Woo Audio GES

[JamesV]

Here you go - let me know if you need a close up.

James

 

 

I had to compress - if you have an email I can send you a much higher res photo.

 

[joehpj]

please use imgur and post the link.

[JamesV]

Will do but will have to do that when I am at home later as my office system does not allow access to these types of sites.

[JamesV]

Here is the link to imgur

https://imgur.com/a/YSksw

 

 

[spritzer]

This is an older amp so it should be ok.  I need close up pics of where the red wire from the headphone socket is connected to be sure.  I can't read the resistors from this angle.   

[JamesV]

Thanks spritzer - let me know if this works or if you need another angle:

 

https://imgur.com/gallery/UbcRU

 

 

I bought the amp in February 2012.

[spritzer]

Ehhh what the fuck is wrong with Woo Audio?  So this is not up to spec but it is at least closer than many of the latter amp.  So this is voltage divider off the main B+ which should be 600V.  It's 121K into a 3M6 shunt which gives us 580V.  That's ok but then they put a 3M6 ballast resistor... It should be 4M7 so this is close but not correct.  I would change it and to a proper high voltage rated resistor too but this is close enough in value to not hurt the phones. 

On the newer amps I've seen it as low as a few hundred K if there is even a ballast resistor at all... 

[JamesV]

Thanks - so you think there is low risk of damage using my Stax or should I get rid of the amp?

[johnwmclean]

I think Bigir just gave it the nod of approval that it won’t damage phones. You should at some stage correct the values of the said resistors to bring up to proper spec, but I wouldn’t sell the amp based on ~$1.00 worth of parts and very simple fix.

[spritzer]

Yup, low risk of damage but I would buy the roughly 1$ in parts and fix this. 

[JamesV]

Spritzer and John thanks so much for this. I am not at all familiar with working on amps - could someone explain which part in the photo I would need to replace and what exact part I would need to buy. My email is [email protected] if we want to avoid using up threads here.  

[JimL]

So, the resistor that needs to be changed is the one which has orange, blue and green stripes on it - there are two of them, so the one to be changed is the one which has one end connected to the junction of all three resistors,  and its other end going to the output socket.  This should be replaced with a 4.7 megohm resistor.  You can get a suitable one at Mouser electronics.  Part number: 594-VR37000004704FR5 or VR37000004704JA100.  It's only 19 cents, or 13 cents for the second option.  Unfortunately shipping is around $7.

 

The other orange-blu-green resistor should not be changed.  You can tell this resistor because with an ohm-meter, there should be zero ohms (or very nearly) between the chassis and the end of the resistor that is away from the junction of the three resistors.  

Edited December 19, 2017 by JimL

[JamesV]

Thanks very much Jim - just to confirm I need to change the resistor that is the higher up in the photo and which connects to the red wire that connects to the headphone socket? Sorry for the newbie questions.

[JimL]

Yes.

[Kung]

Woo has just released their new flagship es-amp 3ES，it seems like another woo stuff as before.

eh， a 6sn7 as input stage and 2 300b output tubes with so many expensive wires and coupling capacitors，maybe there are step-up transformers in the chassis below i guess 

[spritzer]

I'm sure this amp will be of similar quality as the WES...i.e. pretty much shit.  Has there ever been one Woo amp that is good? 

[Thomas Pynchon]

Hello,

Could I post up pictures of the inside of my Woo Wee for someone here to check if it is has the same ballast problem too? I am completely inexperienced about this type of DIY work and would REALLY appreciate the help. Do I open the top or the bottom of the unit? 

[swt61]

I'd say go ahead and post them, and if someone feels like jumping in, they will.

[spritzer]

Feel free to post pics and we'd be happy to take a look at them.  You open up the top panel and there are cans inside of there you need to open up as well. 

[Lord_Rexter]

On 11/28/2021 at 1:18 PM, spritzer said:

Feel free to post pics and we'd be happy to take a look at them.  You open up the top panel and there are cans inside of there you need to open up as well. 

I happen pick up a Woo Audio GES here are a few pics could you please have a quick look @spritzer thank you

https://imgur.com/gallery/D4yO0oQ

 

 

 

 

 

[spritzer]

I can't see where the bias is handled, looks to be missing the adjustment for the second stage plate and no output resistors. 

The bias supply is always where Woo amps have fallen flat without seeing it, hard to give it a clean bill of health.