Mastersound tube amps: 300b vs Dueventi

[albymana]

Hi everyone,

first of all, thanks in advance for your time. I'm new to the world of audiophile gear and recently fell in love with the sound of the Audio Note IZero amp paired with some Devore speakers. It had a magical, tube-like quality that completely captivated me. However, as much as I enjoyed it, I felt the amp was very basic—no remote, quite entry-level, and it seemed a bit cheap overall.

Now I’m exploring alternatives in a similar price range (~2500 EUR), and I’m open to looking for second-hand options if it means finding the right device. I’ve come across two potential candidates from an Italian brand called Mastersound - recommended by a popular shop in Berlin that prioritizes only brands with a strong "musical" attitude (let's say the same Audio Note style). Both would fit my current speakers setup:

1. Mastersound 300B Compact
   • Not the latest model (about 8 years old)
   • From a private seller.
   • The previous owner mentioned they "improved" something internally and replaced original components with higher-quality ones (?)
   • 65% discount over retail price
2. Mastersound Dueventi
   • Latest model.
   • Available from a reliable shop.
   • Fully original and inspected.
   • ~50% discount over retail price

On paper, the 300B Compact seems to have the edge over the Dueventi in terms of design and specs, but I’m concerned about the risks of buying from a private seller and the modifications made by the previous owner. Are these potential red flags, or could this still be a worthwhile purchase? Is there something I am overlooking?

I’d love to hear your thoughts, especially if you’ve had experience with either of these amps (or similar ones).

Thanks in advance for your help and advice!

 

[Purité Audio]

Personally I would try and fall in love with something else, ime tubes are just a pain for no added benefit and a ‘modified’ design the manufacturer may not touch it so when it goes wrong …
Keith

 

[mhardy6647]

On paper, the 300B Compact seems to have the edge over the Dueventi in terms of design and specs...

Wait, are they both 300B amps? Single-ended? EDIT: No, apparently not -- two very different amplifiers, it appears.
Q1: What are the salient differences in design and specs between the two?
Q2: Do you expect that the purported better specs of the former model may have been impacted by the "improvements" made to it?
Q3: If so, which way?

 

[albymana]

right thanks, very good questions.

Those are the respective specs

Dueventi (4500-5000€)
Power: 2 x 20w (2 x 10w triode) class A
Tubes: 2 x ECC802 - 4 x EL34
Input: 3 Line + Phono MM
Output: 1 Line (fixed) + 1 Preamp
Input imped: 50k ohm
Load Impedance: 4 – 8 ohm
Bandwidth: 15 hz / 30k hz 0 db
Automatic Bias
Output Transformer: MastersounD
Supplied with remote control
Negative Feedback: 0 dB
Consumption: 154w
Dimensions: 49 x 33 x 23 cm.
Weight: 23 Kg

300b compact (7000-8000€).
Power: 2 x 11w class A
Tubes: 2 x 300 B - 2 x ECC802 - 2 x 6SN7
Inputs XLR: 1 x Line + 1 Direct
Inputs RCA: 3 x Line + 1 Direct
Input imped: 50k ohm
Bandwidth: 8 hz / 40k hz 0 db
Output Transformer: MastersounD
Automatic settable bias
Load impedance: 4 – 8 ohm
Negative feedback: 0 dB
Supplied with remote control
Consumption: 136w
Dimensions: 45 x 43 x 27 cm
Weight: 33 Kg

The “theory” behind the intervention (he has the invoice) on the 300b is here. What he told me: “The Result was more Detail in The bass range and more Bass itself, without losing the perfekt highs and mid from the 300b”

What makes me a bit skeptical is that I’d basically buy it as a black box , not being really able to decipher what’s been done.

From one end, I’d lean towards the 300b because of its tubes’ famous sound signature, and the higher original price. But I don’t know the counterparty, and the amp is no more in its original state.

From the other end, the Dueventi would come from a trusted store that I’ve experience with, vetted by a professional inspector, no shipment / counterparty risk. Bullet-proof.

Both shares the same sound signature, that is what I am looking for: musicality, engagement, emotion.

 

[SIY]

Dueventi (4500-5000€)
Power: 2 x 20w (2 x 10w triode) class A
Tubes: 2 x ECC802 - 4 x EL34
Input: 3 Line + Phono MM
Output: 1 Line (fixed) + 1 Preamp
Input imped: 50k ohm
Load Impedance: 4 – 8 ohm
Bandwidth: 15 hz / 30k hz 0 db
Automatic Bias
Output Transformer: MastersounD
Supplied with remote control
Negative Feedback: 0 dB
Consumption: 154w
Dimensions: 49 x 33 x 23 cm.
Weight: 23 Kg

300b compact (7000-8000€).
Power: 2 x 11w class A
Tubes: 2 x 300 B - 2 x ECC802 - 2 x 6SN7
Inputs XLR: 1 x Line + 1 Direct
Inputs RCA: 3 x Line + 1 Direct
Input imped: 50k ohm
Bandwidth: 8 hz / 40k hz 0 db
Output Transformer: MastersounD
Automatic settable bias
Load impedance: 4 – 8 ohm
Negative feedback: 0 dB
Supplied with remote control
Consumption: 136w
Dimensions: 45 x 43 x 27 cm
Weight: 33 Kg

Run away. Reading through their web descriptions, what you have there are some table radio amps with possibly some "designer" parts, packed into fancy boxes and stuffed with pretension. If you like the EQ you get with those speakers because of the poor source impedance characteristic, you can dial that in easily and, most importantly, be able to turn the effects off.

 

[JustJones]

Stereophile reviewed the 300B SE which might be the version before the compact, not sure. Might be your cup of tea.

Mastersound 300 B S.E. integrated amplifier Measurements

Sidebar 3: Measurements

www.stereophile.com

 

[albymana]

Stereophile reviewed the 300B SE which might be the version before the compact, not sure. Might be your cup of tea.

Mastersound 300 B S.E. integrated amplifier Measurements

Sidebar 3: Measurements

www.stereophile.com

Thank you so much! Will go through it

What’s your take on:
Buying “modified” device from a private seller vs professionally inspected from vetted store?

Did not make many transactions in this space, so I am maybe over/under estimating risks

 

[JustJones]

I would run away from both. This isn't my idea of good.
Graph from Stereophile

Fig.2 Mastersound 300 B S.E., 8 ohm tap, frequency response at 2.83V into: simulated loudspeaker load (green), 8 (red), 4 (blue), 2 (magenta) ohms (1dB/vertical div.).

This is more my notion of good.

 

[SIY]

Stereophile reviewed the 300B SE which might be the version before the compact, not sure. Might be your cup of tea.

Mastersound 300 B S.E. integrated amplifier Measurements

Sidebar 3: Measurements

www.stereophile.com

The patented Atkinson Tap Dance at the end was, as always, delightfully amusing.

 

[Jim Taylor]

Run away.

This ^^^^ is very good advice.

What sort of car do you have as your daily driver? Would you like to be stuck driving a 1948 Dodge flathead every day? That's the car I learned to drive. I imagine it would be a nostalgic centerpiece if I had it today, or a collectors-club talking point, but I sure as heck wouldn't want to drive it very often, much less drive it every day.
If you get this type of tube amp, it's the same as driving that 1948 Dodge. If you have a decent solid-state amp as your "daily driver", you can relegate this zero-negative-feedback tube amp to the occasional duty of "curio and relic". But if you rely on it for your only amp, you are taking a tremendous gamble. I can count the number of people that have been satisfied long-term by this sort of amp on one hand ... and not use all my fingers.

In the end, you pay your money and you make your choice. All I can ask is that you think about it long and hard before you make that choice.

 

[kemmler3D]

Buying “modified” device from a private seller vs professionally inspected from vetted store?

A very bad idea, unless the person who modified the amp is at least locally famous as a good electrical / audio engineer, there's a near 0% chance their modification made anything sound better, (more detail in bass? How, exactly?) and the reliability is very questionable, warranty nonexistent, etc.

Given that you're using highly sensitive speakers (Devore at least has that going for them) I won't try to talk you out of tubes entirely.

I will say that changing the sound using the amp (for better or worse) runs contrary to the core purpose of an amp, which is to take the input signal and make it bigger ... period.

Trying to dial in a certain sound by switching out amps is like trying to shovel snow by setting little piles of money on fire near the snow. Slow, mostly ineffective, very expensive, and a bad use for the tools.

The modified amp is a risk at best, and the Mastersound amp has a worse frequency response and distortion than some speakers that cost less.

If you like tube distortion and varying the frequency response - all good, go for it. However, my recommendation would be to get a nice clean solid state amp and add the tweaks to EQ and distortion using a tube pre and maybe even DSP if you can stomach it.

 

[sam_adams]

The patented Atkinson Tap Dance at the end was, as always, delightfully amusing.

"I have to say that I have no idea."—John Atkinson

Truer words have yet to be spoken . . .

 

[mhardy6647]

"I have to say that I have no idea."—John Atkinson

Truer words have yet to be spoken . . .

I like @John Atkinson -- who, to his credit, has the cojones (ahem) to participate places like, umm, this... and audioasylum.
So I'll just note that I thought that the penultimate sentence of his part of the review was (also? ) spot on

Did AD like the amplifier because of what it did right despite what it did wrong, or because of what it did wrong?

I enjoy listening to SET amplified music (via 2A3 power triodes, in my case) -- whether for the first or second rationale proffered above, I dunno.


That said, I think the best gambit for anyone who wants such is DIY (or someone else's DIY) to avoid (or at least minimize) the eye-watering street prices of storebought variants.

I.e., I'd agree with @SIY's advice posted earlier.

 

[sam_adams]

I'd agree with @SIY's advice posted earlier.

It is well considered, sage advice.

 

[mhardy6647]

He's a sage kinda guy.

 

[SIY]

He's a sage kinda guy.

And don't forget the Rosemary.

 

[MaxBuck]

Personally I would try and fall in love with something else

If only I had received this pithy, pointed advice earlier in life (and we're not talking amplifiers any more).

 

[mhardy6647]

And don't forget the Rosemary.

Ironically, I was 'harvesting' leaves from some dried thyme from the summer that have been hanging in the garage about an hour ago. We love it in omelets. I make a pretty darned good omelet.

The snow has already deeply, profoundly buried the fresh stuff behind the house, probably for the duration -- although we're supposed to get an inch of rain tomorrow. Thus winter in New England.

 

[SIY]

You're a day or two behind us. We had 30 cm or so on the ground, then suddenly yesterday it warmed up and started raining. Life up in the Allegany foothills. My rear deck on Sunday:

 

[mhardy6647]

The grandkids & I had no mean amount of fun Sunday afternoon tobogganing down our back hill (such as it is) a couple of times -- so, there's that.
Sadly, no photo-documentation... but we did have a blast and kicked up a lot of powdery snow in the process.
Now it's warmed up and it is powdery no more.