU-50. It's really a lovely amp. One of the best I have heard 🙂 Even my friend with his custom designed 6550 amp could not deny that your design was a class above the one he owns.
I agree with you fully Anatoliy... those voltages can kill 😱😱
I am glad I took your advice on the SE GU-50. It's really a lovely amp. One of the best I have heard 🙂 Even my friend with his custom designed 6550 amp could not deny that your design was a class above the one he owns.
Thank you Sidney!
I am glad your friend and yourself like the amp. Gu-50 can be used to cook delicious meal, if to prepare them properly.
Anatoliy
I am glad your friend and yourself like the amp. Gu-50 can be used to cook delicious meal, if to prepare them properly.
Anatoliy
LOL,
Have you got a schematic for a defib 🙂 .
If not then have you got a circuit for an 845 + PSU running approx 900V.
Regards
M. Gregg
Have you got a schematic for a defib 🙂 .
If not then have you got a circuit for an 845 + PSU running approx 900V.
Regards
M. Gregg
Hello Wavebourn
I'm not totally a novice ,I have more than 20 years experience DIY! At the beginning with tube amps after (the last 18 years) only SS amps and some tube amp upgrade.
What I mean at page 2 post 13 you posted some schematic and I'm unable to see that.
Also I worked 3 years with electrician sometimes factories sometimes residential work mostly under power.
You are not responsible if I make a stupid mistake!
So please do not worried about me in case you want to help!
Thanks
Greetings gabor
I'm not totally a novice ,I have more than 20 years experience DIY! At the beginning with tube amps after (the last 18 years) only SS amps and some tube amp upgrade.
What I mean at page 2 post 13 you posted some schematic and I'm unable to see that.
Also I worked 3 years with electrician sometimes factories sometimes residential work mostly under power.
You are not responsible if I make a stupid mistake!
So please do not worried about me in case you want to help!
Thanks
Greetings gabor
quikie22 i will tell you tomorrow about the shipping cost.. i think each transformer weights about 3kg..
Sure high voltage can kill!!!!
But also 100V AC.....
Sure high voltage can kill!!!!
But also 100V AC.....
Do you mean this one? I have not heard from Frank since he posted his version, but I am pretty sure it should work well.
Attachments
Just for interest,
Electra-Print are using chips to drive 211 via Tx on their schematics.
Regards
M. Gregg
Electra-Print are using chips to drive 211 via Tx on their schematics.
Regards
M. Gregg
My point was, to exclude both chips and transformers, but exclude as well a coupling cap to the grid of an output tube because it's input current is non-linear causing dynamic distortions when driven through a cap. That's why it is driven through a cathode follower loaded on a CCS. Also, cathode follower welcomed load of the 1'st tube on gyrator with high dynamic resistance on AC, for minimum distortions.
Thank you Wavebourn!
I'm not sure what you posted there since I can't open the attachment.
How much power I can get from a GU50 power tube at 400V plate Voltage? I see some people use 700V..
I think it would be useful to me to read your website all the way..
Any idea about the GU50 life time , 1 000 hours 5 000 etc. I know it depend on the bias set up also.
Greetings gabor
I'm not sure what you posted there since I can't open the attachment.
How much power I can get from a GU50 power tube at 400V plate Voltage? I see some people use 700V..
I think it would be useful to me to read your website all the way..
Any idea about the GU50 life time , 1 000 hours 5 000 etc. I know it depend on the bias set up also.
Greetings gabor
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