VTV Purifi 1ET400A updates

[chifanpoe]

After reading Amir's review of your Crown amp I can't imagine why you feel the VTV isn't sonically superior. The specs aren't even close. I know we don't listen to specs but they are indicative of performance.

Right, that is why I said it sounded better and I like it better

 

[chifanpoe]

Another question: How do you know the Crown outputs more power? Possibly more power but probably not more clean, undistorted power. I'm not sure most speakers (or certainly eardrums) can utilize in excess of 150 watts of power except during very brief transients. Most are surprised how little power is being delivered to their speakers even when listening at extremely loud volumes.

I am sure the PURIFI is much cleaner at any db range it can push on my LRS speakers. It is certainly much clearer at the 60-80db range I normally listen at.

Magnepans like lots of power as they are pretty inefficient and hover around 80db of sensitivity and run around 2.8-3.33 ohm. So from my basic switching between the two amps while using all the same other equipment and source material I need to turn my volume up several more "clicks" to get the same db range from where I sit. This would tell me that the crown puts out more wattage (clean or not). I am very happy that the PURIFI can drive them just fine for my listening needs.

 

[Rottmannash]

I am sure the PURIFI is much cleaner at any db range it can push on my LRS speakers. It is certainly much clearer at the 60-80db range I normally listen at.

Magnepans like lots of power as they are pretty inefficient and hover around 80db of sensitivity and run around 2.8-3.33 ohm. So from my basic switching between the two amps while using all the same other equipment and source material I need to turn my volume up several more "clicks" to get the same db range from where I sit. This would tell me that the crown puts out more wattage (clean or not). I am very happy that the PURIFI can drive them just fine for my listening needs.

I thought that could be the difference in dB gain.

 

[amper42]

Magnepans like lots of power as they are pretty inefficient and hover around 80db of sensitivity and run around 2.8-3.33 ohm. So from my basic switching between the two amps while using all the same other equipment and source material I need to turn my volume up several more "clicks" to get the same db range from where I sit. This would tell me that the crown puts out more wattage (clean or not). I am very happy that the PURIFI can drive them just fine for my listening needs.

The reason you need to turn up the volume control with the Eval-1 Purifi amp design is it has a lower voltage gain of 26.5dB while the Crown is closer to 30dB gain. I have the same issue when I compare using the Monolith 7x200 amp (28dB gain) compared to the March Audio P452 Purifi (26.5dB gain).

 

[Rottmannash]

Listened til late last night. Streamed Dan Fogelberg's "Portrait-The Music of Dan Fogelberg" via Qobuz. The best way I can describe the sound from this VTV amp is pure, clean, powerful and accurate, at any volume. The reason music, and hence the ridiculous amount of electronics I own is important to me is the effect it has on me-I was listening to this collection of songs and "Leader of the Band" came on and I immediately teared up-it was so beautiful, so "real" it reminded me why I listen. For these moments the price of admission is well worth it to me. I hope to enjoy this amp and the associated electronics for many more years.

 

[mhardy6647]

VTV?
There's another VTV?

 

[Rottmannash]

For anyone interested here's a link to an interview Darko conducted with Bruno Putney, discussing the Purifi module as well as other issues of interest to audiophiles.

https://darko.audio/2020/07/expert-opinion-bruno-putzeys-purifi-hypex-kii-mola-mola/

 

[Rottmannash]

Update: Received my Freya+ and hooked it up to the Purifi amp and let's just say with the tube buffer a bit of wonderful occurs. Sounds good with the solid state buffer but that tube-thing....I highly recommend the pairing. Can't get over how clean and powerful the Purifi amp sounds. Highly recommend buying one before the price goes up yet again.

 

[Rottmannash]

Could you name a couple of song where you found this particularly noticeable? I'd like to see if I can reproduce it on my sistem. I also usa a D90, then into Freya S and a Purifi Eval1 based DIY build, so quite similar electronics.

Cheers,
Seb[/QUOTE

I'm also running E30> Node 2i> Freya+> VTV Purifi Eval 1 and don't hear anything untoward.

 

[Aventador_SVJ]

Having read quite a lot around the Purifi amplifiers, I am slightly confused about what is wrong with the EVAL-1 Purifi version of the VTV amplifier.

I have looked at the data sheet and see that the buffer stage is made up of a dual OPA1612 (it also looks like you can bypass this stage and take the gain down from 27dB down to 13dB by changing the jumpers).

There has been a lot off discussion about the EVAL-1 being unsuitable due to the buffer stage and would like to fully understand this?

All responses are appreciated.

 

[Roger285]

Yes, I have this question too!

 

[Sebastijanovski]

Those comments don't pertain to the Purifi Eval 1 but to the Hypex evaluation boards originally meant for the NCore modules. Those boards don't have any filtering on them to eliminate radio frequency interference and could lead to audible artefacts making their way to the power modules.

There's a lot of confusion around that because the Hypex and Purifi components lie in the same product space. I believe, but I could be wrong, that the Hypex evaluation buffers could also be used to drive the Purify modules.

Cheers,
Seb

 

[Aventador_SVJ]

Those comments don't pertain to the Purifi Eval 1 but to the Hypex evaluation boards originally meant for the NCore modules. Those boards don't have any filtering on them to eliminate radio frequency interference and could lead to audible artefacts making their way to the power modules.

There's a lot of confusion around that because the Hypex and Purifi components lie in the same product space. I believe, but I could be wrong, that the Hypex evaluation buffers could also be used to drive the Purify modules.

Cheers,
Seb

Are you referring to the Hypex SMPS1200 power supply?

I thought that the VTV has RFI filtering on the mains cable input?

 

[Champster]

I have a pair of VTV Purifi (1ET400A) stereo amps with the standard buffer to power my JBL M2s. I love them! They have fantastic soundstage depth, width and the separation of instruments and is great. They are extremely accurate. If you're looking for that lazy rounded off square wave of tube gear, don't get these amps. I really don't understand what people are talking about when they talk about glare and such with them. Now, I don't listen very loudly (85-90dB) and so I am not pushing them very hard. Perhaps that is why I'm not hearing it.

 

[Rottmannash]

I have the VTV amp you're asking about. There is no issue with these amps. The issues are with the Hypex Eval boards, as they were never intended to be used without added filtering. At least that's my understanding. My amp sounds better than any amp I've owned, and I've owned quite a few over the years.

 

[Billy Budapest]

Let me clear up the discussion above because there are a lot of wires being crossed.

1). Hypex evaluation buffer boards do not have filtering that is present in most commercial audio products. That’s why some people say that they should not be used in commercial products and should only be used by companies or DIYers to evaluate their circuit designs. The Hypex evaluation boards are available as a buffer option for VTV Hypex and Purifi amps.

2). Purifi released two evaluation buffer boards (the EVAL-1 [stereo] and EVAL-2 [mono]) that do include proper filtering. VTV sells a Purify Eval-1 amplifier, and therefore its buffer module implements proper filtering.

3). The VTV Purifi amplifiers also include an inline EFI/RFI mains filter built into the IEC socket. It is unclear if this mains filter contains x-capacitors or y-capacitors. Bruno Putzeys has warned that EFI/RFI filters that contain y-capacitors should not be used internally with Purifi modules. An external EFI/RFI filter with y-capacitors is OK to use.

 

[Rottmannash]

Let me clear up the discussion above because there are a lot of wires being crossed.

1). Hypex evaluation buffer boards do not have filtering that is present in most commercial audio products. That’s why some people say that they should not be used in commercial products and should only be used by companies or DIYers to evaluate their circuit designs. The Hypex evaluation boards are available as a buffer option for VTV Hypex and Purifi amps.

2). Purifi released two evaluation buffer boards (the EVAL-1 [stereo] and EVAL-2 [mono]) that do include proper filtering. VTV sells a Purify Eval-1 amplifier, and therefore its buffer module implements proper filtering.

3). The VTV Purifi amplifiers also include an inline EFI/RFI mains filter built into the IEC socket. It is unclear if this mains filter contains x-capacitors or y-capacitors. Bruno Putzeys has warned that EFI/RFI filters that contain y-capacitors should not be used internally with Purifi modules. An external EFI/RFI filter with y-capacitors is OK to use.

Thank you for the clarification. One question: What is the potential negative consequence of using y caps?

 

[Billy Budapest]

Thank you for the clarification. One question: What is the potential negative consequence of using y caps?

Unsure, but someone else will know.

 

[Billy Budapest]

Thank you for the clarification. One question: What is the potential negative consequence of using y caps?

Also, what you posted above was totally clear. There were just a lot of other people asking questions and answering questions, and the posts and responses were a little jumbled.

 

[Aardappel]

Let me clear up the discussion above because there are a lot of wires being crossed.

1). Hypex evaluation buffer boards do not have filtering that is present in most commercial audio products. That’s why some people say that they should not be used in commercial products and should only be used by companies or DIYers to evaluate their circuit designs. The Hypex evaluation boards are available as a buffer option for VTV Hypex and Purifi amps.

2). Purifi released two evaluation buffer boards (the EVAL-1 [stereo] and EVAL-2 [mono]) that do include proper filtering. VTV sells a Purify Eval-1 amplifier, and therefore its buffer module implements proper filtering.

3). The VTV Purifi amplifiers also include an inline EFI/RFI mains filter built into the IEC socket. It is unclear if this mains filter contains x-capacitors or y-capacitors. Bruno Putzeys has warned that EFI/RFI filters that contain y-capacitors should not be used internally with Purifi modules. An external EFI/RFI filter with y-capacitors is OK to use.

Good summary! The only thing I would add to your 2nd point, is that if you decide to bypass the input buffer (to reduce the gain) that you also bypass the filtering on the board.