VOLT+D class D amp , dual mono 2x 60W

[westsounds]

Hi All

 

I reading through/catching up with this thread with interest as I am looking for one of the best price/performance amplifiers I can find. Class D seems to be the place where that is happening big time at the moment.

Some guys even leaving their high priced gear to listen to these almost novelty amplifiers which perform tremendously.

 

I'm sort of looking for the best out there and when I say that, something that performs way beyond what you expect for the price tag. Lots can fit into that category as they all are impressive for what they do / cost, but, we are audiophiles we need to go to the extremes and find best'ies

 

That is why I have arrived at the Allo + D as one possibility. I haven't been lucky enough to try one yet as most of my buying is either used, from china or may be Amazon with the option to return or sell on once I'm finished if not overawed.

 

Others I've tried so far are some from Sure electronics DIY boards, old LEPAIs, the SMSL 50 which wasn't bad for an all in package, and just recently a FOSI 98e which was considerably more powerful on paper but actually wasn't really a world away from the SMSL especially for quality, but it may have had an edge in power. I know these type of amplifiers can suffer with a bit of noise flaw, sometimes in the way of hiss or dreaded bump to the speakers at power on. The hiss Ive heard but luckily not the bump with the ones I've tried.

 

Any other great amps out there with minimum issues and maximum sound I really should consider? It helps if its cheap as well of course and powerful.

 

Another I've arrived at which maybe worth a try and sometimes raved about is the TPA3255 (in link below). They have some on Aliexpress but only in a 3250 version at the moment. Would like the extra power and may wait for it but value for money/perforce is always a big factor as well.

 

https://www.aliexpress.com/item/10000090424182.html?spm=a2g0o.productlist.0.0.44b543bakcY8cp&algo_pvid=a9c34834-b393-4f3c-aa4a-dc4c47350bd5&algo_expid=a9c34834-b393-4f3c-aa4a-dc4c47350bd5-36&btsid=0b0a119a15920543427111416e2d58&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

[Grif]

Great thread and I too am loving the Volt+ D. 
 

The sound when paired with Rpi/Allo boss DAC is superb and I found Moode Audio far better than Volumio for sound quality. Although no idea why! Tried it out today and was amazed at difference. 
 

The sound directly from my MacPro to the Volt is not that good which is probably down to the computer audio line out than anything else. So I’m looking at a usb DAC like an IFI Zen. Although I’d rather just use the rpi/boss if it could take the input somehow. 

Like this combo so much I’m probably going to get a couple of them. 
 

@Chinquapin

Regarding the bypassing of the volume attenuator. If I understand correctly If done I get more output/better sound and volume is controlled via software correct? Or I can add a preamp with volume control? Not sure I’ll bother but interested anyway. 
 

cheers. 

 

 

[Chinquapin]

1 hour ago, Grif said:

Great thread and I too am loving the Volt+ D. 
 

The sound when paired with Rpi/Allo boss DAC is superb and I found Moode Audio far better than Volumio for sound quality. Although no idea why! Tried it out today and was amazed at difference. 
 

The sound directly from my MacPro to the Volt is not that good which is probably down to the computer audio line out than anything else. So I’m looking at a usb DAC like an IFI Zen. Although I’d rather just use the rpi/boss if it could take the input somehow. 

Like this combo so much I’m probably going to get a couple of them. 
 

@Chinquapin

Regarding the bypassing of the volume attenuator. If I understand correctly If done I get more output/better sound and volume is controlled via software correct? Or I can add a preamp with volume control? Not sure I’ll bother but interested anyway. 
 

cheers. 

 

 

Hello, so glad you are enjoying your V+D. With the 10k pot in line, the V+D has 6k to 8k input impedance-a difficult load to be driven. This causes the sound to be somewhat thin. 6-8k relates to the gain setting on the bottom of your V+D (20 or 26dB—-use the 20). With the pot gone, the amp has 60k ohm input impedance-perfect. I use a tube line stage (preamp) for input switching and volume control. Tube equipment is pure magic with these amps. Solid state is fine, just don’t use a passive line stage or you will undo the benefit of this mod. I’m also using two V+D amps-running only one channel on each. This increases separation and causes each amp to work half as hard. Easy enough to do-put a shorting plug in one of the inputs, and a 50ohm 10 watt resistor on the speaker terminals of that channel. Makes these amps seem a lot bigger than they are. Hope this helps.

 

Slainte!
 

[Chinquapin]

22 hours ago, Chinquapin said:

Hello, so glad you are enjoying your V+D. With the 10k pot in line, the V+D has 6k to 8k input impedance-a difficult load to be driven. This causes the sound to be somewhat thin. 6-8k relates to the gain setting on the bottom of your V+D (20 or 26dB—-use the 20). With the pot gone, the amp has 60k ohm input impedance-perfect. I use a tube line stage (preamp) for input switching and volume control. Tube equipment is pure magic with these amps. Solid state is fine, just don’t use a passive line stage or you will undo the benefit of this mod. I’m also using two V+D amps-running only one channel on each. This increases separation and causes each amp to work half as hard. Easy enough to do-put a shorting plug in one of the inputs, and a 50ohm 10 watt resistor on the speaker terminals of that channel. Makes these amps seem a lot bigger than they are. Hope this helps.

 

Slainte!
 

You could put a line stage after the Boss DAC. Schiit Audio Vali2 is a headphone amp and can be used as a line stage. Uses 6DJ8 family of vacuum tubes. I have one in one of my systems and it’s great. $149 is amazing for this level of performance. I like using 6CG7/6FQ7 tube. This is a 9 pin miniature version of the 6SN7. Easy to find these for cheap. RCA, Sylvania, and Tung Sol—all are good. Adds tube magic to the system. Keep me posted on your progress.

[Grif]

12 hours ago, Chinquapin said:

You could put a line stage after the Boss DAC. Schiit Audio Vali2 is a headphone amp and can be used as a line stage. Uses 6DJ8 family of vacuum tubes. I have one in one of my systems and it’s great. $149 is amazing for this level of performance. I like using 6CG7/6FQ7 tube. This is a 9 pin miniature version of the 6SN7. Easy to find these for cheap. RCA, Sylvania, and Tung Sol—all are good. Adds tube magic to the system. Keep me posted on your progress.

 

After some reading think I'll try one of these to handle the audio from my Mac......

https://www.audio “science” review/forum/index.php?threads/review-and-measurements-of-wesiontek-khadas-tone-board-dac.4823/

 

Like the idea of the tube stage too and I'll try it at some stage. 

[Chinquapin]

7 hours ago, Grif said:

 

After some reading think I'll try one of these to handle the audio from my Mac......

https://www.audio “science” review/forum/index.php?threads/review-and-measurements-of-wesiontek-khadas-tone-board-dac.4823/

 

Like the idea of the tube stage too and I'll try it at some stage. 

Khadas tests well and the price is good. Had to wade through 10 pages of comments before finding anyone that commented on how the thing sounds. Comments were favorable. One listener preferred this card to Cord— much more expensive DAC. Wonder how it compares to the Boss? Perhaps it’s a nugget like V+D? I’m familiar with RPI and hat style systems. A little too DIY for my taste. Nothing makes me more evil than working with computers. I’m convinced that if Elvis were alive today, he would shoot his computer. That being said, I’m glad that I have been open minded enough to keep seeking out quality digital devices. V+D was a nugget for me that really changed my mind. Scott Nixon’s Tube DACs are another example. Scott’s DACs have been my standard for almost 20 years. I’m still looking though. I’m considering a Schiit Audio Bifrost2. Plan to order(although it’s on backorder) and see. A little more expensive than the Nixon DAC, but I’ve learned that price point means nothing. 

[Chinquapin]

1 hour ago, Chinquapin said:

Khadas tests well and the price is good. Had to wade through 10 pages of comments before finding anyone that commented on how the thing sounds. Comments were favorable. One listener preferred this card to Cord— much more expensive DAC. Wonder how it compares to the Boss? Perhaps it’s a nugget like V+D? I’m familiar with RPI and hat style systems. A little too DIY for my taste. Nothing makes me more evil than working with computers. I’m convinced that if Elvis were alive today, he would shoot his computer. That being said, I’m glad that I have been open minded enough to keep seeking out quality digital devices. V+D was a nugget for me that really changed my mind. Scott Nixon’s Tube DACs are another example. Scott’s DACs have been my standard for almost 20 years. I’m still looking though. I’m considering a Schiit Audio Bifrost2. Plan to order(although it’s on backorder) and see. A little more expensive than the Nixon DAC, but I’ve learned that price point means nothing. 

Haven’t found a DAC that oversamples and has digital filtering that sound as good as Scott’s non-digital filtered non-oversampled DACs. Pure Redbook.

[happypappy]

On 4/28/2020 at 8:48 AM, Chinquapin said:

Yes, bypassing the pot does improve the sound....

I just did this mod to my Volt +D as you suggested, and yes, a clear improvement in the sound, a tad warmer overall and a lower noise floor maybe.  I've been using the Volt +D with a big solid state Emotiva preamp (a real iron fist of a preamp) leaving the amp's pot all the way up, and otherwise unused.  Great, easy to do mod, and I will also do the Volt D that I have on my desktop rig.  Thank you!

[happypappy]

On 6/13/2020 at 8:29 AM, westsounds said:

...Some guys even leaving their high priced gear to listen to these almost novelty amplifiers which perform tremendously...

 

 

While not really high end, I left behind an Adcom GFA 535ii in favor of the Volt +D.  The Allo eats it alive, anyone could hear it. 

[Chinquapin]

On 7/25/2020 at 2:12 PM, happypappy said:

I just did this mod to my Volt +D as you suggested, and yes, a clear improvement in the sound, a tad warmer overall and a lower noise floor maybe.  I've been using the Volt +D with a big solid state Emotiva preamp (a real iron fist of a preamp) leaving the amp's pot all the way up, and otherwise unused.  Great, easy to do mod, and I will also do the Volt D that I have on my desktop rig.  Thank you!

Welcome!

[Chinquapin]

On 7/25/2020 at 2:20 PM, happypappy said:

While not really high end, I left behind an Adcom GFA 535ii in favor of the Volt +D.  The Allo eats it alive, anyone could hear it. 

Yes, a lot of high priced iron has been made obsolete. Wanna buy some Altecs?

[Chinquapin]

I say, a nice pre-amp, preferably tube, is a magical combination with these Allos. Seemingly archaic, thermionic devices paired with computer controlled amplification a synergistic duo? Don’t believe me? See Darko’s review of Schiit Audio’s Freya+ on YouTube.

[conus]

Hello. Now, too, everything is fine with AIYIMA TPA3251 and Elac BS 243, but I expect to get an audible increase in quality with 24V 5A. Too bad there's no remote. And why does the manufacturer recommend 19 volts when 24 is definitely better?..

[conus]

In General, it is time for the manufacturer to listen to reviews where the quality of the attenuator significantly worsens the sound and either use a decent attenuator or produce a power amplifier without it. By the way. what is the model of the attenuator in the amplifier?

[happypappy]

7 hours ago, conus said:

In General, it is time for the manufacturer to listen to reviews where the quality of the attenuator significantly worsens the sound and either use a decent attenuator or produce a power amplifier without it. By the way. what is the model of the attenuator in the amplifier?

In general, all attenuators degrade sound quality to some degree.  Again, in general, the type included in the Volt+ D with the individual resistors is often considered the best type, and is more expensive than other types.  I don't think it's that this attenuator is so bad, but that any amp sounds better with no attenuator at all.  It's unusual for a power amp to even have one.

[conus]

57 minutes ago, happypappy said:

In general, all attenuators degrade sound quality to some degree.

Do you mean analog attenuators or digital ones? The preamplifier recommended here also has an analog attenuator, which degrades sound quality to some extent. This is why I am asking about a specific attenuator model to understand its potential quality. If it is really decent, of comparable quality in a separate preamplifier, and the sound is clearly degraded, then its implementation in VOLT + D is of poor quality. It is absurd to buy an amplifier, then unscrew it with an obviously sound-spoiling attenuator and buy a DAC with a volume control or a preamplifier with a better attenuator. I want the manufacturer to explain the situation - how much, other things being equal, the attenuator in VOLT + D degrades the sound.

[happypappy]

I mean analog.  The main issue created by the inclusion of this attenuator is that the resultant input impedance is not ideal for use with a separate pre-amp.  Taking the attenuator out of the circuit raises the impedance to a level that a pre-amp is more comfortable with.  It's the unhappy pre-amp that creates a sound quality hit, not the amp.  

 

I'm hesitant to challenge the design thinking of the people at Allo.  Clearly they know what they are doing and make a number of remarkable products, but I think it's an odd choice to put an attenuator on a quality power amp.  Perhaps providing bypass switching would've been a good solution, but would've added cost, complexity, and some would complain that the amplified signal was unnecessarily being run through an extra switch, thus taking a possible hit on sound quality.

 

The original Volt is available with no attenuator at all, if desired.  Maybe it would be a good option to offer the +D without it.  It would be cheaper, and better suited to use with a pre-amp.

[conus]

No one is going to use a standard VOLT+D with a preamp. But after reading the reviews, you can't help but think about removing its attenuator. Why is it a strange choice to install an attenuator on a high-quality power amplifier? - the price determines the quality and the manufacturers decided that THIS power amplifier can be used ).

[happypappy]

1 hour ago, conus said:

No one is going to use a standard VOLT+D with a preamp....

There are several people on this thread using the Volt +D with a pre-amp.  If you're not planning to, then the attenuator will cause you no grief.  

[SMen]

The attenuator is a stepped attenuator. It is not unusual, and for the price it is very good.

I use it on "full" with a very high quality, digital source with a lossless volume control.

Also with a (no longer obtainable) panasonic 'pot'.

I think that the power supply, 24v vs 19 or other, is far more significant.

Allo have actually supplied a high quality attenuator for many users. If there are compatability issues, then, bring on the monoblocks I say.

This is a wonderful amplifier, including stepped attenuator.

[SMen]

The Panasonic attenuator I use with my turntable is one of the best. It is attached to a valve phono pre.

I am not sure what the difference is between the stepped attenuator on the volt D on 'full volume', bypassing all (I assume) resistors, and the direct line modification?!!

I doubt much.

The 24v power supply is much more significant imo, with an over supply of amps.

Maybe Allo are testing with super efficicient speakers, Who knows. The Allo D though is surely purposed for less efficicient, or more mainstream. e.g. 88db and above speakers.

[SMen]

And, at the price, that attenuator will be a revalation for many users in comparison to what they have been used to.

[conus]

12 minutes ago, happypappy said:

There are several people on this thread using the Volt +D with a pre-amp.  If you're not planning to, then the attenuator will cause you no grief.  

The presence of a preamp does not oblige you to use it with +D with your own attenuator. If the volume control implementation in the preamp is superior to that in +D, and it is decided to use a preamp, then it is wiser to wait for the +D version as a power amplifier. Although, no one can forbid you to dig in your own property, but HERE on the taste and color. It is more reasonable for developers to provide a separate input to the power amplifier, as is now customary in almost all modern integrated amplifiers. As well as the second AUX. I don't remember an integral with such parameters.

[conus]

39 minutes ago, SMen said:

This is a wonderful amplifier, including stepped attenuator.

 

And, at the price, that attenuator will be a revalation for many users in comparison to what they have been used to.

That is why I strongly hope for an increase in quality in comparison with the AIYIMA TPA3251 with its smooth controller, which does not cause problems yet.

[GrahamJohnMiles]

A question for the manufacturer. I notice ifi Audio has a new low noise power supply called the Elite. Highest rating is 24vdc at 2.4amps. Is the current too low to optimally power the Volt +D?