Dennis Had Inspire Amps

[Musica Amantem]

Originally Posted by Bombadil

I still haven't listened to the GL KT-77, mostly because my Inspire came with JJ KT-77, which Dennis told me that he liked better than the GL. He's one of the few people I've ever known who has compared the two and liked the JJ better.

That may very well be, but I've had bad luck with other JJ products, either dying on me or sounding mediocre. It is probably circumstantial and they may have improved their act lately. It is good to know the specification of the KT-77 is the reason behind their great sound and not a particular manufacturer's version. Besides, the JJ's are 33 % cheaper.

[FloridaBoy]

Originally Posted by Musica Amantem

That may very well be, but I've had bad luck with other JJ products, either dying on me or sounding mediocre. It is probably circumstantial and they may have improved their act lately. It is good to know the specification of the KT-77 is the reason behind their great sound and not a particular manufacturer's version. Besides, the JJ's are 33 % cheaper.

I have both and prefer the GL's. Both are fine tubes but they are different.

[FloridaBoy]

Originally Posted by Musica Amantem

I hear you, but also FloridaBoy does not like the idea as he has tried it in the past and considers the GL KT-77 unbeatable, which I agree with. I guess you guys are right. OTOH, this would prove or disprove my theory, though, and everything points to something like the 6P3S-E: relatively weak, but very transparent and balanced. The EL34B would also offer an advantage in body of sound thanks to the 55% higher plate current and some of that inherited midrange magic typical of the EL34 family, along with being electrically the best non-Triode output tube for Triode connection... Tempting! If you get a chance to listen to those again, let me know your latest impressions. Thanks!

After the GL KT77 no EL34 comes close for me but you may think otherwise. There are no absolutes in this game and we all have personal preferences in sound reproduction.

[goldhorse]

I passed by a tube dealer today to get a pair of KT88, and while I was looking around in the 6L6GC section, the store staff introduced me to a pair of Phillips ECG 7581A (Sylvania made). It was their last pair in stock. He described them as warm and having a wide soundstage. I decided to try them out, so came home with two pairs instead of one I tried out the 7581A first. Pops, Rock, hmmm I felt I preferred the KT66, or even the KT77. Then I played a Bruckner 9 by Mehta and the Vienna Philharmonic record, and wow did the 7581A just sound sweet. By this time they just had about 5 hours on them, yet they were already singing. I think like these more than the KT77 already for orchestral music. I liked them so much I postponed listening to the KT88 for another day.

They glow very nicely in the dark too.

[Bombadil]

Those Philips 7581a tubes can be pricey. Likewise for the GE versions. I don't know how well today's "Tung-Sols" reissues match up with them. I've read some descriptions which state that the new T-S specs at the vintage 35W dissipation standard. But I've read other sites which state that they top out at 30W, and are basically relabeled 6L6GC tubes.

I did see a post by Dave Gillespie on AK praising the 7581a. That is high praise from a tube equipment guru.

[Musica Amantem]

Originally Posted by goldhorse

I passed by a tube dealer today to get a pair of KT88, and while I was looking around in the 6L6GC section, the store staff introduced me to a pair of Phillips ECG 7581A (Sylvania made). It was their last pair in stock. He described them as warm and having a wide soundstage. I decided to try them out, so came home with two pairs instead of one I tried out the 7581A first. Pops, Rock, hmmm I felt I preferred the KT66, or even the KT77. Then I played a Bruckner 9 by Mehta and the Vienna Philharmonic record, and wow did the 7581A just sound sweet. By this time they just had about 5 hours on them, yet they were already singing. I think like these more than the KT77 already for orchestral music. I liked them so much I postponed listening to the KT88 for another day.

They glow very nicely in the dark too.

Someone in this forum had praised that same tube recently, but I cannot recall who the poster was. Seems there's a consensus on this particular tube. Unfortunately, in my system, 44 mA of max plate current in Triode at 250 V does not do it for me.

I had a chance to more thoroughly test the GL KT-88 direct to the AMP using the balanced signal from the DAC through the ZBit. My observations:

1. The deepest bass I've ever heard in my rig, without masking essential details.

2. Slightly less "air" between instruments than the 6550, but with a larger body of sound and aplomb.

3. Shares the 6550's faithful instrument timbres.

This puts the GL KT-88 on par with the 6550 in my system, each with it's particular strengths.

These two tubes excel when not pushed by the gain of the PRE, allowing their natural sound to come pristinely through. As stated earlier, in the case of the GL KT-77, I prefer the PRE configured for sound opening, as that boost helps it develop higher levels of body of sound and bass combining the best midrange in the business.

Currently, then, I enjoy all three Kinkless Tetrodes enormously, and will be working into dialing-up the 350B and 6P3S-E with the help of two new input tubes coming along (Shuguang UK 6SN7, 6B8G w/adapters, and the RED MOD High Pass filters). Life is good!

[goldhorse]

Originally Posted by Bombadil

Those Philips 7581a tubes can be pricey. Likewise for the GE versions. I don't know how well today's "Tung-Sols" reissues match up with them. I've read some descriptions which state that the new T-S specs at the vintage 35W dissipation standard. But I've read other sites which state that they top out at 30W, and are basically relabeled 6L6GC tubes.

I did see a post by Dave Gillespie on AK praising the 7581a. That is high praise from a tube equipment guru.

Yes, they were pricey. They cost me twice the price of the KT88, but I'm glad I got these after hearing them in action. No regrets whatsoever. It would be nice to compare them with the reissue TS though and as they don't cost that much so I might just grab a pair if I run across them in the future. Local dealers don't seem to carry them though.

[goldhorse]

Originally Posted by Musica Amantem

Someone in this forum had praised that same tube recently, but I cannot recall who the poster was. Seems there's a consensus on this particular tube. Unfortunately, in my system, 44 mA of max plate current in Triode at 250 V does not do it for me.

I had a chance to more thoroughly test the GL KT-88 direct to the AMP using the balanced signal from the DAC through the ZBit. My observations:

1. The deepest bass I've ever heard in my rig, without masking essential details.

2. Slightly less "air" between instruments than the 6550, but with a larger body of sound and aplomb.

3. Shares the 6550's faithful instrument timbres.

This puts the GL KT-88 on par with the 6550 in my system, each with it's particular strengths.

These two tubes excel when not pushed by the gain of the PRE, allowing their natural sound to come pristinely through. As stated earlier, in the case of the GL KT-77, I prefer the PRE configured for sound opening, as that boost helps it develop higher levels of body of sound and bass combining the best midrange in the business.

Currently, then, I enjoy all three Kinkless Tetrodes enormously, and will be working into dialing-up the 350B and 6P3S-E with the help of two new input tubes coming along (Shuguang UK 6SN7, 6B8G w/adapters, and the RED MOD High Pass filters). Life is good!

I had time today to listen to the KT88 and the sound is just huge, and the bass pronounced. I now share your opinion that having the PRE might just be too much of a boost. It was like a caged bull trying to break free As I don't have an attenuator built in in the Hot-Rod I might just look around for a passive PRE. Until I do, I'll play around with the smaller tubes.

With the 7581A, I'm interested to see how they would sound with 6SL7's in the gain stage. These on the other hand may benefit from the extra gain. We'll see.
Life is good!

[BearCityUSA]

Originally Posted by BearCityUSA

Have any of you tested your GL KT77 reissues for grid leakage. I had my tester out and thought I would run the quad I have through the paces. Emission was strong but grid leakage was questionable for all four of a quad. I ran some JJ KT77s through and they did not act the same. These GLs are not that old (new in September and not always in the amp) so I was wondering if maybe this was inherent to the GL make. Any input would be welcome.

Well, All this consistent love for the KT77 had me push the buy button on a new quad. I ran them through my Mighty mite and the new perform the same as my others mentioned above. A tester anomaly I guess. If anyone here knows the settings for KT77 on a Hickok 600a I would be grateful. I have been unable to find them.

[Musica Amantem]

Originally Posted by BearCityUSA

Well, All this consistent love for the KT77 had me push the buy button on a new quad. I ran them through my Mighty mite and the new perform the same as my others mentioned above. A tester anomaly I guess. If anyone here knows the settings for KT77 on a Hickok 600a I would be grateful. I have been unable to find them.

I would guess, as you already concluded, so many coincidences cannot be real, so the tester may need some calibration for those tubes. I have had the GL KT-77's for quite a while now, and never had any issues with them, nor have I heard of anyone else complaining about them.

Now that I'm using the Brimar 5Z4 GY as a rectifier with these, I'm running the same risks as with the 5AR4. I stated the contrary on an earlier post, so I'm correcting it here: both are indirectly heated (Cathode). I could pair the GL KT-77 with the SE 274B (which sounds nice also), but I need to really confirm which combination sounds better, as low Vdrops seem to have an edge with my Kink-Tetrodes.