Mastersound 300b Compact-thoughts???

Sorry to revive an old thread, but can't find much info on this amp online...

I've been considering this amp since it was recommended to me by the speaker-maker of my speakers, but I have some concerns - notably the 15wpc rating on it. As a SET 300b amp, that seems quite high. I'm used to seeing half that in SET applications for 300b, so I'm a little wary as this may negatively impact tube life - which, considering the cost of these 300b tubes, would be a dealbreaker.

Anyone have any experience, thoughts, insight, etc? Reviews online are all quite old and for previous iterations of this model or for the 300b SE or 845.

@charles1dad Yeah, that was my worry, especially if I plan on getting Takatsuki or Elrog tubes to put in it. At that expense for the tubes, it would be silly to put them in an amp that is going to make their lifespan dramatically less. They're just too expensive to do that.

It's too bad there's no documentation that I can find about this amp or any measurements done on it to get a glimpse into how it's operating. While I got offered one at a great price and it came recommended, with so much unknown, it's probably better to look for alternative options maybe.

@jond I'm having Coherent Audio 18s made currently, so investigating amp options that'll take advantage of their high efficiency (102dB). Frank recommended two amps - this one and a Tektron amp, but I'm not too fond of the build quality of the Tektrons (they look pretty thrown together for the price they ask). I'm sure they sound wonderful, but that's a huge turn off for me. Mastersound supposedly has excellent build quality, but I'm just hesitant since there isn't much info out there about these.

Some other short list considerations - triode lab 2a3 integrated, allnic T-1500 mk2, but that's for another thread to discuss 😂

@charles1dad I've seen your system - looks great! I'm sure it sounds even better!

I'm mostly hanging around the 8-10k range all-in as far as pricing goes.

With some of the 300b amps like this mastersound, can find them gently used with low miles for around $5500, which leaves plenty of room to get some excellent tubes, but the power output concerns make it a bit of a risky endeavor. Even Frank switched to using this as one of his rotating amps fairly recently from what he said, so I'm not sure he will have a lot of insight into long term tube life with it.

The allnic can usually be found lightly used for around the same price point as well, and that is rated at 10 wpc output, which seems a little more in the normalish range.

Triode lab would be if I decide to go the 2a3 or 45 tube route instead. I've been eyeing the 2a3 in particular. They're beautiful amps and look very well made.

The tektron amp I was referred to does allow for tube rolling with 45, 2a3, 50, but again, just concerned with the build quality. Looking inside them, there's a lot of wiring and components that aren't supported by anything but their connections. It feels sloppy to me. I know they have a pretty good reputation as far as sound quality goes, but I just can't get over that. Even a reviewer had to re-attach things in their demo model that came lose in shipping (!), which for thousands of dollars just shouldn't be happening IMO.

Ideally looking at integrated amps since I don't have a pre-amp and it's questionable whether I would have enough room to setup mono blocks. I probably could, but it would be pretty tight.

As an update here, I reached out to the US distributor of Mastersound, who reached out to Mastersound directly to get some clarification about my concerns on the 15wpc rating. Answers are below.

1. In speaking with MastersounD, they have given a spec at the “highest” voltage in electricity. For example, in the UK market, voltage is 220v, but in many cases, homes will have 230v or even 240v. In a more normal voltage like 220v, their power is more like 10-11 wpc. This Is still higher than what others are getting out of a pair of 300b tubes, but that is due to the in-house built transformers. These alone have been getting approx 30-40% more output of a tube as they are achieving 95% of the efficiency of the tube. The common characteristic sound of our amps are that they have more energy and dynamics than our competitors amps.

2. MastersounD regulates the 300b at a very “quiet” value without risks to the life of the tube. The 300b tube is a very delicate tube and especially during transport. That being said, they have many customers who are still on their original tubes after 20 years. It all depends on the quality of the tube.

it appears 8-10wpc is expected on 120v US power, which is more in line with what would be expected.

@charles1dad Yes, definitely reassuring! I would have found it an odd choice to overtax 300b tubes, as this would no doubt result in some unfavorable opinions of them due to the replacement cost of the tubes. At sometimes 20,000-40,000 hour ratings for some high quality 300b tubes (like Takatsuki or WE), the expense can be justified, but if an amp is pushing them so hard that they are spent in significantly less time, then it becomes a big problem!

The brand does seem like it's fairly well-respected (though not very well known still outside of Europe).

@david_ten No problem! They were very responsive - I had a reply back within 12 hours and then an answer back after reaching out to Mastersound within 2 days.

The US distributor is Mofi Distribution, so I'm not surprised with the quick service!