March Audio P122 Power Amp

[Rockford 425]

I tried to reply to the original thread I spoke about this on, unfortunately it has been locked...so anyway...

 

As I mentioned before I grabbed one of Alan’s March Audio amps, the 125W one. (I have 4 ohm speakers). @March Audio

 

So here is my review of sorts....

 

The unit comes well packed and Alan kept me up to date of what was going on with it, build, burn in etc. I was a little surprised of the weight of the unit (4-5Kg?), coming from a big iron background where most amps are over 20kgs. The case is solid, as are all the connectors, it is a well-made bit of kit.  The most common comment I heard when showing friends and family was, ‘is that all coming from that little box?’

Now this is where Alan needs to probably stop reading…. Yes I know it has THD + N of 0.0015% and an Output Noise of 30uV and a Signal To Noise Ratio of 118 dB but I have absolutely no idea how these characteristics contribute/translate to what I am hearing…So look away Alan… 🙂

 

The first thing I noticed when listening to music was the control, it seems to just pick the music up by the scruff of the neck and play it, there are no errant sounds waffling about, everything is played almost regimental and with great precision. It sounds cleaner as a result - not clearer but cleaner there is no muddiness to the music – although the instruments sound timbrally the same. It is mainly on single note stringed instruments (Tears in Heaven, Girl from Ipanema) and female voices (Rebecca Pidgeon, Susan Wong, Kina Grannis) that you notice it most - they seem so much more precise and controlled. Maybe this is to do with the lower noise floor the amp exhibits?

The bass has become more prominent now as well, or I’d dialled it up on the speakers for the valve amp. (Genesis 501 with Servo Amps on the bass drivers) so I’ve been trying to dial that back in. Not sure if a by-product of the extra power the speakers now have? It is definitely more punchy on the bass. Bear in mind this is the baby amp of the range. The marimba on Ed Sheerans Shape of You is so tight now and the beat stops on a dime.

 

I am still coming to terms how such a small thing can do what it does so effortlessly and there virtually no heat coming off of it.  

 

One thing I thought was strange is that it has the left and right binding posts/inputs as if you are standing behind the unit. It also has quite a definite click and almost bonk noise when turning it on and off through the speakers, not sure if normal in these amps? (it is not loud but noticeable). The power switch takes a bit of getting used to as well. The branded USB Key with the manual on it is a nice touch, although at barely half a Mb, I am wondering if some test tone FLAC's or something could be put on the other 4Gb of space?

 

Am probably splitting hairs on those quibbles above, as I am very, very happy with it so far. I will give it a few weeks and hopefully build an audio memory, then switch back to the Valve amp and see how it fares.

 

 

Edited October 27, 2019 by Rockford

[aussievintage 4,068]

Thanks for posting your impressions.  Certainly sounds like you think it sounds good. 

 

So, going by the ratings and number, this has the NC122MP  amp modules in it.  Price is nice!   I do like the minimalist look.

[Lashes 9]

Hi @Rockford, I enjoyed reading your review of the March Audio amp. Do you still love it as much 1 year on?

 

It sounded like from your review that you were using a valve amp previously. Valve amps have typically produced more of a warm sound. Did you find the March Audio amp still had enough warmth?

 

Thanks for sharing

[Rockford 425]

I've had a few PM's asking the same, and here is my response... I don't think it's 'warmer', colder or anything, just more detailed and clean. Bear in mind I am using a Weston Acoustics amp with hand wound trannies etc, so that is a very capable and detailed performer, very low noise floor. But the March Audio is just dead silence in the background, black like.

 

"The clicks and bump noise was related to my Roon server USB output (well it is just a std PC) there is still a click but no bump anymore. But it is only when I turn it on so no issue, I've got so many things in the chain PC --> DAC --> Amp --> Speaker onboard bass amp that could be the culprit I didn't really take it further.

 

Still really happy with it, using it right now. No-nonsense amp, just plays it how it sees it, no colouration, very accurate, clean and detailed.

 

Still get comments on the size of it, and 'thats all coming from that little thing?' It really does blow my mind how capable it is for it's size."

[Lashes 9]

Thanks for the update. 
 

I’m exploring adding the power amp to my avr and doing a home theatre bypass. 

[Bunno77 1,528]

Is it comparable to the Primare? Still have the Primare? Cheers

[Rockford 425]

10 hours ago, Bunno77 said:

Is it comparable to the Primare? Still have the Primare? Cheers

 

Primare is DAC and Phono. I've not had a Primare amp. I still have them 🙂

[Sinewave 42]

I have a really loud click when I power down my March 502. 
It is scary for me as my speakers don’t have passive crossovers so I’m very concerned that there is a momentary signal spike unfiltered to my drivers..

[andyr 6,069]

4 minutes ago, Sinewave said:

I have a really loud click when I power down my March 502. 
It is scary for me as my speakers don’t have passive crossovers so I’m very concerned that there is a momentary signal spike unfiltered to my drivers..

 

That is annoying - I suggest you should ask Alan why this happens (and what can be done).

 

Others with more electrical knowledge than me can confirm if this is true ... but I understand some mfrs put a cap + res between active & neutral, on the power switch; I always thought this was to kill such spikes?

 

Andy

 

[Bunno77 1,528]

10 hours ago, Rockford said:

 

Primare is DAC and Phono. I've not had a Primare amp. I still have them 🙂

Ahh thank you, thought the silver box may have been an a34. It is another great class D amp

[March Audio 257]

On 02/11/2020 at 10:11 AM, Sinewave said:

I have a really loud click when I power down my March 502. 
It is scary for me as my speakers don’t have passive crossovers so I’m very concerned that there is a momentary signal spike unfiltered to my drivers..

Hi @Sinewave

 

Just seen this.

 

There shouldnt be any "loud" clicks so should be investigated.  What source are you using?

 

Alan

[Sinewave 42]

Upstream from the 502 is a Dolby Lake processor- an active 3 way crossover. 

 

none of my many other amps have this issue. I have multiple NC400 mono and stereo amps, and several Rotel power amps on this circuit, all have been used in various configurations. 
power is from an Isotek Aquarius. I have tried plugging it into a seperate circuit, and also my additional 15A lines too. 
same loud click on power up and down. Definitely louder when powering down. 

[March Audio 257]

11 hours ago, Sinewave said:

Upstream from the 502 is a Dolby Lake processor- an active 3 way crossover. 

 

none of my many other amps have this issue. I have multiple NC400 mono and stereo amps, and several Rotel power amps on this circuit, all have been used in various configurations. 
power is from an Isotek Aquarius. I have tried plugging it into a seperate circuit, and also my additional 15A lines too. 
same loud click on power up and down. Definitely louder when powering down. 

Hi

 

I just wanted to check as the amp is dc coupled so sources with dc offsets on their outputs can cause similar issues.

 

Please contact me via email so we can arrange some further diagnostics/return for service.

 

Alaln@marchaudio.net.au

 

Regards

 

Alan