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AUDIO FORUMS >> General Discussion and Support >> led biasing 6n1p in se 84cs special
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Message started by ko on 12/12/09 at 16:06:10

Title: led biasing 6n1p in se 84cs special
Post by ko on 12/12/09 at 16:06:10

hello everybody
after putting in this amazing hazen grid mod ,i was reading in a diy audio forrum about replacing the cathode resistor by leds ,i couldnot resist trying it in my very heavely tweakt zen kit so i put 2 red 2volt leds in serie to each of the to cathodes of the 6n1p ev and got a beautiful stabil minus 3,72volts , the sound became more dynamic ,more smooth and vet ,i am loving it

marry xmass everybody

grtz zenlover [smiley=simp38.gif]

Title: Re: led biasing 6n1p in se 84cs special
Post by dank on 12/12/09 at 23:09:01

ko

I'll have to try that. What about the output tubes, have you tried anything like this in that circuit? They should be biased around 10.25v so you would need 5 or 6 of them in series. Or do 5 led's and a foward bias silicon diode. I would guess that any sonic change due to this mod would be more noticable in the output stage than in the input stage. Also might try adding a couple of capacitors across each set of your 2 led's, 100 uf or so.

Dank

Title: Re: led biasing 6n1p in se 84cs special
Post by ko on 12/13/09 at 10:31:48

hello dank
i think that the current[ampere] is to high for leds with the output tubes
the voltage would be ok with 6 leds , with the 6n1p it just about 5ma ,so there it works great ,it really a big improvement in the sonic of my amp
grtz ko :)

Title: Re: led biasing 6n1p in se 84cs special
Post by lightmaster on 12/13/09 at 21:06:37

HI Ko
thxs for the tip, could you please say a little more. What resistors did you have in place before, brand, wattage, value??? and can you say a little more about the differences between now and then?? thxs a lot.

Title: Re: led biasing 6n1p in se 84cs special
Post by ko on 12/13/09 at 22:30:36

wel after soldering and trying many different things to my zen kit ,i found it time for a complete rebuild ,and i wanted to build it like a tank
,all value,s are the same as on the schematics of the zen cs ,de oversized resistors are arecol ,i got all the parts from a army electronical surplus store ,the condentsators are rusian pio ,s 0,22 uf 1000volts ,these gave a real improvement in the sound ,the tubes are voskod 6n1p ev 1970 production as a driver and 6n15p ev [sv83]
as output tubes a 1960,s svetlana 5u4[sint petersburg build ] as rectifier
the bigest improvement in comparesy with the original zen kit where the pio condensators ,the hazen grid modification , the led biasing
the rest will just last for a lifetime because of the oversizing
the power suply was changed because we use 230v here in the netherlands ,
grtz ko

Title: Re: led biasing 6n1p in se 84cs special
Post by CDesign on 01/03/10 at 08:18:55

Quote:

here in the netherlands

Maybe you can help me?

Title: Re: led biasing 6n1p in se 84cs special
Post by ko on 01/03/10 at 14:15:14

what the problem you need help with? i am located in amsterdam
grtz ko :)

happy new year to everybody here ;)