Is there a 300B type amp out there with some WATTS behind it?


I recently acquired a Feliks Audio Arioso 300B amp.  To put it simply, it is incredible.  I understand one way to tackle the issue of using SET amps is with high sensitivity speakers.  Is there a 300B or something that gives you that same sound out there with power so you have more speaker options?

audiovicker

Thanks for the reflection on your Feliks 300B! What speakers do you have it paired with? Some 300B amps are designed as parallel SET making about 15W using 4 300B tubes to create a bit more drive.  There are other SET designs like the LM805ia which use 300B tubes as drivers (805's for power stage) and produces 48W that may accomplish what you're asking about.

Is there a 300B or something that gives you that same sound out there with power so you have more speaker options?

In a strict sense no. Each tube type has their own distinctive sonic character. Can you find other satisfying alternatives? Yes. As mentioned above, an 805 output tube, there’s 845, 211, GM 70 , 6c33c etc. These all can be utilized for higher power SET amplifier.

All are quite capable of exquisite sound quality with good design and excellent implementation. I understand your happiness. The 300b is marvelous in proper circumstances. There are 300b push-pull amplifiers alternatives also.

Charles

 

There is a particular amount of power any given tube type can deliver.  If you push a tube harder to deliver more power, you compromise other aspects of performance, particularly the life of the tube.  Tube life can be dramatically longer if a tube is run conservatively but so few companies do so these days because they want to claim a high output.  
Every design choice has advantages and shortcomings.  Parallel SETs mean doubling output tubes, which means, a high expense when 300b’s are the tube type, and they can be quite hard on the tubes; there is a tendency for one tube in a parallel pair to quickly become weak while the other does the bulk of the work. Pushpull 300b amps will deliver much more power and will typically have a tighter, punchier sound than a SET amp, but the sound is different, and if you seek the SET sound, you have to accept lower output.

While not exactly the same sound as a 300b SET, there are some higher powered tube types, like 845s and 211, that sound quite good.  But, decent designs with these types of tubes can be expensive because the higher voltages involved.

If you want real power with the 300B tube there are a few alternatives but they are crazy $$$ both in terms of the gear and tube cost. For example Canary makes a pair of pushpull 300B monoblocks using 4 300Bs per block. Right there to retube those amps with any decent sounding 300B your looking at $3K or more just for the tubes. As pointed out above there are other avenues to explore and other triodes. Congrats on your new amp!

VAC made stereo amps with multiple pairs of push-pull 300B's about twenty years ago. I remember seeing them advertised on the back covers of Stereophile.

Musical Fidelity Made something called the 550K Supercharger.

These are mono amps that go between your amp and your speakers.

They use the signal from your amp and multiply it X number of times to "Supercharge" the SOUND of your (300B) amp (theoretically).

 

@dweller that is an interesting approach. I would love to hear if anyone has used it and what they think.

I use a 300B (Woo) headphone amp for my headphone system. Then Audio Research tube amp (in triode mode) for my main system where lots of power is required. Once I heard the 300B of my headphone system… I upgraded every part of my main system to achieve a similar sound… natural, musical, detailed. My all Audio Research system does that.

 

I would have a listen to the Audio Research VT80. It has a beautiful warm tube sound and power.

As mentioned above, there are 805 / 845 / 211/ GM70 etc big transmitter tubes that are capable to go into the tens of watts range. These big transmitting tubes have remarkably neutral sound, and they mostly take on the character of the driver tube.

So, if you want 300B sound with more watts, go for an amp with the tubes above, that uses the 300B to drive the power tube. You will get the 300B sound but with a lot more driving power.

Still, as above mentioned, at this point you would fare better upgrading the speakers than changing the amps. No power output can replace dynamics that comes from speaker sensitivity.

However, going for more sensitive speakers means BIGGER speakers, so your choice is down to available space.

Cheers;

Janos

 

 

try Decware for high-efficiency speakers that should pair well with your 300B. They also just released a 300B amp. Even made in USA! I have several of their products, and am not associated with them at all. Just a very happy customer.

@jasonbourne52   I have one, the VAC Renaissance 70/70 Signature, it's glorious. 65 WPC drives anything with in reason. 1-2 ohm taps, 2-4 and 4-8. It in Sarasota right now getting the Signature update.

 

 

I don’t sell this product. It is made in Sofia Bulgaria by Thrax Audio. I spent the summer of 2019 sitting in front of a pair of these amps at the Thrax facility. The specs on this amp are for real, maybe a little understated. This is the best 300b amp I have ever had the pleasure of enjoying!!! It will glue you to your seat. It uses six 300b tubes per amp.

 

Hello Audiovicker.  Do you understand that 9 watts is not an insugnificant amount of "power"?  90 watts is only 10db louder than 9 watts.  If you want to rattle the walls with sound, then the 300B amps are not for you. For most people, normal listening levels are under 5 watts, way under. Give the amp a try on whatever speakers you have and see if the pleasantness of tube amps comes through. If you are a hard rock fan, and want to listen at concert levels, solid state amps are cheaper watt for $$ wise and may better meet your needs. Have you priced 300B tubes? A pair of those can easily set you back for more $$ than a powerful class D super amp. Happy listening.

I've seen push/pull 300B amps with as much as 28 watts. But push/pull can never sound the same a SET due to the topology difference which results in different wave forms from the two different formats. Single ended amps are asymmetrical amplifiers in the sense that if you imagine a simple sine wave signal the single ended amp produces different wave forms for the top and bottom wave portions. The bottom half of the wave doesn't go as low as the top half goes up. This is inherent in SET topology for any parts. Push/pull is symmetrical.  The very high second harmonic distortion that makes SET amps so nice is a result of this anomaly.

But all audio electronics are different compromises. You need to learn which compromises are the ones you need to hear.

An alternative to 300Bs is the Audio Mirror 45w SET monos. Uses two 6C33C power tubes in parallel per channel. I love the sound, power tubes are inexpensive and it pushes my Egglestonworks floorstanders well. 

One more to consider that isn’t a 300B is the Margules I-240 integrated amplifier. While it employs a quad of EL34 to produce 25wpc, it is unlike any other EL34 amp I’ve ever heard. It delivers the golden bloom from the midbass to lower midrange and is slightly softer on the frequency extremes very similar to good 300B amps. And on its own, with no sub and speakers 87db and up it can fill a medium to large room with no problem. Margules has been getting some great attention in the press and in the national shows these past two years.

I am a Margules dealer, but have first hand experience owning 4-5 other very good 300B amps in the past.

If an integrated is not suitable, I will also be receiving the Margules U-280SC 30th Anniversary Limited Edition amps in a week or so and can report my findings once that unit breaks in. It uses. Quad of KT-88, so I expect a different sound signature, but I was blown away hearing them with Raidho at AXPONA last year.  I’m very excited for this amp to arrive. 

@audiovicker ,  I had a similar issue. My 300B wasn't cutting it and I have high efficiency speakers (about 100dB) in a good size room (16 wide, 24 long, 10' high). I tried push pull (Primaluna and Carver Crimson) to decent effect, yet I still missed that 300B magic. 

Atmasphere (Ralph Karsten) educated me on 300B topology. One of the issues is that although you get clean signal through the first few watts, you quickly move into its distortion profile. Maybe the first watt of that is harmonic goodness, but the point is we never really get 8 useful watts a side out of a 300B SET.

At any rate, in December I bought a Willsenton 800 805 tube version integrated.  This is about 45W a side, CLASS A SET.  The amp weighs 100lbs.  The stuff inside it is high quality.  The 805 tubes are driven by two 300Bs and the gain stage is 6SN7s.  I love this combination.  Reportedly, yet unconfirmed, the Willsenton is made in the same factory as Line Magnetic.  I have run across two people who have preferred the Willsenton 805 to the Line Magnetic--but most say they are very similar. I haven't heard the Line Magnetic 805 though. 

This amplifier has changed my outlook.  I'm not sure what loudspeakers you're running or how large your room is--yet 45 watts a side of Class A power is nothing to scoff at. Reviewers have driven speakers far less efficient than I have with the Willsenton.  

If you are in the Chicagoland area (or care to be in the winter months :) ), PM me and you can stop by and put the amp through its paces.  I have vinyl, SACD/CD, and Qobuz via Roon sources.  

Some folks say the Willsenton owners are making a statement with this, they're top of the line amplifier, and that their profit margins are too low on it.  That could lead to issues in the future. But, they have US authorized service. 

I ordered the amplifier, paid about $2850 with shipping and customs; it was at my door in 5-7 days of purchase.  You will need 2 people to lift the beast. Nothing about it feels cheap and it exudes quality (ok maybe the tube cage is a little basic). Highly, highly recommended.  I could've saved a lot of money playing around with other amps had I bought a Line Magnetic or this previously. 

Final note: If you have a smaller to medium room it can heat the room after 3 hours of playtime.  There's no way I'll be using it in the summer months so that's a huge downside for me. Still worth it though. 

@jbhiller 

A fair point with regard to the 300b SET amplifier . I will add however that all 300b SET aren’t created equally for sure. Where some will run out of steam, others continue to cruise along. Three key design factors.

1 Robustness of the power supply.

2 Quality of the output transformer 

3 Driver tube selection and implementation of this section.

Agree with you that if a 300b SET just isn’t suitable for the particular circumstances/speakers,the 805 SET is a terrific alternative suggestion.

Charles

@charles1dad , thank you for clarifying!  That is very true from what I hear and I certainly defer to your knowledge. 

One other thing that I didn't disclose - My 300B amp is NOT a 300B set. It does have a small amount of negative feedback in the circuit per the Stereophile review (Elekit 300B). However, my output transformers and power mains transformer are custom Lundahl Swedish make. So, maybe, just maybe, I get a little more than 1-2 watts before distortion comes in heavily. Not sure!

@jbhiller 

Your general point was well made. No matter how good a 300b SET amplifier may be, it will still have its limits. The 805 with 6x the power is unquestionably going to be more useful with a greater variety of speakers and listening environment demands. 300b SET is superb for my situation. It won’t be for others.

Charles

Well Charles, thanks to you and Ralph Karsten I learned that information!

By the way, what loudspeakers do you use with your 300B SET? 

@jbhiller 

Hi

My audio system is posted on this site. Click my avatar ID. 
Coincident Total Eclipse II.

Charles 

Charles1dad,

That's a really pretty system in a really cool room.  I'm gonna spend some time looking at your set up.  Clearly a lot of thought.  Bet you have a wonderful miles collection.

 

@emergingsoul 

Thank you very much for your kind comments. I do appreciate them. Yes, Miles, Monk, Coltrane, Dexter Gordon and on and on. Jazz is my true passion.

Charles

Canary Audio  Grand Reference 300 B mono amps.  120wpc.  a few used on the market

Canary Audio Grand Reference 300 B mono amps. 120wpc. a few used on the market

No doubt a very good sounding amplifier (I believe "8" 300bs per side). Problem with choosing a push-pull 300b amplifier is that buying multiple sets of these tubes gets expensive pretty quickly. Particularly so if you are purchasing the upper tier 300b tubes.

It is an excellent tube in my opinion, but they are not cheap to buy. Fortunately, the better-quality versions generally have long lifespans. for more SET power I’d consider the larger transmission type tubes as mentioned previously.

Charles

How did everyone miss the Western Electric 91E integrated? A single ended class A making 20 watts pc into 8 ohms. Expensive, but there ya go...

Here are two possible options. This is a good 300b push pull amp that puts out 22 watts (Audio Space Reference 3.1 300b Integrated Amplifier on US Audio Mart):

 

And this 300b SET amp is supposed to be more robust than some others:

https://www.coincidentspeaker.com/mpsip_amps.html

Frankenstein 300b mono amps

Amps build around a higher powered 300B-XLS tube, or the 520B (which is another higher powered 300B type tube) will get you around 24Watts or so. My amp which is Art Audio Jota 300B SET is an example of that design. It worked spectacularly well with speakers such as Tannoy Definition (89db) and now Fyne Audio F703 (94db) while providing the SET magical pure class A amplification.

 I understand one way to tackle the issue of using SET amps is with high sensitivity speakers.  Is there a 300B or something that gives you that same sound out there with power so you have more speaker options?

@audiovicker You have put your finger on the classic issue with tube power. Its expensive and difficult to get right. If you look back to the 1950s before the transistor, you'll see that high efficiency speakers like Altec, JBL, Klipsch and EV were common.

If you really want to hear what your amp is about, in most rooms speakers with efficiency north of 100dB is what you need. My speakers are 98dB but running a 300b amplifier on them will not show off what the 300b does. You really do need that kind of efficiency! This is because if you really want to know what the amp does, it should never be asked to make more than about 20-25% of its rated power! Otherwise distortion colors its presentation too much.

If that's not an option you'll need more power. That likely means a push pull amplifier, since 8 Watts or so is really the upper power limit of SETs where they can be considered 'hifi' in terms of bandwidth. SET's single biggest Achilles Heel is bandwidth and power- above 8 Watts bandwidth suffers so much that if you have a speaker that is truly full range, you'll notice that there's a problem!

If you have three way speakers that can be biamped you can use a 300B SET on the midrange and tweeters and a SS amp on the bass.Then you get the best of both worlds.Supratek make preamps [duals] that even have two different tubes-one for driving bass and the other mid and tweeters so you can further optimize that configuration.