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Tung-Sol EL-34B vs Genalex Gold Lion KT77 for Cayin A100T Integrated Tube Amplifier

Hello,

I recently got a new set of Speakers and an Integrated Tube Amplifier. 

The amp was a used unit and came with stock Cayin tubes (probably 100 hours on them). I guess these Cayins could be any Chinese re-rebranded tubes.

Overall the sound is good but I found the top end to be a little edgy and bright with my system. Therefore, I've been looking into replace these with a new set of tubes.

In the past, I have tried EL34 Mullards, EL34 Electro Harmonix and EL34B Tung Sol. The Mullards have good bass but sounded dull in my system and lacked some detail. The Tung Sols sounded the best.

Now, I've read the Genalex Gold Lion KT77 are also very good, with extreme top end detail and neutral sound.

Ideally, I am looking for power tubes that can extract subtle nuances and detail from recording while still being warm and mellow at the top end, without been harsh or bright; perhaps a hard to find combination?

The Genalex Gold Lion are twice the price of the EL34B Tung Sols. Although, it will cost me a third of what I paid for the amp to replace the 8 tubes, I might go for it if they are much better than the Tung Sol and I get the sound am aiming for.

I might also need to look into the pre-amp tube section. As far as I know, the tubes which will affect the sound quality on this particular amp, are the power tubes (EL 34s) and the pair of (12 AU7s) pre-amp tubes. 

The single (12 AX7) and pair of (6CG7s) are for control only. So I should focus on the power tubes and the pair of 12 AU7s.

The Cayin A100T has the following tube set:


Power Tubes

Eight EL-34 


Pre-Amp Tubes

One 12Ax7

Two 12AU7

Two 6CG7



-Is the Genalex Gold Lion KT77 considered bright and clinical sounding?

-Which pre-amp tubes (12 AU7) should I look into, for a real sound quality improvement?

-Finally, should I care about matching pairs and quads if the amp offers independent bias adjustment on each tube?


Please let me know, your advice will be appreciated,

 

Thanks,


J

--------------------------------------------------------- 

My system:

Rotel RCD 1570 CD player

Sonus Faber Venere 3.0 speakers

Cayin A100T Integrated Tube Amplifier





mamifero
Post removed 
johnss
564 posts
 
If the stock tubes are bright and thin sounding, would suggest you try psvane gray glass EL34s. Very musical, with an open and airy top end.

they have become my favorite EL34 tube.
trelja
3,223 posts
 
@mamifero "I am not very familiar with Variable or Autobias -I'll google it- but I am sure it's not autobias. It has manual adjustment and built-in meter instead, each tube has a knob and -according to the manual- the needle on the meter should be placed in the middle."

Thank you for including this.  You're amp is fixed bias, which means it's adjustable, and is a counterintuitive name if there ever was one, but we won't go deeper than that here.  The first thing you should do is bias the amplifier.  You'll ensure the tubes run at the recommended setting, and also potentially find any defective (they won't bias properly) tubes in the amp presuming you don't have a tube tester to check them.  Again, if the output tubes are biased cold, the amplifier will sound less warm, romantic, and good.  That said, the vast majority of manufacturers recommend too cold a bias setting in the name of preserving the output tubes.  People love to brag about how long their tubes lasted, and praise their amplifier itself and the ability or brilliance of its designer, though it's mostly a reflection of the bias of the output tubes.  For me, in for a penny, in for a pound.  I buy and build tube amplifiers because properly designed, implemented, and run, they provide me more satisfaction than most solid state amplifiers.  I absolutely will not sacrifice that for more tube life.

After single-ended versus push-pull output stage, I feel fixed versus cathode bias represents the most important factor in the character of an amplifier in terms of sound, response, feel, etc.  Fixed bias is more direct, immediate, fast, and tight.  And because of that, more prone to the complaints you raised.  Rectification, front-end topology, and tubes shift a fixed bias amp away from those characteristics.  So after you bias the amplifier, presuming you still want a more romantic sound, it's smart of you to have come here seeking out different tubes as it's the one area you can easily change
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