[jamato8]

Oh, yes I would say so. He is using larger opt's. They might have a better frequency response and just different characteristics all together. They look like they are matched also.

 

[tyrion]

I don't know if there is any relevance but thought I would throw it out there anyway. When I received my WA5, Jack told me that he used new output transformers on the production model from what had been used on the prototype.

 

[jamato8]

Well there is a shield now around the windings, that would help with the flux from the other opt and there are more windings and they are tied together which would help in a few areas.

 

[Ichinichi]

I just sent my WA6 into Jack for upgrades. I told him to just do all four.

WA6 experts, was this a bad idea?

Is it worth my while to have Jack put in the black gate N-series470uF/16v instead of the standard series like takezo has done?

Is there any point in getting bigger opts put into my early WA6?

Thank you thank you thank you!!

 

[jamato8]

On the opt's I would ask Jack. On the cathode bypass caps that is a personal choice but I find better bass response with 470 over 220 but mids can be affected.

 

[Ichinichi]

thanks jamato8! you mention earlier that only the top two mods are recommended by you, what of the remaining 2?

 

[jamato8]

It isn't that I would recommend only the top two but I think they would be the most effective. The other two will be less noticable but I believe they will further refine the sound, though in a more subtle way.

 

[takezo]

ichinichi-san, i wouldn't put in a .15 uF V-cap along with a 470 uF N-series bypass cap...
it may be heaven for the bass-heads but it will most likely compromise the mids, as well
as the highs, as jamato8 mentioned above...

 

[jamato8]

Some people prefer no cap as it is felt that the mids are better without the cap in the cathode bias bypass. It is all a balancing act. The 470uf cap at this point is much more common than a 220uf and a .22 is more common than a .1 or .15 but Jack said he noticed some rolloff with the .22, though this was not a Vcap. He did notice a slight improvement in bass, which I would expect but I have not in the past noticed a rolloff by using .22. .15 is a nice compromise for the coupling cap. It is also dependent on the tube and one thing I have read in the past is that the tube used in the Woo 6 needed more life. It may have been they were using a .22 coupling cap. It is all about implementation and if a .01 worked and sounded good that is all that would matter. I still think a battery bias would be interesting and easy to try but I have no time right now.

 

[fkclo]

Dear all,

Having read all about the VCaps and Blackgates I was tempted to send my beloved WA6 to Jack for the maxxed out internal revamp. It would cost me over US$500 but I think it was worth, given all that I have spent on the WA6 and the tube compliments..... until

Jack told me that in my case it is better to upgrade to a WA4, which will be a definite one no regret step above the WA6. Jack said the WA4 will improve on impact and speed - something more difficult for a tubed amp than a solid state. He went on to explain the WA4 is available in headphone amp only version, and will deliver a performance very close to the WA5. I then have a look at the WA4 specification - indeed it is a class above the WA6. Although both use output transformer coupled topology, the WA4 is luxurious in audio terms : independent power supply for each channel, inductor for each channel, separate high and low voltage supply, dedicated rectifier per channel, and a full assortment of inputs (up to 4) plus loop out. Better still, upgrades like VCaps, Blackgates will also benefit the WA4....

Now I am at the cross-road, and don't know what to do. Yes, there is a huge cost gap between the maxxed out WA6 and a maxxed out WA4 option, but the additional features ( like a much lower THD in WA4) is really tempting. Plus, the use of 12AU7, 6922 will make good use of my tube inventories.

On the other hand, the WA4 does not look pretty - 6 blocks of transformers and inductors have created a over-crowded amp. The tubes are cornered in a small place and does not appeal cosmetically....

So I would like to hear what you guys think. Apparently now many have heard a WA4 but still I would welcome thoughts on which way to go.

Many thanks in advance.
F. Lo

 

[jamato8]

I have used the 12AU7 for a number of years in different applications but as much as I have used it, it doesn't impress me. The 6DJ8 family, which I used to detest, does and I love the tube and prefer it over my huge supply of 6SN7's as a more alive and involving natural sound. I would like an inductor in the power supply, and always use one or two in my amps that I have built. I would also use a 150H to load the input tube rather than resistor load it. An inductor loaded tube is more dynamic and fast. This is another one for the upgrade, in my opinion.

I have never heard the 4 but would imagine it could sound very good. I do not like the looks as it, as you state, is too stuffed and congested looking for my taste but couple it with some Vcaps, Blackgates, inductor loading and a few other changes I bet it would be extremely good and probably is stock.

 

[fkclo]

According to Jack, he is planning to replace the 6922 by 6X4 which he think sounds better in his design. The 12AU7 will stay.

I kind of like going down the WA4 route, and have asked Jack to see if it is possible to rearrange the layout (by hiding 2 of the 6 blocks in the chassis). This will require some re-engineering and customisation and therefore the price will go up quite a bit. Maxxed out we will be talking over US$2k, I think.

F. Lo

 

[jamato8]

So the 6922 tubes will be replaced? I am not sure I understand.

 

[fkclo]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif So the 6922 tubes will be replaced? I am not sure I understand.

According to Jack, the tube chain for each channel for the headphone only version will be 12AU7-6X4-6C19. We talked about keeping the 6922, and even using 2A3 or 5687 for the 6C19, but that will involve more engineering and possibly some change in the transformers.

To quote Jack: 12AU7 is the driver, the 6X4 will be the rectifier, and 6c19 will be the power tube.

F. Lo

 

[Kahuna]

In-directly related...


Has anyone else heard the rumor that Black Gate capacitors are out of production? (Just read this on another forum).