Introducing Vera Audio power amplifiers

[Bjorn]

Vera Audio in Norway was established in 2017 and has since then released two power amplifiers that I would like to introduce. P400/1000 and 150/600 RS. The number in the naming indicates the power output in 8 Ohm and the second number behind the slash is the power output with bridging.

The goal of these two amplifier was to design something with extremely low distortion, high output power in a small but sleek chassis, build quality and cooling that will ensure a long life span combined with several usable functions.

Both amplifiers has a chassis that is cut out from one piece of block of aluminum. There are no seams and no visible screws. The inside of the amplifer has separate chambers to minimize noise. Both units are offered in black or silver finish, brushed aluminum surface.

Vera Audio has developed an input stage (buffer) with only the very best measurable parts. There are no degrading potentiometers in the signal chain. A gain adjustment with 8-step rotary switches with gold contacts 0.004% precision resistor which helps to provide a CMRR (common mode rejection ratio) of at least 100dB at 1kHz. The very low noise and high CMRR making it even a great combination with horns or other high sensitive speakers.


The P400/1000 amplifier is the most powerful one.

Below are specs of the power with rated THD+N distortion. Take note that this continous power.

– Stereo, both channels driven at 8 ohms:
– 400W with maximum 1% THD+N
– 330W with maximum 0.01% THD+N
– 300W with maximum 0.004% THD+N

Stereo, both channels driven at 4 ohms:
– 750W with maximum 1% THD+N
– 620W with maximum 0.01% THD+N
– 550W with maximum 0.004% THD+N

Bridged, driven at 8 ohms:
– 1500W with maximum 1% THD+N
– 1100W with maximum 0.01% THD+N
– 800W with maximum 0.004% THD+N

Considering the high amount power in a small chassis, we chose to use temperature controlled fans besides a cooling block inside. These fans are extremely silent and basically not audible. More about this later.

The second model is the P150/600 RS. This amplifier stays very cool and therefore has no fans like the big brother.




While not as powerful as the P400/1000, the P150/600 RS is the best measurable amplifier. This unit also has an auto standby function where it automaticall goes into the standby if there's no signal for 3 hours. The timing here can be changed.

Below are specifications. Take note that the amplifier measures better than our measuring gear. So the distortion is actually likely somewhat lower than this.

Continuous power:
Stereo, both channels driven at 8 Ohm
– 220W with maximum 1% THD+N
– 180W with maximum 0.01% THD+N
– 140W with maximum 0.0005% THD+N

Stereo, both channels driven at 4 Ohm
– 420W with maximum 1% THD+N
– 340W with maximum 0.01% THD+N
– 270W with maximum 0.0007% THD+N

Bridged 8 Ohm
– 800W with maximum 1% THD+N
– 680W with maximum 0.01% THD+N
– 600W with maximum 0.0005% THD+N

Bridged 4 Ohm
– 920W with maximum 1% THD+N
– 900W with maximum 0,0007% THD+N

Functions:
A 12V trigger input is in the rear and with a LED indicator that lights up when connected.

Both amplifiers are bridged by turning a knob.

The gain control is also controlled for each channel with knobs in the rear. The gain settings are as follows: 12, 15, 18, 21, 24, 27 and 30 dB. There's also a mute function.
As one can see form the table above, the error between the channels is less than 0.00dB for all gain setting except the 12dB setting that has 0.01dB error. The absolute gain error from the indicated gain is maximum 0.04dB at the 30dB setting. This ensures that when the user set the switch to 24dB he knows it is 24dB ant nothing else.



Micro controller and clipping indicator
A micro controller is constantly monitoring the output for clipping. If the load is too low it’s signaled with blue blinks in the front LED light, and if the voltage is too high it will be signaled with green/red blinks depending on the channel. This is very useful function, knowing that when a blink is seen one should dial back a dB or two or consider buying a second amplifier for bridging and more power available.

For only the P400/1000 unit: The micro controller also monitors the heat on both channels and intelligently increase the fan speed as necessary. No internal part will exceed 65° no matter how you use it or where you install it.

RFI/EMI filter and protection
Multi-step EMI filtering in the input stage to effectively keep harmful radio waves away from the audio circuit. In addition, the entire entrance stage is mounted inside a screen in a separate chamber inside the cabinet. The Neutrik XLR connectors are also shielded.
Special ESD precautions then can handle up to 7A short ESD pulses.
Overvoltage precautions that can handle high currents up to several tens of volts without damaging the input.



In the picture below of the P150/600 RS one can see that the entrance stage is in a separate chamber.



Warranty and quality control
We gurantee a warranty of 2 years but a 5 year warranty is also given as long as we can get hold of needed parts.
Every amplifier is tested before it leaves the bench and we measure that everything is within specifications.

We welcome any questions.

 

[AudioLibertarian]

Hi,

What are the continuous and peak currents? Are these stable into 2 ohm loads? Thanks !

 

[Bjorn]

Hi,

Are these Class D amps? What are the continuous and peak currents? Are these stable into 2 ohm loads? Whats the pricing? Thanks !

Yes, these are class D amps. They are stable with 2 Ohm loads.

Prices:
P400/1000: 28 000 NOK excl. VAT and shipping, which is approximately $2828 with today's currency.
P150/600 RS: 30 000 NOK excl. VAT and shipping, which is approximately $3030 with today's currency.

Peak current is 25A. Both amplifiers can also handle 25A current continuously before heat buildup becomes a problem.

 

[gryphongryph]

Was initially interested in these amps but the 2 year warranty and up to five years if parts are to be found put me off, that’s the problem I have with class D, what happens if the amp stop working after seven or ten years? Will there be any parts available?

 

[Kingrex]

If the price is $3k shipped. Who cares if it breaks after 10 years. Get a new one.

 

[gryphongryph]

I am afraid that these class D amps will leave a much bigger footprint on earth than my class A amp that will probably last 15 years plus and where one can get it repaired if needed!

 

[Bjorn]

Was initially interested in these amps but the 2 year warranty and up to five years if parts are to be found put me off, that’s the problem I have with class D, what happens if the amp stop working after seven or ten years? Will there be any parts available?

There are no reasons to believe parts will not be available for a long unforseen future. In absolutely worst case scenario, we would have to use a newer model of an amplifier module or a PSU.

Also want to add that our class D amplifiers are built to last with high building quality and very good cooling solutions. Class D also need to be under a certain temperature in order to last long. I'll write more about in a next post.

 

[gryphongryph]

I see that the P150/600 RS is sold out!
Is there a new/update coming ?

 

[Bjorn]

Power and cooling in class D amplifiers

Let's look at power and cooling requirements in class D amplifiers since there is a widespread attitude that this is not a problem. Chapter Audio was one of those who underestimated this and sold expensive amplifiers that failed after a relatively short time.

If you want to extract high effects from class D, cooling is required, and not in the same way in traditional class A/B amplifiers, where all the effect is transferred in the transistors that are placed on the heatsink.

Class D amplifiers also have switching transistors that must be cooled. These sit on a cooling plate and it doesn't take much to keep the temperature on these under control. As a rule, it is enough that they are screwed to the chassis.

But at the output there is a coil which together with capacitors lowers the switching noise to livable levels, and there a good deal of heat develops both at idle and especially at high currents. Since class D amplifier modules are typically made physically small, the heat from this coil will in practice heat up the entire module to temperatures that will eventually cause the electrolytic capacitors to dry out.

When we designed the Vera Audio amplifier we had a desire to offer high power and before the cooling solution came into place we measured temperatures of over 120° C (248° Fahrenheit) on the modules! The modules can withstand it, but it goes without saying that they will not last long if they are exposed to such temperatures over time.

The Vera Audio P400/1000 amplifier has a power plant that has solutions that no other NC500 manufacturer offers and that allows it to deliver more power without affecting its lifespan.

* Power supply is 3kW

* The output coils are cooled with their own heatsink which is connected to the chassis.

* Fans can kick in if it is run too fast and ensure that the temperature is kept under control.

A picture of the parts that provide temperature control in the Vera Audio P400/1000 amplifier:


The 120g cooling block is machined from a piece of aluminum and transports heat away from the output coils and into the cabinet's 8mm thick cylinder head. The cabinet is milled out of one piece of aluminum weighing 22 kg and ensures a uniform heat transfer. This lowers the temperature of the coils by 20° C (60° F) at idle and up to 50° C (122° F) at full load. This will give the modules much better working conditions and significantly increase their lifespan.

We have equipped the modules with their own temperature sensors that measure the temperature of both modules and report this to a separate control board with a microcontroller. At very high loads or ambient temperatures, the fans will start at very low speed. (400-500RPM).

The specially designed channels focus the air flow to the hottest areas of the amplifier module and even a very modest air flow is enough to keep the temperature below 65° C (149° F) even under very heavy load. The temperature and fan speed are updated every second, start only when needed and will never go faster than necessary.

The fans are of the PWM types for Noctua (NF-A6x25 PWM) and have a maximum sound level of 8dB SPL at 1600RPM. Tests we have done with music signals show that they stay below a completely silent 1000RPM even when the amplifier delivers 1.5kW of power in the peaks at 8 ohms. (280 volts peak to peak out on the speakers). On this amplifier, the module will therefore never get hotter than 65°C (149° F) regardless of load and ambient temperature.

At "normal" listening levels and ambient temperatures, they don't need to start at all.

Here is a thermography image of the coils without the cooling block fitted. We can see that the coils are white and the temperature spreads over the rest of the modules.


This is how a 3D model of the cooling solution looks like without the ducts and the cabinet itself:


This is what the amplifier looks like when it delivers 800W continuous power for 2 hours:

 

[Bjorn]

I see that the P150/600 RS is sold out!
Is there a new/update coming ?

It should be back in stock within some weeks. No update.

 

[Bjorn]

I am afraid that these class D amps will leave a much bigger footprint on earth than my class A amp that will probably last 15 years plus and where one can get it repaired if needed!

That would be the case if they were not built to last. Without mentioning names, many class D amps being sold today have very poor cooling, and we're already seen some of these fail after only a few years. They basically cooked.

Vera Audio's philosophy is however, to built products that will have a long life span. We're opposed to the idea of buying and throwing away electronics after some years.

Repairing is something that's is easy with our amplifiers if something should fail. This means the cost of repairing outside warranty isn't high either.

 

[Republicoftexas69]

That would be the case if they were not built to last. Without mentioning names, many class D amps being sold today have very poor cooling, and we're already seen some of these fail after only a few years. They basically cooked.

Vera Audio's philosophy is however, to built products that will have a long life span. We're opposed to the idea of buying and throwing away electronics after some years.

Repairing is something that's is easy with our amplifiers if something should fail. This means the cost of repairing outside warranty isn't high either.

I will stick with my GaN amplifers from Gold Note. Running bridged PA-10s not quite to the performance of my tube amplification but better than my old 330A. Solid performers and inexpensive.

 

[Bjorn]

The P150/600 RS should be back in stock within a few weeks.

I will present the speaker below in a separate thread when the time is right, but just giving a teaser here. Picture here is shown without feet FIY.


The name of the speaker is Coherence 12. It's an active speaker design with planar magnetic driver that covers both the treble and the midrange. And with a 12" midwoofer with high excursion capability. Sensitivity of 95-96 dB and bass reflex design with large volume and a long port. It's a full range speaker that can deliver high SPL.

It will be sold either with internal plate amplifiers or with the choice of external electronic together with a DSP and the choice of own amplifiers. It requires 4-channels amplification that is directly connected to the two drivers. The DSP will also function as a preamp and multichannel DAC. A few DSP options will be available.

Drivers are time aligned making sure the sound arrives from the drivers to the ear at exactly the same time, and we'll most likely a phase linear crossover. The cabinet is a super elliptical shape with no sharp corners to avoid edge diffraction, and the wide cabinet has a very low baffle step with leads to more engaging sound.

The speaker has a very uniform horizontal dispersion and minimizes detrimental vertical reflections and floor bounce. It measures very evenly when placed in the room and therefore works really well with low distortion amps like our Vera Audio units. With the DSP, one can tailor the low frequency to the specific boundary gain of that room it's placed in. Making sure of correct level in the lows no matter whether it's placed closed to a wall and far out.

It will be quite reasonabled priced due to direct sales. Hopefully ready within early fall.