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Togil
13-12-2008, 15:12
Just wondered what the difference from the designer's point of view was between these two valves, especially for SETs

I detect a slight preference for KT88 on this forum. The 300B is a genuine triode, the KT 88 was never meant to be ( so someone told me ! )

Marco
13-12-2008, 17:52
That's a good question, Hans, and one for Anthony or one of our other resident valve amplifier designers to answer properly. I like KT88s because to my ears, when implemented correctly, they just sound so 'alive', 'real', and 'un-valvey'. They produce the closest sound, in my opinion, to the best transistors but without their sonic pitfalls. SET fans (in general) hate them, but for anyone attempting the transition from solid-state to valves and seeking the smoothest ride, a KT-88 based amp is the one I would recommend.

Regarding the 300B, all I would say from my experience so far is that I rate it very highly as a valve, but much more so in push-pull mode than when used in an SET amp. For example, the World Designs 300B P/P which Greg uses is one of the best valve amps I've heard; conversely some of the low-powered SET amps I've heard using the same valve have been poor – therefore the conclusion? As always, it's all in the implementation!

Marco.

anthonyTD
13-12-2008, 18:58
That's a good question, Hans, and one for Anthony or one of our other resident valve amplifier designers to answer properly. I like KT88s because to my ears, when implemented correctly, they just sound so 'alive', 'real', and 'un-valvey'. They produce the closest sound, in my opinion, to the best transistors but without their sonic pitfalls. SET fans (in general) hate them, but for anyone attempting the transition from solid-state to valves and seeking the smoothest ride, a KT-88 based amp is the one I would recommend.

Regarding the 300B, all I would say from my experience so far is that I rate it very highly as a valve, but much more so in push-pull mode than when used in an SET amp. For example, the World Designs 300B P/P which Greg uses is one of the best valve amps I've heard; conversely some of the low-powered SET amps I've heard using the same valve have been poor – therefore the conclusion? As always, it's all in the implementation!

Marco.

hi hans,
the 300B is indeed a good valve when implemented properly, and in the right system, it can perform outstandingly well. it is a true triode. unfortunately some of the circuits its expected to work in leave a lot to be desired. the main reasons the KT88 valve in my opinion is so well used and loved by many audiophiles and musicians worldwide is because of its sonic qualities and also its power capabilities, for me this makes it a much more versatile valve than any triode, especially when used as it was intended as a TETRODE ! a lot of people make the mistake of using this valve as a triode, sure it will work, but its true potential is wasted in this configuration. KT66 is another story as when connected as a triode it can indeed be considered as a true triode!
most people on here will know that i am biased on this subject to a point, but my bias is not without merit, the reason the KT88 won my heart is simple, when implemented properly, its over-all performance is very difficult to better, sure there are valves that will do some things better, but when it comes down to consistency across the board on the things that matter, ie, linearity, distortion factors, and sheer power output, the KT88 is a hard act to follow.
regards,anthony,TD... :)

Togil
13-12-2008, 21:37
Thanks Anthony.
So do you use KT 88s in your Soul amplifiers in tetrode mode ?
And for the higher-powered ones in parallel configuration ?

Marco
13-12-2008, 21:40
the main reasons the KT88 valve in my opinion is so well used and loved by many audiophiles and musicians worldwide is because of its sonic qualities and also its power capabilities, for me this makes it a much more versatile valve than any triode, especially when used as it was intended as a TETRODE ! a lot of people make the mistake of using this valve as a triode, sure it will work, but its true potential is wasted in this configuration.


Most interesting, Anthony! That may explain why when I've heard it used as a triode the amp it's been used in has sounded soft and lifeless, lacking dynamics, and reproduces nothing like what I would describe as the sound of real music.

Marco.

anthonyTD
13-12-2008, 22:33
Thanks Anthony.
So do you use KT 88s in your Soul amplifiers in tetrode mode ?
And for the higher-powered ones in parallel configuration ?

hi hans,
yes, i use them in tetrode mode in the soul amps, and each valve has its own control circuitry, therefore each valve and its circuitry is classed as one module, and its parameters are locked and cannot deviate from its intended settings throughout the life of the valve. each valve module is contained on its own circuit board, therefore the 15 watt stereo versions have two power modules, one in each channel, the 30watt mono versions have two modules in parallel, and the 60 watt mono versions have four modules in parallel. the soul amplifiers are hybrids, single ended, and directly coupled throughout, so not really fair to put them in the same category as traditional valve amps, they also have multiple boards buried in the chassis where the rest of the power supply circuitry is contained, this was done to keep all the noisy stuff well away from the signal circuitry. they originally had a flat frequency range from 7hz to over 220k but later versions were restricted to around 120kz...
hope this helps.
anthony,TD...

anthonyTD
13-12-2008, 23:11
Most interesting, Anthony! That may explain why when I've heard it used as a triode the amp it's been used in has sounded soft and lifeless, lacking dynamics, and reproduces nothing like what I would describe as the sound of real music.

Marco.

quite possibly,
sadly one of the reasons a lot of amplifiers use tetrodes, and pentodes in triode mode is because the circuitry is so bad, and triode mode simply masks this somewhat, [ as you have already witnessed for yourself] and therefore presents an easier presentation on the year from an amp that might otherwise be in some cases un-listenable... but by doing this as you have clearly pointed out, the sonics in most cases have lost their definition, and the sound can be very tame, and lack lustre.
anyone reading this will by now assume that i am down on triodes, so lets clear that up, in fact the opposite is closer to the truth, an amp designed as a triode amp from ground up can, and will if designed properly give you all of the good properties that a good tetrode/pentode amp can, and in some case even more, so guys lets make this clear, its the circuit design i am condemning, and not the valve.
anthony,TD...

SPS
14-12-2008, 16:47
i would agree with anthony, i am in the Se camp, due to the speakers i use gives me that option.. and i prefer the what the extra simplicity can do the sound.. but its not that easy to get the sound right

some of the worst SE amps i have heard have used the 300b,
and some of the best ones i've heard have used it too
the implementation is important.. but choosing good valves is critical,
old stock valves give much improved sound and tighten the bass.. but because they are so popular. the prices reflect this, old stock kt88 are in comparison cheap..

so...
a good push pull kt88 is a good introduction into valves, when used with more 'normal' speakers,
but as marco has come to realise, there are further gains to be had with higher effeciency speakers that match well
its a slippery slope

steve

Togil
14-12-2008, 17:04
SE :
There are those ( cf the crazy but entertaining Goodsoundclub ) who say that SE only sounds good on horns, even if you have higher power

Anthony would you agree with that or do your Soul amplifiers work on low-efficiency speakers ( eg Quads ) ?

Certainly the Kronzilla ( which uses what I believe is essentially a large triple 300B type valve ) sounded terrible to me on the dynamic speakers in Munich this year.

Mr. Kang-Su Park's ( another genius like Anthony ) 300B Allnic amps sounded excellent in the various systems I heard them in in Korea this summer, but they were mainly horns.

anthonyTD
14-12-2008, 20:12
SE :
There are those ( cf the crazy but entertaining Goodsoundclub ) who say that SE only sounds good on horns, even if you have higher power


Anthony would you agree with that or do your Soul amplifiers work on low-efficiency speakers ( eg Quads ) ?

Certainly the Kronzilla ( which uses what I believe is essentially a large triple 300B type valve ) sounded terrible to me on the dynamic speakers in Munich this year.

Mr. Kang-Su Park's ( another genius like Anthony ) 300B Allnic amps sounded excellent in the various systems I heard them in in Korea this summer, but they were mainly horns.

hi hans,
good question, first of all many people that know me or have had experience of a product i have been associated with will almost definitely know that i only build products that work in what i describe as "the real world" that means any power amplifier i build or have built must be capable of working satisfactory with for eg, speakers from low eighties to well over a hundred db, i do however insist that valve amplifiers need as flat an impedance versus frequency range as possible, this i feel is much more important as far as valve amps are concerned.
i have customers who have used the soul series of amplifiers with great success on a wide range of speakers, ranging from tannoys through to quad 63's and on to wilson grand slams.
i hope this helps.
regards,anthony,TD...:)

Marco
15-12-2008, 00:02
so...
a good push pull kt88 is a good introduction into valves, when used with more 'normal' speakers,
but as marco has come to realise, there are further gains to be had with higher effeciency speakers that match well
its a slippery slope


Indeed, Steve, but as you know having heard it, the KT88-based Copper amp I use works even better with some quality high-efficiency speakers on the end than it does with 'normal' speakers...

This proves that when a valve amplifier design is 'right' to start with it doesn't matter what speakers are used - the results are still fantastic! ;)

It brings us neatly back to implementation and how significant it is in the overall scheme of things, because that wouldn't necessarily be the case with 'normal' or 'bog standard' KT88 amps and high efficiency speakers... So one must always remember that the key to success is not focussing on any one aspect of valve amplifier design but: implementation, IMPLEMENTATION, IMPLEMENTATION! :)

Marco.

SPS
15-12-2008, 20:01
Indeed, Steve, but as you know having heard it, the KT88-based Copper amp I use works even better with some quality high-efficiency speakers on the end than it does with 'normal' speakers...

This proves that when a valve amplifier design is 'right' to start with it doesn't matter what speakers are used - the results are still fantastic! ;)

It brings us neatly back to implementation and how significant it is in the overall scheme of things, because that wouldn't necessarily be the case with 'normal' or 'bog standard' KT88 amps and high efficiency speakers... So one must always remember that the key to success is not focussing on any one aspect of valve amplifier design but: implementation, IMPLEMENTATION, IMPLEMENTATION! :)

Marco.

Spot on Marco.. that was my point really.. there are good and bad in everything, and implementation and selection the right components for a task is key... we could be talking about the way an amp is made... or the speaker/ amp / room combinatation.. or any thing else come to think about it..

Another point is that if one gets into valves and one is then lucky enough to get exposure to what good hi eff speakers can do.... it can change your perception of hi fi...

there are many good amps about..
more depends on your budget (and diy skills....if your brave)

what did you think to those mullard valves i left you with?

steve

Marco
15-12-2008, 20:32
Indeed so, Steve!


what did you think to those mullard valves i left you with?


They were Osram, and I like them! PM me with the price (bearing in mind my special discount ;)) and I'll sort it out :)

Marco.

NRG
15-12-2008, 21:35
Just wondered what the difference from the designer's point of view was between these two valves, especially for SETs

I detect a slight preference for KT88 on this forum. The 300B is a genuine triode, the KT 88 was never meant to be ( so someone told me ! )

The Beam Tetrodes or Kinkless Triodes where designed for audio from the outset IE low third harmonic and very low higher order harmonics (5th) all other valves where designed with something else in mind. I like the 300B, many of the SET guys don't but in a PP configuration they work well given a good cct like the original WAD 300B design...where many ccts fall down is in the driver stage, triodes have a lower input impedance and demand more from the driver stage IE large enough voltage swing. The design of the driver stage becomes more critical than the stage for the KT.

Also, the 300B power o/p is generally lower than that of the KT, the 300B grid would have to be driven positive to get any where near (this is where the likes of the 811 etc score as they are designed to be driven into class A2) and it's not really designed for that.

Another consideration is feedback, the 300B has a natural low output impedance without feedback and therefore its damping factor is relatively low, making it usable in zero feedback designs. Zero or low feedback makes for a very open and natural sound, many like this type of presentation.

The KT on the other hand can also be used without feedback but the o/p impedance is really too high like this so either local or global feedback is used to lower it. Adding feedback though alters the transfer characteristic of the amplifier and given a highly reactive 'speaker load the amplifier response can start to take on the same shape of the 'speaker...but feedback tightens the lower registers and narrows the sound stage, many prefer this type of presentation.

A mainly resistive and efficient 'speaker tends not to highlight these differences but use a high;y reactive 'speaker with low efficiency and the differences between topologies is very marked.

anthonyTD
15-12-2008, 21:47
The Beam Tetrodes or Kinkless Triodes where designed for audio from the outset IE low third harmonic and very low higher order harmonics (5th) all other valves where designed with something else in mind. I like the 300B, many of the SET guys don't but in a PP configuration they work well given a good cct like the original WAD 300B design...where many ccts fall down is in the driver stage, triodes have a lower input impedance and demand more from the driver stage IE large enough voltage swing. The design of the driver stage becomes more critical than the stage for the KT.

Also, the 300B power o/p is generally lower than that of the KT, the 300B grid would have to be driven positive to get any where near (this is where the likes of the 811 etc score as they are designed to be driven into class A2) and it's not really designed for that.

Another consideration is feedback, the 300B has a natural low output impedance without feedback and therefore its damping factor is relatively low, making it usable in zero feedback designs. Zero or low feedback makes for a very open and natural sound, many like this type of presentation.

The KT on the other hand can also be used without feedback but the o/p impedance is really too high like this so either local or global feedback is used to lower it. Adding feedback though alters the transfer characteristic of the amplifier and given a highly reactive 'speaker load the amplifier response can start to take on the same shape of the 'speaker...but feedback tightens the lower registers and narrows the sound stage, many prefer this type of presentation.

A mainly resistive and efficient 'speaker tends not to highlight these differences but use a high;y reactive 'speaker with low efficiency and the differences between topologies is very marked.

i agree,
this is why it is very important when using KT88's with low global feedback to use speakers with a very consistent impedence versus frequency characteristic, ie no serious dips or troughs in their impedence curves over as wide a frequency range as posible,[no over complicated cross-overs allowed to acomplish this either] or, as you have quite rightly pointed out, the amplifier will indeed be dictated to by the characteristics of the speaker load.
anthony,TD...

Ali Tait
15-12-2008, 22:20
I think the main reason some think 300b amps are poor is that it is a very difficult valve to drive properly.When this is done it's one of the best out there,as Steve said.I still remember his lovely vintage 300a's in Nick's amp at a previous fest.Sublime...

anthonyTD
15-12-2008, 22:25
I think the main reason some think 300b amps are poor is that it is a very difficult valve to drive properly.When this is done it's one of the best out there,as Steve said.I still remember his lovely vintage 300a's in Nick's amp at a previous fest.Sublime...

agreed ali,
potential 300b amp users,repeat after me,YOU CANNOT DRIVE THE 300B WITH AN ECC83!!!
:lolsign:

Togil
16-12-2008, 07:31
Mr. Park the Korean 300B designer also told me he thought the 845 usually had bad driver designs including the Nagra VPA

Ali Tait
16-12-2008, 20:15
The 845 is even harder to drive than the 300b!

Dr. Flicker
27-06-2009, 22:57
some of the worst SE amps i have heard have used the 300b,
and some of the best ones i've heard have used it too

Just goes to show you that people put far too much importance on the tube, as if a pair of WE 300B's will magically make every other inadequacy in the amp somehow disappear. Everything before and after it has so much effect on what the amp will sound like.

I've had two different models of 300B amps (from the same manufacturer), and the difference was night and day (the much better one was only marginally more expensive than the other one). Good design is key, and not easily accomplished, even by the most seasoned tube amp designers. There's simply too much voo doo alchemy in audio to guarantee a great sounding amp on paper.

Also, I think the 300B has such a cult reputation (not entirely undeserved mind you) and track record that it simply attracts fans because of it's "holy grail" status. They can also be stupidly expensive, and people do associate price with quality and desirability.

The 300B's do have one silly drawback (which doesn't bother me of course), but sort of seems like your getting short-changed in the "tubes are cool" game....they don't have much of a "glow" like most other tubes.

I am a current 300B fan though, and if you love that SET midrange magic, then the 300B will maximize the role of the tube in that regard very well. But the sound does not begin and end with the tube, and I would not hesitate to buy an amp with different tubes if the results were better.

Giant Haystacks
28-06-2009, 13:37
talking purely about these 2 valves there are so many amplifiers that use these 2 particular output valves in there amplifiers ,that means there are so many people looking for the same n.o.s. valve that you want.
there are so many opinions on what valve gives the best sound , and talking purely about output valves ,mine is i think the finest sound lies within( 2a3,6a3,px4,vt52,) i also think the 211 is an option and it was an actual audio valve, i have tryed 300b and type45 ,not tryed type10,type 50,
there are many many senarios that need to be discussed as we all want the same result and i am trying very hard but i know i am heading in the right direction
there are so many other parts to be discussed eg. the engineer, power output,parts used , the senarios never end

Clive
28-06-2009, 14:03
I'm getting the impression that there is an especially good sounding topology that works well for those who like SE and PP but hanker after the best of both worlds. This is:

- single ended driver valve
- interstage transformer
- PP output stage (pick you fave valve)

This is what the WAD 300B PP clone uses and others amps (eg 45) PP seem to be especially well liked too. Should be great with KT88 too. I need to get around to building such an amp.

Giant Haystacks
28-06-2009, 15:58
everyone has to make up there own minds but a lot of people work it out this valve that transformer there is so much to read into this,i have one such friend who has spent so much on his diy 300b single ended but it does not work it is supposed to on paper ,

SPS
28-06-2009, 19:55
Just goes to show you that people put far too much importance on the tube, as if a pair of WE 300B's will magically make every other inadequacy in the amp somehow disappear. Everything before and after it has so much effect on what the amp will sound like.

.

thats a very interesting view point..

the WE does not have a wobbly bass or mid range bloom, its a well balanced (as in good though the freq range) valve.. unlike every new production 300b valve i've heard...
yes you need a good amp to get the best from 300b valves, thats the same what ever valve you use..

recently swapping out a pair of modern, very expensive kr's and putting the we's in place, the amp's bass was suddenly tight and deeper, mids where more detailed and a good top end... plus that sweet lifelike sound came forth

thats why they are so sought after...
and some would like to think old ones are not much better than new production?

people spend a fortune on power supplies to get try and get the valve to sound right.. which is not really possible to achieve with new production valves, whilst the old valves will sound good on quite a basic supply...


The 300B's do have one silly drawback (which doesn't bother me of course), but sort of seems like your getting short-changed in the "tubes are cool" game....they don't have much of a "glow" like most other tubes.

I am a current 300B fan though, and if you love that SET midrange magic, then the 300B will maximize the role of the tube in that regard very well. But the sound does not begin and end with the tube, and I would not hesitate to buy an amp with different tubes if the results were better

My guess is if you think sets only do midrange magic you've not really heard what a good one can do ...

steve

Giant Haystacks
29-06-2009, 01:22
i think dr flicker was using a western electric 300b as an example that the finest valve will not make an amp that the engineering is not in work
dalek supreme tryed new 300b globe mesh plate in chinese mono blocks and said they did not even deserve to be on the same planet,
i have heard western electric300b cinema amps there are a set of these in ireland very fine but i would like to hear much more of a listen to these
the problem with 300b is value for money how good are replacements ,maybe the other cinema valve the type 50 which there are n.o.s around or a px25,or the engineer who built my amplification goes on about the svetlana sv811-10 the debate goes on

TheMooN
29-06-2009, 06:44
Greetings Folks :wave:

The designer of the interesting Vacume State dpa-300B would also appear to be going down a less than conventional route , the 500K PDF file for details.

http://www.vacuumstate.com/index.tpl?rubrik=11&lang=2&a=%253BvK%25E8v%25E3i%252525&b=733952.2842919769

Haselsh1
29-06-2009, 15:58
One of the best sounding systems I have ever heard or owned was a WAD 300B PP amplifier with Audio Note AZ-2 speakers. My only issue was that the amplifier hummed like a bugger through the speakers and the humbuckers couldn't reduce it. On a positive note, this system had more air and atmosphere than I have ever heard since.

I do intend to re-invent the speakers when funds allow but would not go anywhere near another WAD 300B PP amplifier...!

NRG
29-06-2009, 16:33
Then you would be missing out big time. I use a WAD 300B PP as my main amp...had it for 15 years and I've tried to replace it many times but I keep coming back to it.

The hum issues are caused by poor / sloppy layout of the earth returns, many builders didn't follow the instructions correctly and found the hum too much with sensitive 'speakers...even some of the ones built by WAD themselves where not correctly laid out...more recently Richard over on the WD board reworked the returns and came up with a new layout that managed to get the hum even lower...so never say never...;)

NRG
29-06-2009, 16:37
Regarding the WE 300B this is one of my least favorite versions of the valve, to me is sounds congested and closed in when compared to some of the alternatives like the TJ mesh plates. A good all rounder is the Electro-Harmonix Gold Grid 300B. It strikes a good balance being a good performer but at a more reasonable cost than the WE or TJ

Haselsh1
29-06-2009, 20:34
Then you would be missing out big time. I use a WAD 300B PP as my main amp...had it for 15 years and I've tried to replace it many times but I keep coming back to it.

The hum issues are caused by poor / sloppy layout of the earth returns, many builders didn't follow the instructions correctly and found the hum too much with sensitive 'speakers...even some of the ones built by WAD themselves where not correctly laid out...more recently Richard over on the WD board reworked the returns and came up with a new layout that managed to get the hum even lower...so never say never...;)


Mine was built by Nick Lucas at WAD...

NRG
29-06-2009, 22:09
Mine was built by Nick Lucas at WAD...

So was the second one I bought.....which I then sold on to Richard over on the WD forum ;) It had other problems as well...

Dr. Flicker
30-06-2009, 04:19
My guess is if you think sets only do midrange magic you've not really heard what a good one can do ...

Hmmm....I don't recall saying or implying that they only do anything.

With the right speakers, SET's can have great sounding frequency extension. But they certainly aren't known in general for being the end-all-be-all of bass & treble, and I don't think it's all a case of mass hysteria. Audio is about compromises, and SET has them like anything else.

But what a 300B in a great SET amp does to voices & strings is so unlike anything else, how could you not single it out as its greatest attribute? (And that's without the luxury of being able to strap on a pair of vintage Western Electrics to my amp).

Giant Haystacks
30-06-2009, 14:17
a single ended bass is the finest bass of all and this is the hugest part of a single ended sound but very few valves can convey it properly ,
i think my own personal hifi reference is marching brass ,a sense of movement ,and energetic bass,
so finest single ended is the nearest i have come ,the 300b is so nice it is a beautiful sound but it is to kind
i have heard spectacular sound bangs and crashes and bass that would put the window out but i think music should not be a tiring formula 1 experience it should be more like a moth to the blue light
a good test for an amplifier is big altec-tannoys how the valve gets on controlling the big 15 inch cones
on the subject of triode push pull the probably most highly rated amp of the valve era was a brook 2a3 which was push pull these fetch huge prices now

Dr. Flicker
02-07-2009, 17:57
a single ended bass is the finest bass of all and this is the hugest part of a single ended sound but very few valves can convey it properly

I've heard plenty of valve amps that gave great low end in certain speaker combos, but I would not say the "best", and I would not say it is what it does best.

The best low frequency reproduction I ever heard (in fact, the best sound reproduction I've ever heard to date...period), was over 20 years ago downstairs at the old Brack Electronics, demo'ing the Scintilla's with Krell KSA 100 & Classe DR3 VHC (with a Oracle Delphi as the source).

We're talking reasonably flat responses down to the 20hz regions....very fast and tight. Needless to say, it was a religious experience.

Now, a SET simply could not drive these speakers anyway (1 ohm load, dipping to .6 ohms, and an efficiency rating of 79db), and neither could a PP.

A full range ribbon speaker (like the Diva) at a 4 ohm load could be driven by a PP valve amp, but still, not a SET.

SET simply has limitations in terms of speakers, and at the end of the day, it's the speakers that must move the air. I've heard SET's do amazing things with low frequencies (very fast & airy) on custom horns, but still, I'd say it wasn't the finest low frequency reproduction I've ever heard, and the mid-range was still the high-lite anyway.

If you want it all IMHO, older high current, single-ended, pure class A solid state amps (like the Classe Audio DR3 VHC) driving huge panel speakers is the best combination of SS & tube sound. Some day I hope to have this combination when space & budget allow.


I'd love to hear what amp/speaker combos you think convey the low frequency reproduction you are speaking of.


Cheers.

Marco
02-07-2009, 18:37
Very well reasoned posts, Dr Flicker. I am in complete agreement :)

What's your first name and where are you from?

Marco.

Giant Haystacks
03-07-2009, 02:25
hi i have a small pre power called ecofan from new zealand which dalek supreme done a story on in strokes of genius , this with a klipsch horn is good
maybe my views are a little from mainstream and anyway tread says difference 300b/kt88

Dr. Flicker
03-07-2009, 05:19
Well, you either love or hate the KHorns.

They certainly are efficient and dynamic, but simply too coloured and unrefined for my taste. But when you just need to blast some AC/DC (and let's face it...we all do from time to time), you can't beat them.

SPS
03-07-2009, 08:44
maybe my views are a little from mainstream and anyway thread says difference 300b/kt88

yes... i think ,most of the posts are off topic, the only 'facts' are is there are good and bad, in all amps, regardless of the valves used

and both valves can be very good at what they do.. and maybe that is just opinion?

anthonyTD
03-07-2009, 10:32
yes... i think ,most of the posts are off topic, the only 'facts' are is there are good and bad, in all amps, regardless of the valves used

and both valves can be very good at what they do.. and maybe that is just opinion?
so true!!!
A...

Marco
03-07-2009, 10:33
Hi Dr Flicker,

May I draw your attention to this, which you seem to have missed:


What's your first name and where are you from?


We like to be friendly by being on first name terms here, and also that we know basically where each other are from.

So come on, don't be shy! :)

Marco.

Dr. Flicker
03-07-2009, 15:07
Hi Dr Flicker,

May I draw your attention to this, which you seem to have missed:

Quote:
What's your first name and where are you from?


Oh...I didn't miss it...I'm not blind, shy nor unfriendly. Being an admin, I just assumed you checked the "welcome" section, where following forum instructions, I made my first post giving my name, location, equipment, etc.

But it's Kevin...from Toronto.

anthonyTD
03-07-2009, 16:20
Oh...I didn't miss it...I'm not blind, shy nor unfriendly. Being an admin, I just assumed you checked the "welcome" section, where following forum instructions, I made my first post giving my name, location, equipment, etc.

But it's Kevin...from Toronto.
thats told him!!!:lol:
welcome kevin.
anthony,TD...

Marco
03-07-2009, 18:07
LOL. Very good, Kevin! :lol:

Do you expect me to memorise everyone's name or something? ;)

That's why it needs to go into your signature so that it appears under all your posts. So please add "Kevin" to that, and "Toronto" to your profile.

Cheers! :cool:

Marco.

Dr. Flicker
04-07-2009, 03:08
Do you expect me to memorise everyone's name or something?

Uh....yea?

But what's the point of being Dr. Flicker, anonymous internet chat forum audio fool, if you know my real name (but don't really unless it accompanies every post I make)?


Ok...so let's get back to 300B vs KT88.

The 300B is a triode and the KT88 is a pentode

A pentode can be run as a triode, but a triode cannot be run as a pentode

Triodes are generally used for single ended and pentodes are generally used for push-pull, although there's nothing stopping you from doing either with either tube. Either can also be used in parallel single ended or parallel push pull.

The KT88 run as a single ended triode will give you 5 watts pure class A, and the 300B run as a single ended triode will give you about 7 1/2 - 9 watts pure class A. I think most people would agree the 300B sounds better, as well as having the power advantage.

You can run the KT88 as a single-ended pentode for about 15 watts of pure class A, but again, not going to sound like the 300B. As a matter of fact, it is debatable whether running a pentode in triode mode is even a great idea at all.

You can run the 300B and KT88 in push pull, and the resulting advantage is more power, but now you lose any advantages of single ended and pure class A sound (if you indeed consider those advantages in the first place). More output tubes also mean more cost.

A lot of people believe that the 300B does its "magic" in SET configuration, and using it any other way takes away from that. The KT88 can be used quite successfully in many ways, as it doesn't seem (to me anyway) to be that special as a SET, making it quite equally adaptable for more power, and hence able to drive many types of speakers.

The 300B sounds best as a SET, but suffers the problem of low power output, making it limited in speaker choice because of efficiency and loads. But, this problem can be overcome by simply being very careful with speaker choice. The push pull amps solve the problem of low power, but cannot sound like a SET.

What this boils down to I guess is not which tube...but SET vs push pull. For SET, my vote goes to the 300B. For push pull...not sure...let's call it a tie?