VTV Purifi Amplifier Review with Weiss Buffer

[vkvedam]

Woah! Talk about a company's design DNA, it is there no matter what

 

[Matias]

Any tear down pictures of this particular sample to see if the workmanship, wire routing, etc., is consistent between both VTV units?

Isn't this the same unit from the teardown but Amir just swapped opamps?

 

[Billy Budapest]

Isn't this the same unit from the teardown but Amir just swapped opamps?

I thought it was a different unit sent to Amir by a different member.

 

[restorer-john]

Steel is a cheap solution, just like Apollon did with the Purifi Mini.
https://www.apollonaudio.com/apollon-1et400a-mini-stereo-amplifier/

So you reckon that L-shaped piece of metal is steel for shielding purposes? It looks about 3-4mm thick.

The rest of the chassis is supposedly Aluminium.

 

[amirm]

I thought it was a different unit sent to Amir by a different member.

No, both are owned by the same owner and hence back to back review. I need to get them back to him.

They are indeed identical units sans the op-amp choice. I will do a teardown later tonight.

 

[Rja4000]

@amirm
Does this one also have the double SMPS1200A400 power supply ?
It doesn't seem to improve anything compared to a single PS, does it ?
Especially, power doesn't increase.

So that's just a waste of money ?

On Purifi website, we can read "Most frequently it is the system power supply that becomes the limiting factor in a application incorporating the 1ET400A module(s).".
Comparing measurements, it doesn't seem to be true in practice. Or is there another limiting factor ?

May it even be the cause of this performance degradation ?

Edit: I've just read other comments above after posting

 

[redshift]

No, both are owned by the same owner and hence back to back review. I need to get them back to him.

They are indeed identical units sans the op-amp choice. I will do a teardown later tonight.

Maybe try add some ad-hoc shielding cans and tinfoil to isolate the input section if there is some EMI interference with improperly designed/laid out electronics?

 

[GWolfman]

I'm curious to know just what you mean by "stock" buffer: are you referring to the Hypex buffer? I first order my VTV Purifi stereo amp, (i.e. single PSU version), with the Hypex buffers. Much to my surprise the high frequencies seemed bright and harsh, especially at higher volumes which I found intolerable. I replaced the Hypex cards with a pair of VTV buffers with Sparko SS3602 op amps which solved the problem.

Stock buffers as in Hypex evaluation buffers. (I don't think they make any others.) I’ve read in other places these weren't intended for use in production use/builds.

 

[amirm]

Maybe try add some ad-hoc shielding cans and tinfoil to isolate the input section if there is some EMI interference with improperly designed/laid out electronics?

This is not mine to mod. That is assuming I had the time for such a project which I don't.

 

[Francis Vaughan]

I’ve read in other places these weren't intended for use in production use/builds.

They measure as exemplary implementations. So much so that you would have to come up with a really good reason not to use them. Really good reasons will include their price and lack of flexibility. Putting the amplifier modules in a real product will likely be better served by a custom interface board that is exactly crafted for need. That might be a single board that provides buffering and interface for many more boards, or improves packaging and layout. In that respect this interface board is not suitable for production use, as, in particular, it dictates the precise layout of the connectors.

But for a simple box builder like VTV the only reason not to use it is to craft the sound away from perfect, or to add some undefined magic dust. I wonder if anyone has bought the version with a tube stage in the way?

 

[Zoomer]

I've read both reviews and the teardown.

Performance: "superb", "top of the class".
Price: unbeatable (lower than sellf-sourcing the components)

Recommendation: nope.

Compared to some other reviews I find this very harsh.

I would understand if it was out of security concerns, but are we even talking about audible sound degradation here?

 

[vkvedam]

I've read both reviews and the teardown.

Performance: "superb", "top of the class".
Price: unbeatable (lower than sellf-sourcing the components)

Recommendation: nope.

Compared to some other reviews I find this very harsh.

I would understand if it was out of security concerns, but are we even talking about audible sound degradation here?

You would think the same if you had read Amir's explanation after the conclusion. I agree. As much as he wants to recommend it he can't given the broken implementation.

 

[DSJR]

So you reckon that L-shaped piece of metal is steel for shielding purposes? It looks about 3-4mm thick.

View attachment 140603


The rest of the chassis is supposedly Aluminium.
View attachment 140602

I know, to me that pic is eye-fi, but that one looks superbly put together. What amp is it from please?

 

[redshift]

I've read both reviews and the teardown.

Performance: "superb", "top of the class".
Price: unbeatable (lower than sellf-sourcing the components)

Recommendation: nope.

Compared to some other reviews I find this very harsh.

I would understand if it was out of security concerns, but are we even talking about audible sound degradation here?

Bad analogy time; would you consider it a-ok to have your V8 to fire on only seven cylinders? After all; it still produces 450hp instead of 650. Don’t be so demanding.

 

[restorer-john]

I know, to me that pic is eye-fi, but that one looks superbly put together. What amp is it from please?

That's the Apollon Purifi mini someone mentioned. It's about the only one of these Purifi jobs that is mildly appealing IMO. Not cheap, but very well executed. If I wanted a Purifi power amp, I'd buy that one. And, thank goodness, properly earthed. Nice set of adjustable gains, SE and Balanced, dimmable logo and proper rear panel markings.

https://www.apollonaudio.com/apollon-1et400a-mini-stereo-amplifier/

 

[DSJR]

That's the Apollon Purifi mini someone mentioned. It's about the only one of these Purifi jobs that is mildly appealing IMO. Not cheap, but very well executed. If I wanted a Purifi power amp, I'd buy that one. And, thank goodness, properly earthed. Nice set of adjustable gains, SE and Balanced, dimmable logo and proper rear panel markings.

https://www.apollonaudio.com/apollon-1et400a-mini-stereo-amplifier/

For us in the UK, almost affordable when you look at the stuff Naim Audio make and how much they sell for via their very enthusiastic dealer base!

 

[Francis Vaughan]

So you reckon that L-shaped piece of metal is steel for shielding purposes? It looks about 3-4mm thick.

If it is, and if it worked, it would be by pure luck. As I wrote earlier, you can't shield magnetic fields like this. So much so that there is just as good a chance that a random lump of steel placed like this could concentrate the field somewhere you really don't want it. Magnetic and electrical fields work in fundamentally different ways and you can't use an intuition from one for the other.

∇.B = 0
∇.E = ρ/ε0

 

[redshift]

If it is, and if it worked, it would be by pure luck. As I wrote earlier, you can't shield magnetic fields like this. So much so that there is just as good a chance that a random lump of steel placed like this could concentrate the field somewhere you really don't want it. Magnetic and electrical fields work in fundamentally different ways and you can't use an intuition from one for the other.

∇.B = 0
∇.E = ρ/ε0

How about magnetic shielding?

 

[Rja4000]

That's the Apollon Purifi mini someone mentioned. It's about the only one of these Purifi jobs that is mildly appealing IMO. Not cheap, but very well executed. If I wanted a Purifi power amp, I'd buy that one. And, thank goodness, properly earthed. Nice set of adjustable gains, SE and Balanced, dimmable logo and proper rear panel markings.

https://www.apollonaudio.com/apollon-1et400a-mini-stereo-amplifier/

Unfortunately, they don't provide measurements to prove their buffer does no harm.

Why not the DIY/Eval 1 + Ghent case version ?
It's cheaper and, well, we know how it measures.

I would also prefer XLR and Speakon only personnaly.

 

[Stoutblock]

This is not mine to mod. That is assuming I had the time for such a project which I don't.

Ha! Feel free to experiment a bit if you wish...