Small desk-friendly power amp recommendations

[jammymalina]

Hi Audiosciencereview,

I am getting Radiant Acoustics 4.2 for my desk and I need a power amp. I already have Violectric headphone amplifier which I will use as a preamp and volume control. My current favourite is Cambridge Audio MXW70 because it's quite small and the reviews are solid. I am open to other suggestions. My budget is max 1000€, I am willing to go a few hundred above if the quality justifies it. Also I am willing to buy used.

Feel free to share your suggestions!

 

[Roland68]

Hi Audiosciencereview,

I am getting Radiant Acoustics 4.2 for my desk and I need a power amp. I already have Violectric headphone amplifier which I will use as a preamp and volume control. My current favourite is Cambridge Audio MXW70 because it's quite small and the reviews are solid. I am open to other suggestions. My budget is max 1000€, I am willing to go a few hundred above if the quality justifies it. Also I am willing to buy used.

Feel free to share your suggestions!

I wouldn't pay too much attention to the price; it really doesn't need to exceed €1,000.
The Cambridge CXA81 MKII didn't perform any better in the ASR test than, for example, a Fosi Audio V3 Stereo for €100. My own listening impressions were consistent with this.
Amplifiers such as the 3E Audio A5, A5se, A7, A7se, A7 Mono, Topping PA5 II, B100/B200, Fosi Audio V3 Mono, etc. have significantly better measured values and, in my opinion, also sound better.
The Sabaj A30a, or the identically constructed SMSL VMV A2, in particular, should be a good and powerful partner for the Radiant Acoustics 4.2. These amplifiers also don't require an additional DAC.

 

[DanielT]

Consider this regarding appropriate power level on the amplifier:

Low harmonic and intermodulation distortion is promised, and indeed the Clarity 4.2 achieves a very low ~0.05% THD before crossover in the midband while holding to just 0.7% at 100Hz (all ref. 90dB SPL/1m). This is particularly impressive bearing in mind that the Clarity 4.2 musters a mere 78.7dB (ref. 2.83V/1m) sensitivity, or 78.3dB over 500Hz–8kHz. The rated sensitivity is 78dB at 2.83V/1m, so Radiant Acoustics is not only bang on the money here but also fully transparent about the tradeoff between achievable bass extension, response uniformity, distortion, load impedance, and sensitivity, competing parameters that all speaker designers face—but bass and sensitivity are especially tricky to optimize in a box as compact as the Clarity 4.2.

Radiant Acoustics Clarity 4.2 loudspeaker Measurements | Stereophile.com

Sidebar 3: Measurements

www.stereophile.com

But on the other hand TS says: ..for my desk... so TS may not play at such a high volume plus the speakers will be close. In that case not much amp power is needed.
@jammymalina will have to tell us more about that. Listening habits that is.

 

[jammymalina]

But on the other hand TS says: ..for my desk... so TS may not play at such a high volume plus the speakers will be close. In that case not much amp power is needed.
@jammymalina will have to tell us more about that. Listening habits that is.

Yup, the speakers will be definitely very close to my listening position the vast majority of time. Also I don't tend to play music loudly.

 

[DanielT]

I wouldn't pay too much attention to the price; it really doesn't need to exceed €1,000.
The Cambridge CXA81 MKII didn't perform any better in the ASR test than, for example, a Fosi Audio V3 Stereo for €100. My own listening impressions were consistent with this.
Amplifiers such as the 3E Audio A5, A5se, A7, A7se, A7 Mono, Topping PA5 II, B100/B200, Fosi Audio V3 Mono, etc. have significantly better measured values and, in my opinion, also sound better.
The Sabaj A30a, or the identically constructed SMSL VMV A2, in particular, should be a good and powerful partner for the Radiant Acoustics 4.2. These amplifiers also don't require an additional DAC.

SMSL VMV A2 , 200 watts into 4 Ohms. Decent, a bit on the way to powering a pair of 78.5 dB sensitive speakers.
That's equivalent to 25 watts for a pair of 87.5 dB sensitive speakers.

 

[Roland68]

SMSL VMV A2 , 200 watts into 4 Ohms. Decent, a bit on the way to powering a pair of 78.5 dB sensitive speakers.
That's equivalent to 25 watts for a pair of 87.5 dB sensitive speakers.

Yes, they both have plenty of power, and Amir confirmed this performance in his test. I've already run them on very difficult and impedance-critical speakers.
I recommend the A30a/VMV A2 not just for its power, but also for the overall package and the analog and digital inputs, which eliminate the need for an additional DAC.
It's also very efficient, so it doesn't matter whether you need the power or not.

It also sat on my desk for a while, but in the long run it became a bit too big for my desk. I regret that a bit.

 

[DanielT]

Yes, they both have plenty of power, and Amir confirmed this performance in his test. I've already run them on very difficult and impedance-critical speakers.
I recommend the A30a/VMV A2 not just for its power, but also for the overall package and the analog and digital inputs, which eliminate the need for an additional DAC.
It's also very efficient, so it doesn't matter whether you need the power or not.

It also sat on my desk for a while, but in the long run it became a bit too big for my desk. I regret that a bit.

But if @jammymalina would like more power, this is actually within his budget: Radiant Acoustics 4.2 has Purifi drivers. Maybe more Purifi with a 450 watts into 4 ohms PURIFI 1ET6525SA 2-Channel (2nd Gen EIGENTAKT) amplifier for 989 Euro (if I counted correctly with today's exchange rate):

Buckeye Amps

Buckeye Amps utilizes the most advanced audio amplifier technologies available. Authorized seller for Hypex and Purifi Class D amplifiers. Based in the US. Free shipping and worldwide service!

www.buckeyeamp.com

Yup, the speakers will be definitely very close to my listening position the vast majority of time. Also I don't tend to play music loudly.

Which I doubt you need, 450 watts that is, considering what you just wrote.

Plus, the manufacturer writes this about your speakers:
Power handling 200W
That should also be factored into the equation.A 200 watt amp will be perfectly fine for you.

Clarity 4.2

Compact high-end 2-way speakers with deep bass, and PURIFI USHINDI drivers for no distortion. Exceptional sound and dynamic range. Sold direct-to-consumer

radiantacoustics.com

 

[Roland68]

But if @jammymalina would like more power, this is actually within his budget: Radiant Acoustics 4.2 has Purifi drivers. Maybe more Purifi with a 450 watts into 4 ohms PURIFI 1ET6525SA 2-Channel (2nd Gen EIGENTAKT) amplifier for 989 Euro (if I counted correctly with today's exchange rate):
View attachment 485772

Buckeye Amps

Buckeye Amps utilizes the most advanced audio amplifier technologies available. Authorized seller for Hypex and Purifi Class D amplifiers. Based in the US. Free shipping and worldwide service!

www.buckeyeamp.com

Which I doubt you need, 450 watts that is, considering what you just wrote.

Plus, the manufacturer writes this about your speakers:
Power handling 200W
That should also be factored into the equation.A 200 watt amp will be perfectly fine for you.

Clarity 4.2

Compact high-end 2-way speakers with deep bass, and PURIFI USHINDI drivers for no distortion. Exceptional sound and dynamic range. Sold direct-to-consumer

radiantacoustics.com

But I think that's a bit excessive for a desk.
The Audio MXW70 suggested by @jammymalina only has 70 watts. A Cambridge Audio EXA100 with 100 watts, used in the Radiant Acoustics 4.2 test, is said to be perfectly adequate for rooms of about 20 square meters. Since the Cambridge speakers don't reach these power ratings, a real 100 watts at a desk should be more than sufficient, even for a smaller living room.

 

[DanielT]

But I think that's a bit excessive for a desk.
The Audio MXW70 suggested by @jammymalina only has 70 watts. A Cambridge Audio EXA100 with 100 watts, used in the Radiant Acoustics 4.2 test, is said to be perfectly adequate for rooms of about 20 square meters. Since the Cambridge speakers don't reach these power ratings, a real 100 watts at a desk should be more than sufficient, even for a smaller living room.

It sounds a bit, or rather a lot of overkill with 450 watts for a desktop amp. That based on the described conditions. That even if it involves powering up a pair of really low-sensitive speakers. In addition, the speakers cannot handle more than 200 watts, so you shouldn't stress them.

Impressively low distortion with those Purifi drivers in that Radiant Acoustics 4.2 speaker, I must say. Is absolutely worth having an amp with low distortion together with them. Which I think, if I remember correctly without looking it up, all your suggested amplifiers have.

 

[Lars Risbo]

one can never get enough peak power. it’s the average power that kills speakers. A 20dB peak to loudness ratio means about 100x in power headroom required.

 

[smokeymackinsey]

I also use the Clarity 4.2 in a desk setup and chose the Lyngdorf TDAI-1120. You can find it used for around 1300-1400€ so a couple bucks above your budget. But very dearly worth it. I chose or three main reason: obviously, it has enough power for its size. Also the room correction helps enormously, even in nearfield, since desk setups often have their speakers places close to the backwall. Thirdly, for low volume listening you can easily create a custom voicing to accomodate for equal loudness curves.
For me these speakers, room correction and voicing created a package that sometimes feels better than my admitedly much more expensive home cinema setup...

And one tip: get some proper desk-stands for the speakers to angle them properly vertically and to isolate the vibrations from the desk!

 

[Petrushka]

one can never get enough peak power. it’s the average power that kills speakers. A 20dB peak to loudness ratio means about 100x in power headroom required.

I have trouble imagining anyone needing one watt average on their desk. And few sources have 20 db peak to average.

 

[Lars Risbo]

And few sources have 20 db peak to average.

yes and that is a problem. real life audio gets there