Impedans of trafo for EL504 inSE

Ryssen · 25th June 2006, 01:29 AM

What impedans should the trafo be for triodmode.Is 2,5k to low?

Fuling · 25th June 2006, 08:10 AM

2,5k is a bit high, I used something like 1,3k in my prototype PL504 SE triode amp.

Ryssen · 25th June 2006, 07:23 PM

Ok,hello "Fuling"

.What if I use 2,5K is the "only"side effect less outputpower,or are there more?

Fuling · 25th June 2006, 07:35 PM

It will probably work just fine, as long as the transformer can handle ~100mA DC. EL504 seems to work best at low voltage and high current.

Ryssen · 26th June 2006, 02:29 PM

I have 2 tubes by the number of"76" can these be used as a driver for the El504,if I use the 504 at 80mA 175v.The 76 have a ampl.faktor of 13.8, does that mean that if i send 2v in I get 27,6 out?If its to low I ment to use a 6DJ8

Ryssen · 27th June 2006, 03:32 PM

What driver did you use?Any feedback? Do you have a schema?

Fuling · 27th June 2006, 08:52 PM

If I remember correctly I used PC86 as drivers, loaded with Hammond 156C chokes. The OPT´s was my own design that involved 25% cathode feedback.
The amp put out a couple of watts and sounded quite darn good, but for various reasons it never got further that the prototype stage. No schematic available.

edonion · 24th December 2010, 11:45 PM

This is my PL504 push-pull amplifier.
I have good results with 750 Ohms Plate to Plate.
http://edonion.com/documents/EdonionSpeedy.pdf

You can see it here
Transformadores

I hope you enjoy it. Sounds very good

pilovis · 16th August 2012, 08:14 PM

The correct value for PL504 is 800 ohm.

edonion · 09:24 PM

Quote:

Originally Posted by pilovis

The correct value for PL504 is 800 ohm.

I can not be as accurate. Since my components have 5% tolerance and the impedance of a speaker is not a constant.
The only thing I can say is that the amplifier is constructed as the above scheme and it works flawlessly.

25th June 2006, 01:29 AM	#1
Ryssen diyAudio Member Join Date: Dec 2003 Location: Sweden--> Here	Impedans of trafo for EL504 inSE What impedans should the trafo be for triodmode.Is 2,5k to low? __________________ Regards Åke

25th June 2006, 07:23 PM	#3
Ryssen diyAudio Member Join Date: Dec 2003 Location: Sweden--> Here	Ok,hello "Fuling" .What if I use 2,5K is the "only"side effect less outputpower,or are there more? __________________ Regards Åke

26th June 2006, 02:29 PM	#5
Ryssen diyAudio Member Join Date: Dec 2003 Location: Sweden--> Here	I have 2 tubes by the number of"76" can these be used as a driver for the El504,if I use the 504 at 80mA 175v.The 76 have a ampl.faktor of 13.8, does that mean that if i send 2v in I get 27,6 out?If its to low I ment to use a 6DJ8 __________________ Regards Åke

27th June 2006, 03:32 PM	#6
Ryssen diyAudio Member Join Date: Dec 2003 Location: Sweden--> Here	What driver did you use?Any feedback? Do you have a schema? __________________ Regards Åke

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25th June 2006, 08:10 AM	#2
Fuling diyAudio Member Join Date: Aug 2001 Location: Sweden (Mora)	2,5k is a bit high, I used something like 1,3k in my prototype PL504 SE triode amp.

25th June 2006, 07:35 PM	#4
Fuling diyAudio Member Join Date: Aug 2001 Location: Sweden (Mora)	It will probably work just fine, as long as the transformer can handle ~100mA DC. EL504 seems to work best at low voltage and high current.

27th June 2006, 08:52 PM	#7
Fuling diyAudio Member Join Date: Aug 2001 Location: Sweden (Mora)	If I remember correctly I used PC86 as drivers, loaded with Hammond 156C chokes. The OPT´s was my own design that involved 25% cathode feedback. The amp put out a couple of watts and sounded quite darn good, but for various reasons it never got further that the prototype stage. No schematic available.

24th December 2010, 11:45 PM	#8
edonion diyAudio Member Join Date: Feb 2004 Location: Aveiro	This is my PL504 push-pull amplifier. I have good results with 750 Ohms Plate to Plate. http://edonion.com/documents/EdonionSpeedy.pdf You can see it here Transformadores I hope you enjoy it. Sounds very good

16th August 2012, 08:14 PM	#9
pilovis diyAudio Member Join Date: Jan 2012 Location: Nizza Monferrato - Italy	The correct value for PL504 is 800 ohm.

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