Review and Measurements of Purifi 1ET400A Amplifier

[phoenixdogfan]

Does anyone make a case that works with the Eval 1 KIT and a single Hypex SMPS1200A400 power supply? I bought a Ghent case that 300mm wide, but I dont know if it's long enough to accommodate both the power supply and the eval kit. Looks like it should be a breeze to connect the SMPS 1200 to the Eval1 but even if I were able to use the Ghent case, I would need a new back panel. Anyone know who might make me one of those?

Think this is a better amp than the dual NCore 400, but trying to source a case is the problem I see here.

 

[Labjr]

Is anyone making a case for the EVAL1 that uses the PCB as is by adding extensions to the XLR connectors?

 

[Tartaruga]

Guys someone ordered the vtv stereo amp and got it shipped?
https://vacuumtubevalues.com/product/27564/
Any thing that I should consider? The lack of buffer will result in lower volume? (but better sinad?)
My speakers are 90db and my listing room is pretty small.

 

[Matias]

Guys someone ordered the vtv stereo amp and got it shipped?
https://vacuumtubevalues.com/product/27564/
Any thing that I should consider? The lack of buffer will result in lower volume? (but better sinad?)
My speakers are 90db and my listing room is pretty small.

https://www.audiosciencereview.com/forum/index.php?threads/diy-purifi-amp-builds.10478/post-368849

 

[Labjr]

I suppose Purifi will make a higher power module at some point, so you won't have to decide between power and sound quality. But maybe won't be available to DIY?

 

[JustJones]

You can choose the buffer.

https://vtvamplifier.com/product/vtv-amplifier-stereo-purifi-audio-1et400a-amplifier/

 

[Karu]

Which of the opamps offered for the VTV is the best fit for the purify module to get? The stock one?

 

[JustJones]

Which of the opamps offered for the VTV is the best fit for the purify module to get? The stock one?

I have no idea here is a link where the sparkos and sonic imagery were compared. Not sure if they are the same model numbers.

I was looking at these I would probably get the stock or go all out and get the Weiss.

https://www.audiosciencereview.com/...-opamp-review-sonic-imagery-vs-sparkos.10325/

 

[phoenixdogfan]

You can choose the buffer.

https://vtvamplifier.com/product/vtv-amplifier-stereo-purifi-audio-1et400a-amplifier/

That's the 300 mm Ghent case they are using.

 

[phoenixdogfan]

Is anyone making a case for the EVAL1 that uses the PCB as is by adding extensions to the XLR connectors?

Apparantly Vacuum Tube Values is.

 

[phoenixdogfan]

"The Amp Connector board is offered as convenience. In that regard, I tested the amplifier with and without the extra gain that the connector board provides. Alas, I wish there was something in between. You get full power with as little as 1.5 volt with the extra gain but need 11+ volts without it. I like to see manufacturers build a gain stage that produces full power at 4 volt which we routinely get out of source products (e.g. DACs)."

To me this sounds like an exercise in gain staging. If someone wanted to pair this particular flavor of amplifier with an Octo Research Pro 8, it might be possible to bypass the gain stage in the amp connector board, and have the folks at Okto set the output voltage on the Pro 8 where you would need them.. I seem to recall Pavel promised he would allow custom settings for output for the Octo. Assuming he could do that would you want its output to be set to, say 12 volts? Could something like that be done without compromising the performance of the Octo while maximizing the performance of the Purifi?

 

[JimB]

Apparantly Vacuum Tube Values is.

From the linked ad, they do not offer the Purifi input buffer board as an option.

 

[TabCam]

"The Amp Connector board is offered as convenience. In that regard, I tested the amplifier with and without the extra gain that the connector board provides. Alas, I wish there was something in between. You get full power with as little as 1.5 volt with the extra gain but need 11+ volts without it. I like to see manufacturers build a gain stage that produces full power at 4 volt which we routinely get out of source products (e.g. DACs)."

To me this sounds like an exercise in gain staging. If someone wanted to pair this particular flavor of amplifier with an Octo Research Pro 8, it might be possible to bypass the gain stage in the amp connector board, and have the folks at Okto set the output voltage on the Pro 8 where you would need them.. I seem to recall Pavel promised he would allow custom settings for output for the Octo. Assuming he could do that would you want its output to be set to, say 12 volts? Could something like that be done without compromising the performance of the Octo while maximizing the performance of the Purifi?

The AudioPhonics HPA-Q400ET offers user configurable (jumpers) gain stages for no gain, 7.2 and 12.5 dB gain for maximum output with ±10V ±4.2V and ±2.2V RMS respectively.

 

[JustJones]

The VTV purifi uses the stock NC500 eval board or the upgrade options. Yes it's the 300mm Ghent case as well.

 

[Labjr]

A lot of companies have popped up in the amplifier assembly business.

 

[Matias]

A lot of companies have popped up in the amplifier assembly business.

Rightfully so. What differentiates them is the parts quality, assembly best practices and price of course.

 

[orangejello]

Here is a picture of the VTV. With stock buffer it cost $900. Anyone care to comment on the build? It looks like scant attention has been given to cable dressing, but does that matter much in this case? Looks a little rough to me, but the price is compelling.

 

[Labjr]

Can the buffer be configured for single ended input?

 

[March Audio]

Here is a picture of the VTV. With stock buffer it cost $900. Anyone care to comment on the build? It looks like scant attention has been given to cable dressing, but does that matter much in this case? Looks a little rough to me, but the price is compelling.

View attachment 59624

Please Note my vested interest here but these are genuine observations

No mains safety earth connection. The mains wiring doesn't confirm to class 2 standards so it is required for safety. Add it in yourself for your own safety.
Speaker post soldering quality.
XLR screen incorrectly wired.
General wiring routing and hygiene. Yes it matters. Tight twisting required to minimise switching radiation and pickup.

 

[JustJones]

I have the VTV Purifi with the stock Ncore 500 buffer the one you are showing looks like the sparkos buffer or the upgrade stock buffer it isn't the Ncore. Yes the wiring is messy. I haven't decided if I will keep it or redo the wiring myself.