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Woo WES revision

post #1 of 15
Thread Starter 

I recently gave my WES - originally El_Doug's WES - over to Jack for implementation of his latest "revision".

Something to do with 4 filter chokes.

As far as I know, replacing the old ones with upgraded new ones.

A $750 job.

I had asked Jack to look into the inside of the amp while doing the revision to see if there was anything else

that could be done to improve its performance.

Jack's answer: there was nothing inside which needed upgrading.

But he did move a few wires around.

Now...

I had spoken to Jack about the fact that I found the Stax SR-007 mk I unlistenable through the WES.

Too dark for me to hear the full range of highs present in the music - highs which were noticeable to me through

other set ups - even with my very pronounced hearing loss in the high frequency range.

Jack said that the 007 was a dark phone, but that a change of tubes might help some.

But...but...but...surprise...

When I got the revised amp back home, I discovered that, even without any tube changes, the SR-007s

were now quite listenable.

The highs were there and, as far as I could tell - please take into consideration my paucity of critical listening

skills and substantial hearing deficit - nicely balanced with the rest of the tonal range.

Completely satisfying!

I am writing this report so that others who have the WES may have an idea of the value the new revision may

make in improving their enjoyment of the SR-007 with the WES amp.

Particularly since there have been reports on this forum indicating that several WES owners  had found these

phones were unnaturally dark with this amp.

Also:

(And I haven't found a discussion of this)

I am wondering what changes others who have done this filter choke revision may have found in the sound - in

general or in whatever respect - of  the new improved WES.

post #2 of 15

Subscribed, interested popcorn.gif

post #3 of 15

haarvi, it's to hear your thoughts on this upgrade.  At the last RMAF meet I was offered to have this upgrade for a similar price, after I heard my O2 Mk1 on their Mk2 WES and thought it sounded improved (I didn't know about the upgrade until after I made my comments).  But my pre-production WES still sounds pretty good as it stands.  

 

I own the demo unit that Steve Guttenberg reviewed for Stereophile magazine in 2009, which he absolutely loved.  It's only slightly dark with O2 Mk1 vs my KGSS, but with better sparkle than my LCD-2 rev1 via my ZDT amp.  I wouldn't say that is is any darker than my KGBH.  My particular WES is also a bit better with my O2 Mk1 than my old Maxed GES was.  

 

I do think my WES sounds better with my SR-009 and HE-60 than it does with O2 Mk1, but I could still be happy with only the O2 on this amp.  Before I got my SR-009 my whole family actually preferred the WES/O2, after being forced to sit down and try several rigs. (including ZDT and WA6 amps with HD800, HE-6, HE-500 and LCD-2)

 

This makes me wonder if there was something up with El_Doug's WES because if I recall correctly he tried some high cost capacitor upgrades and sold them, then later sold the amp because he wasn't totally happy with it.  Neither were you until now.  But Spritzer complains all the time about the WES he heard in NYC, so the other possibility is that my pre-production WES for some reason sounds better than others, and somewhere between the Mk1 and Mk2 WES.  

 

Even with a DIY KGSS and KGBH in the house, I have not been in a rush to sell my WES although it scores a little higher in looks than sound vs the others.  And my KGBH is running higher voltage rails and custom CCS and transformers, with Mullard XF2 EL34.  All the amps have excellent imaging and detail, with adequate power for O2 Mk1.

post #4 of 15
Thread Starter 

Thanks Larry for all the info in your post:

Details about my (El_Doug's) WES.

And your pre-production demonstration model.

You say that, though a bit on the dark side, your WES has been workable - even enjoyable with the SR--007.

Got it - good for you.

It could be that the unlistenability I experienced has something to do with the particulars of my model.

And perhaps something to do with my hearing deficit pattern in having a pronounced fall off for high pitch sounds.

To the point where I really would do well to be fitted for hearing aids.

But...somehow...I still have always been able to ...with other headphones with the WES and headphones with other

amps...been able to hear satisfying sparkle and shimmer.

And, now, as detailed in my first post, also with the SR-007 out of the filter choke upgraded WES.

One point that you don't mention in your post - above - but which is relevant to this discussion:

As you wrote  in our recent pm exchange - when I invited you to come by and put something up here - is that you had

a chance to listen to the SR-007s through revised (MkI) WES at a meet and found that there was a noticeable uptick in

the treble tonality.

So we are on the same page there.

I have some other listening to do with other phones with my revised WES and am looking forward to doing so, but I don't 

expect any other changes I may suspect I hear to be anything like as dramatic as going from the one I experienced with

the SR-007s.

I considered selling them for not being able to use them.

And now I like them.

BTW:

Congratulations on your picking up the 009s.

post #5 of 15
Quote:

Originally Posted by HeadphoneAddict View Post

 But Spritzer complains all the time about the WES he heard in NYC, so the other possibility is that my pre-production WES for some reason sounds better than others, and somewhere between the Mk1 and Mk2 WES.  

 

I have drawn up the schematic of your amp and there is nothing special about it.  It was due to your impressions and posts that we sourced pics of the WES circuit as there was clearly something wrong with it so that's something to think about. 

 

I'll post the full schematic for my fixed version of the WES as soon as I'm done with it but it keeps getting postponed due to other projects.  The main fix is removing any and all inductors from the amp though and replace them with far superior SS current sources. 


Edited by spritzer - 5/18/12 at 10:15am
post #6 of 15
Quote:
Originally Posted by spritzer View Post

 

I have drawn up the schematic of your amp and there is nothing special about it.  It was due to your impressions and posts that we sourced pics of the WES circuit as there was clearly something wrong with it so that's something to think about. 

 

I'll post the full schematic for my fixed version of the WES as soon as I'm done with it but it keeps getting postponed due to other projects.  The main fix is removing any and all inductors from the amp though and replace them with far superior SS current sources. 

 

Very interesting, Spritzer.

Look forward to the schematic.

Regards,

Erico

post #7 of 15

Had the same impression as you, Haarvi.

Bought my WES in 2010 (the maxxed version).

Through 2011 I talked to Jack Wu a lot of times because I felt the 007 sounded quite dark too me.

He told me to try different tubes and also that he was working on new filter chokes for the amp. The tubes didn't work as planned althoug some do sound warmer or brighter than others.

When the revision was ready I bought the new filter chokes, but had problems with custom (a pain here in Brazil).

So I had to send him the WES for revision.

After I received it back I noticed a slight change for the better, but the 007 was still dark compared to the 727 and the BHSE.

When I bought my 009, I felt the combination very good. So now I use the 009+WES. Don't think the 007+WES as a proper combo, I prefer the BHSE and even the 727 and 007T for it.

That's my two cents.

Regards,

Erico 

 

Quote:
Originally Posted by haarvi View Post

Thanks Larry for all the info in your post:

Details about my (El_Doug's) WES.

And your pre-production demonstration model.

You say that, though a bit on the dark side, your WES has been workable - even enjoyable with the SR--007.

Got it - good for you.

It could be that the unlistenability I experienced has something to do with the particulars of my model.

And perhaps something to do with my hearing deficit pattern in having a pronounced fall off for high pitch sounds.

To the point where I really would do well to be fitted for hearing aids.

But...somehow...I still have always been able to ...with other headphones with the WES and headphones with other

amps...been able to hear satisfying sparkle and shimmer.

And, now, as detailed in my first post, also with the SR-007 out of the filter choke upgraded WES.

One point that you don't mention in your post - above - but which is relevant to this discussion:

As you wrote  in our recent pm exchange - when I invited you to come by and put something up here - is that you had

a chance to listen to the SR-007s through revised (MkI) WES at a meet and found that there was a noticeable uptick in

the treble tonality.

So we are on the same page there.

I have some other listening to do with other phones with my revised WES and am looking forward to doing so, but I don't 

expect any other changes I may suspect I hear to be anything like as dramatic as going from the one I experienced with

the SR-007s.

I considered selling them for not being able to use them.

And now I like them.

BTW:

Congratulations on your picking up the 009s.


Edited by ericohgb - 5/18/12 at 11:24am
post #8 of 15
Thread Starter 
Quote:
Originally Posted by spritzer View Post

 

I have drawn up the schematic of your amp and there is nothing special about it.  It was due to your impressions and posts that we sourced pics of the WES circuit as there was clearly something wrong with it so that's something to think about. 

 

I'll post the full schematic for my fixed version of the WES as soon as I'm done with it but it keeps getting postponed due to other projects.  The main fix is removing any and all inductors from the amp though and replace them with far superior SS current sources. 

 

Your "schematic for the fixed version" could possibly provide the blueprint for a 2nd revision to the WES.  

Potentially great news for WES owners.

post #9 of 15
Quote:
Originally Posted by haarvi View Post

Thanks Larry for all the info in your post:

Details about my (El_Doug's) WES.

And your pre-production demonstration model.

You say that, though a bit on the dark side, your WES has been workable - even enjoyable with the SR--007.

Got it - good for you.

It could be that the unlistenability I experienced has something to do with the particulars of my model.

And perhaps something to do with my hearing deficit pattern in having a pronounced fall off for high pitch sounds.

To the point where I really would do well to be fitted for hearing aids.

But...somehow...I still have always been able to ...with other headphones with the WES and headphones with other

amps...been able to hear satisfying sparkle and shimmer.

And, now, as detailed in my first post, also with the SR-007 out of the filter choke upgraded WES.

One point that you don't mention in your post - above - but which is relevant to this discussion:

As you wrote  in our recent pm exchange - when I invited you to come by and put something up here - is that you had

a chance to listen to the SR-007s through revised (MkI) WES at a meet and found that there was a noticeable uptick in

the treble tonality.

So we are on the same page there.

I have some other listening to do with other phones with my revised WES and am looking forward to doing so, but I don't 

expect any other changes I may suspect I hear to be anything like as dramatic as going from the one I experienced with

the SR-007s.

I considered selling them for not being able to use them.

And now I like them.

BTW:

Congratulations on your picking up the 009s.

 

Yes, I did think the WES Mk2 at RMAF was improved over my pre-production Mk1, based on auditory memory.  But I don't really recall what any other production WES Mk1 sounds like other than mine.  i.e. the only WES I recall hearing is my pre-production Mk1 and the revised Mk2 at RMAF 2011.  And above Spritzer is saying that my particular WES pretty much fits the schematic for the production Mk1 WES.  Note - when I first heard the WES at RMAF 2009 I didn't like it much, but it was changed a bit before it went into production, and at RMAF 2009 it sounded much better.  I kept going back and forth between the WES and my GES and my auditions convinced me to talk Jack into selling me the demo, to ship to me after the Nov 09 NYC meet.  

 

I did say I think the WES sounds better with SR-009 than it does the 007, regardless of revision.  Fortunately the rev2 or Mk2 changes that improved the Mk2 with my O2 at RMAF didn't hurt it at all with the SR-009.  I said I'd be happy using the O2/WES but that's if I didn't have another choice, and I do.  Since I have too many stat amps I'm starting to think about just using the KGBH in my main basement rig and the KGSS and in my bedroom rig, and cutting lose the WES.  I just haven't been forced to decide yet.

 

While the WES has adequate power for the O2 Mk1, it won't play the O2 as loudly as the KGSS or KGBH without the sound starting to break up (especially with heavy deep bass notes in electronic or rock music).  But it sounds wonderful with my SR-009, HE-60, SR-003, and Lambda Nova Signature.  I also really liked it with the SR-404LE, but I don't have those anymore.

post #10 of 15

Once again Larry you have no idea what amplifier power really is.  What you are hearing is clipping which is the definition of lacking power. 

post #11 of 15

I do not own a WES, but how a filter choke is implemented in a circuit can have this kind of impact from my understanding.  This and some other forms of filtering intended to lower noise floor and prevent hum can deaden the sound and kill dynamics if implemented wrong or implemented to excess.  Always a fine balancing act.....

post #12 of 15

Well the choke isn't a filter choke, it's the load for the output stage in the same way an output transformer is the load in a SET amp.  That's the problem as this isn't a SET amp... 

post #13 of 15

Ah, I see, thank you for the clarification.  Always learning.  :)  I imagine Woo just switched to a design offering higher bandwidth then which helped open up the top end a bit more.

post #14 of 15

They still haven't fixed the underlying issue so any "upgrade" will be marginal at best. 

post #15 of 15

I also have the SR 007s.  Yes they are not as "special" as the SR 009s, but still great nevertheless.  All my comments relative to gradual break-in improvements via the SR 009 apply to the 007s as well.  At my "man cave," during listening sessions we frequently swap "cans".... I mean earspeakers  (forgive me)

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