Allo "Revolution Dac"

Audio Gear Talk Allo
1

Hi,

I was thinking maybe interesting to share, a new box from Allo.
Love my Boss 1.2 with Ropieee however alway into something new :slight_smile:

Cheers John

The audiophile community is one big family united by the love of music.

There is however, a fundamental split on how we judge audio hardware. One camp (objectivist) swears by THD+N and the opposition (subjectivists) swear by what they hear.

We started Revolution as an attempt to unite both camps.

Objectivist side:
Revolution THD+N is -114.5. However, look closer. THD is the main problem since N (noise) is always around us and as such human ear/brain can tune it out. THD of Rev is at around -122 to -124 making this one of the best tested DACs (unbalanced outputs) in the world. 20Hz to 20Khz THD stays same (does not rise).

Subjectivist side:
Great THD numbers do not exclude great sound quality.

Revolution DAC was subjectively tested for many months and delayed until we were satisfied with SQ. What we have found out is that some practice (like audiophile caps in opamp rails) indeed increased the SQ, and we were able to see small reduction on harmonics on THD.

One area of concern was what itā€™s been referred to as ā€œbright soundsā€ on Ess DACs. We believe that main reason comes from datasheet implementation and lack of filtering before second opamp (summing). Most designs we see lack this fundamental passive filtering (again they just copy of datasheet) and the HF noise (one parameter, there are others), while it should not be audible, somehow creates this fatiguing sound. We are pleased to say that Rev does not have the bright sound associated with ESS.

Not everyone has the same taste though and we decided to give you full control and decide what you like best:

1. Sync / Async

Since we are using 2 clocks, in synch mode, we can feed an exact multiple of FS (called 128fs mode by Ess sabre) and DPLL is removed (dpll 0). Jitter is from the clocks direct ( NDK SDA).

In Asynch mode the dijittering of ess IC is enabledā€¦but at the absolute minimum (1).

2. H2/H3 Harmonic Control

Harmonic components of THD can be tweaked (increased) from ā€œbest THD valuesā€. Why? Simply because harmonic components are known to introduce a euphonic effect (we like some increased harmonics, it sounds better while measuring slightly worst).

3. OSF Bypass

Oversampling filter will be bypassed. As a result, some people hear increased SQā€¦ but you will lose hardware volume control.

4. Filter

All filters are available. Chose what you like best.DSD 512 /PCM 384Khz tested and stable under both Linux (yes RPI) and Windows.

Enjoy!

1 Like
2

Interesting approach from Allo. I like Allo products bang for buck ā€¦this is a bold move.

I have a top-ish Chi-Fi ESS DAC (not that cheap) with great measurements and a poor measuring expensive FPGA DAC. A/B blind testing was not necessary the cheaper hi measure DAC could not come close to the SQ of the poor measuring DAC which was better in every way to my ears and all the family for SQ. It took 2 tracks as it was clear what was the winner within 10 seconds.

I await with real interest how this ā€˜Revolutionā€™ will be received by users and how it compares.

(The Chi-Fi DAC is now part of a 2nd Headphone setup. I fell for the Hype of ā€œas good as x-times the priceā€¦ in the top 3 measurements in the tableā€ etc etc. Never again and one of the few times I did not home audition. I home auditioned the Chord Hugo when the press said ā€œReference Dacā€ against at the time my Chord QBD76 - no contest the QBB76 was the clear winner and was then Chords reference DAC. IMHO the quality of the output stage is where higher priced DACā€™s also win).

3

I agree, measurements are only part of the equation. O love my Audioquest Cobalt, Red and Black and can hear a difference between them, slight with the Red and Cobalt. Yet they get persecuted by a certain reviewer who so many on here seem to hold respect for. I donā€™t really understand what half the measurement reviews are on about if I am honest dont care, I just care what it sounds like. I also donā€™t want the piss taken either.

But like all things in this game itā€™s down to a userā€™s own preference and taste. I just got an RME ADI 2 itā€™s measurements are amazing apparently , but I only read the bits about how it sounds to make the decision to try one and it does also sound amazing. One can have best of both worlds or one of the other and still be happy.

1 Like
4

I really appreciate measurements too but I also have a dragonfly red and enjoy the sound out of it even though it does get slated.

5

Some more technical info, measurements, from Allo in the mail today.

Cheers John

https://www.amazon.com/clouddrive/share/kgLwnDWctUBMbNd6HlkWu3Em2JRspvFejm7Gw3QvwK

6

The supercap power supply is exciting

1 Like
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Thanks James I will have a look @ this power supply.

Cheers John.

8

does it support MQA?

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Hi I donā€™t know thereā€™s not much info about the Allo Revolution. Maybe Allo has more specific technical detailsā€¦

@allo_audio_boards

Cheers John

10

MQA is not supported . DSD 512 compatible on both Win and Linux (RPIs)

11

Thanks Johan!