[takezo]

well... the 5r4gy may be a direct type... now, i'm confused...

yeah, i'm pretty sure it's a directly heated type... i'm surprised
they've held up all this time...

*the only indirect types used in the wa6 is the gz34/5ar4,
the gz32/5v4g and the gz30

** i've been using the rigid plate valve art 274b since late last
year and they've held up fine. they can handle up to 160mA...

 

[jamato8]

Most of the directly heated rectifiers recommend a 4uf first cap or inductor input.

The GZ33 is a nice tube as is the GZ32 but the GZ33 has a nice slow ramp up voltage and has a lower voltage drop, sag, than some other rectifiers. It also depends upon the amp. You change the B+ and you change the bias. This is often what you are also hearing, a change in the bias from a change in the B+. Most tube experts really keep to the cap specs for the first cap after the rectifiers for long rectifier tube life.

 

[atbglenn]

Any opinion on a Shuguang 274B ? I can get one on ebay for $15 delivered. Is it worth getting?

 

[jamato8]

Get it and let us know. Please.

 

[atbglenn]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif Get it and let us know. Please.

ok, I just ordered it. I just hope it arrives in one piece. It's coming from China.

 

[jamato8]

What did shipping cost? For it to get here very fast the shipping would be more than the tube. I look forward to what you hear. Any images or a link to the tube?

 

[atbglenn]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif What did shipping cost? For it to get here very fast the shipping would be more than the tube. I look forward to what you hear. Any images or a link to the tube?

It was $10 for the tube $5.00 for shipping. He has 38 in stock. Item # 180224092917

Let me know what you think.

 

[jamato8]

It is a nice looking tube. Now for how it performs.

 

[cAsE sEnSiTiVe]

Jam,

Would your reservations about implementing the 274B be the same in a max'd WA6? Just wondering if the values are the same in both yours and mine.

 

[jamato8]

There is still a large cap right after the rectifier. Jack is the manufacture and says it's ok. The specifications say it isn't for a long life. I checked the rectifier specs at different voltage uses and the cap remains the same. I don't know what to say. If it works for some reason great. I would much prefer it to work than not.

 

[cAsE sEnSiTiVe]

Well, I ordered one from Jack today....we'll see how it does. I also have a 1958 NOS cryo'd Mullard GZ34 black base coming. They'll soon throw down for supremacy.

 

[DoubleEs]

Does this mean Jack will sell you a Sophia Princess Mesh Plate 274B valve on its own and not as part of a amp package?

BTW, could someone point me in the right direction to some good quality 6DE7s

 

[Barbaresco]

By the way: are there any 6DE7 substitutes which sould be considered?

Regards

Barbaresco

 

[jamato8]

6DE7 and 6EW7 are all that I know of. Most of the 6EW7's are a fat bottle so they don't fit in the standard 6 unless you use an adapter or find some of the RCA small bottle 6EW7 tubes.

I haven't compared the 274B mesh plate directly with the GZ34 metal base at this time as the caps I installed are still breaking in/forming.

 

[Barbaresco]

Thanks Jamato

I've looked for those 6EW7. Fat. Fat. And fat again. Difficult.

Do you know anything about those TJ Fullmusic 274Bs, that are actually running on ebay? They look really nice. But not as cheap as the Shuguangs. They are about half the price of a Sophia.

Regards

Barbaresco