6N1P & SV83 mu stage driving 845?

dr.strangelove3 · 7th October 2004, 08:35 PM

According to the Svetlana, the 6N1P & SV83 mu stage is suitable for driving a SE 845.

see technical bulletin:
http://www.svetlana.com/docs/TechBul...noteNO.27.html

Has anyone built something like this?

Thanx for any comments about this combination.

Brett · 7th October 2004, 10:02 PM

Quote:

Originally posted by dr.strangelove3
According to the Svetlana, the 6N1P & SV83 mu stage is suitable for driving a SE 845.

see technical bulletin:
http://www.svetlana.com/docs/TechBul...noteNO.27.html

Has anyone built something like this?

Thanx for any comments about this combination.

Gain will be around 30, and depending on where you bias your 845, you're going to need maybe 100V or more to drive it to full capacity. Is it enough gain?

Personally, I'd use something like a D3a in pentode.

jrdmedford · 7th October 2004, 11:14 PM

If you read the article, 100Vrms with 0.45% THD. This is quite good!

The output impedance is quite low, 100 ohms, so such an amplifier
built with the mu stage ought to take a 211 by simply screwing in the
new tube and back off the fixed bias setting...

Yeah you could use D3a et cetera, but this is cheap to build using
tubes that cost less than usd$10.00 each.

-- Jim

Brett · 7th October 2004, 11:38 PM

Quote:

Originally posted by jrdmedford
If you read the article, 100Vrms with 0.45% THD. This is quite good!

The output impedance is quite low, 100 ohms, so such an amplifier
built with the mu stage ought to take a 211 by simply screwing in the
new tube and back off the fixed bias setting...

Yeah you could use D3a et cetera, but this is cheap to build using
tubes that cost less than usd$10.00 each.

I read the article, and I don't question the swing, but is the gain enough? I've seen plenty of 845 amps biassed around -145V, and I just don't think it's enough in most systems. A 211 is a different subject.

BTW, I've never paid more than $US10 for a NOS D3a.

211audio · 7th January 2007, 01:22 PM

Hi Dr. Strangelove,
If you like I have a mu-stage schematic for you, based on a 6H30p and a D3a, driving a 845 on 20W. Send me an email.

dr.strangelove3 · 7th January 2007, 01:53 PM

Hi 211audio,

I would love a schematic using based on the 6h30p, d3a and the 845!!! I love those toobz.

but... your e-mail button is off. So I can't email you directly... can you send me a message so I can email you back?

Thanks

mus · 8th January 2007, 01:44 AM

Hi, (6N1P + SV83) this is the Mu-stage schematic that I used for my Line-Amp. The sound is very nice and detailed. In fact I'm using 300V B+ and changed the 6N1P's Rk=2.2K. I had tried the D3a instead of SV83, but I don't like the result! The overall sound is too bright and forwarded, a bit like metalic sound? The D3a that I used is Siemens from eBay http://cgi.ebay.com/4-x-D3a-Siemens-...QQcmdZViewItem
Is there anyone know why?

Wavebourn · 8th January 2007, 05:26 AM

I suppose SV83 is EL84 without internal connection G3-K.
Probably it has more precision winding of grids, or just more strict limits in datasheet to meet better linearity needed for TV amplifiers where 6P15P (original name of SV83) were used.

Tubelab, did you torture them? How different they are really from 6P14P?

211audio · 8th January 2007, 04:20 PM

Hi Dr. Strangelove,

My email button is on now, but I can't send you a mail because my account is under moderation, due to my first steps on this board.

About Siemens D3a:

All of my amps utilized the D3a penthode and I can't say anything else than that it maybe have something to do with the way you bootstrapped the tube. I've used it in several 300B and 211 amps.

211audio · 8th January 2007, 04:23 PM

dr.strangelove3,

The schematic you have attached to your reply is not a mu-stage (Alan Kimmel) but a mu-follower circuit. That is something totaly different....

211audio

7th October 2004, 11:14 PM	#3
jrdmedford diyAudio Member Join Date: Mar 2004 Location: Medford, MA	Yes. Please try it. It's cheap. If you read the article, 100Vrms with 0.45% THD. This is quite good! The output impedance is quite low, 100 ohms, so such an amplifier built with the mu stage ought to take a 211 by simply screwing in the new tube and back off the fixed bias setting... Yeah you could use D3a et cetera, but this is cheap to build using tubes that cost less than usd$10.00 each. -- Jim

8th January 2007, 05:26 AM	#8
Wavebourn diyAudio Member Join Date: Sep 2006 Location: Pleasant Hill, CA	I suppose SV83 is EL84 without internal connection G3-K. Probably it has more precision winding of grids, or just more strict limits in datasheet to meet better linearity needed for TV amplifiers where 6P15P (original name of SV83) were used. Tubelab, did you torture them? How different they are really from 6P14P? __________________ If I disappear suddenly, that means I finally created a time machine and pushed wrong button that brought me to Stalin's Russia. In any experiment any result is the result. Even if it is negative.

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7th January 2007, 01:22 PM	#5
211audio diyAudio Member Join Date: Feb 2006 Location: Netherlands	Hi Dr. Strangelove, If you like I have a mu-stage schematic for you, based on a 6H30p and a D3a, driving a 845 on 20W. Send me an email.

7th January 2007, 01:53 PM	#6
dr.strangelove3 diyAudio Member Join Date: May 2004 Location: Leeuwarden	Hi 211audio, I would love a schematic using based on the 6h30p, d3a and the 845!!! I love those toobz. but... your e-mail button is off. So I can't email you directly... can you send me a message so I can email you back? Thanks

8th January 2007, 01:44 AM	#7
mus diyAudio Member Join Date: Mar 2006 Location: bc	Hi, (6N1P + SV83) this is the Mu-stage schematic that I used for my Line-Amp. The sound is very nice and detailed. In fact I'm using 300V B+ and changed the 6N1P's Rk=2.2K. I had tried the D3a instead of SV83, but I don't like the result! The overall sound is too bright and forwarded, a bit like metalic sound? The D3a that I used is Siemens from eBay http://cgi.ebay.com/4-x-D3a-Siemens-...QQcmdZViewItem Is there anyone know why?

8th January 2007, 04:20 PM	#9
211audio diyAudio Member Join Date: Feb 2006 Location: Netherlands	Hi Dr. Strangelove, My email button is on now, but I can't send you a mail because my account is under moderation, due to my first steps on this board. About Siemens D3a: All of my amps utilized the D3a penthode and I can't say anything else than that it maybe have something to do with the way you bootstrapped the tube. I've used it in several 300B and 211 amps.

8th January 2007, 04:23 PM	#10
211audio diyAudio Member Join Date: Feb 2006 Location: Netherlands	dr.strangelove3, The schematic you have attached to your reply is not a mu-stage (Alan Kimmel) but a mu-follower circuit. That is something totaly different.... 211audio