Video Summary - 2.1 Class d board || comparision of Zk-tb21 | Zk-mt21

Product(s) reviewed

The video compares three popular 2.1 Class-D amplifier boards (audio amplifier boards) commonly sold with TPA/316x-style “original IC” claims:

ZK MT21 (mentioned as “MT 21 model”)
ZK TB21 / TB21 (latest generation; red/blue variant references)
A third board referenced by model markings: CA-3169B / C3169B (blue board with model number C3169B)

It also explicitly calls out one board as essentially non-reviewable due to failing on power-up (see Cons / critical safety note).

Key points about each board

1) ZK MT21 (“garbage board”) — strong negative

The creator shows an “original TPA 3162 IC” photo and says their “job is to throw this in the garbage.”
Failure claim: on connecting power + speakers and turning volume up, smoke comes from the IC immediately.
If smoke doesn’t happen, they claim it may:
- burn tracks,
- damage speakers, or
- produce rubbish sound quality even if it works briefly.
Verdict in-video: removed from consideration (“we will remove this board”).

Uniquely stated issue: immediate smoke/IC failure risk.

2) ZK TB21 (latest generation referenced)

Price

Current price: 1750 (currency not explicitly stated)

Design / hardware

Described as compact and “next level” looking.
Heat sink: decent; open inductors are used.
Uses thermal pad instead of thermal paste.
Controls / interface:
- Separate subwoofer bass volume
- Treble and left/right channel volume shown via knobs
- Master volume with push functionality to switch modes (e.g., Bluetooth, AUX)
“ROB” function is mentioned as not available on this board.

Connectivity

Built-in Bluetooth v5
Supports AUX
Does not require an extra USB panel for Bluetooth/AUX use (the video notes some setups need a USB panel for USB/pen-drive playback).

Heat / long-run expectation

Open inductors may increase heating under continuous use, but the creator does not make a strong fan/necessity claim in the TB21 comparison.

3) ZK C3169B / CA-3169B (blue/red board with stated prices)

The video references multiple color/model pairings; the blue board is clearly stated:

Model number: C3169B
Current price: 1650

Design / features (as described alongside the TB21 comparison)

Uses sealed inductors.
Heaviest heat sink among the three.
Sound controls include:
- Subwoofer volume
- Frequency / left volume + treble
- Master volume with push to switch modes
No “ROB function” here either.

Connectivity (for the “complete amplifier” description)

Built-in Bluetooth v5
AUX + USB support are claimed (USB may require installing a USB panel in some boards; the creator suggests buyers may need a USB panel or can rely on AUX).

4) The compact option: “red board” C3116P (lowest price among the working boards)

Model number: C3116P
Current price: 80

Controls / interface

Compact.
Subwoofer bass volume and treble volume (left/right and overall volume referenced).
Input options limited to:
- RCA/AUX pins, or
- a direct 3-pin connector.
Heat sink: “quite decent,” with open inductors (gets heated a bit with continuous play).

Connectivity limitation (important)

No Bluetooth/USB described for this red board; it appears more DIY/basic, requiring AUX/RCA/3-pin inputs.

Connectivity / user experience notes (general)

Some boards require installing a USB panel to use USB/pen-drive playback; otherwise AUX works.
For at least one board set (TB21 / C3169B), it’s presented as fully functional with:
- Bluetooth v5
- AUX
- USB support (USB may require panel installation)

Performance & sound quality comparisons

Main claim: the sound quality of the two non-bad boards is “almost the same.”

Differences:

Between the two “better” boards (TB21 vs the other working one):
- one has more treble
- the other has a little more bass
The remaining board (the compact basic one) is positioned for DIY/battery use due to low power and a basic input design.

Sound signature expectations:

More treble → aimed at people wanting loudness
Balanced sound → described as the variant that avoids excessive treble/bass

Power / power supply guidance (practical)

The creator says:

“On paper”: a 200V supply is needed, but practically they observed:
- around ~4–5A consumption at maximum load (for TB21 / similar pair)
Voltage range suggested:
- can run from 12V to 24V
A 24V 5A adapter is said to be “more than enough” for TB21 / comparable boards.
The “compact/basic DIY” option is said to consume about ~3A (approximate).

Use-case fit: recommended for DIY, portable boom box, and battery-powered use due to low power consumption.

Pros (as stated)

Good heat handling on the higher-tier option:
- “heavy heat sink” and “will not even need a fan” (for long use)
Bluetooth v5 + AUX on the more complete boards
Usable controls:
- separate bass (subwoofer), treble, and master volume
- mode switching via push function on at least two boards
Low power consumption (especially the compact/basic board) for long/battery usage
“Original ICs” claimed for all the boards the creator recommends showing

Cons / risks (as stated)

Critical safety risk: the MT21 board is claimed to smoke from the IC on first power-up, potentially damaging speakers.
Open inductors on at least one working board can mean it heats more during continuous long runs.
If you use a board via AUX, some claimed “USB/Bluetooth functions” may be effectively unused (creator warns about function mismatch).

Pricing mentioned (key numerical info)

Working boards:

C3116P (red): 80
C3169B (blue): 1650
TB21 (latest gen): 1750

Non-recommended board:

No price given for the “garbage board / MT21” that smokes.

Overall verdict / recommendation (concise)

Avoid the MT21 board as presented: the creator claims it fails immediately (smoke/possible speaker damage).
Among the others:
- Choose the compact C3116P for budget DIY and low power (AUX/RCA/3-pin input only).
- Choose TB21 / C3169B (the heavier heat sink one) for longer reliable running and loudness, with a more premium build and better thermal design.
- For sound: the two better boards are very similar, with a small tilt toward more treble vs more bass depending on variant.

Unique points mentioned (all distinct items)

Goal: compare popular 2.1 boards to identify “good vs bad.”
Safety/quality claim: one board smokes immediately on power-up.
Additional failure claims: burnt tracks, speaker damage, poor sound quality even if it “works.”
Basic setup description: power + speakers + volume leads to smoke (for the bad board).
Three main boards placed/compared.
Prices provided: 80, 1650, 1750.
C3116P described as compact; open inductors; decent heat sink; only input via RCA/AUX pins or 3-pin connector.
TB21 described as “next level” with thermal pad and push mode switching (Bluetooth/AUX modes).
TB21 lacks “ROB function.”
Third board described as having sealed inductors and heaviest heat sink; no ROB function.
Controls include subwoofer bass, treble/left-right related control, and master volume.
Bluetooth v5 described for the complete boards.
USB may require installing a USB panel; AUX can be used without it.
Sound-quality comparison: two good boards are almost the same.
Only difference in sound signature is more treble vs more bass (loudness vs balance).
AUX/USB warnings: using via AUX can waste some claimed functions.
Power supply: “on paper” 200V, but practically 12–24V and observed ~4–5A max load, around ~3A for the low-power one.
Recommendation for long-run: heavier heat sink may avoid needing a fan.
Recommended adapter: 24V 5A for the main boards.

Speaker-specific views

No separate speakers are clearly identified; the same narrator provides all assessments and comparisons.

2.1 Class d board || comparision of Zk-tb21 | Zk-mt21 | Ca-3169b || best 2.1 amplifier board

Key takeaways