March Audio P701 Mono Block Power Amp

[Olli]

@DonH56 after a look at the NC1200 modules I have decided that I will be at least testing an external buffer. I do need to implement some input filtering with this module as the on board buffer is wide open, so I am going to knock up a board for this and to use either the LME49724 or the OPA1632 as a buffer.

Alan - how is it going?

 

[March Audio]

Hi Ollie

I am waiting for enclosures at the the moment. Should have arrived last week but another Chinese holiday has delayed them. Also need to finish off a pcb for the piezo power switch. So we are a few weeks away.

Otherwise I have been testing the modules and they sound great.

 

[Olli]

Great. What‘s the verdict on the input stage?

 

[March Audio]

Great. What‘s the verdict on the input stage?

The standard LM4562 sounds/performs just fine

 

[Beerwithme]

Would it be possible to get these amplifiers in silver finish?

 

[March Audio]

Would it be possible to get these amplifiers in silver finish?

Hi

Sorry I missed your post. Unfortunately no. I found with previous products that I did produce in silver that the demand was so low it was not worth the extra production costs. Most people seem to want black.

 

[March Audio]

OK the P701 mono block is finally ready !

There is introductory reduced pricing of $1395 each, but this will only be available for a short period.

The web shop will be updated and the units available form tomorrow.

 

[maty]

Aluminum box? Thickness?

Have you measured how much is heated working at a high power?

 

[March Audio]

You can see the P252 amp passing the FTC power test linked below. Note this is a stereo amp so 500w RMS total output. A video of the P701 being tested will follow in due course. Heat is not an issue, particularly with music. Sine testing is an extreme case and not encountered in real life. Music RMS levels will typically be only 1/5th peak.

 

[March Audio]

I am pleased to announce the P701 is now available in our webshop

https://www.marchaudio.net.au/monoblock-power-amplifiers

 

[RayDunzl]

Is the price in AUD?

 

[PierreV]

Is the price in AUD?

Scrutinize, man, scrutinize.

 

[March Audio]

Is the price in AUD?

Hi Ray,

As Pierre points out pricing is in USD. Its a global business (most sales go to the States) so the logical choice for shop currency.

 

[RayDunzl]

Doh!

 

[Daverz]

I'll keep these in mind if I need to do any seismic structure testing.

 

[March Audio]

I'll keep these in mind if I need to do any seismic structure testing.

Funnily enough fatigue vibration testing on jet engine components with shakers and large audio amps is something I used to do !

They are very good for those difficult speaker loads. Their low impedance drive capabilities are significantly improved over other Hypex modules. I think @Blumlein 88 says his speakers do go sub 2 ohms at certain frequencies.

 

[Thomas savage]

I am pleased to announce the P701 is now available in our webshop

https://www.marchaudio.net.au/monoblock-power-amplifiers

View attachment 27800

Awesome mate , absolute beasts.

 

[Matias]

Can we get an inside picture?

 

[March Audio]

Can we get an inside picture?

There are some above, but I will add more later. Due to the construction in two halves its difficult to show it fully connected up, but I can show the two halves seperated.

Mains wiring is twisted, double insulated with glued heatshrink and covered with braiding. The rear of the IEC mains connector is fully insulated with a boot.

The power wiring from the supply to the amp is again tightly twisted and sheathed with braiding. It's as short and routed as directly as possible. Same with the speaker cable, The board has two sets of connections to minimise output impedance which I utilise. . Note that I use BS free copper cable for superior conductivity .

The XLR connector has an input RF filter PCB on its rear to minimise the possibility of issues such as IM. The signal cable is low noise with a secondary conductive sheath between the screen an signal conductors. This minimises tribo electric noise. Its screen correctly goes to chassis as does the xlr connector. It's physically seperated from the mains and smps power cables. The amp module has the Hypex low noise voltage regulators on board to power the input buffer.

There is a very low power standby Psu board which also has the toggle circuit for the piezo touch switch.

Hope that helps, please ask questions

Cheers

Alan

 

[restorer-john]

I do believe you should amend your specifications as they currently incorrectly state the amplifier will deliver 1200W @2ohms with a THD of 0.001% which is not the case is it?