[schw06]

 I own a pair of 845 based SET monoblocks on Zu Definitions(101db, 6ohm) and it is a spot on match for the speaker. That being said, I have noticed that the Zu's really come alive with high watt amps despite the need for only a few watts to drive them to satisfying levels. I was considering having a kt88 push pull amp made and it was suggested to me by a great amp designer that a hybrid amp (not a hybrid integrated) using 5687 tube input and mosfet output would be a great alternative to a pure tube amp and he believes his hybrid amp "smoked" a no holds barred amp he created. I am very reluctant to bite on this idea given my track record of never enjoying a single solid state amp enough to keep. I'm wondering if any tube lovers have had success with hybrid amps that make them not miss their tube amp?

[Niteshade]

If you were to go hybrid, go with a system that has a tube output stage (AKA: KT88 or 6550) and a solid-state driver stage. It has to be a design which is uncluttered or else it's all for naught.

The added power brings with it better, cleaner dynamic range. Nothing wrong with a high wattage ceiling!

[schw06]

Blair,
   Why a tube output stage and a solid state input stage rather than the other way around?

[Wayne1]

Are you willing to look at DIY solutions?

http://www.diyhifisupply.com/node/812

DIYHiFiSupply sells a module designed to boost the output power of most tubes amps. By adding modules you can increase the output power. Here is a manual which explains it

http://www.diyhifisupply.com/files/Fusion%20Installation%20Manual.pdf

Here is the Fusion Whitepaper: http://diyhifisupply.com/files/Fusion%20WhitepaperR1.1.pdf

If you are not up for building, they also make a 300B amp with the modules installed. it can produce 10 watts with the module off or 40 with them on.

http://www.diyhifisupply.com/catalog/32

It's designer, Thorsten Loesch, is fairly well known. He also designed most of the AMR gear. He had some comments about the 300B Fusion amp: "To be honest, I have major issues telling if it is in or not, the 300B Fusion Amp, which is so far our only application, unless I turn up the volume past what the 300B Amp handles on it's own.

I think it is the little extra circuit trick described in the whitepaper on page 3 that makes all the difference to conventional buffers, as I have heard a few of these."

[DARTH AUDIO]

I own a pair of 845 based SET monoblocks on Zu Definitions(101db, 6ohm) and it is a spot on match for the speaker. That being said, I have noticed that the Zu's really come alive with high watt amps despite the need for only a few watts to drive them to satisfying levels. I was considering having a kt88 push pull amp made and it was suggested to me by a great amp designer that a hybrid amp (not a hybrid integrated) using 5687 tube input and mosfet output would be a great alternative to a pure tube amp and he believes his hybrid amp "smoked" a no holds barred amp he created. I am very reluctant to bite on this idea given my track record of never enjoying a single solid state amp enough to keep. I'm wondering if any tube lovers have had success with hybrid amps that make them not miss their tube amp?

Just wondering, who is the "Great Amp Designer"? What is the company name? Thanks

[Ericus Rex]

In my experience, hybrid amps have never given me the magic tubes amps give.  Though makers try and try to combine the two technologies the 'tube sound' seems to be in the power tubes and not inputs/drivers.  I'd stick with higher powered P/P designs if tube sound is what you're looking to keep.  Just my humble opinion.

[Niteshade]

A hybrid design with a tube output stage will have a much cleaner circuit. The amount of feedback necessary with be exactly the same as a 100% tube circuit as well, which is very low. The amp will have a more open presentation due to its speed. Something else to consider: the output tubes are user replaceable while a solid state output would be nearly impossible to do home maintenance on. The transistors in the driver stage of a hybrid design will most likely never go bad since they are not handing large amounts of current and they can be set up to run well within their means.

This design has the potential to sound much better than one using a solid state final stage. The electrical benefits of a clean design do translate into a high performance product.

Note: I have worked with HF transceivers that are hybrid and use tubes in their output stage. They always sounded better to me relative ones which used a solid state power section. Granted, that was RF, but the difference was still easy to identify. The tubes used in those 70's transceivers were usually 6146W's. (Kenwood TS-830S, Yaesu FT-10ZD, Tempo 2020, etc...)

[carusoracer]

I have had SS, Big SS Power Dual Mono Configuration, Hybrid, Integrated Tube, and Tube Dual Mono's.
I have yet to try the SET Amps as the speakers I have would need to be Bi Amped to achieve full range.
The Hybrid sound in a good application IMHO, is very nice to hear and certainly is non fatiguing. The reason I go off on a tangent would be if you have the SET sound you are already far off into the "Tube Sound" extreme. I'm not sure how long you would stick with the Hybrid.

BTW, Luv the Avatar Go Buc's! Man was it cold and windy at the game.

[Quiet Earth]

I'm not a big fan of hybrid amps because it seems like you're just sitting on the fence. 

I own a pair of 845 based SET monoblocks on Zu Definitions(101db, 6ohm) and it is a spot on match for the speaker. That being said, I have noticed that the Zu's really come alive with high watt amps despite the need for only a few watts to drive them to satisfying levels.

Frustrating, isn't it?

I wonder how many high efficiency, pro-audio born, single driver with whizzer type of speakers are really voiced with an SET amplifier? Probably none of them. Where does that leave the customer? Trial and error.

What amplifier does Zu use to determine that they have reached their design goal? That's probably the amp you want to buy. I'd like to see more manufacturers build entire systems in the future, instead of just producing pieces and parts for the customer to sort out. Ok, the crying is over now . . . . .

[schw06]

Quiet Earth,
   It is extremely frustrating! Other than taking educated guesses, there isn't really a good way to choose associated equipment and this whole trial and error thing has gotten really expensive! I've come to the conclusion that having it all in one amp has turned in to the search for a unicorn. My analogy is wanting a Burger King Whopper, McDonald's french fries, and a Wendy's shake all in one store.
   I want an amp that sounds high power SET without tubes! Whoever creates an amp like this will be a very wealthy individual.
   As an aside, do any other high efficiency speaker owners prefer high power tube/ss amps on their speakers?

[satfrat]

If you were to go hybrid, go with a system that has a tube output stage (AKA: KT88 or 6550) and a solid-state driver stage. It has to be a design which is uncluttered or else it's all for naught.

The added power brings with it better, cleaner dynamic range. Nothing wrong with a high wattage ceiling!

 
 
Butler Audio, this is 1 channel of 150watts @ 8ohms, compact enough for ya Blair? Butler has 2, 3, and 5 channels, all sharing same designed case but with different front/rear faceplates(the 2 channel is a 250watt board that unlike the 150w boards is bridgable), all sharing a single large transformer and the same modular tube output so the whole Butler line is completely modular within itself and very easy to work on. From the Butler Audio website:

Previous designs generally employed vacuum tubes in impedance-isolated preamp or pre-driver stages. BK Butler's Tube Driver BLUE technology places the triodes exactly where they should be: DC coupled through the output power devices to the speakers. Therefore, the tubes are positioned to naturally and actively respond to the dynamic speaker load. This also completely eliminates one of the most inefficient and non-musical components in a typical tube power amplifier: the Output Transformer. Without the phase shift and induction generation caused by hundreds of turns of wire and massive core iron to overcome, BK Butler's newly patented current multiplying DC coupled circuitry allows the 6SL7GT output driver tubes to directly operate into the constant ratio-reduced speaker load. This novel design allows the tubes to safely produce authentic power vacuum tube dynamic characteristics hundreds of times greater than their original design capabilities.
 

I of course am an owner of 2 Butler 3150's for my 6 channel system for a good 7 years now, just had them reconditioned with a bias tweek this year from BK Butler. While I wouldn't recommend Butler amps to any tube geek who has to have that soft tube sound, if you crave system dynamics like I do yet still want a little tuby glow about your system and it's sound, then Butler's your beast. I'll never part with mine. 
 
Cheers,
Robin

[lonewolfny42]

From a past Rave....The Zu Tour....Zu powered by Butler...sounded good.

[ltr317]

I agree with Eric and Quiet Earth.  I also have had countless tube, hybrid, and ss amps in my audio journey.  While I ultimately decided a warmer sound is what I prefer, since it sounds more like live music, I also prefer the bass control of a ss or hybrid.  But since I can't bi-amp for several reasons, I chose to live with a tube amp for my reference system. 

You may get a slightly warmer sound from a hybrid than a typical ss amp, but no hybrid I have ever heard can match the tonal fullness, or beautiful harmonics of a typical full tube amp.  Of course, a designer can also design a tube amp to sound more neutral, but I'm speaking of the vast majority of tube amps available.  And since you have SET amps, rather than a pp design your amps tend to have a more tonally richer mid-range than the average.

Getting a higher powered full tube amp, either SET or pp will provide tonal fullness and harmonics, but not bass definition/detail.   I think Wayne's suggestion is a good one, as you want to improve on the overall dynamics and probably bass definition/impact without upsetting the tonality of the mid-range which you like. 

[lonewolfny42]

David/schw06....

You might check out a Moscode - that's a hybrid.....they have a 33 1/3 days home audition.

http://www.moscode.com/products/index.htm

[schw06]

Chris,
   Thanks for the Moscode advice. I've heard those amps are not fans of impedance dips below 8 ohms and the Defs are 6 ohm so I have been reluctant.
David
P.S.- Still listening to all the cd's you sent me...thanks again

[lonewolfny42]

David....

When you hosted the Zu tour....did you hear any other amps then with the Zu's that might fit the bill ?

Another idea....drop Srajan Ebaen/6moons an email... srajan @ 6moons.com

[datman]

Having owned a Butler TDB2250, I can enthusiastically recommend it.  No, it doesn't sound like an SET.  It does have the midrange "magic" of an SET but with DRIVE!  This is especially noticable on dynamic, full range orchestral music.  Where I think it gets most everything "right"  is in its lack of feedback.  I find this makes more of a difference than output circuit topology.  It was one of the best amps I have used in my 40 years of audiophile insanity.  By way of comparison, this is a partial list in no particular order (I can't remember them all) of the amps that I have had over the years:

SAE MK II
Audio Research D76A
SAE MK XXIII
VAC 100/100
Sonic Frontiers Power II
Innersound ESL amp
Genesis Stealth
New Audio Frontiers 845SE Special Edition

As you can see, I have had amps of all flavors and sizes.  The one thing I can say is tubes are NOT inherently better than SS/hybrid amps.  It all depends on your room and speakers.

[raindance]

To add my usual 2c worth:

• Why would you want a hybrid with a solid state driver stage and tube outputs? You end up with all the hassle of tubes and lose some of the advantages (output tubes wear out, biasing is a worry, you have no small signal tubes to swap out to tailor the sound to suit you, etc. Plus rolling power tubes yields much less of a change than rolling small signal tubes
• An all tube amp with transformers at the output can do a really fine job of reproducing natural sounding music. I believe that the non-linearity of the transformers is what adds a lot to the tube sound
• A hybrid amp with a tube front end and a solid state output stage can give you a taste of what tubes are like and you can have fun rolling small signal tubes - the Unico amps spring to mind as a really fine example, but there are plenty others
• Tube amps don't always sound better than solid state. There are a lot of very poor designs out there that produce nasty odd order harmonics just like solid state. With push pull amps you have to slightly unbalance the drive to the output tubes to improve even harmonics and when cathode followers are used they usually add nasty odd harmonics - interesting point here is that most hybrid tube input SS output amps use a tube cathode follower at the input and this is where they fail. Single ended non-push pull tube amps have the best even order harmonic reproduction (pleasing to the ear) but are limited in power. You want even order harmonics to dominate
• Tube amps don't do bass as well as solid state. Ever. This is where you have to audition and decide which route you prefer - a lot of folks end up using tubes for everything above low bass and a sub for low bass (making sure you have a way to cross over and drive this setup)
• Tube amps without a transformer (OTL) can sound nice depending on your speakers. They always have a poor damping factor due to tubes being high impedance devices relative to speakers, so you have to try them with your speakers. These amps have a very different presentation to transformer coupled amps. They generate lots of heat and are fairly unreliable, plus they use lots of expensive power tubes
• There is no easy answer. It is all a matter of personal taste. Avoid cheap tube amps or hybrids that use cathode followers. Maybe try Class D for some of the "tube" character but with better bass control. Unfortunately Class D amps are not particularly warm sounding although they get mistaken for being warm if they have a slightly rolled off or very sweet top end. Ultimately it is sweetness, lack of harshness and lifelike rendering of harmonics that you are probably after

[satfrat]

As you can see, I have had amps of all flavors and sizes.  The one thing I can say is tubes are NOT inherently better than SS/hybrid amps.  It all depends on your room and speakers.

I gotta say that your blanket statement doesn't quite cut it, from 1 Butler owner to another. AFAIC, it all boils down to personal preference. There is no right or wrong, tube/SS, whatever it all depends on what satisfies the end user. Everyone's opinion what what's the best option is just that,, their own opinion based on their own personal preference and all these blanket statements on the subject of audio preference just doesn't cut it for me. But I have no problem hearing what each individual person's idea of ideal audio is, so long as you don't raindance on my own personal audio preferences as so many seem to want to do..   
 
Cheers,
Robin

[ltr317]

Having owned a Butler TDB2250, I can enthusiastically recommend it.  No, it doesn't sound like an SET.  It does have the midrange "magic" of an SET but with DRIVE!  This is especially noticable on dynamic, full range orchestral music.  Where I think it gets most everything "right"  is in its lack of feedback.  I find this makes more of a difference than output circuit topology.  It was one of the best amps I have used in my 40 years of audiophile insanity.  By way of comparison, this is a partial list in no particular order (I can't remember them all) of the amps that I have had over the years:

SAE MK II
Audio Research D76A
SAE MK XXIII
VAC 100/100
Sonic Frontiers Power II
Innersound ESL amp
Genesis Stealth
New Audio Frontiers 845SE Special Edition

As you can see, I have had amps of all flavors and sizes.  The one thing I can say is tubes are NOT inherently better than SS/hybrid amps.  It all depends on your room and speakers.

No one here said tube amps are inherently better than ss/hybrid amps, but Schw06/David did state he didn't like the ss amps enough for him to keep.  Yes, room and speakers are important, but the most important factor is the listener's sound preference.