• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Genalex Gold Lion KT77

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Tam Shaun said:
Anybody have the experience of the re-issue Genalex Gold Lion KT77 I want to order octal set for my michaelson tube amp.


I am a bit skeptical of any tubes coming from New Sensor/Sovtek these days.

It is great they are making decent quality tubes, but at nearly 2x the price of the JJ KT77 I suspect you are paying more for the hype around the long defunct Genalex name rather than the actual tube.

I feel like they added that tube just because JJ was the only current KT77 offering the past few years.

YMMV of course.
 
Administrator
Joined 2004
Paid Member
I think you might want to wait until Jim McShane weighs in on this subject.. JJ lately has had serious quality control issues with many of their octal power tubes, and the JJ KT77 does not seem to have a stellar track record in this regard. The ones I've seen were nothing to write home about..

The current New Sensor products have better process control and quality assurance than a lot of the vendors out there - guess that comes from owning the plant you make your tubes in, and frequently being directly accountable to your end customer which JJ is not.

No, they're not the cheapest option out there, but my recent experience has been that their production is consistent and bad tubes don't frequently get into customer hands.

Ever try returning a defective tube?
 
I'm very happy with my re-issue Tung Sol 6550s. Very neutral, great bass, and a very holographic, 3d soundstage.... using them in my Simple SE amp w/ Omega XRS single driver speakers.

I tried a friends re-issue GL KT88s, and liked the Tung Sols better by quite a bit.

Dave
 
Of Course tube vendors opinions have a lot of weight when deciding on tubes, but they also sometimes contain a bit of bias.

JJ did indeed have a couple issues at the introduction of the KT77 series tubes. That left a bad taste in many vendors mouths which are still voiced today.

Having used several dozen KT77's the past couple years, I have only had but a small sampling compared to a vendor, But I for 1 have been very pleased with the 40+ JJ KT77's I have gotten.
 
Administrator
Joined 2004
Paid Member
Trout said:
Of Course tube vendors opinions have a lot of weight when deciding on tubes, but they also sometimes contain a bit of bias.

JJ did indeed have a couple issues at the introduction of the KT77 series tubes. That left a bad taste in many vendors mouths which are still voiced today.

Having used several dozen KT77's the past couple years, I have only had but a small sampling compared to a vendor, But I for 1 have been very pleased with the 40+ JJ KT77's I have gotten.

Definitely a good point, I too have had limited exposure, but unfortunately I have had a lot of problems with JJ KT88 failing in some of my older designs - to the extent that I can't recommend them at all. (525V/60mA UL operation) The KT77 is obviously a different animal, but I am hesitant because of problems with the '88.
 
kevinkr said:


Definitely a good point, I too have had limited exposure, but unfortunately I have had a lot of problems with JJ KT88 failing in some of my older designs - to the extent that I can't recommend them at all. (525V/60mA UL operation) The KT77 is obviously a different animal, but I am hesitant because of problems with the '88.


I can totally understand the point of view

:D

A couple years back I had gotten burned on a batch of 12AX7EH's and some 12AX7LPS's, So after that it took me a couple years before I bought another New Sensor Tube.

To me it looks like a either company has its share of " Bad Batches" Hit it right they are gold, Hit it wrong and your stuck with 50 rejects.
 
Trout said:
Of Course tube vendors opinions have a lot of weight when deciding on tubes, but they also sometimes contain a bit of bias.

JJ did indeed have a couple issues at the introduction of the KT77 series tubes. That left a bad taste in many vendors mouths which are still voiced today.

Having used several dozen KT77's the past couple years, I have only had but a small sampling compared to a vendor, But I for 1 have been very pleased with the 40+ JJ KT77's I have gotten.

I have no bias except towards quality. JJ octal tubes have serious quality problems and have for a long time. I tried to warn people about them, but somehow the message that got out was that the small pins were the only problem.

Not true. There are a lot of other problems too. And although nowadays the pins sometimes are the right diameter, they aren't straight, they're usually poorly soldered, and the tubes have failed often enough to discourage even some of the tube's biggest "boosters". Yes I know some people got JJs and they've been fine. But as the old saying goes - even a blind pig sometimes finds an acorn. The odds aren't real good for you with the JJs.

I can sell KT-77 JJs if I want. I don't want to. My rule is if I won't use it in my own gear I won't use it. So no JJ octals around here. Not until the quality improves.

New Sensor/Saratov isn't perfect - but their Genalex KT-77 is a very high quality tube, no doubt about it.
 
It is interesting how some people will have problems with a particular tube and others will not. I'll bet I've used more than 50 JJ E34L's in guitar amps over the years and I can't think of a single failure that I could blame on the tube. I've had some die from bias failures, spilled drinks etc but other than that they have been fine. Of course this is not using them in any sort of critical application like hifi where they may have been more of a problem in some way or another. Also these guitar amps mostly Marshalls and Hi Watts place the tubes inside of a head and they are not pounded on by the speaker.

Who knows, the next set I install could blow up instantly! Do you think the JJ quality varies from batch to batch or from year to year gradually getting better, worse or staying hit and miss?
 
JJ stuff was great at first...

Then the 12AX7 families tanked, then they cheapened the 6L6GC by abandoning the high quality red base, then they put out the miswired 5AR4s, then the pin size fiasco, then the pin soldering/alignment/razor sharp edge troubles along with strange contaminant deposits on the inside the glass and loose material inside the tubes; then the KT-77s started running away and shorting, then the bottles started showing up horribly crooked on all the octals.

They've gone downhill steadily. With one exception - their 6922/E88CC is the best it's ever been right now. Go figure, 'cause it used to be trash too.

I would also tell you that some real tube experts who really know how to use them had problems with the KT-77s blowing up.

Once upon a time - right after they took over from Tesla - they did great. Now - no thanks, not until they get it right or at least close enough to right to make the tubes usable.
 
Hi, Experience with EL84s, Yes. One of my projects uses them. The amp is class A UL mode pp and with EH EL84s it is quite good. No NFB and very low distortion. I can only compare it to other non-EL84 amps I have, but it holds its own for sound quality. Others with different tubes please chime in. I am always on the look out for good things to try.
 
I remember the JJ tubes with the reddish brown bases, yes... That's been a while ago.

I'm curious about the Genelex branded tubes that New Sensor has put on the market as well. How good are they when compared to the EH, Sovtek and other brands New Sensor sells? For instance is the KT77 really all that different than the EH EL34? What about the KT66 is it the same as the Sovtek or Tungsol version or is it closer to the original or even the Saratov version from a few years ago?
 
DaveMcLain said:
I remember the JJ tubes with the reddish brown bases, yes... That's been a while ago.

I'm curious about the Genelex branded tubes that New Sensor has put on the market as well. How good are they when compared to the EH, Sovtek and other brands New Sensor sells?

They are significantly better, without question. That's not just my opinion, I hear that all the time from customers.

For instance is the KT77 really all that different than the EH EL34? What about the KT66 is it the same as the Sovtek or Tungsol version or is it closer to the original or even the Saratov version from a few years ago?

The KT77 is definitely different. For one thing, all the Genalex tubes use gold plated grids - and speaking of grids, the '77 grid must be wound slightly differently than the EL34s, since they bias slightly cooler.

They all use carbonized plates as well, and in the case of the KT66 it uses the proper sized brown base.

All the tube must use different cathode chemistry too. I certainly can't confirm that (I'm no chemist), but they sound so much more refined that the less expensive Saratov made tubes.

There are many who believe that the KT88 Genalex is every bit as good as the original, and a good number who think it's better! The KT66 is a killer, and while the KT77 results are just starting to come in, so far the reports have been superb.

Don't get me wrong, I think the KT-88 EH (as an example) is a VERY good tube. It needs a bit more bass energy, but it has the tightest an best bass control of any tube I've heard other than a good Ei KT-90. But trhe bit of missing bass causes some people to think the tube is too hot on top. You never hear that sort of thing about the Genalexes.

One EH tube that's just a steal is the 6CA7 though. It doesn't sound exactly like an EL34, it probably could be best described as a "baby 6550". The people who use them love them, and they are still a bargain.

The bottom line is that the Genalex reissues get the best construction materials and techniques, and it shows. It is more expensive though, which has been aggravated by the weak US dollar (in the USA obviously), the increasing cost of raw materials, and the increase in labor costs in Russia.
 
One fellow I know of was interested in trying some of these New Sensor "Genalex Reissue KT-77" tubes. He did a bit of research (this in the past two weeks), and reported back:

Talked with someone from Tube Depot this morning and he said wait for a while before ordering any of the Gold Lion KT77 tubes. He said they were getting people that would report that the tubes sounded good for about 15 minutes before they DIED!

So I'll save my money for now until I start hearing some good reports. You could substantiate the above claim I guess by calling Tube Depot yourself, or some other mass quantity tube movers, and see what the story is.

New Sensor does respond to email, and you could give them a try. Whether they'll be openly honest about massive failures in this, their first run of these particular KT-77s, I can not possibly say.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.