Miniwatt tube amp

[anm]

Hi,
Came across miniwatt amp in one of the posts in forum.
It is available for $269 delivered to India (not sure about duty but should be ~17% for personal use).

Any feedback, or guesses based on design?


EDIT

Frankly, after interacting with Viren and listening to Lyrita amps, I have lost interest in the thread (I am the OP). There are no headaches involved if you buy from him.

The 22.5k INR amps sound extremely good, are decently priced, and handmade with good power supply and components (my belief, no objective evaluation done). Over and above this, Viren is a gentleman. He is no regular hi fi dealer. Once you meet him, you will realize that Lyrita is more about passion than "dhandha". So you don't really need to get into verifying parts etc, just buy with your eyes closed.
And then, if you talk to Viren, he may be able to make your piece a little special by adding different configs. He may also provide exchange option if you want to upgrade in future. I hope I am not over-committing on his behalf. But you can talk to him to figure out the details.

regards

 

[jai1611]

There's a review up on 6moons. Quite complementary. I'm not sure what sort of speakers will work with something like this though.

 

[MiniWatt]

Hi All,

Thanks all for your interest on MiniWatt!

MiniWatt is able to work from 176-265Vac, and it works well even the input AC voltage is fluctuating in India.

If you need more info or any questions on MiniWatt, please kindly drop us an email [email protected]

MiniWatt

 

[anm]

Hi Mini,
Great to know that you watch this forum.
I had a question regarding power supply. Does this unit has an SMPS supply and not a linear supply?

Other forum members can comments on merits of different psu in an amp. Cranky, where are you?

 

[MiniWatt]

Hi anm and all,

I had a question regarding power supply. Does this unit has an SMPS supply and not a linear supply?
<MiniWatt> It's using our in-house designed SMPS supply.

Other forum members can comments on merits of different psu in an amp. Cranky, where are you?
<MiniWatt> I'm in Hong Kong. :lol:

Thanks!
MiniWatt

 

[anm]

Cranky is a forum member we trust on tech issues. :lol: I am not name calling you
But good to know you are at hong kong. And I hope you are a person with a name, and not a robot employed by the company :lol:

Cranky, where are you?
<MiniWatt> I'm in Hong Kong. :lol:

Thanks!
MiniWatt

 

[anm]

Cranky and Mini,
Can this amp be used as a headphone amp? If not, why?
Cranky - there is another thread on headphone amp - hope you read that.

regards

Miniwatt, that question I think was directed to me.

In my mind, an amp is nothing but a modulator of a power supply into a load, one that follows an input signal. In many ways, a power supply is as much a part of the amp as anything else, and is a pretty critical factor in its performance. It needs to have low output ripple, good slew rate, very low output impedance and so on. All of these performance parameters are measurable and quantifiable, no mumbo-jumbo is involved.

Though it is possible to get a switching supply that performs similar to linear supplies, it is not easy to design or produce such a supply. Removal of all harmonics are simply not possible without huge amounts of post-filtering (IIRC), and this (may) affect the output impedance of a supply. However I am not qualified to comment on specifics of products I've not seen, and the only thing I will say is that Hypex, pretty much the best switching *amp* producer in the world, still sells only linear supplies for their amps.

It is much easier and cheaper to run a tube amp off a switching supply, I'll admit. The 6moons review is pretty good, but what I'd really like is for John to run some measurements on this. Besides, for about 12K before customs, it might be totally worth the risk, if you have the right speakers. I think Audire and Rethm, as well as Viru, would have speakers that would work with such a small power output, though tubes generally sound a lot louder than their power ratings would suggest.

 

[psychotropic]

hey cranky and others (including miniwatt),

would you need rethm saadhnas and audire and the like (ie costing 2000 USD and above) for this amplifier to sound good? what 'budget' speakers (ie costing less than 300 USD) might sound good with these? or is that an unworkable proposition?

The 6moons review says it works well with 86 db desktoppers....would this mean that a PSB Alpha B1 (with 89db sensitivity) or something similar be a reasonable match for these?

 

[anm]

I guess klipsch should be a good match.
Also lyritas are not that expensive - though I still feel they just so slightly expensive.

 

[jai1611]

AFAIK Klipsch dont sell their bookshelf speakers in India. Only towers and home theatre packages. I was interested in their horn loaded bookshelves so had called the Mumbai Onkyo shop (Onkya India are dealers for Klipsch)

 

[anm]

this 86 db on applying 1 watt - what distance is it at? 1 meter from the speakers?
In that case, I may shift back by further 2 meters (total distance being about 9-10 ft from speakers) - and the fall will be 9.5dB?

Here is what I am referring to - Damping of sound level with distance - damping calculation distance calculator dB distance decibel sound reduction free field - decrease in sound over distance microphone - sengpielaudio Sengpiel Berlin

But do we need to push the entire 2.5 watts into the headphone? We can keep the volume down?

Cranky - any inputs on smps power supply rather than usual linear psu?

 

[MiniWatt]

Hi Cranky, anm, psychotropic, jai1611 and others,

Thanks! Yes, it's truth, it is not easy to design a SMSP to have low output ripple, good slew rate, very low output impedance, especially when operating in high voltage.

We have a R&D team (specialists in SMSP design) to design this MiniWatt and able to achieve residual noise < 0.8mVac.

Definitely, we're happy to offer a group order discount for the members in HiFiVision.com.

Thanks!
Derek
Director of Business Development
MiniWatt

 

[anm]

Can you pls ask your rnd dept how can it be used for a headphone amp? My point is, if I can not use it with my current speakers, at least I should be able to use it with a headphone.
Can it be modded to be a headphone amp as well? I can then buy with confidence.

regards

 

[stevieboy]

hey cranky and others (including miniwatt),

would you need rethm saadhnas and audire and the like (ie costing 2000 USD and above) for this amplifier to sound good? what 'budget' speakers (ie costing less than 300 USD) might sound good with these? or is that an unworkable proposition?

The 6moons review says it works well with 86 db desktoppers....would this mean that a PSB Alpha B1 (with 89db sensitivity) or something similar be a reasonable match for these?

psychotropic,

basically any speakers with sensitivity 89 and higher, preferably 91 and higher and a simple crossover, two drivers max would be better. single driver best. my amp is bout 3.5 watts and my speakers are 92 db sensitivity. goes pretty loud! SET amps are more dynamic than push pull amps so dont let the mini wattage fool you!

regards

 

[jai1611]

my amp is bout 3.5 watts and my speakers are 92 db sensitivity. goes pretty loud!

Stevieboy, could you tell us which speakers are you using? I was considering getting a valve amp and was looking around for high sensitivity speaker to pair with it.

 

[stevieboy]

hi jai,

am using lyrita audio single driver fostex fe 167 speakers. if you're looking to get a valve amp and single driver speakers talk to viren. his SET amp is superb! he makes a 3.5 watt 2A3 SET, a 1.5-2 watt el84SET which is very affordable and a powerful 15 watt russian tube SET i forget the tube name.

regards

 

[Jith77]

@miniwatt...will it be possible for one of more knowledgable members to get a review sample ....
it will be easier to pitch in for a group order after having a final opinion on what speakers it would gel with... afterall considering the relatively higher pricing of other amplifiers here, a group order for the miniwatt should be non issue

P.S: 6moon writes pages on it and still doesnt give a good picture of the sound

 

[anm]

I find 6moons reviews full of fluff and less of substance. It is sometime real pain to figure out the crux of the review.

 

[odyssey]

Folks
a Group buy may not work - if you do do this, pls be ready to pay the full amount for customs duty. Customs guys seem generally reasonable for private use packages, but if there is a group buy and a 10 pcs of this amp come to one address, you would be hard pressed to prove that its not for a resale but for private use.

cheers

 

[anm]

group buy but deliver in individual package. Will not help much on shipping cost but a group bargain + custom duty saving should offset that.