SMSL VMV P2 Headphone Amp Review

[restorer-john]

It does indeed get warm just sitting there.

A nice winter headphone amplifier.

 

[Music1969]

Expense, noise and long term reliability.

Their much cheaper SMSL SH-9 features relay based volume control and has lower/same noise levels.

In terms of reliability, what happens when a relay fails (specifically for volume control) out of interest?

Does it just mean you have bigger jumps in volume as each relay fails ?

 

[Chagall]

Expense, noise and long term reliability. They made the right choice in my opinion- as long as the pot is a good one. A decent pot lasts 30-40 years. If you'd replaced as many small signal relays as I have, you'd steer clear of relay based volume controls too.

Thank you for the info.

Quick question if you don't mind: what happens when the relays fail? I mean they don't all fail at the same time. Is just one part of the volume control not usable or does the whole array need to be changed? Thanks!

EDIT: nevermind, the question was asked already

 

[restorer-john]

Their much cheaper SMSL SH-9 features relay based volume control and has lower/same noise levels.

In terms of reliability, what happens when a relay fails (specifically for volume control) out of interest?

Does it just mean you have bigger jumps in volume as each relay fails ?

It depends how the relay ladder is arranged, but noise, intermittent signal etc. can be a problem. Consider headphone output signal level really is chickenfeed in terms of current. Contacts oxidise over the years and there simply isn't enough current to 'burn' through the oxide layers, resulting in poor contact.

Sure, if the relays are super high quality, inert gas-filled and sealed, silver/gold contacts, maybe you'll get a good life out of them. But I doubt they are anything more than poverty spec 'sealed' 'small signal' relays.

A pile of relays is a pile of reliability issues and a pile of expense. They are moving electromechanical parts with moving contacts and you need quite a few in a balanced 2 channel unit if you want fine volume control.

A relay driven volume is not a sign of a quality headphone amplifier. To me, it's just a box ticking exercise to sell to headfi type guys.

 

[restorer-john]

Quick question if you don't mind: what happens when the relays fail? I mean they don't all fail at the same time. Is just one part of the volume control not usable or does the whole array need to be changed? Thanks!

It's not applicable to this product.

Relays last a long time, mostly, but not always. It's less about outright failure and more about contact degradation.

 

[Anthony T]

Only a mother could love that face…

 

[Ajax]

I voted "not terrible" as I don't see the point of spending $1k for a headphone amp.

I would much prefer it be incorporated in a "pre amp" such as a Benchmark DAC 2 HGC, which is available second hand for the same price.

 

[Human Bass]

A90, I dont trust the 70, too many failed units

Yeah, A70 Pro is a better option

 

[peng]

Thanks for amirm's review

Please make a version that includes a 3rd and/or 4th lower cost DAC chip such as a ES9010K2M channel for use with subwoofers and room correction software such as Dirac Live bass control. No one has done anything like this so far, they seem to go from 2 to 8 channels (Topping for example), I wonder if someone will ever fill the void with a 3, or 4 channel version, and would be extra nice if a lower cost version, say at below $600, albeit with lower cost chips such as the new ES9017S.

For example, two main channels using the ES9017S in differential mode and one more, using a ES9010K2M for two subwoofer outputs that don't need differential implementation. Same idea for Toppin if @JohnYang1997 is still around.

 

[oscar_dziki]

Only a mother could love that face…

Maybe it's very expensive, but at least it's ugly as hell. It would sit nicely in the home of a lonely guy who is collecting ceramic dolls and brass ring bells.

 

[Ra1zel]

It depends how the relay ladder is arranged, but noise, intermittent signal etc. can be a problem. Consider headphone output signal level really is chickenfeed in terms of current. Contacts oxidise over the years and there simply isn't enough current to 'burn' through the oxide layers, resulting in poor contact.

Sure, if the relays are super high quality, inert gas-filled and sealed, silver/gold contacts, maybe you'll get a good life out of them. But I doubt they are anything more than poverty spec 'sealed' 'small signal' relays.

A pile of relays is a pile of reliability issues and a pile of expense. They are moving electromechanical parts with moving contacts and you need quite a few in a balanced 2 channel unit if you want fine volume control.

A relay driven volume is not a sign of a quality headphone amplifier. To me, it's just a box ticking exercise to sell to headfi type guys.

What would you consider a better alternative for perfect channel balance then

 

[GWolfman]

Not sure what this has to offer over other products other than matching a DAC if you already have it.

 

[Dmitri]

Definitely has taken all the cosmetic benefits of well considered streamlined industrial design and ignored them completely.

Interesting product. Basically more available power than 99.9 % of users could possibly need. Feels like SMSL’s high gain is more for bragging rights than any actual utility for the end user, and money wasted on a product that could be more affordable.
Never seen that before.

Liked the give and take on volume pots. It’s not always just the product reviews I find interesting around here, but the learning potential that comes from the discussion afterwards.

Thanks for the review Amir!

 

[DLS79]

@amirm, the vertically oriented graph is so much easier to read, thankyou for including it.

 

[Mikig]

Reserved for specs.

good morning amirm
on the specifications of this device I read that it can also be used as a hi-end 2 channel preamplifier. Is it possible to measure the same as a preamplifier? Thank you

 

[levimax]

just regular pot, opportunity lost.

I think for a "high end" product, a good pot that works as well as this one, adds to the value of the product. I have had several SMSL and Topping DAC's with volume controls and while they "work" the "feel" is not even close to the same as a good analog pot. While a digital volume control with relays is technically superior and cheaper and easier to make the feel of good analog pot can not be beat. Good analog costs more than perfect digital so in this case it looks like you are getting something for the extra cost.

 

[maverickronin]

A relay driven volume is not a sign of a quality headphone amplifier. To me, it's just a box ticking exercise to sell to headfi type guys.

You can't argue with more parts in a relay system being less reliable but it's still a very useful feature. Headphone sensitivities cover a range of near 50dB. If you want one setup which handles everything then you need something better than an average pot and a couple gain levels.

 

[alekksander]

quite interesting design, but the price is absurd

 

[levimax]

you need something better than an average pot and a couple gain levels.

This is very far from an "average pot". A well executed analog pot is better in every way, it is just hard and expensive to execute well.

 

[JSmith]

FYI company claims that there are 99 opamps used in the P2!

Thanks for the testing Amir.

99

But how am I supposed to roll 99 opamps? I may have to host an opamp rolling get together...

A most unusual design, externally and internally.


JSmith