Mastersound 300b Compact-thoughts???

@mmcgill829 

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.

These are valid concerns. 15 watts from a single 300b is very high and certainly suggests that the chosen operational points are very aggressive and pushing the 300b quite hard. In this scenario a shortened tube lifespan is very likely. The sweet spot for SET 300b is usually 6 to 8 watts per channel. Now there could be some innovative circuit that can achieve this level of power without stressing the 300b. If so I’m unfamiliar with such.

Charles 

@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.

I wanted to experience the 300b sound. So I got the Woo 300b amp for my headphone system. I also put in Takatsuki tubes in them. Honestly my headphone system became incredible sounding. So much so that I had a hard time listening to my $70K main system. The realism, natural musicality, detail… emotional draw. So, this caused me to completely upgrade and reconfigure my main system. Now both my main system have the same character, detail, midrange bloom, emotional connection. It is an all Audio Research Reference system… but you get the same warmth, natural sound, detail, musicality with the foundation series and even the integrated. 
 

Let me suggest, you are going at this in the most difficult way possible. Trying to power a main system with a 300b is a very difficult thing requiring lots of big compromises. You can get the character in a main system and with lots of power by using Audio Research, Conrad Johnson, Cary, or VAC. You can then choose from lots of great speakers.

If you must experience the best the 300b has to offer… get a headphone amp and power some great headphones. You can see my headphone system and main system under userID. A fantastic headphone system will cost 1/10th thst of a main system and you can get the magic of the tube through great high power components made to power the pajority of speakers on the market.

@mmcgill829 I'd say if your speaker maker recommends the amp they obviously have experience with it perhaps they can answer your questions? BTW what are your speakers?

@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 😂