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For 6AS7G tube rollers here ..... - Page 28

post #406 of 1527

The copper grid posts is the only difference construction-wise that I could identify.  All the Chatham 6AS7Gs have this too so it seemed to be the one thing they singled out to make the tube more "premium" over the Tung Sol.

post #407 of 1527
Quote:
Originally Posted by ValentinHogea View Post

I have a question...

 

Since one of my RCA Reds arrived broken whilst my 5998's and 7236's arrived from another source I was forced to use my older driver tubes,

Black Metal Svetlanas "6SJ7"-wannabe's and Sylvania 6SJ7GT

 

So my first round of listening was 6SJ7GT + 5998's .... Mmm... Fantastic sound. Albeit not that much gain that I was expecting. I was running the amp at 9 to 10 o'clock. Wide, liqud soundstage and magical texture in the bass... When I tried to switch to the Svetlanas, which seem to have more gain than the Sylvania's, the sound distorted. Like a soft fuzz/overdrive-effect for guitars (I'm an electric guitarist). I was a bit shocked and thought that I had somehow broken the 5998's. Switched back to 6SJ7GT. No problem.

 

Weird.

 

Tried the 7236's, sound great with both the 6SJ7GT and Svetlana "6SJ7". Actually better with the Svetlanas. Insane gain. Really great bass quality and quantity. Almost too loud at 7'o'clock. Not the same magic mids and wide soundstage as 5998's, but not that shabby either. Great for modern music.

 

Anyways..

 

Why did the 5998's behave like that with the "6SJ7's"?


It's funny, that's exactly how I felt hearing my TungSol 5998s (non-A) in my WA2, but in my case no matter what driver I tried (besides the sputtering on startup issue I had with at least one tube). I thought they might be faulty because of that issue, and that it maybe carried over into the sound quality even after they were warmed up and otherwise quiet.

 

And like you, my well-matched pair of Sylvania 7236 sounded consistently and more importantly noticeably better to my usually not-so-critical ears in the same setup...

 

I have put the 5998s now in my very new WA22 and cannot comment on it yet, but they'll be driven by a pair of highest grade Psvane CV181-T so hopefully that's enough power to drive them properly because I can't think of what else would provide much more...

post #408 of 1527

FWIW I've driven the 5998 with over a dozen kinds of GT, GTA and GTB 6SN7, along with various other tubes such as a 6AH7, 6E6, and 6BL7.  I never experienced distortion or a sense of weak drive with any of those tubes in front of the 5998.  I think this sort of problem is very circuit/amp dependent.

post #409 of 1527

Just received working 5693's now. Mmm.. Fantastic.

 

This led me to another question. Why are there no "premium"-manufacturers of 6080/5998/7236-etc such as Shunguang? Are they that uncommon in audio hi-fi?

A beginners question, but highly warranted considering the eBay-status on 5998's etc...

 

Tx,

post #410 of 1527

These are voltage regulating tubes, they were never intended for audio service.  They are very popular in OTL designs because they are one of the very few tubes with low enough internal plate resistance that they can drive the load (the headphones) directly without having to use an output transformer.  Most tubes have resistance in measuring in the thousands of ohms so if you tried to drive the load directly off the plates very little power would transfer which is why transformers are used in most tube amps to couple the output tube to the load and provide impedance matching.

 

New tube makers are interesting in bringing back popular or successful classic audio tubes, where as the 6080 family and OTL amp designs in general are considered rather niche I think even though they are very successful designs and have some of the best bang for the buck in terms of sound quality.

post #411 of 1527
Not only that, but current tube makers are making tubes which can fetch a decent buck, which means a tube like the 6SN7 or 12AX7, where the NOS varieties are often very pricey. With nice RCA 6AS7's easy to get at $15, and 6080's more like $10, there is no incentive to make new ones of these, especially given the size of them.
post #412 of 1527
Quote:
Originally Posted by Skylab View Post

Not only that, but current tube makers are making tubes which can fetch a decent buck, which means a tube like the 6SN7 or 12AX7, where the NOS varieties are often very pricey. With nice RCA 6AS7's easy to get at $15, and 6080's more like $10, there is no incentive to make new ones of these, especially given the size of them.

 

Absolutely, tubes are expensive even the new reissues. 4 matched Genalex 12ax7 reissues can easily cost over $100. 4 matched Genalex gold lion kt88 reissues are over $200. And these are ebay prices.

post #413 of 1527

Some makers still use the 6AS7G for some of the best amps around.

 

 

1000

post #414 of 1527

If I could just find a pair of TS5998/Chatham's quiet and fairly priced...more concerned with the former than the latter.


Edited by Silent One - 8/15/12 at 12:35am
post #415 of 1527

I think it could be said that OTL amps are good in spite of the tubes they are required to use, not because of them,  due to the inherent advantages of the circuit design.  That doesn't mean the 6AS7 is a bad tube of course,just that if you are talking purely about linearity there are better ones for audio duty.

 

I've heard the AtmaShere amps are very good sounding.  It's a good thing there are so many Russian 6AS7 around, I couldn't imagine what it would take to get matching sets for those things otherwise.  The MA-3 uses eighty four 6AS7 tubes.  I don't even want to imagine the sort of heat it produces.

post #416 of 1527

Xcalibur I couldn't agree more.

Even though the 6AS7G is not an audio tube it can still sound great in the right amp.

Plus there is a huge variety to choose from.

Same story as with the 6SN7.

In SET amps a lot depends on the quality of the output transformer.

Today's transformers are nowhere near as good as the vintage ones.

post #417 of 1527

Anyone know anything of United Electron 6AS7(G)?

 

How do they sound? Are they really made in the UK? What is a quad matched set worth?

post #418 of 1527
My understanding is they are rebadges. They could be GE made in the USA, so that's what they should be priced as. I could be wrong.....
Quote:
Originally Posted by ValentinHogea View Post

Anyone know anything of United Electron 6AS7(G)?

How do they sound? Are they really made in the UK? What is a quad matched set worth?
post #419 of 1527

 

That's what they look like... Any new clues?

post #420 of 1527
That looks like a Svetlana.
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