[10068]

Quote:

Originally Posted by euclid LOL, send them over, im sure i can incorperate the tubes somehow

i dunno, make sure you wipe the tubes off afterwards. wouldn't wanna have any funny burning smells now would we.

 

[adhoc]

those are some seriously beautiful photos!

I've been trying to do the same with my Eddie Current for some time now, but lacking a tripod...

 

[Capt. Z]

If you don't have a tri pod, you can use a bean or rice bag.

 

[Capt. Z]

Hi euclid;

Starting at the back right corner where the AC connection is.

You must have the switchable 120/240 Volt option.

Than right close to it, the big cap - power line conditioner is missing.

Behind the RCAs there are 2 Fotolash caps, in yours they are from Rubycon. Same goes for those 2 caps next to the power tube.
Right behind (toward the RCA and IEC) I have green Sanyo caps. Yours look black.
Mine also has a Red Wima cap across the power tube socket.
Also, Dr. Woo also moved the small red Wima caps from the output RCA to the small signal tubes.
A few resistors have a different color, but that may mean nothing.
And he last thing I could see is that you have a different Phono plug. Yours is closed (inside) mines open and the nut outside is balck and not silver.

Those are the differences I can see.

I wander, if I could just desolder the big Wima cap across the powertube?

 

[jamato8]

This is my Woo3 with Amperex PQ input tubes and a Western Electric 421A.

shot with a Canon Rebel XT, 28-135 IS Canon zoom, Gitzo carbon fiber tripod.

Close-up 421A top

180 Canon Macro, same tripod

Heart of a tube, the heater

I have shot up to 8x10 view cameras and used the 4x5 format for a long time but the digital revolution is the most fun I have had in some time.

 

[Capt. Z]

I love those "coke bottle" style tubes.

How does the WE 421A compare to the 6080 or 6AS7?

What other substitute tubes could be used in the Woo3?

 

[jamato8]

To my ear the 421A is more romantic sounding than the 7236 but some might prefer its sound. The 421A is about the same as the 5998 in sound but maybe just a step above. I have used the 6080, 5998, 6AS7, 421A, and the 7236 as power tubes, prefering the latter.

John

 

[euclid]

thanks capt. z, i ill add cap to filter ac line as first mod, i can only imagine woo took them out to cut costs b/c it should help performance if one is present.


jamato8 those tubes look great, i have been reading your modification thread for a couple weeks and i will be using your recomendations for sure. is the 421a just a drop-in tube?

edit: 180f3.5Lmacro

congrats jamato8, ill be settling for the 100f2.8macro when the time comes, i was really wishing for macro capability when i was shooting this amp, the aluminum grain is gorgeous. nice tripod too, *sigh*(maybe one day).

 

[KZEE]

Quote:

Originally Posted by Capt. Z I love those "coke bottle" style tubes.

Well then you're going to love the Tung Sol 5998 that I'm sending you because it also has that Coke bottle shape. And it sounds good too.

 

[jamato8]

Quote:

is the 421a just a drop-in tube?

Yes, you can plug it in with no changes.

John

 

[Capt. Z]

The newes version of the WooAudio 3 has no more cap across the power tube socket. Can this cap be eliminated or bypassed?

http://i7.photobucket.com/albums/y27...1/IMG_1428.jpg

 

[jamato8]

I would imagine it can be eleminated. I will look at my amp as I never paid much attention to the cap. I need to look at what pins it goes to and then what it is doing.

John

 

[Capt. Z]

I just received an email from WooAudio in regard of this cap question.

The big caps are used for feed to output. This is the OTL design, and cannot
be removed. The reason that removing the big cap was the newer caps have
larger capacity - no effect was made due to the this wiring. Thank you.


Best Regards,
Jack Wu
Assistant

 

[jamato8]

I don't think they know which cap you are referrring to. There is a cap from the heater of the 6080 to the plate of the tube. This is not on the latest version and doesn't have to be there. Ofcourse the caps on the output have to be there or output transformers but this is a OTL amp. So, they have gone to higher capacitance on the output, which would increase the bass response and should make it tighter and the frequency response could be flatter, though with the Black Gates for my outputs, the bass is fast and solid.

John

 

[jamato8]

These are images of the added caps for the power supply (solen fast caps bypassed) and of the Wima that is on the output tube from the heater to the plate. The large caps with the round end towards you are the pairs of Black Gate stacked for the output caps.

John