Millennia Media imersiv D1

Thanks, this is very helpful.
I'm not sure if I qualify as an audiophile. I am definitely not a pro user. What I like about Allnic is its great combination of tonality / timbre, resolution / detail, and dynamics.
I really like my current Aqua DAC, but when I compared it to a friend's Allnic D10000 DAC in his system, the D10000 was clearly better, to my chagrin. 
Btw - my friend also has the NS5000 speakers, L10000 Allnic pre, and Dartzeel NHB108; a great system!
The Allnic is a natural match for my system, but  I'm intrigued by the D-1. I want to make sure it fits well with my system and does not lead to fatigue. 
I'll give Danny a call tomorrow. 
The Denver show sounds tempting too (I'd like to try the MPD-8 too), especially with a few days on the slopes added. 

Danny has a ton of Allnic gear at his location. I think he has their amps too. The D-15000 DAC is supposed to be a bit unique in the Allnic lineup.

You are more than welcome to come and listen at my place after the holidays (when the kid is back at school and the house is quiet). My D-1 is fully broken in, and it sounds way better than the first day I got it home. It was good then but much better now.

The fact that you are going to use a preamp makes me think the Allnic lineup is better suited. However, I only tested my D-1 with only 1 preamp, so my info is limited.

yyzsantabarbara OP - thanks, I'd love to take you up on that offer & visit after the holidays. 

I'm open to all options - while I do like what the L8500 brings to my system, I'll definitely consider the alternatives.

Happy holidays!

 

ChatGPT Explain

F0 Fast Roll-off Linear Phase (default) 
F1 Slow Roll-off Linear Phase 
F2 Apodizing Fast Roll-off Linear Phase 
F3 Fast Roll-off Minimum Phase 
F4 Slow Roll-off Minimum Phase 
F5 Hybrid Fast Roll-off Minimum Phase

These labels describe digital reconstruction filters inside a DAC.
They all do the same job (rebuild a smooth analog waveform from discrete samples), but they make different trade-offs between frequency response, time behavior, and ringing.

I’ll explain this in plain language first, then get a bit technical.

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Big picture (what these filters change)

Digital filters mainly affect:

1. Ringing (tiny ripples around transients)

2. Phase behavior (timing accuracy vs symmetry)

3. High-frequency roll-off (how close to Nyquist the response stays flat)

None of these change bass, volume, or bit depth.
They subtly affect transients, imaging, and “feel.”

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Two key axes to understand first

1️⃣ Linear Phase vs Minimum Phase

Linear Phase

• Perfect phase accuracy

• Time-aligned frequencies

• Causes pre-ringing (ringing before a transient)

• More “precise”, sometimes described as clinical

Minimum Phase

• No pre-ringing

• All ringing occurs after the transient

• Phase is altered (time smear)

• Often perceived as more natural or analog

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2️⃣ Fast Roll-off vs Slow Roll-off

Fast Roll-off

• Very sharp cutoff near Nyquist

• Maximum frequency extension

• More ringing

Slow Roll-off

• Gentler cutoff

• Slight HF attenuation near top octave

• Less ringing

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Now let’s explain each mode.

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F0 — Fast Roll-off Linear Phase (default)

What it does

• Sharp cutoff

• Perfect phase

• Symmetrical ringing (before & after transient)

Sound character

• Maximum detail

• Precise imaging

• Can sound “digital” on sharp transients

Why it’s default

• Measures best

• Technically “correct”

• Matches textbook DAC design

Use if you want

• Studio accuracy

• Analytical listening

• Best frequency extension

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F1 — Slow Roll-off Linear Phase

What changes

• Gentler HF cutoff

• Still linear phase

• Less ringing

Sound character

• Slightly smoother

• Less edge on cymbals

• Tiny loss of air at extreme HF

Use if

• F0 sounds too sharp

• You want linear phase without aggressiveness

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F2 — Apodizing Fast Roll-off Linear Phase

Key idea: “cleaning upstream damage”

What apodizing means

• Suppresses ringing caused by earlier ADC filters

• Especially relevant for older recordings

What it does

• Still linear phase

• Fast roll-off

• Reduced pre-ringing artifacts from source material

Sound character

• Cleaner transients

• Slightly smoother than F0

• Often preferred for older digital masters

Use if

• Listening to early digital recordings

• You want precision with less harshness

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F3 — Fast Roll-off Minimum Phase

Major change

• No pre-ringing

• Phase is no longer linear

What you gain

• More “natural” transients

• Punchier attacks

What you lose

• Perfect phase alignment

• Some spatial precision

Sound character

• More analog-like

• Slightly thicker

• Less etched imaging

Use if

• You dislike pre-ringing

• You value musicality over measurement perfection

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F4 — Slow Roll-off Minimum Phase

Most relaxed filter

What it does

• No pre-ringing

• Gentle HF roll-off

• Least ringing overall

Sound character

• Warm

• Smooth

• Forgiving

Trade-off

• Softest treble

• Least “air”

Use if

• Bright system

• Long listening sessions

• Older or harsh recordings

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F5 — Hybrid Fast Roll-off Minimum Phase

Best of both worlds attempt

What “hybrid” means

• Fast roll-off

• Minimum phase behavior

• Ringing optimized to be less audible

Sound character

• Good attack

• Cleaner highs than F3

• Less HF loss than F4

Use if

• You like minimum phase

• But don’t want slow roll-off dullness

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Quick comparison table

Filter	Phase	Roll-off	Ringing	Sound
F0	Linear	Fast	Most	Precise, analytical
F1	Linear	Slow	Less	Smooth, accurate
F2	Linear	Fast	Reduced	Clean, refined
F3	Minimum	Fast	After only	Punchy, analog
F4	Minimum	Slow	Least	Warm, forgiving
F5	Minimum	Fast	Optimized	Balanced, musical

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Practical advice (important)

You will not hear massive differences.
These are micro-tuning tools.

Common preferences

• Measurement / reference → F0 or F2

• Audiophile listening → F3 or F5

• Bright systems → F4

• Older digital masters → F2

If you want one safe recommendation:

F5 (Hybrid Fast Minimum Phase) is often the most universally pleasing.

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Final takeaway

These filters are about how transients behave, not tone control.
Choose based on:

• Recording quality

• System brightness

• Personal sensitivity to digital edge