Tube Suggestions

[zee]

Well I finally made the step from solid state to tubes! I’m running a Cary SLI-80 now in front of my Sequell IIs. I can say the low end is nothing like the solid state but after a few hours of listening I think I can live with it. I have KT-88s in it right now would a 6550 make the low end better? Or what tubes do you all suggest rolling?

 

[roberto]

Well I finally made the step from solid state to tubes! I’m running a Cary SLI-80 now in front of my Sequell IIs. I can say the low end is nothing like the solid state but after a few hours of listening I think I can live with it. I have KT-88s in it right now would a 6550 make the low end better? Or what tubes do you all suggest rolling?

Hola Zee. The KT-88s are a better (design tubes) than the 6550s, you can replace them direct with no problem. The KT-88s have more power disipation and handle more current at the plate. Stay with the KT-88s. Also IMHO they have a warmer sound than the 6550s. Listen the detail of the strings and the wind instruments...also if you listen to a piano, (any work of Mozart better) try to understand the left hand of the musician...for me, with the KT-88s are easier to do that...I know that there are many of you who likes SS better than tubes; it is a matter of liking and it is O.K., and others like me, we like tubes. When listening music, listen the musician playing the music and there...for you, not just the music itself. Trust your ears and happy listening,
Roberto.

 

[zaphod]

Well I finally made the step from solid state to tubes! I’m running a Cary SLI-80 now in front of my Sequell IIs. I can say the low end is nothing like the solid state but after a few hours of listening I think I can live with it. I have KT-88s in it right now would a 6550 make the low end better? Or what tubes do you all suggest rolling?

i'd suggest you look at biasing. tubes have a bias setting and amps have a prefererred bias (or adjustable bias). this blurf is from the tube store in the "power tube matching" page of the "Answers and Info" section.

9. What does it mean to "bias" the amplifier?
Just like the idle of your car may need adjusting when a major change is done to the engine, new power tubes need their idle (the "bias") adjusted to make sure the amp sounds as good as possible. Some amps do this automatically, but many do not - particularly in the world of guitar amps. Many tube amp owners are unaware of this simple regular service for their amp that will keep it sounding it's absolute best. The bias methods of amplifiers fall into several basic categories:
- fixed bias amplifiers
- cathode bias amplifiers
- adjustable bias amplifiers.
Each of these types is unique. Fixed bias amplifiers CAN'T be biased. These amps (for example, some Fender and Mesa Boogie models) are designed to run with tubes that have a specific current draw (see question 4) and should only use tubes that fall within a certain range. Fortunately, these amps are usually pretty forgiving and will work well with a pretty wide range of tubes. For the best results, specify the make and model of your amp in the "Comments" of your order and we will make sure you get the best tubes for your amp.
Cathode bias amplifiers shouldn't require any adjustments and will work with a wide range of tube plate currents, as the circuit is "self adjusting".
For adjustable bias amplifiers, the amp should be biased by a tech with experience with this procedure. It's not difficult, it doesn't take long, but if you don't know what you're doing you may hurt yourself (amps can give lethal electric shocks even when unplugged, and NO, we're not just saying that to scare you). Also, your amp may sound horrible or cause undue wear and tear on the tubes or power supply. Until you learn how to do it correctly by yourself, it's best to pay a technician a few dollars to do it for you.
​

Cary also has a nice section on biasing your amp which can be found here


the other thing - and you are lucky here - is that i have found that amps with tube rectification are much better in the bottom end. i put some NOS 5u4G in a pair of Mac 50w-2 and the bottom end really tightened up. since the SLI-80 is tube rectified, you might consider rolling some different rectifiers. the shouldered NOS phillips i found made me gooey.

 

[roberto]

i'd suggest you look at biasing. tubes have a bias setting and amps have a prefererred bias (or adjustable bias). this blurf is from the tube store in the "power tube matching" page of the "Answers and Info" section.

9. What does it mean to "bias" the amplifier?
Just like the idle of your car may need adjusting when a major change is done to the engine, new power tubes need their idle (the "bias") adjusted to make sure the amp sounds as good as possible. Some amps do this automatically, but many do not - particularly in the world of guitar amps. Many tube amp owners are unaware of this simple regular service for their amp that will keep it sounding it's absolute best. The bias methods of amplifiers fall into several basic categories:
- fixed bias amplifiers
- cathode bias amplifiers
- adjustable bias amplifiers.
Each of these types is unique. Fixed bias amplifiers CAN'T be biased. These amps (for example, some Fender and Mesa Boogie models) are designed to run with tubes that have a specific current draw (see question 4) and should only use tubes that fall within a certain range. Fortunately, these amps are usually pretty forgiving and will work well with a pretty wide range of tubes. For the best results, specify the make and model of your amp in the "Comments" of your order and we will make sure you get the best tubes for your amp.
Cathode bias amplifiers shouldn't require any adjustments and will work with a wide range of tube plate currents, as the circuit is "self adjusting".
For adjustable bias amplifiers, the amp should be biased by a tech with experience with this procedure. It's not difficult, it doesn't take long, but if you don't know what you're doing you may hurt yourself (amps can give lethal electric shocks even when unplugged, and NO, we're not just saying that to scare you). Also, your amp may sound horrible or cause undue wear and tear on the tubes or power supply. Until you learn how to do it correctly by yourself, it's best to pay a technician a few dollars to do it for you.
​

Cary also has a nice section on biasing your amp which can be found here


the other thing - and you are lucky here - is that i have found that amps with tube rectification are much better in the bottom end. i put some NOS 5u4G in a pair of Mac 50w-2 and the bottom end really tightened up. since the SLI-80 is tube rectified, you might consider rolling some different rectifiers. the shouldered NOS phillips i found made me gooey.

Hola Zaphod...you are just right!!!...you have to follow the bias instructions at the owners manual and it is a very easy task to do. Agreed 100% with you. Due also, even in a match pairs, there are always a little difference in gain on each tube, so it is good advise to do adjust the bias to all output tubes at the amp. When this task is done properly, your ears also can tell...happy listening,
Roberto.

 

[zee]

Hola Zaphod...you are just right!!!...you have to follow the bias instructions at the owners manual and it is a very easy task to do. Agreed 100% with you. Due also, even in a match pairs, there are always a little difference in gain on each tube, so it is good advise to do adjust the bias to all output tubes at the amp. When this task is done properly, your ears also can tell...happy listening,
Roberto.

Biasing has been done and I've gone back and checked it each day so far and it stays right at 75 like cary says.

is that i have found that amps with tube rectification are much better in the bottom end. i put some NOS 5u4G in a pair of Mac 50w-2 and the bottom end really tightened up. since the SLI-80 is tube rectified, you might consider rolling some different rectifiers. the shouldered NOS phillips i found made me gooey

Currently I have some RCA 5u4Gs I think I'll double check this.


I’m really liking the sound of the tubes so I don’t think ill be going back to solid state I just cant feel the bass like I used to.

 

[jjqiv]

Hola Zee. The KT-88s are a better (design tubes) than the 6550s, you can replace them direct with no problem. The KT-88s have more power disipation and handle more current at the plate. Stay with the KT-88s. Also IMHO they have a warmer sound than the 6550s. Listen the detail of the strings and the wind instruments...also if you listen to a piano, (any work of Mozart better) try to understand the left hand of the musician...for me, with the KT-88s are easier to do that...I know that there are many of you who likes SS better than tubes; it is a matter of liking and it is O.K., and others like me, we like tubes. When listening music, listen the musician playing the music and there...for you, not just the music itself. Trust your ears and happy listening,
Roberto.

Hola Roberto,

Have you tried KT 90's?

 

[zee]

Hola Roberto,

Have you tried KT 90's?

Please pardon my ignorance here but would the KT-90s offer more power than the 88s?

 

[DTB300]

I’m really liking the sound of the tubes so I don’t think ill be going back to solid state I just cant feel the bass like I used to.

There are plus and minus issues that you will get with Tubes and Solid State Amps. One has to determine which they can live with or live without.

Remember you can Bi-Amp your Sequel's so you may want to try the tubes on the panels and your solid state amp (if you still have it) on the woofers and see how that plays out.

Dan

 

[Spike]

Bi-amping with tubes & solid-state

I’m really liking the sound of the tubes so I don’t think ill be going back to solid state I just cant feel the bass like I used to.

From this description, it looks like bi-amping is the way to go in order to get the bass back to your liking. You can do a search for my posts here on the subject of bi-amping using tubes for the panels and solid-state for the bass.

Remember you can Bi-Amp your Sequel's so you may want to try the tubes on the panels and your solid state amp (if you still have it) on the woofers and see how that plays out.

Yes, the Sequel allows for bi-amping and bi-wiring options, but the Cary SLI-80 does not have pre-amp (RCA) output to feed signal to the solid-state amplifier. Given that it's a Cary, you should call or email Dennis Had to see if there's an option to add pre-out to your SLI-80. If you do ask, let Dennis know that you're heading toward bi-amping and need to control both amplifiers using the volume control on the SLI-80. Dennis is very pleasant to deal with and he's been very accomodating toward his customers. Good Luck.

Spike

 

[DTB300]

Yes, the Sequel allows for bi-amping and bi-wiring options, but the Cary SLI-80 does not have pre-amp (RCA) output to feed signal to the solid-state amplifier. Given that it's a Cary, you should call or email Dennis Had to see if there's an option to add pre-out to your SLI-80. If you do ask, let Dennis know that you're heading toward bi-amping and need to control both amplifiers using the volume control on the SLI-80. Dennis is very pleasant to deal with and he's been very accomodating toward his customers.

Spike...Good point......I forgot the SLI-80 was an Integrated Amp and not just a "normal" Pre Amp. Using seperates myself, sometimes I forget about Integrated Amps

Dan

 

[roberto]

Please pardon my ignorance here but would the KT-90s offer more power than the 88s?

Hola...power disipation of the KT-90s is bigger than the KT-88s, but this does not mean that changing them on your amplifier, it will deliver more power. The plate voltage is the same, so you don´t get more power. You have to change the whole circuit to get more, begining with the power transformer. In other words, if the amp. was designed with 6550s, then you can replace these 6550s for KT-88s or KT-90s, but if the design was done with KT-90s, then you can´t use the others...only KT-90s.
To my ears, the KT-90s are very close to KT-88s...but I don´t know why I keep liking these ones. Long time ago, when I was in my 30s, I used to listen the sound of the system with bass, mids and highs. I don´t do that anymore. What I do is listen the whole musical instrument and if I get the soul, the feeling of the musician playing that song or work. Then I listen for scenario, image, size of the instrument, size of the theater or room...live performance is the best here...air between instruments or between even with the notes...I use different parameters than most of others...and it is just a matter of taste and liking. What I do is I trust in my ears!!! not in specs. The measurements that are done for test the goods, are linear and our ears have a logarithmic behaviour and can detect many things good or wrong that the test instruments can´t....happy listening,
Roberto.

 

[Spike]

Long time ago, when I was in my 30s, I used to listen the sound of the system with bass, mids and highs. I don´t do that anymore. What I do is listen the whole musical instrument and if I get the soul, the feeling of the musician playing that song or work. Then I listen for scenario, image, size of the instrument, size of the theater or room...live performance is the best here...air between instruments or between even with the notes...I use different parameters than most of others...and it is just a matter of taste and liking.

Hmm, that sounds like a perfect description for EL-34 tubes Your journey also mirrors mine where I was looking specifically for amplifiers optimized with EL34 tubes in triode mode and ended up with the SixPacs.

Spike

 

[roberto]

Hmm, that sounds like a perfect description for EL-34 tubes Your journey also mirrors mine where I was looking specifically for amplifiers optimized with EL34 tubes in triode mode and ended up with the SixPacs.

Spike

Right Spike...the 6CA7s/EL34 are one of the best sounding tubes, even in these days. I´m using KT-88s because the amp that I´m using now came with 6550s. They deliver a little bit more power than the 6CA7s, and my speakers loves power (CLS IIz)...but I think that the EL34s are more delicated with the sound for good...happy listening,
Roberto.