300B vs. KT88 SET?


Hi guys, I've heard so much ABOUT tubes that I want to try them. My speakers are very efficient, so there should be no problems with 7 watt SET amps. Unfortunateely, I can't find place to audition them so I need your help. There are number of amps available here on the Agon. Some of them based on 300B tubes and some are using KT88. Thouse that use KT88 are less expencive to buy, and so are the tubes.
But how different do they sound?
All you inputs and opinions are appreciated.
zoya
Audio Note tube gear is one of the best too and at a much more reasonable cost here in kits or already put together for you
 
  They also have Audio Note Alnico speaker kits too with the speaker cabinets already put together for you

https://www.ankaudiokits.com 
 
 Not connected with this company in any way
I also highly recommend the eml xls 300bs. Bulletproof reliability (mine still tested good after 5 years of daily use and I bought them used), great extension on both ends of the frequency spectrum, and a more reasonable cost than most of the other top 300b competition.
I had coincident Frankenstein 300b monos and they excelled at every genre on my coincident super eclipse iii speakers. Only sold because they didn’t have enough power to drive the coincident pres I upgraded to. I adored those amps and highly recommend trying out a good 300b amp.
The Forte's will easily be driven by a 10w SET and many enjoy rolling 300Bs though it is not an inexpensive hobby.  You will find their are a surprising number of new 300Bs available that sound quite different.  

I am not sure what the benefit of a KT 66-KT150 amp would be as you don't need the power.  The only benefit would be the opportunity to roll relatively inexpensive tubes rather than the pricier 300Bs.  

Picking the exact SET (PX25, 300B, 845, etc...) to get the right sound profile for your taste is probably an interesting place to start.  300Bs will give you most flexibility for Tube rolling but have a specific sound profile that may or may not appeal to you.  
Appears this thread is a decade old, yet this was my question as I educate myself as I embark on my "Tube Audiophile" journey. I'm guessing I'm going to need 2 amps; a 300B, and a "rolling amp (KT66-KT150)". 

I own a pair of Klipsch Forte III's powered by an Onkyo AV receiver, that I'm planning on selling/trading-in. 
I have both SET amps. Both are custom made with high quality parts. The kt88 SET amp is using Shuguang Treasure 'Black bottle" kt88-z output tubes and NOS Raytheon 6sl7 "red base" driver tubes and Sovtek 5ar4 rec tube. This is a stereo amp. The circuit is from JE Labs. The 300b SET is in mono block form. It has Sophia electric Princess 300B carbon plate output tubes and the circuit employs a 2 stage driver consisting of vintage type 27 and type 56 tubes. It uses tung sol 5u4g rec tube.

The kt88SET has better top end, sounds a little smoother. The 300b SET has better bottom end (not as slow) and mid bass. Both amps have that magical midrange that I love but the 300b is more lush and renders voices with a more realism. The kt88 does a real good job of projecting a holographic and realistic soundstage. The 300b does also but it is deeper with more air around the voices, it has a higher spooky factor, especially with the lights off. The kt88 SET is still a sweet sounding amp and does voice better than any other amp(besides my 300b amps) that I have heard, that include high end SS amps PP tubes too. both of these amps blows away my Single ended SS amp "Pass Labs aleph 3" amp. One thing nice about the kt88 Set amp is I can also roll tubes, I got a pair of vintage Telsa el34 coming.
I am also interested in the difference between 300Bse vs. KT88se at some point the conversation seems to have jumped to 300Bse vs. KT88pp not sure why. I know more KT88pp amps exist then then do KT88se amps. But there are a few nice looking KT88se and EL34se out there Decware's model SE34I.2+ (www.decware.com ) and www.hifiandaudio.com has a fine looking KT88 se as well. In all of the se KT88 / EL34 amps I have seen the the KT88 / EL34 are interchangeable.

From the examples I have seen you can get:

5watts from KT88se with a 5K opt running with no nfb
12watts from KT88se with a 2.5K opt running with nfb
8watts from 300B running 3k with no nfb

I am sure other operating points are possible.

I had been running a cheap se 6N8P / 6P13P (the 6P13P is very smiler to the EL34 ) which I won at an headfi auction for $150. After 3 hours the output transformers get very hot. It's rated at 12W per-side. The opt are 2.5K load and they are run in UL (it's an ultra-linear se amp) to the 6P13P and it uses NFB (don't know how much).

Now just yesterday I picked up a 6J4P/300B it is a Jas Bravo 2.2. I have not looked inside so I can't tell you anything about the 300B other then what tubes it uses.

Now comparing the $150 se 6P13P to the $1700 300B, these two amp sound totally different it would be easy to pick one out in a side by side test. The 6P13P is not really a HiFi amp, it can't really do rock, lacks base slam and what base you do get is kind of lose.

The 6P13P does well with high/mids where the 300b jas does well with low/mid. Its like there is a window and each amp does well with a different part of the range. The 6P13P is more smooth and the 300B is clear however the 300B is dark I believe this is a trait of the 300B others will agree with.

I watch a lot of British Mystery movies (Inspector Morse mostly) with my amp. With the 6P13P when Morse is interviewing suspects the presents of a clock in the room ticking away is really clear his voice is better with the 6P13P. Deep background music is better with the 300B. For most of the episodes the 300B is more well rounded. But there is one episode called “Death Is Now My Neighbor” where I like the 6P13P better. I can site one seen where an organ and quire are playing in an Oxford college and the academics are filling in to take there seats for mass.

Before I got the 300B I had assumed it was going to be the sweeter sounding of the two set amps, I was wrong. That said, I would be interested to hair a KT88 se in a 5k opt non-feedback arrangement.

Leve
Long Island, N.Y.
Bemopti123- Yes, you've put together some nice systems there. A good friend just went from a longtime devotion to Theta DAC's to a BelCanto DAC 2 and he's been really delighted with the improvements. Also, I've been very curious to hear the 47Lab stuff, as well as the Voight Pipes. I get to NYC about once a year....are you there or nearby? Yes, I've been taking pictures since I was six and haven't stopped. Yes, it is my profession. I've never done anything else, though, since you asked, I reacently delved into some graphic design combined with illustration. There is a very poorly placed full-page ad I designed running in the March 04 Stereophile that is commemorative of the 100th birthday of Paul W. Klipsch. It will be running in the April-May TAS and Absolute Vision as well as the March AudioExpress. I was pretty happy with the design, but it looses a lot in Stereophile placed against the busy page it is. Hopefully the other rags will place it better. It looks great in AudioExpress, which ironically is followed two pages later with a tribute to Peter Walker (Quad) who just passed away. PWK passed away two years ago at 98.

Zoya - My expertise is mostly in "making" pictures as opposed to "taking" pictures. I have tremendous respect for those in both specialties, but I may not be the one to ask to comment on your photography since it is so different from what I do. I did look at your site, and will consider sending you my comments if you are still interested. Probably this is not the place to share those comments though.

As far as comments thus far regarding 300B SET - I think you have some pretty good input and many valid comments and observations. As I said, the only comment that I'd take strong exception too is any that would imply one type of amplification is necessarily "better" than another. Art Dudley wrote what I thought was an excellent piece in the December 03 issue of Stereophile on SET as well as arguments pro and con, and folks silly need to make the other camp wrong. It makes for some excellent reading and may lend for yet another perspective. I do enjoy his writing. Check it out if you get a chance. I'm not sure if they run that colum in their online issue.

Marco
Jax2, thanks for the offer. If I ever swing by Seattle, I would love to hear your rig. When the time arises, I will offer you the same opportunity, to listen to my rig in NY. Nice pics. Are you a photographer by profession? Nice pics in your website. Check my stereorig in Audiocircle, I have two albums going. One has a MR-78 Mcintosh tuner first and the other one, the Zhorn with Fostex drivers.
Zoya,

I think, based on what you have written and your speakers, you'd be happiest with a 300B amp. But remember, all 300B amps are not equal. It's very important to get a properly designed one with proper circuitry and transformers.

After having 7 different tube amps over the last 17 years , I settled on an AirTight 300B with Tamura transformers and point-to-point wiring. The sound is superb and I get musicality, slam, dynamics, extended high frequencies, space, soundstaging, transparency, detail, delicacy, etc. However, my speakers are 87db (but don't drop below 6.5 ohms) so I don't get the best bass performance. That is why I use a good subwoofer - an REL.

Your speakers look like they'd work great with 8-10 wts and I think you'd be completely happy with a 300B SET. I think you really should go signle ended triode (which is what the 300B is) instead of push/pull (which is what the KT88 is). Remember, the simplest way of doing something is usually the best.

I have heard the Wright Sound 300B are supposed to be quite good and very afordable. And, just to give you and idea about how long 300B tubes last (they are quite expensive), my AirTight tubes are 3 1/2 years old with lots of use and the tubes spec out just fine. I expect to get another 3-4 years out of them without a problem. I have heard that 300Bs can give 15-20,000 hours of use!

I have owned 4 push/pull tube amps and 3 SETs, I will not be going back to push/pull any time soon. By the way, My AirTight is built like a tank and I expect it to last 20-30 more years at least, but I'll probably sell it before then!
Marco, GREAT pictures - I hope you don't mind me looking there. Photography is my other hobby, Would you offer your professional opinion on some of mine http://public.fotki.com/brightonpic/my_favorite_shots/.
Back to the main topic - I really appreciate all of you sharing your knowledge - it trully helps.
If you find yourself in Seattle Paul, just send me an email and you can come by and hear either rig. Always happy to stand around and kick tires, er, wires, and share music. Tom also suggested I try voight pipes. You can find my email link on my website. Thank you for the offer which I'd happily take you up on were I closer. I'm actually from NYC and got eight years off for good behavior in Vermont, where my folks still live. I don't think I'll ever move from Seattle though. Been loving it out here for over ten years now.

Marco
Noise, be it from tube heating via high sensitivity speaker or in my case, due to what is called "battery" noise, it unavoidable, unless you have one of those new fangled digital amps. I have a pair of Voigt pipes, just the cabinets left. I made them about 3 years ago, and for whatever is worth, they sounded pretty good to me, until I got a pair of Zhorns, at which point, I decided to cannibalize the Fostex drivers from them, and now, I am rocking. If you were close to me, I would have lend them to you permanently! Well, that is not the case, for it seems that you live in the West coast. Jax2, what also fascinates me is the Voigt pipe, as it is described in TWL's system. It seems to me that he was able to overcome some of the most common complaints of their design, chiefly the lack of low frequencies. He is a mad tweeker and experimenter, so things might be different for most of us. Anyway, you can build yourself a pair of Voigts for about $450, drivers included. Affordable. That is the story. I would love to hear your job rig.

PAUL K
Hey Bemopti123 - thanks for the compliment. I actually moved that system to my workspace where I listen to it now. Mostly for WAF per my system description. A more modest, KT88 based sytem is currently in my home where that one was. The LaScalas now have much more space to breath! Hey, how do you like your Voight-Pipes? I've been thinking of trying a pair of those at some point. Terry Cain lives only a few hours from me and I keep threatening to go out and visit him in the stick and listen to his speakers. I have a feeling they may hook me! Good input on the differences too (thread subject). Zoya - 98db is just fine for SET in most rooms, though I've never heard your speakers so cannot comment beyond that general observation. 300B tubes are direct heated and are therefore prone to some low level noise when at idle. With my LaScala's (104 db) you can hear it, though I never found it annoying. Less so with speakers af less efficency. KT88's are not direct heated tubes, at least I'm pretty sure they're not (someone correct me here if I'm wrong), so that idle noise does not exist there (if it does it is not likely the KT88 tubes). As far as the 300B's once they are playing music, I find the background to be quite black. This is with my system in my room, to my ears. The idle noise has never been an issue when music is playing, even at low level....at least for me it has not.

Marco
Guys, thank you all for your great inputs. As you can see from my system - I don't expect any problems from the speaker's end, they are 98dB. My biggest concern is musicality, transparancy and blackness of the sound (absence of added noises). Am I asking for too much?
:)
Zoya and Ykk - just to reiterate, SET and push/pull are two different animals. They sound very different so Ykk (do you have a zipper fetish:-) do try to take a listen to a 300B SET before giving up your current amp. I'd disagree with any statement that implied one was necessarily "better" than the other. They are different......the "better" part is entirely up to the listener. 300B SET lends a sense of holographic presence that I've never heard before (good SET amps share this quality I think). KT88 sacrafices some of that 'presence' and airiness for a more authorative, dynamic slam (though not your typical SS kind of slam....a kinder, gentler slam if you will). There are plenty of folks who you could find that would speak highly of each, and perhaps put down the other. My advice would be to ignore such input and make your own judgement, preferably in your room with your system. In the case of 300B SET vs KT88 Push/Pull you can probably get a very good sense of the differences in any thoughtuflly set up system with each in place. Keep in mind too that in going to the lower powered SET amps you will really need to have very efficient speakers to make them sing. I wouldn't consider any speakers below 90db, and that would be my rock bottom for a smaller room. Better still 94db and up. KT88 push/pull arrangements come in all kinds of power depending on the design and how many KT88's are used in it. Therefore they are less demanding of speaker efficiency, though speaker matching is always important.

Ykk, certainly having both types of amps would be ideal if you listen to a diverse and wide range of music of which a good amount is suited to each of the two types of amplification. If I had to live with just one, for me it would be SET. But my musical tastes are more strongly in those areas that SET really shines. If I had to point to one that is most versatile, I'd likely point to the KT88 Push/Pull. Just one humble opinion though.

Marco
I agree with Jax2 and others, that the inherent qualities of either 300B tubes and Kt88s are evident, according to the type of music that is demanded of them. I tend to associate Kt-88 tubes with powerful and high wattage wise tube amps. Due to the higher wattage of most Kt-88 tubes gear makes me think that they were intended for high energy music such as rock, or heavy orchestral. Although there are several manufacturers that have multiple 300Bs in order to produce more useful wattage, for medium sensitivity speakers, the most refined 300B amps seem to be those producing 9 watts per channel max. Being an owner of both high powered tubed gear and low, SET 300B amplifier, I notice a large different in sound, as it was well explained by one of the posters above.

Yes, you need to have two different amps or maybe two different systems in order to enjoy the best musical "fit" that one can, but honestly, most people do not have the space.

I personally, kept my 300B amp and I am presently running a low battery powered SS amplifier, which sonics are at least 95% comparable to my 300B amp, especially in the midrange.

BTW, my goal is to have a system like JAX2 has. Beautiful and simple set up.
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I am now using KT88 amp, but also contemplating to move to 300B amp. Zoya, from the inputs given above, it sounds like the best thing is to own both KT88 and 300B amps. I wonder if anyone out there find it necessary to have both amps?
I can think of no amps that will allow you to interchange those tube types. They have entirely different qualities, and amps that utilize each type will have their own strengths and weaknesses subject to your own personal preferences. I have 300B SET amps in my work system, and now am using my KT88 based amps at home (contrary to what you will see in my Virtual System). For Jazz and vocals I can think of no better way to listen, to my ears, than SET. Classical is a pretty broad category. If your classical tastes lean towards more dynamic and layered orchestral music, as Ctran60 points out, KT88 based amps may offer you a fuller, more forceful presentation. 300B SET is all about air, atmosphere, refinement, soundstage, holography. Sacrafice is often in the low end, and KT88 amps will almost certainly maintain an edge there. The best way to find out which you prefer is to try to listen to good examples of both. They are so different that the experience should leave you with an unmistakable impression of each I would guess. I enjoy each one for their strengths. For most acoustic music, vocals, jazz, small ensembles, I'll take SET every time. For orchestral music, or if you like any rock or perhaps bigger jazz bands, the KT88's would bring out the most there IMHO.

Hope that helps. Most important - Yes, they are very different and distinctive - listen and use your own judgement and take what you read here with a grain of salt. I think it is a good place to get some guideance and broad generalizations, but you're the only one who knows what you really prefer.

Marco
Ctran, thank you for the reply. Did you have to change amps or you could switch 300B for KT-88 in the same amp?
Sorry if it's a fullish question, but I'm new to this tube thing, and I do love musicality - my main music pleasures:
jazz, vocals, classical.
300B may be expensive, but they last much much longer than KT-88. It depends on your taste. If you like dynamic and power go for KT-88. If you want musicality and refinement go for 300B. I had 300B based system for 3 yrs then change to KT-88. After 2 short months, I decided to change back to 300B...