Purifi with VTV & March Audio

[theSven]

I'm considering upgrading to a new amp for the Ardent D's. Two brands that I like so far are:

https://www.marchaudio.com

https://vtvamplifier.com

Has anyone ever listened to either of these brands? Open to other recommendations such as DIY kits too. Share your thoughts if you have any 🤔

[JonMarsh]

Well, although I am not using PuriFi in my system at present, I do have some of their modules and SMPS power supply for them, and when I manage to dig out from under all the speaker development work I'm committed to, I'll be taking a closer look.

I've come across March Audio before, more because of the speaker stuff they are doing. I won't comment on that here.

They have two stereo amps, and two mono amps. The curious thing about the two stereo amps is that though the power ratings are basically doubled for the more expensive version, the maximum output current rating is the same, at 25 amps. I'm sure this has to do with the specific modules being used and the power supply.

if cost is not a particular barrier, I'd recommend two of the 501 mono amps. More headroom all around, and should handle low efficiency speakers effortlessly. I mention that because low efficiency speakers of a given bandwidth are always smaller, and for some reason (often called "wives") many folks don't want money coffins in the living room. Even the Isiris gets pushback from wives (just ask me- but something are non-negotiable for me).

As to fundamental quality of the power cell, there's no substitute for the PuriFi site... of interest but not described, is how March Audio approaches the front end. The architecture is VERY similar overall to the Hypex OEM modules, and in fact, with a change on one pin of the power module interface, you can operate either a Hypex or PuriFi module. Some of the "secret sauce" is going to be the input driver setup- I suggest looking at the Class D section here for a bit more about that. I've designed my own front end using some higher performance components, but the standard one works pretty well. The selectable gain is available in the PruiFi EVAL board configurations, and if you want to spin your own chassis and procure the power supplies seperatedly, that's a viable option. Cable kits, bare modules, and complete Eval kits are available direct online from PuriFi. I have an EVAL1 kit.







Purely as an aside, it's "interesting" dealing with a woman that comes from a culture where home workshops and designing and building stuff yourself is essentially unheard of... quite a bit of difference, say, between even Estonia and the Ukraine versus Russia. (I have photos of a set of Isiris built in 2015 in the Ukraine, but in all fairness it was by a contractor)(OTOH, our own Ergo has done quite a few builds on his own... Minerva and Wavecor Ardent- I even had the opportunity to demo those for him when he was on a business trip in the USA).

[theSven]

Any thoughts on the VTV amps JonMarsh? Thanks for sharing the other thoughts on the March amps!

[JonMarsh]

I have no direct experience of them but can offer comments about some things discussed on the web site, which I like...


For those that haven't been to the site yet, a quick precis quote:

VTV Amplifier is a custom builder of the latest generation of Class D amplifiers. As an authorized dealer for Hypex, PASCAL A/S and Purifi-Audio, we can customize a design for your specific application. From the economical, integrated MP series NCore modules, ideal for home theater or multiway speakers to high end NCore and Purifi-Audio modules suitable for studio monitoring or high-end home systems, we can build the ideal amplification package for you.

VTV is also an authorized dealer for Mola Mola, Bruno’s other project. Mola Mola offers the ultimate in flexibility and performance.,,,,,,the perfect pairing for your VTV Amplifier!

Note particularly the association with Mola Mola.


In their feature list, this is most intriguing to me, as it implies a higher level of design capability than most of the builders using PuriFi modules.

• VTV Amplifier Custom Input Buffer using a range of discrete opamps from New ClassD, Sparkos, Sonic Imagery and Weiss (optional)

Now, some of the other landing page info definitely highlights their marketing prowess (vacuum tube input buffer; unless it benches better in CMRR and all forms of distortion, I wouldn't recommend that over a more conventional high performance buffer input- but hey, the world goes around based on opportunities for choice, and there are those who will love that because of what's in their heart, not what measurements may tell them... and they won't care about someone pointing out on a AP analyzer that the harmonic richness is due to higher HD2...) (this is the ultimate freedom of choice, after all).

I do suggest watching the "Bruno Strikes Again" video on YouTube, ( I downloaded it) and by all means check out their custom input buffer...

https://vacuumtubevalues.com/product/vtv-amplifier-custom-input-buffer-hypex-nc500-nc1200-nc2k/

Which takes advantage of the feature I've pointed out that you only have to change to functionality on one pin for a driver module to be compatible with both Hypex and PuriFi. And since they don't seem to have figured out or followed my own input module secret sauce concept, I'm not worried...


🤣



And of course, I do fully support the idea of their using APx5x analyzers, as the hardware and software is IMO and experience a big step up for AP, and that they include documentation of measurements with each shipped product. OTOH, why didn't they include the full part number of the analyzer variant they are using? Hmmm? Like my APx555?


😏

OK, enough snark from me, I'm just grumpy because all this reading and posting stuff has put me behind schedule for my to-do tasks this morning. "Sunday Day of Rest" applies to some folks, but I think in my case there is an override due to the "No Rest for the Wicked" principle!

[technodanvan]

I think in general they should sound identical, remember they are just assembling the amplifiers really. I think VTV might have some various options as far as buffers go, but otherwise you're buying the case and the warranty. I've considered both, and really like the 1200 watt/channel NCore version VTV sells for a possible future application.

[JonMarsh]

Again, one might want to read the CLASS D topic section which used to be private.


Now, for those with a more DIY bent of mind, this video is worth a watch (assuming you have some time, but you don't do DIY if you don't have time...)

I have all the bits sitting around, including a chassis, to do this, but it's under the "Deferred Gratification" category for now.



This capture early in the video shows the pieces laid out, and a familiar looking analyzer at the upper right.

[theSven]

Again, one might want to read the CLASS D topic section which used to be private.


Now, for those with a more DIY bent of mind, this video is worth a watch (assuming you have some time, but you don't do DIY if you don't have time...)

I have all the bits sitting around, including a chassis, to do this, but it's under the "Deferred Gratification" category for now.


This capture early in the video shows the pieces laid out, and a familiar looking analyzer at the upper right.

I have been trolling Tom at Neurochrome for some time! Now I may have to try this DIY approach as an interim. To bad Steve Manning doesn't live closer to give me solder lessons 🤣

Thanks for the opinion on the VTV. I will need to dig around the forum and search for more VTV and tag the posts. I have been slowly adding tags to posts now that way searching will be better when I need to look for something and only need to think of a word.