Modify your Woo 6. . Sophia and EML 274B . Images pages 32, 33, 34 of int. and ext. and discussion of the SE . . .

[Gradofan2]

Quote:

Originally Posted by sillysally /img/forum/go_quote.gif Don't worry about it. jamato8 has a very heavily mod DYI WA6. After a few minutes of warm up you should be ready to go, at least that's all the time my WA6SE max takes. However your new WA6SE max will take a few hundred hours to really reach the sweet point and start to stabilize. But after about 50 hours it will start to sound very nice. ss

My WA6SE always sounds great... though... I usually allow it to warm up for at least 10 minutes... before listening through it.

But... it sounds much better... after its warmed up for a couple of hours, or so - much more detailed, with a more open, airy, 3D sound stage.

I've only got about 150+ playing hours on it - so, it may be much more stable after a lot more burn in (with less variation in its sound as it warms up).

 

[sillysally]

Quote:

Originally Posted by Gradofan2 /img/forum/go_quote.gif My WA6SE always sounds great... though... I usually allow it to warm up for at least 10 minutes... before listening through it. But... it sounds much better... after its warmed up for a couple of hours, or so - much more detailed, with a more open, airy, 3D sound stage. I've only got about 150+ playing hours on it - so, it may be much more stable after a lot more burn in (with less variation in its sound as it warms up).

Yes your WA6SE will continue to stabilize until about 800 hours.
I should note that my 6SE has the upgraded parts and the DACT.
Also note that Mesh plate Rectifier tube's are more sensitive to vibration.

ss

 

[Cyberevo]

Hello Grandofan2 and Takezo:
 
Would you mind if I cite your comments in another forum?
 
AndAudio is the biggest Headset forum in Taiwan and we have more and more Woo users here.
However, most of us don't have knowledge and experience of tubes.
I decide to share the knowledge I learn from Headfi.
 
If you don't feel comfortable about it, please let me know.
I will remove it.
 
Thanks & regards;
Ivan.
 
your comments are shared here: http://www.andaudio.com/phpbb3/viewtopic.php?f=25&t=82571&p=758053#p758053

 

[torara]

Hi,
 
Understand that this thread has been inactive for a while.  Have been reading through the mod topic and info is very very good, and I definitely understand a lot more about the Woo6.  I am completely new to DIY but this thread got me interested and now I have changed the coupling caps to Mundorf Evo silver/gold/oil.
 
Bought Woo 6 early 2013 and it is probably 2012 model.  Components and layout inside my Woo 6 is clearly different to pictures I have seen in this thread, now Woo uses some PCBs instead of direct wiring.  I have a question on why the amp has resistors connecting input signal from potentiometer to grids of the first section of the tubes?  Is it possible to switch these resistors to direct wiring?  Hoping to get a  more direct signal connection to the amp.
 
Thanks 

 
 

 

[clowkoy]

Those resistors are grid stoppers. They are there to prevent oscillation (?). Value is not critical. I've seen 100, 220, 1k or even higher.
The only thing I worry about the circuit is the 330uf C1 in the PS, considering it's tube rectified and can use the Sophia 274b.

 

[torara]

I guess I will put Sophia in drawer until I change the 1st cap to 4 or 10 uf. Can I use non-polar cap for this? Like the cap the use in speaker cross over. Or this is limited to polarized cap? Any recommendation on the brand I should use for this?

 

[clowkoy]

Best would be to use metallized polypropylene . They are also non-polarized. I've tried a Clarity cap 4.7uf but hum level is unacceptable so I put back the stock cap. Right now, I only put 5ar4.

 

[torara]

Hi,
 
Have been modding WA6. Now have the first cap after rectifier as 30uf Mundorf.  After modding I have about 100V to 105V going to plates of driver tubes.  I forgot to measure before modding, so not sure if it's too low or too high.  But the amp has been sounding alright with no distortion or clipping for the past several months. 

 
Do you know if my voltage to plates of driver tubes is too high or not?
I also heard some talk in this thread about raising B+ (voltage to plate).  What voltage are you aiming for?
 
I also changed the interstage coupling cap to Mundorf EVO silver/gold/oil 0.15uf.  Thinking about changing the value of this interstage cap to higher value like 0.47uf.  What would the higher value of this cap do the the sound?
 
Many thanks...