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
@mamifero "I guess these Cayins could be any Chinese re-rebranded tubes."

99% of Chinese EL34s came from the Shuguang factory, with the almost all of those you'll encounter over the past dozen or so years being the second generation aka EL34B.  You can distinguish them by the color of the base; EL34 are black base, and the EL34B are red base.  The EL34 are poor sounding, the EL34B made a most significant improvement.  In fact, I consider it one of the bargains in output tubes.  I will guess your Cayin has the EL34B, but it could have the earlier variant.

You may have come to conclusions on tubes based on listening to them in other amplifiers, but not having experienced the Shuguang EL34B in that lineup?  I own both the Shuguang EL34B and Tung Sol EL34, and find the Shuguang much more to my liking. The Tung Sols have a much less natural and pleasing sound, in my opinion.  Based on my experience with the Shuguang versus the Tung Sol, I would instead focus on the smaller tubes, and see if changing those out bring you happiness.  Also, is your amplifier fixed (variable) or cathode bias (autobias)?  If it's fixed bias, having the output tubes biased too cold will definitely produce a colder, harsher, less romantic / beautiful, less extended sound with poorer imaging.


Beyond that, a bit better than the new Mullards, Tung Sol, EH, and Shuguangs to my ear and at pretty much the same bargain basement Shuguang cost are the JJ EL34 and E34L, depending on the sound one targets. More or less everyone I know who has tried the Genalex Gold Lion KT77 likes them a great deal, but as you've laid out, they're significantly more expensive.  At that price point, you may also consider the Shuguang Black Treasure 6CA7-Z, which I find outstanding, though different than the Genalex.  Best of all, the old school Mullard EL34, but also another step or two up the price ladder, which I don't recommend for you, as I'd first move to a different amplifier
Thanks for the detailed information.
Now I have a better idea of the current tubes' sound signature. Indeed, the Cayin tubes have the red-burgundy base.

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.
OP - I would strongly recommend you contact Ron Sheldon at Cryoset.  I get my Gold Lion 12Au7s and GZ34 rectifier tubes from him..  The cryogenically treated tubes from Cryoset  last a real long time.  They start off and stay quiet!  Very even, linear sound.  Here is a link to Cryoset's matched quads of Gold Lion KT77s.
http://www.cryoset.com/catalog/product_info.php?cPath=22_49&products_id=254&osCsid=qcr3sv88jfu2k8u91lnfe2uhe1
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.
I've tried them as well. The Mullards will work with front-end components that are revealing. The T-S did not sound organic or realistic and had a sharp top-end.

I'm using the Genalex Gold Lion KT77's and they have everything I've been looking for; XL dynamics, extended yet smooth highs, a spacious soundstage in all directions, and a sense of realism. Not wanting to take a chance due to their high price, I contacted a couple of members who highly recommended them.


I've never tried the Cryoset, but that's a good price; better than the big name dealer who sells the KT-77s.
   I've read the benefits, but always wondered if a cryo'd tube will truly last as long since it affects the structure of delicate filaments and solder joints.
here's a tube to look into, the 6ca7-eh
Thank you all for the valued advise.
Is anyone familiar with pre-amp tubes? I read somewhere that for this particular amp, only the 12AU7 will affect the sound quality, the rest (12AUX7 and 6CG7) are for pre-amp control only and are not affecting the sound. Is that correct?
Which ones should look into for sound improvement?
If the two 12au7’s are the preamp tubes, then rolling them will provide the greatest change in sonics.

I suspect the other small signal tubes are the inputs for the amp section. The 12AX7 would be the gain tube and would also have a major influence on overall sound.
   These are the tubes that most affect the timbre or tone of the amp. Also imaging and dynamics.

Do you have the manual to confirm the tube configuration?

Thanks for the links, there is plenty of information on how small tubes sound!

Well the manual is very brief (3 pages) and it only says that One 12Ax7, Two 12AU7 and Two 6CG7 are used in the pre-amp section.

I'll have to do some more research to find out which pre-amp tubes are worth changing.


The 2 12au7s. They are the tone tubes on the pre. I have a Cayin hybrid with 2 12au7s. I’m thinking it should be the same though yours is not a hybrid. 
I agree. The 12AU7’s would be the preamp tubes. The 6CG7’s are typically used as phase inverters.
I have the Cayin A-50T and from the construction of them I'm pretty sure the stock Cayin-branded power tubes I got are Russian reissue El34s. They sounded ok but the Gold Lion KT77s are considerably better. I bought them, along with Gold Lion 12AX7s and 12AU7s from Jim McShane. Couldn't be happier with the sound.
Post removed 
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.
@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