6H30 VA stage?

deicide67 · 10th December 2012, 12:12 AM

Does anyone have a link to a 6H30 as a VA stage? I am working on an amp, and I have 184V on the plates with a 28.8K anode resistor, and 11.7V on the cathode. Just wondering what is "normal" for this tube. I have a 1.5K cathode resistor.

Thanks for any information!

Blair

Charm · 05:58 AM

http://klausmobile.narod.ru/testerfiles/6n30p.htm

''Èñòîê2''. Ðàäèîëàìïû - ïî÷òîé. Ïàðàìåòðû è õàðàêòåðèñòèêè 6Í30Ï-ÄÐ êëàññèêà

Next-Tube. Ñïðàâî÷íûå äàííûå ïî ëàìïàì è òðàíñôîðìàòîðíûì ñåðäå÷íèêàì.

http://www.tubes.ru/techinfo/HiFiAudio/6n30pdr.html

http://www.tubeampdoctor.com/images/...ns%206N30P.pdf

Google steers!

deicide67 · 10th December 2012, 11:31 AM

Hi,

Thank you! I can find the tube data, but I wanted to see if anyone had a working schematic of this tube as the VA stage of their or a commercial amplifier. In my amp, I have:

Using a 28.8K plate resistor and 1.5K cathode resistor:

184V on the plate, and 11.7V on my cathodes.

I have never seen cathode voltage that high in a VA stage and wondered if it looked OK to run like this.

Thank you!

Blair

TheGimp · 10th December 2012, 12:03 PM

You are running 7.8mA for cathode current, which is well within the spec of the tube.

However, this is a low for best performance for this tube. Also your anode voltage is a too high. The two together will put you out of the most linear bias region.

I would suggest decreasing your cathode resistor significantly, to increase anode current and lower anode voltage.

deicide67 · 10th December 2012, 12:13 PM

Thanks!

Looking at the tube specs, it looks like I need to also decrease the plate resistor from almost 30k to around 6-10K and change my dropping resistor in my PS to lower the plate voltage.

You think 250-560 ohms for the cathode resistor?

Ill tinker with it and post some voltages if you don't mind.

Thanks again!

Blair

12B4A · 10th December 2012, 12:28 PM

pRC put some 6H30Pi experimentation up on his website. AudioVidioPhilia: Mambo Foreplay

deicide67 · 10th December 2012, 02:41 PM

I tinkered with it a bit by changing the dropping resistor, plate and cathode resistor.

Now, I have a B+ of around 150V

72V on the plates, and 3.45V on the cathodes.

Look better?

Thanks?

Blair

euro21 · 10th December 2012, 04:51 PM

My suggestion.

12B4A · 10th December 2012, 07:36 PM

Is that for both sections in parallel?

deicide67 · 10th December 2012, 07:58 PM

It was a single side. I ditched the 6H30. It acted very unstable and both that I have are fairly noisy. I had some wicked 120hz artifacts.

I swapped plate resistors, changed my cathode resistor, dropped a 6CG7 in and away went the noise and wobbly sine waves.

I got the 6H30s from a buddy, so god knows what they went through.

Thanks!

10th December 2012, 12:12 AM	#1
deicide67 diyAudio Member Join Date: Aug 2008	6H30 VA stage? Does anyone have a link to a 6H30 as a VA stage? I am working on an amp, and I have 184V on the plates with a 28.8K anode resistor, and 11.7V on the cathode. Just wondering what is "normal" for this tube. I have a 1.5K cathode resistor. Thanks for any information! Blair

10th December 2012, 05:44 AM	#2
Charm diyAudio Member Join Date: Dec 2009	http://klausmobile.narod.ru/testerfiles/6n30p.htm ''Èñòîê2''. Ðàäèîëàìïû - ïî÷òîé. Ïàðàìåòðû è õàðàêòåðèñòèêè 6Í30Ï-ÄÐ êëàññèêà Next-Tube. Ñïðàâî÷íûå äàííûå ïî ëàìïàì è òðàíñôîðìàòîðíûì ñåðäå÷íèêàì. http://www.tubes.ru/techinfo/HiFiAudio/6n30pdr.html http://www.tubeampdoctor.com/images/...ns%206N30P.pdf Google steers! Last edited by Charm; 10th December 2012 at 05:58 AM.

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10th December 2012, 11:31 AM	#3
deicide67 diyAudio Member Join Date: Aug 2008	Hi, Thank you! I can find the tube data, but I wanted to see if anyone had a working schematic of this tube as the VA stage of their or a commercial amplifier. In my amp, I have: Using a 28.8K plate resistor and 1.5K cathode resistor: 184V on the plate, and 11.7V on my cathodes. I have never seen cathode voltage that high in a VA stage and wondered if it looked OK to run like this. Thank you! Blair

10th December 2012, 12:03 PM	#4
TheGimp diyAudio Member Join Date: Aug 2009 Location: Johnson City, TN	You are running 7.8mA for cathode current, which is well within the spec of the tube. However, this is a low for best performance for this tube. Also your anode voltage is a too high. The two together will put you out of the most linear bias region. I would suggest decreasing your cathode resistor significantly, to increase anode current and lower anode voltage.

10th December 2012, 12:13 PM	#5
deicide67 diyAudio Member Join Date: Aug 2008	Thanks! Looking at the tube specs, it looks like I need to also decrease the plate resistor from almost 30k to around 6-10K and change my dropping resistor in my PS to lower the plate voltage. You think 250-560 ohms for the cathode resistor? Ill tinker with it and post some voltages if you don't mind. Thanks again! Blair

10th December 2012, 12:28 PM	#6
12B4A diyAudio Member Join Date: Aug 2012 Location: Right here, on this screen	pRC put some 6H30Pi experimentation up on his website. AudioVidioPhilia: Mambo Foreplay

10th December 2012, 02:41 PM	#7
deicide67 diyAudio Member Join Date: Aug 2008	I tinkered with it a bit by changing the dropping resistor, plate and cathode resistor. Now, I have a B+ of around 150V 72V on the plates, and 3.45V on the cathodes. Look better? Thanks? Blair

10th December 2012, 07:36 PM	#9
12B4A diyAudio Member Join Date: Aug 2012 Location: Right here, on this screen	Is that for both sections in parallel?

10th December 2012, 07:58 PM	#10
deicide67 diyAudio Member Join Date: Aug 2008	It was a single side. I ditched the 6H30. It acted very unstable and both that I have are fairly noisy. I had some wicked 120hz artifacts. I swapped plate resistors, changed my cathode resistor, dropped a 6CG7 in and away went the noise and wobbly sine waves. I got the 6H30s from a buddy, so god knows what they went through. Thanks!