Sophia 300B vs Jeff Korneff 45 Amp

Anyone have anyway of describing the sonic differences between Sophia Electric 9101 300B monoblock single ended amps and a Jeff Korneff 45 SET amp? (Let's assume the JK 45s have enough power to drive the speakers at around 100dB efficiency.) Thanks

- a related question would be which tubes would be preferred, Sophia, EML, solid plates or mesh plates, etc
My experience is that power kills. The 45 or the 50 tube is the best output tube for SETs. You just have to have the right speaker. High efficiency,low driver count,benign impedance and the 45 will walk the dog!
Jeff K build quality's far higher. 45 will limit what you can drive. But for your use a JK 45 Is the better sounding choice. Still why Sophia 300b? Far better 300b amps about.
Hi Philefreak, Thanks - When I look at the Cornwall II I think I count 3 drivers - is that going to be an issue with a 45 amp? (The specs say it's 8 ohms, but I'm not sure if about how that applies across the frequency spectrum.) Thx again
Hi Johnk, Thanks. I'm thinking about Cornwall II speakers; I thought i might need the power, including the headroom, of a 300B for the Cornwalls (but if I don't need the power, I could move to a 2A# or a 45 - depending on what is needed to drive the speakers. In general, I'm hearing/reading that the 45 is the ticket if you don't need more power; if you do then the 2A3 is up to bat; if that doesn't do it, then the 300B is the next choice. If this is the wrong approach, I'm open to a better approach. Also, to answer your question, the Sophia Mesh Plates get pretty good reviews; in fact, some people who like the Jeff Korneff amp (almost everyone seems to agree it's a good amp) think the Sophia 45 Mesh Plates are superior to the well regarded EML 45 tubes; so I figured if I need a 300B (which is still TBD) and Sophia makes good tubes, why not a Sophia 300B amp? But if you have amps you like better for the same or less price, either among the 45s, or the 300Bs, (or even the 2A3s), I'm open to suggestions. Right now, the Cornwalls are more likely to be the constant and the amp and tubes are open to discussion. I'm still trying to figure out what sonic differences one could expect to hear between the Sophia 300B amp (or another comparably priced 300B amp) and the Jeff Korneff 45 amp - assuming the 45 power is sufficient (which it might or might not be). Thanks for any advice.
By now I suspect that you've made your decision to go w/the 300b or the 45's.

In general, what I have read in many forums and by talking to very knowledgeable people, 45s are the holy grail of the SET's.

I spent most of my audio life in SSland, until I heard tubes. My first tube amp was KT88 based, then I went to 845's because I wanted SET but my speakers were only 90 db efficient.

Yet, I still craved midrange magic and was introduced to BLHs made by johnk in this forum. Ahhh, that single driver and horn combo @ 98db efficiency is hard to beat. Yet, I wanted more and figured that the BLH speakers could deliver. johnk shared w/me that a number of his BLH users were employing Jeff Korneff's 45 SET amp with great success.

Whithout hesitation I plunged in and replaced my 845 amp with a Korneff 45 SEi integrated amp. Best audio decision I ever made. I'll put it in my will to be buried w/this amp.
Very liquid and detailed. In a word, refined. If you are looking for power, with the right speakers 2 watts can make the walls rattle. I am using mine in a room that is 20 x 30 and have more than plenty sound. Aside from the magical sound, dealing with Jeff Korneff is a distinctive pleasure. I dealt with the folks at Sofia and their practices are worlds apart.
I can't tell you how the Korneff 45 compares to the 300b since I never did that one on one comparison. All I can tell you is that you can't go wrong with the Korneff, and if you need service, your manufacturer is in Pittsburgh which is a lot closer than China.
This all depends on what you want sonically. I am a convert to the 45 tube (EML mesh in flavor). After trying a hand full of well received 300b amps, and if you can use a small 2watt amp, I think ultimately the 45 is the finest I have heard.

There is the hybrid Tom Evans Linear A or B which is a powerful SET that I feel is very close to a well done 45 amp in its transparency and naturalness but has lots of power.

After having a 45 then going back to a 300b, I found the 300b to be course, slightly unresolved and less natural in comparison. There is something about the bloated nature of the 300b which is fun for a while, but I found the 45 removed thoughts of hifi. Bare in mind my speakers are 109db/watt sensitive, but I think if you have 100db or so speakers you will be fine with the 45.
>>10-01-10: Chadeffect
There is the hybrid Tom Evans Linear A or B which is a powerful SET......<<


Neither amp is a true SET.

Dealer disclaimer
Hi audiofeil,

I was under the impression the Tome Evans Linear was a single ended amp. In fact I would go as far as saying he said it himself to me himself on the phone. But I will not argue the point and I bow to your knowledge of such things. I have no axe to grind.

The Tom Evans is still one of the finer amps I have had. I doubt many would dislike it apart from its bread bin appearance. It has the noise floor and speed of an ICE power amp, but with harmonic textures left in tact. I believe there is a special edition finish which is better looking if that matters to you.

I can say my 45 amp is an SET ;)
The 45 is one of the best sounding SET tubes. It is partially because the tube is very linear and possibly because it is much easier to build wide-bandwidth output transformers for low-power SET.

A 300B - almost any - with some somewhat thicker, slower, and less extended than a good 45. And the Korneff amp is one of the very best. I have not heard better. I prefer it ultimately to the Yamamoto.

This may not be quite true for extremely expensive 300B SET amps. Certainly you will need to spend much more money to get the transparency, speed, and extension the 45 will give you.

However, while a 45 will play your speakers quite well, at loud volumes it will suffer dynamically in comparison.

Still, I'd go with the 45. I've had K-horns and Fortes.
By definition an SET uses one output tube i.e. 2A3, 45, 50, 300B, etc. per channel.

The Linear A is a single ended, Class A, ultralinear stereo amp. It employs 4 tubes per channel.

Perhaps you misunderstood what Tom was saying.

Dealer disclaimer
Hi Audiofeil,

thanks for clearing it up. It is quite possible I misunderstood what Tom was saying. But what I did take from the conversation with him was the way the tubes are implemented was quite novel. A nice chap and fabulous amp.

To get back on message I would agree with Paulfolbrecht. I have tried and heard some very expensive 300B amps and I would still go as far to say that a good 45 prevails in terms of naturalness and extension. I have a modded Yamamoto A08s with EML tubes, and I spent time with Welbourne Labs star chief.

With a 300B (and I have had the 300B XLS in KR amps along with the usual 300B Audio note amps etc) my Trios demonstrated amazing and impressive dynamic contrast and weight, but somehow it always brought attention to itself. I found that 300B thickness masked important information.

The 45 amps I have tried just seemed to get out of the way and still had enough contrast and weight with superior PRAT. Maybe not quite as pumped up. This will always be system dependent and down to your personal taste. Again ultimately either path you choose will be fine and hopefully you will be listening to music not your hifi. Just make sure you get some good modern tubes whichever way you go.
I think you've characterized the 300B accurately. It's a wonderful tube if mid-range and warmth is your deal.

Personally, and provided the speaker is amplifier friendly, I prefer the 45, 50, PX-25, and 2A3 in that order.

Bill, a minor point, but it is not true that a SET "by definition uses one output tube per channel". Single-ended-triode: single-ended topology and triode output devices. No assumption is implied on the number of output devices. A parallel output triode amp using single-ended topology is SET. In other words a parallel SET is SET.
A lot will depend on your personal tastes. I currently own 45,2A3,300B and GM70 SET amps and enjoy each with different types of music. There are times I really want the warm, liquid tone of a 300B. Likewise, for large orchestral recordings the GM70 is hard to beat. The 45 is an excellent tube but the others have their magic as well. It would be tough for me to live with one SET across all musical genres.
Incorrect Paul

From Wikipedia:
>>A single-ended triode (SET) vacuum tube electronic amplifier uses a single triode to produce an output...............<<

The same or similiar definition can be found in a number of other reference documents.

A parallel output triode amp using single-ended topology is abbreviated as PSET; it is not a true SET

I hope that helps.
Wikipedia schmikipedia

Others do disagree, and if one looks at the name literally, there is nothing at all that speaks about number of output devices.

Single-ended, and triode. Period.

The thing is many people do not seem to understand what single-ended means - they assume it means "one output device" when, of course, it means nothing of the sort, and has nothing to do with the number of output devices.

I am sure you are aware of that.
Please elaborate, Bill. There's no need to make it a pissing contest.

Do you agree that the name - single-ended-triode - implies nothing about the number of output devices?
Well, Hi_hifi, it has been almost two and a half years since I posted on this thread, and I for one, would be curious to know which way did you go? 300b or 45's. If you read this please send a response.
By the way, I still have my Jeff Korneff 45SEi, which gets a lot of play time and I have not had a good reason to replace the National Unions 45 I got it with. Some day, $$ permitting, I'd love to try the EML mesh 45's.
A year and a half ago I replaced the Fostex drivers on my BLH's with Audio Nirvana's Super 8 Cast Frames. The dynamics, instrument separation and soundstage, especially for their meager price are unreal.
Happy listening.
Here is my thoughts I had a Sophia Electric 300B dual mono amp for about 4 years loved it, very lush and relaxing sound did most everything good. Now comparing it to my Korneff 45/EML solid plate tubes just can't be done!!!
There is a huge difference in sound between the two, the 45 is a much more linerer tube and just cleaner sounding in every aspect. Kinda night and day difference...
the only reason to get a 300b amp instead of a 45 amp is if you need the power. period. the 300b gives one a lot more choice in speakers, but imo the 45 is superior on all counts. (assuming comparable parts/build quality)
I have both a 300b audio note 8watt amp and a triode lab 4x45 tube parallel stereo dual mono 4watt amp. The 45 EML mesh tube is the clear winner.  It’s just more refined and elegant. Music just sounds natural and pleasant. I am using 94db single driver Omega super alnico moniter speakers.

The 300b sounds a little warmer, still very nice.  45 is more precise, detailed and holographic. 
Apart from considering the specific models of amps, there are many listeners who adore the sound of amps running 300b tubes.  I will agree that the midrange, in particular, of 300b amps sound saturated and beautiful.  The upper bass/lower midrange prominence also gives that tube an invitingly warm sound.  But, for others, like me, the sound is a bit too lush and warm and amps running that tube tend to sound a bit "polite" and lacking in punch and micro-dynamics.  

The 45 tube offers, in my opinion, a much more neutral tonal balance, and has a much tighter lower bass than the 300b, and is a more lively sounding tube (apart from the lack of power output).  I own a push-pull 45 amp and I like its sound a lot.  

I also own a parallel SET 2a3 amp (Audio note Kageki).  I've run NOS RCA, EML meshplates, and EML solid plate tubes in it.  I like the sound, but, 2a3s do tend to be on the lean side (thinner upper bass than the even the 45 tube).  My Kageki amps are on loan to a friend who will be converting them to running on 45's because we both like the sound of 45's.

I have heard Korneff amps and I liked the sound and the build quality of those amps.  I've heard Sofia amps that sounded okay (not bad, but not standouts), but I wasn't that thrilled with the construction.  But, overall, I think the choice comes down to personal preference and there is no way to say whether one will like one sound over the other.  I know a lot of people who will take a 300b amp over any other type of amp because of its glorious midrange, while I prefer the 45. 

I like many other tube types and topologies as well.  The amp I currently run in my system is a pushpull amp running 349 pentode tubes; I like this amp a lot.  I also like many amps that run 6L6/KT66 tubes.  The amp I think is the best I've ever heard is a custom-built output transformerless amp running a television sweep tube of some sort.