Mastersound 300b Compact-thoughts???


I am considering this amplifier and wondered if anyone as experience with it? Also, it seems from what I can read it is SS rectified, can anyone confirm this, or am I missing something?


Many thanks




Your budget range will allow you to purchase an excellent quality amplifier. I’m much more familiar with the 300b genre than the 2A3 but I believe that either would work in wonderful fashion with your Coherent Audio speakers. Triode Lab uses Hashimoto transformers and chokes. I know that Allnic goes a different route with “permalloy “ iron in their amplifiers.

Allnic also believes a “bit” of NFB is desirable (Lower output impedance thus higher damping factor/DF).  I’m pretty certain that the Triode Lab is purist zero NFB. Does Frank feel the added NFB is necessary or a factor with his speakers? Allnic utilizes 6 db NFB. Anyway both of these brands are well thought of. With those speakers get the best amplifier you can afford. You’ll have superb sound quality for many satisfying years.


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.


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

That is reassuring particularly the comment addressing tube lifespan. Their in-house built transformers are universally acknowledged to be very high quality. 

@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).