# Traynor YCS50



## ezcomes (Jul 28, 2008)

two questions...

my manual says i can run 6L6's but since its stock with EL34's and the book references a bias of +/- 75mv , assuming thats for the EL34's...what do i set the bias to for the 6L6's?

second...
how many gain stages does the lead channel have? with or without the boost engaged?


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## GuyB (May 2, 2008)

I have a YCS 50 combo, they come with 5881 (6L6). The YCS 50 head comes with EL 34. For what I understand from the manual, the bias recommended is the same for both.
There are four gain stages.


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## Stephan1980 (Oct 1, 2009)

I have the combo. Tried both 5881s and el34s... I had to add a resister to the bias circuit to get the amp to bias the el34s properly... The plate voltage is around 500V so perhaps that will help you. divide the mV by 2 to get the mA.... 75mV = 37.5 mA.... .0375 X 500 = 18.75 watts per tube... They say to bias to around 70% of max plate dissipation.... so... for an el34.. max is usually around 25 watts..... Then 18.75 watts is about 75%... perhaps a little hot... perhaps not. depends on your tube. I had some GT el34M tubes that sounded great at 60% but didn't sound so nice above that... best to bias by ear and then check to make sure you're within an acceptable range so you don't burn up your tubes too quickly.

As for 6L6s... you will have to see first if you can bias them to around 75mV.. then you can do the math and find out whether you're biasing within the proper range if it sounds good there... 6L6 generally have a max plate dissipation of 30W compared to 25W for the EL34s.


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## ezcomes (Jul 28, 2008)

do you get more gain with the 5881's (6l6's) compared to the EL34's?

which tube did you prefer and why?


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## Stephan1980 (Oct 1, 2009)

I'd say if there was more gain with one tube over the other it would be the EL34s. They were pretty great in this amp. But I love the 5881s as well. I'll probably use the 5881s I have in there now until they're dead... and then look for some Mullard xf2s


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## ezcomes (Jul 28, 2008)

ok...so now that i'm actually doing this...i want to make sure i'm doing it right before i do anything...

with the EL34's in place i'm getting a reading of 57mv which means its actually 28.5...but if i set it to 70% then its roughly 3.5mv too high...right?

so...with the 6L6's i want to put in...i should set it for 30mv if i want the 70%

but what i don't get is...the manual says...set it to 75mv...which would be way too high...isn't it?


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## ezcomes (Jul 28, 2008)

so i emailed Traynor/Yorkville...this is what they wrote:



> Biasing of the YCS50 calls for about 35ma per tube with a plate voltage typically running just under 500v. When you have 35 ma passing through the 2 ohm cathode resistor, it also passes through the power tube to which it is attached. The static dissipation is then E x I or 500 x .035 which is about 17.5 watts. It is understood that 70-75 MV to measured from ground through a 2 ohm resistor is 35-37.5ma of cathode current. This is an average setting for either type of power tube you choose. Because the two types of tube have a different rp (plate impedance) you will find that you will have to move the bias pot to return the reading to the required 70-75mv every time you switch types. You may read the bias current for each tube but the process is moot if the tubes are not closely matched as you only have a single bias control with which to adjust the pair of tubes. In any case for either EL34 or 6L6 you still want to read the same current through the cathode resistors because the plate dissipation is about the same for each tube and the plate voltage remains relatively constant.


so...installed the 6L6's at lunch...

here is what I learned:
a) although it may seem easier to not do it, it is easier to get a good bias reading if the chassis is removed from the head shell...being in such cramped quarters i had a hard time getting a good reading on the meter, or at all
2)always watch what you are doing and be careful, in removing the spring clamp off of the still good EL34, it slipped and caught the edge of the top of the tube, and now I'm out a tube...S**T

so the 6L6's are in, and the bias set at 76mV...i let them sit for about 20 mins and then took another reading...still the same...put it back together plugged a guitar in for a min for a quick test...

so far on the gain channel it appears there if more omph in the low end...it seemed to chug a lot more...clean channel USA was great, but BRIT i couldn't get a tone i liked from...but this was only after 5 mins of noodling...and on the 15W mode...

tomorrow after a good flogging...i'll post again


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## prodigal_son (Apr 23, 2009)

I'm in the Kingston area. Did you get this head locally? I was thinking of trying one as well.


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## ezcomes (Jul 28, 2008)

i actually bought it from a friend who bought it at Renaissance...i know L&M in ottawa had one the last time i was up there...

i really like mine...i would suggest trying it...

if you can't find one...let me know...perhaps we can arrange something...


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## hollowbody (Jan 15, 2008)

ezcomes said:


> i actually bought it from a friend who bought it at Renaissance...i know L&M in ottawa had one the last time i was up there...
> 
> i really like mine...i would suggest trying it...
> 
> if you can't find one...let me know...perhaps we can arrange something...


So, ezcomes, after all this time, what tubes are you running and what do you like best?

I have the combo with the 5881s in it currently and am thinking about switching to the EL34s. I'll probably run the 5881s til they die and then switch, but I thought I'd see what your thoughts were after making the swap.


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## ezcomes (Jul 28, 2008)

http://www.guitarscanada.com/amps-cabs/38791-traynor-ycs50h-el34-vs-6l6.html

check out that thread...what i said a year ago...is pretty much still true...

for the band i'm playing in...i've put the EL34's in...turned the gain down a little, and love it...like seriously love it...our other guitarist, whom is a cork sniffer, loves the tone i get out of that amp...

to me...it turned out that i just love the sound of the 34's...to me, and my style of music its a better fit...the 6L6's were awesome for cleans and heavy distortion, but that kind of distortion isn't really my thing...i love playing it some times, so i keep a set around, (just to pop in and get some nice heavy thumping going)...but my sound is built on the 34's...

that being said...if i got into a band where the other guitarist had a wicked tone that was conflicting with mine, i could still get an awesome sound out of the 6L6's...

a friend of mine had the YCS90 and ran the 5881's...he really liked it...so if anything...its user preference...

what i would love to hear is...once you change them...let us know what YOU think!


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