First tube gear- Is a 300b amp a good place to start?

KPC

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Dec 4, 2019
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After 5 years of intensive research, I’ve nearly completed my first bucket list analog+digital audio chains emphasizing linearity and neutrality hoping to land somewhere mid-fi - Constellation Inspiration Pre+Stereo electronics to a Magico A5.

In addition, I subsequently want to explore quality “tube” sound and it seems that the 300B amp is maybe one of the best tube sounds. So I’m targeting the Volti Rival 100db speakers (seems relatively uncolored vs other efficient speakers) and am considering the following 300B amps:
1.5 ELEKIT TU-8600S kit
2.5 Line Magnetic LM-210 IA 300B
4.0 STEREO TUBE AMPLIFIER INSPIRE by DENNIS HAD CLASS A 300B
6.0 Woo Audio WA5 300b
6.5 Coincident M300B Frankenstein MK III
and plan to hook it up to my Constellation Inspiration Pre.

I know other options include a tube preamp or a tube integrated.

For tube sound to this newbie, am I going in the right direction?
 

Addicted to hifi

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After 5 years of intensive research, I’ve nearly completed my first bucket list analog+digital audio chains emphasizing linearity and neutrality hoping to land somewhere mid-fi - Constellation Inspiration Pre+Stereo electronics to a Magico A5.

In addition, I subsequently want to explore quality “tube” sound and it seems that the 300B amp is maybe one of the best tube sounds. So I’m targeting the Volti Rival 100db speakers (seems relatively uncolored vs other efficient speakers) and am considering the following 300B amps:
1.5 ELEKIT TU-8600S kit
2.5 Line Magnetic LM-210 IA 300B
4.0 STEREO TUBE AMPLIFIER INSPIRE by DENNIS HAD CLASS A 300B
6.0 Woo Audio WA5 300b
6.5 Coincident M300B Frankenstein MK III
and plan to hook it up to my Constellation Inspiration Pre.

I know other options include a tube preamp or a tube integrated.

For tube sound to this newbie, am I going in the right direction?
I think your going the right way about and volti rival are excellent speakers.
 
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DasguteOhr

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Sep 26, 2013
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I would take the Line Magnetic and combine it with an Altec 604 8g loudspeaker. that is an unbelievably harmonious combination.
that plays rousing emotional you will love it. 15 "bass + 1" horndriver at 100db / 1watt.
When i would start with 300b this Speaker is my perfect choice.
Altec speakers are only used, if you want something new ignore my tip.
I can't say anything about your chosen speakers, I don't know them.
A 300b amplifier plays better on a light load and simple crossover.
Exsample Picture Speaker;)
2518373-726b74a4-altec-lansing-model-17-604-8g-speakers-620-cabinets.jpg
 
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Kingrex

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Feb 3, 2019
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Your jumping right into the deep end. KT88 PP amps are forgiving and play 88db speakers. Basically you have 0 noise issues.

A 300B on a 100db speaker may come with hum. Why is it humming. Then your tearing you hair out trying to figure out what is up.

In the end, I find my low watt SET 845 on a 96db PAP Trio 15 Coax to be the best I have had in my house. But it has been a challenge. It's still not dead quiet. 1 amp is noiser than the other. A new Bobs Device SUT is hyper reactive to shielded interconnects. And the high sensitivity speaker lets you know.

I think you should go for it. But be prepared to really dig in and spend time setting it all up right. Once you get close, the magic is very much there.
 

Tim F

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Jun 11, 2018
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I’ve owned 300b Amps that only sounded good on vocals and acoustic guitar. Can’t do bass and any sort of complex pieces but are beautiful if the music was simple. Last 300b I listened to also couldn’t do bass but was much brighter, and lacked texture. The implementation of this valve will create different sounds. You must make sure they can drive your speakers or bass can be bloated. Why the 300b and what kind of sound do you like?
 

Atmasphere

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May 4, 2010
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www.atma-sphere.com
After 5 years of intensive research, I’ve nearly completed my first bucket list analog+digital audio chains emphasizing linearity and neutrality hoping to land somewhere mid-fi - Constellation Inspiration Pre+Stereo electronics to a Magico A5.

In addition, I subsequently want to explore quality “tube” sound and it seems that the 300B amp is maybe one of the best tube sounds. So I’m targeting the Volti Rival 100db speakers (seems relatively uncolored vs other efficient speakers) and am considering the following 300B amps:
1.5 ELEKIT TU-8600S kit
2.5 Line Magnetic LM-210 IA 300B
4.0 STEREO TUBE AMPLIFIER INSPIRE by DENNIS HAD CLASS A 300B
6.0 Woo Audio WA5 300b
6.5 Coincident M300B Frankenstein MK III
and plan to hook it up to my Constellation Inspiration Pre.

I know other options include a tube preamp or a tube integrated.

For tube sound to this newbie, am I going in the right direction?
Kingrex is offering some good advice. So is DasguteOhr above.

Here's something to keep in mind about SETs: If you really want to hear what they are about you need to have a speaker efficient enough that you never need push the amp past about 20-25% of full power. This is because the SET will start to make more higher ordered harmonic distortion around that level and the ear uses those harmonics to sense sound pressure. Since the power is in the transients, if your speakers lack efficiency, the amp will sound 'dynamic'. If you look at reviews of SETs, you'll often see that the amp had 'way more dynamics than you would expect for an amp of such low power' or something to that effect. This is entirely due to distortion.

With a 300b (and depending a bit on which 300b is used) this means you have about 2 watts of really useable power. So in the average room 100dB is the minimum efficiency to be considered.

IMO/IME you might want to consider supplementing the bass with a distributed bass array, perhaps using a set of Swarm subs made by Audiokinesis, and then have something (electronic crossover) to keep that bass out of your 300b amps. That will help you out a lot with the power issue.

Or you could try something that is push-pull.

I've done a variety of experiments trying to sort out why SET lovers prefer SETs over PP amps and from what I've deduced, the main reason is that the PP amp they are using when doing comparisons is considerably higher power than the SET and quite often isn't even triode. So for my experiments I started with a type 45-based SET. I then built up a pair of type 45 PP amps, using the same tube complement in the driver circuitry as the SET and the same types of coupling caps and resistors. The resulting amps, instead of 0.75 watts, made about 6 watts. They were far more musical and in every way- wider bandwidth (easily heard as speed and bass impact), more definition (vocals were far easier to discern for example) and smoother sound. But I felt one problem with that experiment was that the resulting amp had too much power which might have been unfair.

So a second experiment involved a 2A3-based amp, and to come up with a PP amp of the same power (about 4 watts), I built up a PP amp using a pair of EL95s in ultralinear mode (also running class A), driven by a single 12AT7 configured as a differential amplifier. One grid of the 12AT7 was thus the input signal and the other was to accept feedback, which was only used to reduce gain since the circuit was already quite linear. The idea here was to use pentodes since they are the most commonly used in the sort of PP amps that are typically compared to SETs. Again in comparisons the PP amp was better in every way- more detailed, obviously wider bandwidth (on the bench proved to be full power to over 100KHz) and every bit as smooth.

So I'm unconvinced that SETs offer any real advantage whatsoever although they do have a rather gothic appeal. They are likely to have a good distortion signature (innocuous and therefore musical), but you can get PP amps to have a good (innocuous and therefore musical) distortion signature as well.
 
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KPC

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So I'm unconvinced that SETs offer any real advantage whatsoever….
I had to choose someplace to to start my “tube sound” exploration. The 300B seems to be a unique favored sound that at some point I had to try out. So instead of someday, I chose to start with the 300B. I’ll likely try other tube amps typologies later.

Thanks for the Subwoofer suggestion. I’ll further research the swarm, Rel, Jl Audio, Vandersteen, Perlisten, and the JL Audio C1 crossover at a later time. If I find my Magico A5 bass satisfying, then likely only need the swarm to fill out my flea watt system, otherwise I may have to spend more if subwoofer(s) are used in both systems.

I generally like variety (different, not good vs bad) so am exploring sonics from 2 different systems.
 
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Hear Here

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In the end, I find my low watt SET 845 on a 96db PAP Trio 15 Coax to be the best I have had in my house.
I'd agree with you there. With 100dB speakers the 300B will be OK for most jazz and female vocal, tc but it won't have enough welie for big orchestral stuff. I found the 845 a pretty good SET solution for my 102 dB Avantarde Unos. In fact for music such as jazz or female vocal I found the similarly low-powered PX-25 far superior than the 300B. A pretty rare valve but the Art Audio PX-25 was truly subline (and far nicer than the AN 300B) on this smaller scale music. Peter
 
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matakana

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Aug 26, 2020
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I had to choose someplace to to start my “tube sound” exploration. The 300B seems to be a unique favored sound that at some point I had to try out. So instead of someday, I chose to start with the 300B. I’ll likely try other tube amps typologies later.

Thanks for the Subwoofer suggestion. I’ll further research the swarm, Rel, Jl Audio, Vandersteen, Perlisten, and the JL Audio C1 crossover at a later time. If I find my Magico A5 bass satisfying, then likely only need the swarm to fill out my flea watt system, otherwise I may have to spend more if subwoofer(s) are used in both systems.

I generally like variety (different, not good vs bad) so am exploring sonics from 2 different systems.
The latest Elekit 8900 does 2A3 as well as the 300b, This will be a killer SET for the price especially with upgraded transformers.
 

RidingBean72

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Sep 2, 2020
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After 5 years of intensive research, I’ve nearly completed my first bucket list analog+digital audio chains emphasizing linearity and neutrality hoping to land somewhere mid-fi - Constellation Inspiration Pre+Stereo electronics to a Magico A5.

In addition, I subsequently want to explore quality “tube” sound and it seems that the 300B amp is maybe one of the best tube sounds. So I’m targeting the Volti Rival 100db speakers (seems relatively uncolored vs other efficient speakers) and am considering the following 300B amps:
1.5 ELEKIT TU-8600S kit
2.5 Line Magnetic LM-210 IA 300B
4.0 STEREO TUBE AMPLIFIER INSPIRE by DENNIS HAD CLASS A 300B
6.0 Woo Audio WA5 300b
6.5 Coincident M300B Frankenstein MK III
and plan to hook it up to my Constellation Inspiration Pre.

I know other options include a tube preamp or a tube integrated.

For tube sound to this newbie, am I going in the right direction?
I have not had the opportunity to hear the Triodelabs 2A3, but read good things about it. I think they would be a good match with the Volti speakers you are looking at. Best of luck to you in what ever you choose.
 

DasguteOhr

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Sep 26, 2013
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i can say the Altec 604 8G works pretty well >5 Watt SET Amp F2a11.
orchesteral music like 1812 overture kicks you out of your chair ;), one problem it is no small speaker
you need space big room.
Dimensions (W x H x D): 660 x 1016 x 457 mm (26" x 40" x 18")
Weight: 62,6 kg (138 lbs) net
Listen to this speaker and judge for yourself
 

morricab

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Apr 25, 2014
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Kingrex is offering some good advice. So is DasguteOhr above.

Here's something to keep in mind about SETs: If you really want to hear what they are about you need to have a speaker efficient enough that you never need push the amp past about 20-25% of full power. This is because the SET will start to make more higher ordered harmonic distortion around that level and the ear uses those harmonics to sense sound pressure. Since the power is in the transients, if your speakers lack efficiency, the amp will sound 'dynamic'. If you look at reviews of SETs, you'll often see that the amp had 'way more dynamics than you would expect for an amp of such low power' or something to that effect. This is entirely due to distortion.

With a 300b (and depending a bit on which 300b is used) this means you have about 2 watts of really useable power. So in the average room 100dB is the minimum efficiency to be considered.

IMO/IME you might want to consider supplementing the bass with a distributed bass array, perhaps using a set of Swarm subs made by Audiokinesis, and then have something (electronic crossover) to keep that bass out of your 300b amps. That will help you out a lot with the power issue.

Or you could try something that is push-pull.

I've done a variety of experiments trying to sort out why SET lovers prefer SETs over PP amps and from what I've deduced, the main reason is that the PP amp they are using when doing comparisons is considerably higher power than the SET and quite often isn't even triode. So for my experiments I started with a type 45-based SET. I then built up a pair of type 45 PP amps, using the same tube complement in the driver circuitry as the SET and the same types of coupling caps and resistors. The resulting amps, instead of 0.75 watts, made about 6 watts. They were far more musical and in every way- wider bandwidth (easily heard as speed and bass impact), more definition (vocals were far easier to discern for example) and smoother sound. But I felt one problem with that experiment was that the resulting amp had too much power which might have been unfair.

So a second experiment involved a 2A3-based amp, and to come up with a PP amp of the same power (about 4 watts), I built up a PP amp using a pair of EL95s in ultralinear mode (also running class A), driven by a single 12AT7 configured as a differential amplifier. One grid of the 12AT7 was thus the input signal and the other was to accept feedback, which was only used to reduce gain since the circuit was already quite linear. The idea here was to use pentodes since they are the most commonly used in the sort of PP amps that are typically compared to SETs. Again in comparisons the PP amp was better in every way- more detailed, obviously wider bandwidth (on the bench proved to be full power to over 100KHz) and every bit as smooth.

So I'm unconvinced that SETs offer any real advantage whatsoever although they do have a rather gothic appeal. They are likely to have a good distortion signature (innocuous and therefore musical), but you can get PP amps to have a good (innocuous and therefore musical) distortion signature as well.
You would have to compare a PSET to a push pull amp for a fair comparison. I have done this with the very good VAC 30/30 and a JJ-322. Both have two 300bs per channel and both are Class A triode without feedback. The JJ is PSET and makes an honest 15 watts (seen the measurements in. Polish magazine) with 1% distortion (It has huge Double C core output trannies). The VAC is PP making around 30 watts and also has big trannies.

The result? On sensitive speakers (97db) the JJ was clearly superior in terms of tone and texture and bass was about equivalent...there was more inner resolution with the JJ as well. Dynamics were similar.

On normal sensitivity speakers the VAC was better with more grunt and better dynamics. That being said, the JJ was one of the weaker sounding SETs I have owned when played on normal speakers...other SETs, particularly Aries Cerat and KR Audio drive normal speakers effortlessly.

Another example recently was a friend of mine has a pair of 50 watt Nagra 845 PP monos. My 20 watt Ayon Spark SET sounds better on his Sonus Faber Olympica 2 speakers.
 

morricab

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Apr 25, 2014
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I had to choose someplace to to start my “tube sound” exploration. The 300B seems to be a unique favored sound that at some point I had to try out. So instead of someday, I chose to start with the 300B. I’ll likely try other tube amps typologies later.

Thanks for the Subwoofer suggestion. I’ll further research the swarm, Rel, Jl Audio, Vandersteen, Perlisten, and the JL Audio C1 crossover at a later time. If I find my Magico A5 bass satisfying, then likely only need the swarm to fill out my flea watt system, otherwise I may have to spend more if subwoofer(s) are used in both systems.

I generally like variety (different, not good vs bad) so am exploring sonics from 2 different systems.
From your list I would try the LM amp or the coincident amp. Another to put on your list is a KR Audio VA300...this has the balls and the highs that other 300bs may lack. Another consideration would be the WAVAC MD300. Finally, something with a bit more grunt like an Ayon Spark or Spitfire would make an interesting 300b alternative.
 
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Kingrex

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A big consideration is how do you play your music. My friends play way to loud for me. A phone sound pressure device says I listen around 46db to 76db. 80db max at my home. That's when I really open it up.

Ear splitting loud amplification is not musical to me. Its uncomfortable. I generally avoid the sweet spot at friends houses as it hurts to be there.

There is a happy point where a speaker and amp play together. If you play at reasonable levels where the amp is in its comfort zone (low distortion) and the speakers are moving enough, receiving enough power to move in optimum excursion, then the chance a 300 will blend with a speaker in your room is better. Better than if you're one of those thats wants to push it to extremes. Pushing it further than its design parameters.

My experience is that a speaker will only grow in scale as the volume goes up, so much. At a point lower in volume than most seem to play at, that expansion in scale slows to a stop and clipping/distortion takes over. So what type of listener are you. Are you the open it up as wide as it goes pusing it to extremes. Peaking into the 90db. If you are, a SET 300B is not going to operate in its sweet spot. If you truely find modest levels. Maybe 76db to 80db is comfortable and optimally expressing what the system can express, then a 300B may work.
 
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KPC

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A big consideration is how do you play your music. My friends play way to loud for me.
I listen at moderate levels but may turn up the volume rarely for musical envelopment. I’m very careful to protect my hearing, the rest of my body is a work in progress :)

I’m aware of the typical frequency extreme limitations of tube gear so I’m not expecting much there. What I’m after is experimenting (some tube rolling) and experience the magic of tube sound that draws tube gear enthusiasts. The 300b is not the endpoint of my tube audio journey, rather, the starting point. Other tube gear advise is welcome.

@morricab.5671
Thanks for all your suggestions- I’ll research further.

I just missed purchasing a used Art Audio Diavolo SET 300B for $3.6k - wasn’t sure to pull the trigger.
 
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Thaluza

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First post on this forum.

I can vouch for the Coincident Frankenstein monoblocks, which is on your list. I have owned the MK2 version for the past 5 years. No hum, no buzz, and no other issues. Bass is very good, but I have Von Schweikert speakers with powered woofers. The powered woofers supposedly retain the sonic characteristic of the amp that is hooked up to the speakers. With that caveat, I can say that the bass I am hearing from the Frankensteins through the powered woofers is very satisfying. I would guess that a good solid state amp would provide more grip, but not necessarily more weight. Regarding the ability of the Frankensteins to play loud, I can play music (mostly rock and jazz) at 90db peeks without fatigue, but most of my listening is in the range of 75-85db. It took some experimentation with cables and room treatment to get the ability to play loud without fatigue, though. The Franks are very emotionally involving and sound more real to me than any other amp that I have owned. They rule the roost in my system among the three sets of amps that I currently have (300B, OTL, 45 set).
 
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