[takezo]

you should definitely try tube rolling with the wa5...it doesn't make sense that
the transient highs are off on this unit...i'd try tube rolling the rectifiers first,
as the 5u4g are colored and not the most transparent tube out there...

the wa6 would benefit from tube rolling as well...the gz32 has a nice colored midrange
but limited highs and bottom register...it's not the most airy either...if you covet
transparency, neutrality, airy headroom/soundstage then i'd suggest you go
for the large bottle 6ew7 for the drive tubes (need to get adapters from jack woo)
and a 5r4gy brimar or a gz30 mullard...the 5r4gy is the most airy, whereas the
gz30 flat tubular tube is the most transparent of all the rectifiers i've tried to
date...the metal base is nice too but expensive and colored more than the two
mentioned above but may have the best resolution of all the rectifiers or at the
least on par with the gz30...

have fun!

 

[jamato8]

I agree that the metal base is too expensive but having used it for about 15 years in many different amps, I do not agree that it is colored but how do you find it colored?

I will have to look into the GZ30's, having never used them.

 

[takezo]

to me, the metal base is colored slightly compared to the 5r4gy brimar
and the gz30 mullard...what i mean by "colored" is that it adds to
the original music, like the heightened sense of the bass and the
highs, which tends to hide some of the music...i was listening to
a tune with the gz30 in which a men's choir sings in the background
just audible in a subtle way but listening to it with
the metal base, it wasn't as salient as with the other tube and
i had to listen hard for it...but the gz34 does really add impact
and live energy at the top like no other rectifier...

 

[mikeymad]

Thanks for the input guys.

Of the weekend at the Mayberry Meet. I confirmed that I did have a tube issue. Now I am not going to re-test everything, but I can say that my amp is sounding much better. The lower bass flabbiness that I was hearing is gone, and the graniness is mellowed.

Thanks to Voltron, I was able to borrow a pair of different 6sn7's. They made a world of difference. So I will be in the market for a new set of tubes (except for the WE 300B's, I will keep those).

Cheers,

 

[jamato8]

Yes the choice of the 6SN7 will make, at least to me, a huge difference in ultimate quality and some 6SN7's will sound grainy and again, to my ear, plain unmusical, especially some of the new offerings. I have some 1952 Sylvania 6SN7's and some 1940's Tungsol black glass nos in the most beautifully deep printed thick boxes (print is in blue) that look new, that are extremely fine. I almost like the USN boxes for the Tungsols as much as the tubes. lol

 

[mikeymad]

Well my new 6sn7's are in and they have made a world of difference right off the bat.

Sylvania JAN CHS 6SN7WGT matched pair 'silver top' to be specific. They look something like this:

The very deep bass is not all the way there, but I didn't expect it to beat the STAX setup. But the impact and resolution throughout the range is very well presented. They are quick as well. Very happy so far.

Now I have to return the loaner tubes to Voltron, and continue my research into the replacements for the 5U4G's. There was a lot of talk of gz34, gz32 and gz30's, but these don't seem to be drop-in replacements for the 5u4g, they match up with the 5AR4's. I am trying to figure out the voltage impact, and then again the sonic impact in dropping these in.

So, I have been looking for the best direct replacement 5u4g's.

Cheers,

 

[Voltron]

Quote:

Originally Posted by mikeymad /img/forum/go_quote.gif Well my new 6sn7's are in and they have made a world of difference right off the bat. Sylvania JAN CHS 6SN7WGT matched pair 'silver top' to be specific. They look something like this: The very deep bass is not all the way there, but I didn't expect it to beat the STAX setup. But the impact and resolution throughout the range is very well presented. They are quick as well. Very happy so far. Now I have to return the loaner tubes to Voltron, and continue my research into the replacements for the 5U4G's. There was a lot of talk of gz34, gz32 and gz30's, but these don't seem to be drop-in replacements for the 5u4g, they match up with the 5AR4's. I am trying to figure out the voltage impact, and then again the sonic impact in dropping these in. So, I have been looking for the best direct replacement 5u4g's. Cheers,

I am glad that I could help you find out how great one of my very favorite amps is. Given that I happen to have a pretty good pile of rectifiers that might swap in to your amp, once you figure out which ones are possible and which aren't, maybe I could come over to try some out and pick up my Sylvanias. I'd like to hear your setups in their native environment as a little side benefit. Let's talk...

*Quick edit* I should read more carefully, and I also wanted to add that your close-up pic is quite nice.

 

[mikeymad]

Thanks Voltron.... Your tube library comes to the rescue again.

I will shoot you a PM.

Oh, and maybe some scotch tasting as well.. for the get together

 

[Voltron]

Quote:

Originally Posted by mikeymad /img/forum/go_quote.gif Thanks Voltron.... Your tube library comes to the rescue again. I will shoot you a PM. Oh, and maybe some scotch tasting as well.. for the get together

Mmmm, whisky . . .

 

[fkclo]

Quote:

Originally Posted by mikeymad /img/forum/go_quote.gif Now I have to return the loaner tubes to Voltron, and continue my research into the replacements for the 5U4G's. There was a lot of talk of gz34, gz32 and gz30's, but these don't seem to be drop-in replacements for the 5u4g, they match up with the 5AR4's. I am trying to figure out the voltage impact, and then again the sonic impact in dropping these in. So, I have been looking for the best direct replacement 5u4g's. Cheers,

Hi,

According to Jack Wu of Woo Audio GZ34, 5AR4 can be used interchangeably with 5U4G on a WA5. He also remarked that there is no need to have exactly matching tubes for the rectifiers of WA5.

I am planning to drop in a pair of metal base GZ34 and see how it sounds.

F. Lo

 

[jamato8]

I have used pair of rectifiers in series and in parallel and it isn't necessary to have them matched.

The GZ34 should give you a stiffer B+, with a noticeable quality in the bass. Put those GZ34 metal base in and it should really sing.

 

[mikeymad]

Thanks fkclo... I was going to contact Jack...

That is good to hear. There are so many great ratings of the gz34/5ar4 that I would really like to try them out. Let us know how your rolling goes.

Cheers jamato8.... thanks for your imput in this thread. I am looking forward to another change in this amp....

Time for a little more research and a visit with Voltron....

Cheers,

 

[fkclo]

Quote:

Originally Posted by mikeymad /img/forum/go_quote.gif Thanks fkclo... I was going to contact Jack... That is good to hear. There are so many great ratings of the gz34/5ar4 that I would really like to try them out. Let us know how your rolling goes. Cheers,

I used to have a good pair of metal base GZ34 but sold one to raise some money for my other purchase. Luck is on me that I just have the opportunity to buy one 1957 metal base GZ34 so by end this month I will be able to see how these famed babies performed on my WA5.

The WA5 project turns out to be more expensive than I expected. Besides the investment on the amp itself, I now have spent close to US$2,000 on 300Bs, 6SN7s and now the metal base.

But the sound is heavenly and organic that I can easily forget the pain on my wallet

Will report back later.

F. Lo

 

[jamato8]

The one thing people often forget is that a tube is part of the circuit. You have the grid, plate, heater, depending upon the type of tube. There are also other parts to power tubes and regulator tubes and so on but they are circuits, like an opamp but bette. So an investment in a tube is like buying a different circuit, though often with the same specifications but as we know, a slightly or significantly different sound. They also light up our life! :^)

 

[takezo]

Quote:

Originally Posted by mikeymad /img/forum/go_quote.gif ...Now I have to return the loaner tubes to Voltron, and continue my research into the replacements for the 5U4G's. There was a lot of talk of gz34, gz32 and gz30's, but these don't seem to be drop-in replacements for the 5u4g, they match up with the 5AR4's. I am trying to figure out the voltage impact, and then again the sonic impact in dropping these in. So, I have been looking for the best direct replacement 5u4g's. Cheers,

as far as i'm aware, the rectifiers used in the power section of your unit should
allow for any rectifiers in the 5v range, direct or indirect heating...the wa6
transformer can handle the 5u4g, 5ar4, gz30 and even the 5as4 with 3A
plate current max dc ouput of 275mA @500v...i'm certain the high-end
transformer on the wa-5 can handle any 5v rated rectifier...

the following rectifiers rate at 5V should be fine on your wa-5:

5ar4, gz30, gz32, gz33, gz34, gz37, 5u4g, 5as4, 5r4gy, 274b, 422a and more...

like jamato mentioned, they don't need to be matched electrically nor brand
name-wise...as long as the pair are the same heating type (direct/indirect)...