Allo Volt+ D Amplifier Review

[howard416]

At -95db, its going to be way below any background noise you have where ever you listen to music. Bear in mind the cost of this amplifier, and I don't really get "higher than it should be".

For many amps, the harmonic distortion products descend in level as they increase in order. So you would expect 2 > 3 > 4 > 5 > 6 > 7 > 8 > 9 > 10 > ... Although in a lot of cases 3 and 5 tend to be higher than 2 and 4 respectively, for some reason.

Would you be happier if I instead said that H5 was surprisingly low compared to the other orders?

 

[sychan]

For many amps, the harmonic distortion products descend in level as they increase in order. So you would expect 2 > 3 > 4 > 5 > 6 > 7 > 8 > 9 > 10 > ... Although in a lot of cases 3 and 5 tend to be higher than 2 and 4 respectively, for some reason.

Okay, I see what you were thinking now. But having watched some of the amplifier design threads on DIYA, it seems that they can sometimes push H2 and H3 low enough that the higher harmonics end up pretty high in comparison. Take a look at the harmonics in the later measurements on the TPA3255 amp in this thread (there's a bunch of graphs, keep going and you'll see when the higher harmonics start to match the lower ones)
https://www.diyaudio.com/forums/gro...eference-design-class-amp-gb.html#post5869422

Here's the final measurement:

 

[howard416]

Yes. Actually, this post is by me:

https://www.diyaudio.com/forums/gro...eference-design-class-amp-gb-post5981986.html

So you can see that I am very consistent

 

[Paulz]

My Volt+D came with an extra capacitance multiplier which I mounted on top. It's my understanding the CM reduces the noise if using a cheap power brick. Allo recommends 19v for the +D.

View attachment 79842

 

[Paulz]

My +D came with an adaptor.

I just bought the allo amp+d and noticed the three selectable switches underneath the amp labeled "switching frequency selection." Since I haven't seen this discussed yet, I was wondering what it was and if the factory preset was appropriate. Very grateful for any thoughts on this.

 

[Poultrygeist]

As I recall they are gain settings. Try each one and see what works for you. I suggest leaving them in the one position you like as they're fragile and won't take a lot of switching.

 

[Paulz]

Gotcha. Really appreciate your help.

 

[HionHiFi]

YMMV, but I for one wouldn't worry about UL listing -- or, for that matter, how many prongs the mains plug has -- and I suspect Europe's "CE" mark denotes (at least) UL-equivalent safety criteria. I found this somewhat pricier 24VDC 10A power brick to be just right for the little TPA3116-based 2.1 chip amp that rocks my TV room -- with volume and clarity to spare -- and I suspect your Allo would thrive on having all that current available to handle musical peaks:

24VDC 10A power brick

Is a 10A power brick necessary to extract the best out of the Amplifier or will a 5A work? I currently have the Alitov 24v 5a.

 

[Poultrygeist]

Is a 10A power brick necessary to extract the best out of the Amplifier or will a 5A work? I currently have the Alitov 24v 5a.

5A is all you need.

 

[Bruce Morgen]

5A is all you need.

Maybe for stereo amp like the Allo, but in my experience a 2.1 amp with two TPA3116s needs more current than that for a solid low end.

 

[Poultrygeist]

Maybe for stereo amp like the Allo, but in my experience a 2.1 amp with two TPA3116s needs more current than that for a solid low end.

The power supply that allo sells for the Volt+D TPA3118 is 19v 3 amp.

 

[HionHiFi]

5A is all you need.

Ok, thanks for that.

 

[HionHiFi]

Fragonard yes you can use anything under or equal to 31V

I got what I thought was the answer but now I'm confused with the statement above. Johan, will I get better performance out of the Amplifier with 24v 10a as opposed to 24v 5a?

 

[Poultrygeist]

I got what I thought was the answer but now I'm confused with the statement above. Johan, will I get better performance out of the Amplifier with 24v 10a as opposed to 24v 5a?

If the two power supplies used with the Volt+D are equal quality there will be no audible difference between 10 amps vs 5 amps. Allo uses built-in capacitance multipliers which mean even lesser quality power supplies can be used without negative effects.

 

[HionHiFi]

If the two power supplies used with the Volt+D are equal quality there will be no audible difference between 10 amps vs 5 amps. Allo uses built-in capacitance multipliers which mean even lesser quality power supplies can be used without negative effects.

I understand the quality part. My question is about getting the most power out of the amplifier. Would the 10a get more power out of the amplifier than the 5a?

 

[Poultrygeist]

I understand the quality part. My question is about getting the most power out of the amplifier. Would the 10a get more power out of the amplifier than the 5a?

You won't get anymore power.

 

[tomtoo]

Wi

I understand the quality part. My question is about getting the most power out of the amplifier. Would the 10a get more power out of the amplifier than the 5a?

With 24-30v/5A you are hard on the specifications on this Amp. More makes not realy sense. If you need more Power, you need bigger guns.

Edit says bigger guns are in the 200W class, realy big guns are in the 2kW class.

 

[HionHiFi]

Wi

With 24-30v/5A you are hard on the specifications on this Amp. More makes not realy sense. If you need more Power, you need bigger guns.

Edit says bigger guns are in the 200W class, realy big guns are in the 2kW class.

I have 90db efficient speakers, a medium size room and I don’t listen loudly. I’d be ok with 100 watts. Maybe even less. Heck the little Volt +D so far is just fine. The volume knob on my Soncoz SGD1 is cranked clockwise a lot further than it normally is though.

 

[Poultrygeist]

Wi

With 24-30v/5A you are hard on the specifications on this Amp. More makes not realy sense. If you need more Power, you need bigger guns.

Edit says bigger guns are in the 200W class, realy big guns are in the 2kW class.

Power is relative to speaker efficiency/sensitivity. 2 watts powering 96 db speakers is equivalent to 70 watts powering 84 db speakers.

 

[tomtoo]

Power is relative to speaker efficiency/sensitivity. 2 watts powering 96 db speakers is equivalent to 70 watts powering 84 db speakers.

Yeap thats why bigger guns follow the logarithm. If you need them go 10 times higher in Power(W). If you dont need them, 5W more in the 20W region are useless. What means a situation where a bigger PowerSupply than 24V-30V/5A is usefull is hard to think of.

Edit says: Couse the chip does not much more. Its finished at this level.