Topic: tube bias set up

[tinabal]

hi,  i just receive my yaqin mc10t and immediately hooked up on my kef q300 and i am not impress on the outcome, try to bias and set it to 375mv although it has improvement but still not impress on it. tanong ko lng sa may mga tube using el34 kung ano ang voltage setup?  salamat..

[CoolTOYZPH]

It will take around 150 hours to break in the new tubes. Only then will you hear the real sound quality.
Easy on the Bias as it may result to burnt out tubes.

[rochie]

when i still have my MC10T i usually bias it at 350mv,let it warm up for at least 10 minutes before adjusting, and i usually check the bias every couple of months. mc10t is a very nice tube amp for its price point,if your amp is brand new as what cooltoyz said let it burn/break-in for at least 150 hours,usually its the preamp tube(12AT7) that has a significant improvement in SQ but i wont suggest replacing it right now,how long have you been listening to it? it usually takes 15min to 1 hour for a tube amp to perform on its optimal.

[tinabal]

boss roche may i know what kind of tubes for future upgrade? i have notice after maybe 30 minutes there is improvement, ang mahirap kc na try ko yung speaker ko ma hooked up to a friends arcam amp dun kc ako nag set ng standard, i dunno kung kya talunin ng yaqin yung arcam sa performance. the bad thing is im just using mac as the source, yung friend ko kc gamit nya oppo and i just use muse dac cheapo kc hehehe.

[rochie]

boss roche may i know what kind of tubes for future upgrade? i have notice after maybe 30 minutes there is improvement, ang mahirap kc na try ko yung speaker ko ma hooked up to a friends arcam amp dun kc ako nag set ng standard, i dunno kung kya talunin ng yaqin yung arcam sa performance. the bad thing is im just using mac as the source, yung friend ko kc gamit nya oppo and i just use muse dac cheapo kc hehehe.

actually madaming pwedeng pagpilian depende sa budget hehehehee,there's the cheap chinese tubes and the expensive russian nos or US brand pero pagsawaan mo muna yang stock tubes bago ka mag upgrade,i think your source and dac also contribute to the SQ of your system if you can borrow a decent cd player or dac may improvement talaga yan. yeah it will take a while for the tubes to heat up, ako nga sa KT88 tube nakakatapos muna ako ng isang cd album bago talaga mag-init yung tube at lumabas yung magandang tunog nya

[ATJr.]

hi,  i just receive my yaqin mc10t and immediately hooked up on my kef q300 and i am not impress on the outcome, try to bias and set it to 375mv although it has improvement but still not impress on it. tanong ko lng sa may mga tube using el34 kung ano ang voltage setup?  salamat..

the EL34 is rated at 24 watts plate dissipation,
exceed this and you might see red plating which is bad...http://www.r-type.org/exhib/aaa0014.htm

so that if you are running a B+ of say 400 volts,
then 60ma is your limit, the object is to set the plate
current to a level that minimisez cross-over distortion,
the 375mV translates to 37.5mA if your cathode resistors are 10hms....
you can try up to 600mV but look out for red plating,
if it shows up, back down to say 400mV

keep in mind that as you operate very close to the plate dissipation limits,
tube life is at its shortest than when you bias to say 40mA....

so it is your choice, which would you prefer, nice sounds or shorter tube life?

[ATJr.]

boss roche may i know what kind of tubes for future upgrade? i have notice after maybe 30 minutes there is improvement, ang mahirap kc na try ko yung speaker ko ma hooked up to a friends arcam amp dun kc ako nag set ng standard, i dunno kung kya talunin ng yaqin yung arcam sa performance. the bad thing is im just using mac as the source, yung friend ko kc gamit nya oppo and i just use muse dac cheapo kc hehehe.

minsan me mga nagbebenta ng kt88/6550 dito, pwede yan sa amp mo,
set mo lang sa mababang bias say 100mV yung EL34 bago ka magpalit ng kt88
then once nakaplug na yung kt88, saka ka magbias ulit, pwede hanggang 600mV...

[obsi]

so it is your choice, which would you prefer, nice sounds or shorter tube life?

Good question, I decided on nice sound, life's too short

50ma on my el34's

"The light that shines twice as bright burns half as long..." - from Blade Runner

[tinabal]

minsan me mga nagbebenta ng kt88/6550 dito, pwede yan sa amp mo,
set mo lang sa mababang bias say 100mV yung EL34 bago ka magpalit ng kt88
then once nakaplug na yung kt88, saka ka magbias ulit, pwede hanggang 600mV...

bosing clarify ko lng coz i'm noob in this field this is my first tube amp. you mean i can use kt88 on my yaqin mc 10t?

[ATJr.]

bosing clarify ko lng coz i'm noob in this field this is my first tube amp. you mean i can use kt88 on my yaqin mc 10t?

YES, why not? you can even try the 6l6GC...

[tinabal]

YES, why not? you can even try the 6l6GC...

no need to change the transfomer? or even the  tube socket?

[remington]

learn from the master creator and designer of tube amp sir tinabal. got my el34 push pull tube power amp from master tonyt aka ATJr.He really knows a lot when it comes to tube amps

[ATJr.]

no need to change the transfomer? or even the  tube socket?

you may want to research the internet..

the KT66/6L6GC, the EL34 and the KT77, KT88/6550 all share the same socket pinouts, so plug-in and bias is possible...
in fact, a lot of other tv vertical output tubes such as the 6V6, 6W6, 6EZ5 etc. share the same socket configuration...
the thing is, it is not the tubes per se but the output transformers that define the character of your tube amp,
so no matter what you do with the tubes, if your OPT is not up to it,
then you may not get more mileage...

here are two scenarios....
1. replacing your EL34 with KT88/6550 will let you bias it to say 60mA per tube,
the B+ will drop further than say 400, power will most likely stay the same,
but distortion characteristics will surely change...

2. replacing your EL34 with KT66/6L6GC, B+ will most likely be higher than 400v,
bias is at 30mA, again power stays the same and distortion characteristics change...

which one you will like remains to be seen...

[tinabal]

you may want to research the internet..

the KT66/6L6GC, the EL34 and the KT77, KT88/6550 all share the same socket pinouts, so plug-in and bias is possible...
in fact, a lot of other tv vertical output tubes such as the 6V6, 6W6, 6EZ5 etc. share the same socket configuration...
the thing is, it is not the tubes per se but the output transformers that define the character of your tube amp,
so no matter what you do with the tubes, if your OPT is not up to it,
then you may not get more mileage...

here are two scenarios....
1. replacing your EL34 with KT88/6550 will let you bias it to say 60mA per tube,
the B+ will drop further than say 400, power will most likely stay the same,
but distortion characteristics will surely change...

2. replacing your EL34 with KT66/6L6GC, B+ will most likely be higher than 400v,
bias is at 30mA, again power stays the same and distortion characteristics change...

which one you will like remains to be seen...

that is the best info i have just receive. thanks for that sir. i'm starting to get happy now as i have tried celine dion on cog player with flac file, man the yaqin surprises me. i have auditioned before on  HIFI store, the b&w 685 hooked up on denon amp playing celine dion as well, i couldn't say that my amp will eat the denon alive but yaqin is much better.

[qguy]

What tube is installed right now ?

I have tried the JJ E34L. not the EL34 and the tone was warm and mataba ang tunog.

[ATJr.]

that is the best info i have just receive. thanks for that sir. i'm starting to get happy now as i have tried celine dion on cog player with flac file, man the yaqin surprises me. i have auditioned before on  HIFI store, the b&w 685 hooked up on denon amp playing celine dion as well, i couldn't say that my amp will eat the denon alive but yaqin is much better.

there are better explanations than mine at youtube....http://www.youtube.com/watch?v=ZvW3D3XoHWY

Good question, I decided on nice sound, life's too short

50ma on my el34's

"The light that shines twice as bright burns half as long..." - from Blade Runner

if your standby B+ is 440volts, then 50mA is just about right,
22 watts plate dissipation, or 44 watts for both plate,
meaning your classA window is about 11watts,
any more than this and you leave classA and transition
to classAB, 11 watts classA is just about all you need...
so if you are enjoying your music, this is the explanation for it....
as always, the thing to watch out for is red plating, left unchecked
it will kill the tubes, but if you see it, you still have time
to turn off your amp....

Disclaimer: this type of tube rolling is truly for the bold and daring, do not do this
if you are not ready to spend for tubes, but you can always borrow from friends...
and i will not be responsible for broken amps should your try to do this...

[obsi]

if your standby B+ is 440volts, then 50mA is just about right,
22 watts plate dissipation, or 44 watts for both plate,
meaning your classA window is about 11watts,
any more than this and you leave classA and transition
to classAB, 11 watts classA is just about all you need...
so if you are enjoying your music, this is the explanation for it....
as always, the thing to watch out for is red plating, left unchecked
it will kill the tubes, but if you see it, you still have time
to turn off your amp....

Disclaimer: this type of tube rolling is truly for the bold and daring, do not do this
if you are not ready to spend for tubes, but you can always borrow from friends...
and i will not be responsible for broken amps should your try to do this...

Sung to the tune of "Someone's waiting for you"

Be brave little one
Make a wish for each sad little ear
Hold your screw and the volt meter near
Good sound is waiting for you

[tinabal]

Sung to the tune of "Someone's waiting for you"

Be brave little one
Make a wish for each sad little ear
Hold your screw and the volt meter near
Good sound is waiting for you

idon't know about b+ or rating of plates, im gonna bias it again maybe loading 400 mv to achieve sweet sounding.