TPA 3116 vs the tripaths

Not only does the Volt+D have an on board capacitance multiplier but mine came with a second CM to add in series ( see picture below ). So there are two for this dual mono version. According to allo the CM is an added circuit in the PS that rejects spikes and noise to about 60 dbs. "Capacitance multipliers are often used in DC power supplies where very low ripple voltage ( under load ) is of paramount importance such as in class A amplifiers". I have not tried the additional CM yet as I've been so preoccupied with the stock unit. I surmise that the CM's allow the Volts to be used with cheap and sometimes noisy power bricks which would negatively affect the sound otherwise. I'm using a 19V brick which is the recommended power supply for the Volt+D. Down the road I'll probably try it with a linear regulated Astron PSU to see if there's a difference. The +D's sound quality is down right amazing as is and getting better as the film caps burn in.

allo-capacitance-multiplier-noise-reducer-for-allo-volt-or-class-d-amp.jpg
 
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Not only does the Volt+D have an on board capacitance multiplier but mine came with a second CM to add in series ( see picture below ). So there are two for this dual mono version. According to allo the CM is an added circuit in the PS that rejects spikes and noise to about 60 dbs. "Capacitance multipliers are often used in DC power supplies where very low ripple voltage ( under load ) is of paramount importance such as in class A amplifiers". I have not tried the additional CM yet as I've been so preoccupied with the stock unit. I surmise that the CM's allow the Volts to be used with cheap and sometimes noisy power bricks which would negatively affect the sound otherwise. I'm using a 19V brick which is the recommended power supply for the Volt+D. Down the road I'll probably try it with a linear regulated Astron PSU to see if there's a difference. The +D's sound quality is down right amazing as is and getting better as the film caps burn in.

allo-capacitance-multiplier-noise-reducer-for-allo-volt-or-class-d-amp.jpg

That looks like a simple DC-DC linear reg circuit to me.
 
Well I wouldn't be able to come up with it but I'm not an engineer.

:D

The question I'd have is does it need to be fed a slightly higher voltage than otherwise. There are "low drop out" linear regulators that work with very little voltage drop input->output but they're more finicky about capacitive loading/filtering than more traditional ones that need ~2v of voltage overhead on the input.

They have sophisticated internal circuitry that allows them to output an incredibly stable voltage. I've used the TL780 series from TI and it has a ripple rejection ratio of over 70dB!

That said, I'd have to see part numbers on the board to really know what they're doing. I'm not sure what those two little to-92 devices are doing.
 
The TPA3118 can take up to 24v but I'm thinking there could be more distortion at that voltage. Perhaps that's why allo recommends 19v.

With the original Volt+ I get excellent results from a 12v linear regulated PSU as I don't need the extra power for HE speakers.
 
What would be cool is if it had separate power connections for each channel. You could run two linear reg boards with something like the 3A capable units from Analog/Linear and a nice transformer or switched wall wart with plenty of headroom. :)
 
The TPA3118 can take up to 24v but I'm thinking there could be more distortion at that voltage

Distortion does vary depending on voltage used, but only within a very narrow range.
So narrow, that's impossible to say one is all that much better than the other.
In fact, if one wants to look at distortion figures, the TPA 325x family often tests at much lower figures by a factor of 10.


Here are the distortion graphs for 3116/8 at both 12v and 24v input.
They're for a single chip operating in BTL mode, but they're essentially the same for PTBL mode [a la the Volt+D].
thd voltage 3116_202.jpg

The main advantage, as can be seen, is that higher voltage extends the range of power on tap before hitting major distortion.
Here's the graph showing the relationship between voltage and power output in PTBL mode before hitting 1% and 10% THD.
Compared to BTL mode [single chip Volt+], PTBL mode produces considerably more power with the same voltage.
power vs supply 3116_205.jpg
 
With the original Volt+ I get excellent results from a 12v linear regulated PSU as I don't need the extra power for HE speakers.

How many amps?

Also one thing I don't get about the Volt+D is the whole dual mono concept. I listen to tons of 70's JA Dub and the producers loved to pan sounds between left and right channels. But with dual mono you lose that producer intended effect - Is that right?
 
How many amps?

Also one thing I don't get about the Volt+D is the whole dual mono concept. I listen to tons of 70's JA Dub and the producers loved to pan sounds between left and right channels. But with dual mono you lose that producer intended effect - Is that right?
No. Dual transformers is to prevent noise-inter modulation distortion. Two channels talking to one another by sharing the same transformewr.
 
How many amps?

Also one thing I don't get about the Volt+D is the whole dual mono concept. I listen to tons of 70's JA Dub and the producers loved to pan sounds between left and right channels. But with dual mono you lose that producer intended effect - Is that right?

I guess I have 8 or 9 TPA amps ( 3110, 3116 and 3118 ) but the new Volt+D is clearly the best of the bunch.
 
I'm not all that comfortable with the concept of board heat sinking.
Other than that, I like the idea of film caps and switchpoint level control.
 
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How many amps?

Also one thing I don't get about the Volt+D is the whole dual mono concept. I listen to tons of 70's JA Dub and the producers loved to pan sounds between left and right channels. But with dual mono you lose that producer intended effect - Is that right?

The only difference between a stereo amp and a dual mono amp is that in the stereo amp the channels share a power supply (often the most expensive part of the amplifier). In dual mono, each channel gets its own power supply and sometimes its own chassis or box. It minimizes crosstalk and isolates any strain put on the power supply to whatever channel its running through. The signal itself goes through the two channels of the amplifier in the same way.
 
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