[insearchofsound]

I have searched the net and through the forums (although I confess I haven't read the entire woo owners thread) and I haven't really been able to find many detailed comparisons of the three amps. In fact, the 3+ isn't even on woo audio's website.
 
Additionally, there seem to be a lot of (oftentimes unadvertised) modifications and upgrades to be done. I am assuming this is what the wa3+ is to the wa3 and there's also the PDPS mod to the wa6. I am sure there must be more!
 
Maybe we could try to turn this thread into a reference for prospective woo audio customers. If there are lots of good replies (as I'm sure there will be) I will try and keep everything organized and updated at the top.
 
In short:
1) What are the differences (sound, features, driving ability, headphone compatibility, etc) between the three models that aren't necessarily featured or explained well on the woo audio site.
2) What are the different modifications and upgrades you can order with your amp that aren't on the site and, if possible, explain the impact on the listening experience and give a price range for the mod (if you know it).
 
I saw a lot of posts where people regretted not getting a certain mod done because they didn't know about it at the time they ordered their amp, and I figured maybe this thread will help alleviate that and lead to more customers getting the wa amp they really want.
 
Thanks!

 

[MooBin]

The WA3+ is now renamed WA3. There is now a "preamp" option available with the WA3.
 
I think that all official mods are explained on the Woo Audio Website, as are the characteristics of the models itself. Above that some threads here help. So many to choose from.
 
Finally I think that tube rolling is definitely a "mod" by itself. It has great influence on the sound. Tube rolling threads are abundant in this forum as well.

 

[insearchofsound]

Thanks for the reply. I thought that the wa3+ might have been replaced by the wa3 and also see that the PDPS is now standard on the w6. But I haven't been able to find much of a comparison between the w3 and w6. I thought I had looked through the forum, but if you remember a few thread titles to get me headed in the right direction, it would be much appreciated. Maybe the unadvertised mods with woo audio were more prevalent a few years ago and are not anymore.
 
All I found on the wa site were technical specifications, which I have a hard time translating into how it would sound (and specs aren't everything either, as I have seen in threads comparing the wa amps to Little Dots, for example).
 
Thanks again!

 

[TheWuss]

yes.  PDPS standard on the WA6 since January of this year. 
it was a nice mod, and Jack incorporated it into the production amp.

 

[hodgjy]

The Woo 3+ had a power choke that helped it with lower impedance cans.  The regular 3 did not have the choke, but had a preamp out.  When Woo redid their line, they renamed the 3+ to the 3 (has power choke) and offered a $100 preamp option.

 

[BIG POPPA]

I have the 3+ with all the options and then some. It is perfect with high impedance cans. You need to warm it up good with high voltage cans. With the WA6 you have some good voltage. With my custom set up it will better a WA6 with HD 800's. Have Blackgates, WBT connectors, Furutech Rhodium IEC, Isoclean fuse, Gold plated tube bases. Plus all the tubes and cables I have for it.

 

[Skylab]

The primary difference between the WA3 and WA6 is that the WA3 is an OTL (Output Transformer-Less) design, and the WA6 is transformer-coupled, meaning it has an output transformer.  The practical impact of this is that in an OTL design, the output impedance of the amp is determined by the impedance of the output tube itself, and typically results in a high-ish output impedance.  That means that OTL amps are not at ideal, technically, for driving low-impedance headphones.  They typically shine with high-impedance headphones, where the impedance of the headphone is some multiple of the output impedance of the amp.
 
So why make OTL amps?  Because good sounding output transformers are expensive, and that means either that transformer-coupled tube amps will be somewhat costly, or have some sonic compromises, again generically speaking.
 
There are other differences too of course - the WA6 uses tube rectification, whereas the WA3 does not, and the amps use completely different tube complements. 
 
All that said, I have found both the WA3 and WA6 to sound excellent for their asking price, but the WA6 is clearly the better choice for low-impedance headphones of the two, no doubt about it.

 

[hodgjy]

Picking the WA3 vs. the WA6 is, in my mind, a choice that comes down to which cans you want to drive.  IMHO, you pick your cans first, and then decide which amp you want to power them.  I knew I wanted to drive some high impedance cans, so making the choice for an OTL amp (WA3) was obvious to me.  If you know you want to drive low impedance cans, or at least retain that possibility in the future, the WA6 is a more obvious choice.

 

[sonq]

Do you guys mean the WA6 is unsuitable to drive high impedence cans like the HD800 or the lower cost WA3 can drive it better, and better in which area?
 
Some advise will be helpful as I'm starting with the HD800 from scratch and about to pull the trigger on a WA6 with Sophia Princess tube.

 

 

[insearchofsound]

Hi, Sonq, the wa6 has an output transformer, which means it can drive both high and low impedence headphones well. My impression is that the wa6 will drive high impedence headphones just as well, and possibly better, than the wa3. The Sophia tube in the wa6 is supposed to be incredible. Color me jealous!

 

[kingtz]

How low is low in regards to low impedance? Are we talking IEM low, or stuff around 20-50ohms? Just wondering if the WA3 will be OK with the SRH840 (~40ohms).

 

[insearchofsound]

High impedence generally refers to 250/300/600 ohm phones. 40 ohms would be considered low impedence.

 

[sonq]

Quote:

Hi, Sonq, the wa6 has an output transformer, which means it can drive both high and low impedence headphones well. My impression is that the wa6 will drive high impedence headphones just as well, and possibly better, than the wa3. The Sophia tube in the wa6 is supposed to be incredible. Color me jealous!

Thanks for the feedback. Hope they pair well; esp for acoustic tracks.

 

[BIG POPPA]

Phil LaRocco left my house just a little while ago. My 3+ is fine besides my opinion to drive high current cans. Listening to his new DAC at the moment. Only complaint I have it need to warm up for a couple hours to do it well.