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Opinnions on Gold Lion KT77

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Panos Adam

Panos Adam

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Joined 2014
#1
I'm opening this thread in order to discuss or share some of my thoughts on the Gold Lion KT77 tubes.

I'm using a Luxman SQ-38U integrated amplifier which factory installed a quad of Electro Harmonix EL34. I didn't like the sound of these tubes and in combination with my speakers (a pair of audio physic scorpio 2) the result wasn't that pleasing in terms of mid presence and bass articulation. So placed a quad of Electro Harmonix 6CA7 but I never adjusted the bias (I know..bad thing) The result was the 6ca7 to have a lifespan of about 1 1/2 years. They are still strong but they start to loose the grip and articulation in low frequencies (possibly because of high bias).

So I'm thinking to replace them with a quad of Gold Lion KT77 reissues as I read that this tubes are the best of the el34, 6ca7 and kt77 family. Most reviews or articles write that they are the most clean dynamic and full bodied in low frequencies.

So I'd like to discuss it a bit. I'm excluding JJ because of low reliability.

Till now the Electro Harmonix for me was the ultimate solution but will I get better results using Gold Lion KT77?

Thanks in advance!🙂
 
#3
Here's what I came up with:
A quick laundry list of features and information include the following. The Luxman uses two EL34 tubes per channel in a class-A/B Ultralinear circuit, for a total of 25Wpc into 8 or 4 ohms, or 30Wpc into 6 ohms. The SQ-38u is a fixed-bias design which makes use of both local and global feedback. The unit has chunky output transformers and a large mains transformer encased in black enamel metal covers.
Click to expand...

This amp incorporates NFB, and that makes the characteristics much less dependent on the actual active and passive devices used here. That's one of the reasons for using it in the first place. "Tube rolling" makes more sense with designs that run open loop with no NFB.

The Gold Lions get good reviews, FWIW. Never used them myself as I prefer designing with different types (TV deflection power amp tubes or RF amp types). These don't carry the audiophool premium, and really do sound quite good. Also, the big cathodes and unusually large current sourcing capability really help give bass "authority".

If you're having problems with mids and lows, I'd be more inclined to believe it could be due to squirrelly impedance behaviour of the speeks, and/or something to do with the phase compensation of the gNFB loop.

It could also be a case of excessive NFB, VT amps don't really do well with excessive NFB.
 
#4
I have used Gold Lion (reissue) KT-77 in two different amps and have been very pleased in each case. They are smooth, detailed and very dynamic. They tend to have a warm midbass, slightly loose, which some might consider a problem (I don't). They also have slightly soft highs which again some might consider a problem. Overall I think the Genalex reissue KT-77's are among the most musically satisfying tubes I have used. I go back and forth between the 77's and KT-120's and like each one even though they sound quite different.
 
#5
Miles Prower said:
Here's what I came up with:


This amp incorporates NFB, and that makes the characteristics much less dependent on the actual active and passive devices used here. That's one of the reasons for using it in the first place. "Tube rolling" makes more sense with designs that run open loop with no NFB.

The Gold Lions get good reviews, FWIW. Never used them myself as I prefer designing with different types (TV deflection power amp tubes or RF amp types). These don't carry the audiophool premium, and really do sound quite good. Also, the big cathodes and unusually large current sourcing capability really help give bass "authority".

If you're having problems with mids and lows, I'd be more inclined to believe it could be due to squirrelly impedance behaviour of the speeks, and/or something to do with the phase compensation of the gNFB loop.

It could also be a case of excessive NFB, VT amps don't really do well with excessive NFB.
Click to expand...
Thanks for the reply.

Basically I'm very satisfied with my 6CA7 of Electro Harmonix. I have no problem with lows and highs. I would say the opposite. The amp is quite capable especially since I installed the 6CA7's. But they start to become weak and I'm looking for the next quad of tubes. So If I install a quad of KT77 will I get a more dynamic result or generally better the with the 6CA7. I know that I wiil know when I;ll make the move but I'm asking for your experience.
 
#6
Salectric said:
I have used Gold Lion (reissue) KT-77 in two different amps and have been very pleased in each case. They are smooth, detailed and very dynamic. They tend to have a warm midbass, slightly loose, which some might consider a problem (I don't). They also have slightly soft highs which again some might consider a problem. Overall I think the Genalex reissue KT-77's are among the most musically satisfying tubes I have used. I go back and forth between the 77's and KT-120's and like each one even though they sound quite different.
Click to expand...

Thanks Salectric.

I'm very interested in dynamics and low frequency behaviour concerning KT77. The 6ca7 I'm using are superb but I keep reading that KT77 are more dynamic and they have better bass (speed, dynamic, articulation etc)
 
#8
Biasing certainly affects the sound of the tube, but the qualities of each tube type or brand are still evident, at least in my experience. Most of my amps are fixed bias so I can try different bias settings to find what sounds best (to my ears) for a given type.

My experience with EH 6CA7's was too long ago for me to say anything about them.
 
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