• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

P452 and Sointuva from March Audio

ozric

Member
Joined
Jul 31, 2020
Messages
22
Likes
43
It's hard to tell from the picture, do these have a stain, or just oil rubbed?
 

Phorize

Major Contributor
Forum Donor
Joined
Apr 26, 2019
Messages
1,533
Likes
2,060
Location
U.K
In case it’s of interest, I asked Alan March for measurements of the P452 buffer. He sent me some adhoc measurements a few months back that he took and was happy for me to share them. Diagrams are below, I’ll just post what he said:


‘I haven’t much time available but you prompted me to very quickly hook up a Purifi eval buffer and our own P452 buffer on the bench and take a measurement.

Now we do have a limitation in that our measurement system isn’t quite as good as an AP555 hence I wanted to show you a comparison between the two boards. The noise and distortion would be a bit lower if measured on an AP.

I couldn’t do a full amp measurement comparison because we are actually completely out of stock of Purifi modules. The P451/P452 have been extremely popular for us and we are waiting for Purifi to send a new batch of modules through. They have been hit somewhat by the covid issues WRT component shortages.

So the set up

Diagram 1 attached.

Both buffers are driving a 4.4kohm load which is the same as the Purifi amp module presents.

The voltage output is set to 1 volt rms which is the level required to output 5 watts from the amp.

Red is the Purifi black is our own buffer.


See attached chart.



Our buffer has very slightly lower 2nd and 3rd harmonic distortion. It also has a lower noise floor by around 4dB.

Overall amp gain with our board is 26.5dB. With the Purifi its slightly higher at 27.5dB which will account for a small amount in the noise floor, but ours is still quieter.’
 

Attachments

  • 30FFB2A0-48B5-4E93-BF40-09B61A30A926.jpeg
    30FFB2A0-48B5-4E93-BF40-09B61A30A926.jpeg
    386.2 KB · Views: 152
  • D0A73498-55AE-4B18-B9FB-4C24F740F2DF.jpeg
    D0A73498-55AE-4B18-B9FB-4C24F740F2DF.jpeg
    264.3 KB · Views: 169
  • 903EDE7B-F083-4A38-A247-1EEB406F7C94.png
    903EDE7B-F083-4A38-A247-1EEB406F7C94.png
    68.5 KB · Views: 171

boXem

Major Contributor
Audio Company
Joined
Jun 19, 2019
Messages
2,014
Likes
4,852
Location
Europe
Noisy high voltage rails are connected to the Purifi buffer while left unplugged for the March buffer.
Measurement wires are running along the same noisy high voltage rails wires on the Purifi while running on a nice clean environment for the March buffer.

Unsurprisingly one is noisier than the other.
 

Phorize

Major Contributor
Forum Donor
Joined
Apr 26, 2019
Messages
1,533
Likes
2,060
Location
U.K
Noisy high voltage rails are connected to the Purifi buffer while left unplugged for the March buffer.
Measurement wires are running along the same noisy high voltage rails wires on the Purifi while running on a nice clean environment for the March buffer.

Unsurprisingly one is noisier than the other.
Well spotted. I guess the measurement for the March buffer is still useful, factoring for the caveat of it being a) from the manufacturer b) ad hoc c) a very basic test.
 

Phorize

Major Contributor
Forum Donor
Joined
Apr 26, 2019
Messages
1,533
Likes
2,060
Location
U.K
Noisy high voltage rails are connected to the Purifi buffer while left unplugged for the March buffer.
Measurement wires are running along the same noisy high voltage rails wires on the Purifi while running on a nice clean environment for the March buffer.

Unsurprisingly one is noisier than the other.

Of course if manufacturers would publish full measurements themselves we wouldn’t be left speculating.
 

restorer-john

Grand Contributor
Joined
Mar 1, 2018
Messages
12,579
Likes
38,280
Location
Gold Coast, Queensland, Australia
Noisy high voltage rails are connected to the Purifi buffer while left unplugged for the March buffer.
Measurement wires are running along the same noisy high voltage rails wires on the Purifi while running on a nice clean environment for the March buffer.

Unsurprisingly one is noisier than the other.

A loopback of the setup is also needed. The interface may be the main contributor to the harmonics for all we know. And those spikes starting to rise up at >17kHz...
 

Mutsu

Member
Joined
Mar 13, 2020
Messages
79
Likes
150
Location
Japan
Sointuva's arrived today, nice and carefully packaged. They look even nicer in person, are very hefty weight wise and feel extremely solid and well made.

I don't have anything to properly measure them with at the moment, but they sound a lot more linear than my old speakers (in a good way). I was getting some considerable booming on certain bass frequencies on my old speakers which I had just assumed were room modes, but I'm not experiencing any of that with the Sointuva's.
 

AudioJester

Addicted to Fun and Learning
Forum Donor
Joined
Jan 7, 2020
Messages
912
Likes
1,211
Sointuva's arrived today, nice and carefully packaged. They look even nicer in person, are very hefty weight wise and feel extremely solid and well made.

I don't have anything to properly measure them with at the moment, but they sound a lot more linear than my old speakers (in a good way). I was getting some considerable booming on certain bass frequencies on my old speakers which I had just assumed were room modes, but I'm not experiencing any of that with the Sointuva's.

Thanks for the feedback. Any pics to share?
Usually less "booming", activation of room modes is a reflection of less bass output (the old my sealed sub sounds better than ported argument). What were your previous speakers?
 

Mutsu

Member
Joined
Mar 13, 2020
Messages
79
Likes
150
Location
Japan
Thanks for the feedback. Any pics to share?
Usually less "booming", activation of room modes is a reflection of less bass output (the old my sealed sub sounds better than ported argument). What were your previous speakers?

I started another thread about them here but there is also a picture below:

sointuva.jpg


That's probably the case about the bass response, I've not seen any frequency response graphs for my old speakers but read that there is a lot of peaks and troughs in the bass response sub 500hz.

My old speakers are Tannoy Precision 6.2, floor standing, rear ported.

Last night with some more listening with the Sointuva's I did notice some slight blooming (to a much lesser degree than the Tannoy's) on 1 or 2 frequencies. They were much lower frequencies by comparison though, which might make sense as I think the Sointuva's also see to go down lower than the Tannoy's.
 

strummr

Member
Joined
Oct 20, 2020
Messages
74
Likes
60
Location
LoCo, VA
Are you talking about the small darker colored patch to the right side of the woofer? If so this is a natural discoloration in the wood grain. See below the cabinets as they came back from the carpenter.

View attachment 148455
Stunning, solid wood beauties! Do we know any more about the 'australian timber' qualities? densities compared to known hardwoods? (I have a number of guitars with wood ranging from ash, alder, mahogany...etc., so curious, since I don't know if it's more like mahogany compared to say, indian rubberwood :p) In regards to March Audio's build quality - I replaced a couple of Bryston mono blocks with the P452 amp, and the power and build quality has exceeded my expectations.
 

NTK

Major Contributor
Forum Donor
Joined
Aug 11, 2019
Messages
2,656
Likes
5,819
Location
US East
Stunning, solid wood beauties! Do we know any more about the 'australian timber' qualities? densities compared to known hardwoods? (I have a number of guitars with wood ranging from ash, alder, mahogany...etc., so curious, since I don't know if it's more like mahogany compared to say, indian rubberwood :p) In regards to March Audio's build quality - I replaced a couple of Bryston mono blocks with the P452 amp, and the power and build quality has exceeded my expectations.
March Audio has posted a link in this post on some reference information on the woods available in Australia.
https://www.audiosciencereview.com/...dio-sointuva-speaker.17162/page-7#post-567364
 

Billy Budapest

Major Contributor
Forum Donor
Joined
Oct 11, 2019
Messages
1,810
Likes
2,674
Oh, I must have missed this, didn't realize they had parted ways. Seems a really poor business decision to alienate such an important source of potential support. Oh well.
Had no idea about this either. Too bad. I liked Alan’s contributions but gosh he could be abrasive.
 
Top Bottom