Dennis Had Inspire Amps

[Musica Amantem]

Originally Posted by Bombadil

I have tried vintage Sylvania fat boy 6CA7 and EI 6CA7, comparing to my JJ KT77. I liked the JJ better, to my surprise. But I should run that comparison again, as I am now driving different speakers in a different room.

Cool! Let us know. Thanks!

[FloridaBoy]

Originally Posted by Bombadil

I am not sure there is a problem. He wrote that all of his GL KT77 tubes showed a grid leakage on his tester. Perhaps it is just some quirk of that tube and his tester. These tubes are drawing raves from many quarters, with few problems as far as I can determine. So it seems odd that all 4 of his are showing the same problem, while all playing well in his amp.

So is it 1) all of his tubes are defective? 2) his tube tester readings on that tube are wrong? 3) his amp has somehow damaged those tubes?

It's probably the tester. I think Dennis gets tubes from The Tube Store.

[FloridaBoy]

Originally Posted by Bombadil

I am not sure there is a problem. He wrote that all of his GL KT77 tubes showed a grid leakage on his tester. Perhaps it is just some quirk of that tube and his tester. These tubes are drawing raves from many quarters, with few problems as far as I can determine. So it seems odd that all 4 of his are showing the same problem, while all playing well in his amp.

So is it 1) all of his tubes are defective? 2) his tube tester readings on that tube are wrong? 3) his amp has somehow damaged those tubes?

It's probably not the tubes if they all read the same and he was not running the GL's when the amp went nuclear.

[FloridaBoy]

Originally Posted by Bombadil

I have tried vintage Sylvania fat boy 6CA7 and EI 6CA7, comparing to my JJ KT77. I liked the JJ better, to my surprise. But I should run that comparison again, as I am now driving different speakers in a different room.

The JJ is a bit darker than the GL KT77. Both are good tubes. Excepting 6V6's I have no old production power tubes that are 'better' than new production.

Someone here compared the original Genelex KT77 to the GL and preferred the GL. In a different system the results may have been different. All that really matters is how a tubes sound in your rig.

[CoGT3]

You guys are killing me with the GL KT77 talk. Got a quad for the PSE from Jim McShane sitting on the door step. Only problem, on vaca with the family. Will be a bit before I can play too.

Will try them initially with the KenRad 6SN7 to see how they differ from their KT66 brothers. Suspect from what has been said here Sylvania VT231, GTB, Psvane cv181 may be a better fit. Will see.

[Bombadil]

Okay, I ran some comparisons this morning. Quick ones, using 2 cuts from Patricia Barber and one from Sade. So female vocals with simple instrumentation. Listening to vocals, piano, acoustic bass, and percussion. No rock music, no classical.

Rectifier a vintage Sylvania 5U4GB, driver tube Westinghouse 6SN7GTB

Power tubes compared: vintage Gold Lion 6CA7 (same as Sylvania Fat Boy), EI coin-base 6CA7 (made in 1990s in Yugoslavia using Telefunken equipment), JJ KT77

I have recently been listening to Tung-sol KT120 so some comparisons made here too.

GL 6CA7: Immediately noticed less high frequency detail. Snares, bells, etc, receded more into background. Vocals were rich and had more body to them. Mid-bass seemed a little warmer while deep bass was looser. More of what can be described as a "classic tube sound."

JJ KT77: Much more high frequency detail, but not harsh. Wider soundstage than GL 6CA7, probably due to the extra detail. Vocals a bit thinner, but closer to what I consider to be accurate. Bass not as defined and tight as my KT120s but solid. A good tube, very listenable, accurate but without the power of the KT120. Nice overall balance.

EI 6CA7: To my surprise, it didn't really sound that similar to the Gold Lion 6CA7. More high frequency detail, almost as much as the JJ. Vocals not quite as prominent and euphoric as the GL, but more in that direction than the JJ or KT120. But a bit on the lush side. Bass is slightly warmer and looser than the KT120. Good imaging. Overall more like the JJ than the GL.

I'm going to leave the EI in my amp for a while. I like their overall balance. Good detail but not harsh at all. A bit of midrange warmth. A little fuzzy on deeper bass but in a smoky jazz club way. Sade sounds really good through them. These EI are difficult to find as the factory went out of business in the early 2000s They made great EL84 tubes, I have an octet of them. 15 years ago their tubes were inexpensive, now the real ones are collectables and you have to be careful when buying as there are counterfeits floating around.

[FloridaBoy]

The EI factory was bombed by NATO.

http://www.eierc.com/rc/who_we_are.htm

[Bombadil]

That is a false rumor. They weren't touched during the war and continued to make tubes for several years afterward. But they were unable to obtain materials in post-war Yugoslavia and eventually shut down, around 2002-2003. Western Electric attempted to purchase their equipment around 2006-2007 but that deal fell through. It is said that all of their gear, including some of the old Telefunken gear, sits in a warehouse.

[Musica Amantem]

Originally Posted by Bombadil

Okay, I ran some comparisons this morning. Quick ones, using 2 cuts from Patricia Barber and one from Sade. So female vocals with simple instrumentation. Listening to vocals, piano, acoustic bass, and percussion. No rock music, no classical.

Rectifier a vintage Sylvania 5U4GB, driver tube Westinghouse 6SN7GTB

Power tubes compared: vintage Gold Lion 6CA7 (same as Sylvania Fat Boy), EI coin-base 6CA7 (made in 1990s in Yugoslavia using Telefunken equipment), JJ KT77

I have recently been listening to Tung-sol KT120 so some comparisons made here too.

GL 6CA7: Immediately noticed less high frequency detail. Snares, bells, etc, receded more into background. Vocals were rich and had more body to them. Mid-bass seemed a little warmer while deep bass was looser. More of what can be described as a "classic tube sound."

JJ KT77: Much more high frequency detail, but not harsh. Wider soundstage than GL 6CA7, probably due to the extra detail. Vocals a bit thinner, but closer to what I consider to be accurate. Bass not as defined and tight as my KT120s but solid. A good tube, very listenable, accurate but without the power of the KT120. Nice overall balance.

EI 6CA7: To my surprise, it didn't really sound that similar to the Gold Lion 6CA7. More high frequency detail, almost as much as the JJ. Vocals not quite as prominent and euphoric as the GL, but more in that direction than the JJ or KT120. But a bit on the lush side. Bass is slightly warmer and looser than the KT120. Good imaging. Overall more like the JJ than the GL.

I'm going to leave the EI in my amp for a while. I like their overall balance. Good detail but not harsh at all. A bit of midrange warmth. A little fuzzy on deeper bass but in a smoky jazz club way. Sade sounds really good through them. These EI are difficult to find as the factory went out of business in the early 2000s They made great EL84 tubes, I have an octet of them. 15 years ago their tubes were inexpensive, now the real ones are collectables and you have to be careful when buying as there are counterfeits floating around.

Thanks for the feedback. Interesting results. It seems I'll stick with the GL KT-77 for now.

[FloridaBoy]

Originally Posted by Bombadil

That is a false rumor. They weren't touched during the war and continued to make tubes for several years afterward. But they were unable to obtain materials in post-war Yugoslavia and eventually shut down, around 2002-2003. Western Electric attempted to purchase their equipment around 2006-2007 but that deal fell through. It is said that all of their gear, including some of the old Telefunken gear, sits in a warehouse.

I should have read the link. They just stopped producing tubes.