# Amplifier Master Course
17 modules, built directly on `` . Real, quizzable depth exists only for FX-4 (Class AB) — Class D modules have no local manual, so working-principle detail is PENDING VERIFICATION beyond the tagline.
## Exercises & Homework (course-level)
Homework: using FX-4's real Bridged Mode power table, calculate the % power gain from Nominal to Max at both 4Ω and 8Ω bridged. Dealer Tip: always quote the Nominal (RMS) figure to customers, never Max — this matches FX-4's own manual convention of listing both.
### Module 1: Class AB
FX-4 tagline: 'Class AB 4 Channels Amplifier'. Long description: 'Hi-End grade single differential circuit design. Independent symmetric power supply design. All capacitors use high ripple series.' Other Class AB SKUs per Master Data tagline: FM-1 ('Class AB Mono Channel Amplifier'), FS-6 ('Class AB Six Channels Amplifier').
**Exercise:** Using the real data above, explain class ab behavior for the SKU(s) cited.
**Certification question:** PENDING VERIFICATION — draft one using the cited real values above once reviewed by a Technical Engineer.
### Module 2: Class D
Per Master Data tagline across the Amplifier category: FC-1/FC-1-V2/FC-4/FC-4-V2 ('Class D Mono/Four Channels Amplifier'), FH-4/FH-4-MINI/FH-4-ULTRA ('Class D 4 Channels Amplifier'), FD-1-V2/FD-4-V2 ('Class-D Mono/Four Channels Amplifier'), FS-1-V2 ('Class D Mono Amplifier'). No local manual nciple detail beyond the tagline is PENDING VERIFICATION.
**Exercise:** Using the real data above, explain class d behavior for the SKU(s) cited.
**Certification question:** PENDING VERIFICATION — draft one using the cited real values above once reviewed by a Technical Engineer.
### Module 3: Power Supply
FX-4: '+12V=POWER SUPPLY — Connect the +12V terminal to the positive pole of the battery with a lead cable and add a fuse in the power cable not more than 30cm from the battery. 3 meters of cable: minimum 8 AWG. 6 meters of cable: minimum 6 AWG.' Operating voltage 9-16VDC. Negative ground 12V DC operation only. _(Source: ual)_
**Exercise:** Using the real data above, explain power supply behavior for the SKU(s) cited.
**Certification question:** What is the minimum AWG for a 3-meter FX-4 power run? (Answer: 8 AWG, per the Operation page distance table.)
### Module 4: Heat / Cooling
FX-4 long_description: 'advanced heat dissipation structure solves the heat generation problem caused by high power output.' Precautions page : avoid high temperatures/direct sunlight/hot air; allow the unit to cool before operation if the car has been in direct sun; when installing horizontally, do not cover the heatsink fins with floor carpet.
**Exercise:** Using the real data above, explain heat / cooling behavior for the SKU(s) cited.
**Certification question:** PENDING VERIFICATION — draft one using the cited real values above once reviewed by a Technical Engineer.
### Module 5: Gain
FX-4 Troubleshooting : 'If you use a 2 Ohm speaker in stereo mode... and the set is overloaded, turn the gain control to "min" until the operation is free of trouble.' Confirms a physical gain control exists and is user-adjustable. Exact gain range in dB: PENDING VERIFICATION (Input Sensitivity 380mV-7.5V is documented, but not a gain-control dB range).
**Exercise:** Using the real data above, explain gain behavior for the SKU(s) cited.
**Certification question:** PENDING VERIFICATION — draft one using the cited real values above once reviewed by a Technical Engineer.
### Module 6: Bridging
FX-4 has a dedicated 'Bridged Mode' page in its manual (y diagram/image content, minimal machine-readable text — PENDING VERIFICATION for the written procedure). Bridged power specs ARE documented: Bridge Max @4Ω: 880W x2 / Bridge Nom @4Ω: 440W x2 / Bridge Max @8Ω: 570W x2 / Bridge Nom @8Ω: 285W x2. Precautions page confirms: '4 to 8 Ohm when used as bridging amplifier' (speaker impedance for bridged mode).
**Exercise:** Using the real data above, explain bridging behavior for the SKU(s) cited.
**Certification question:** At what impedance does FX-4 deliver its maximum bridged power, and what is that power figure? (Answer: 880W x2 @4Ω Max.)
### Module 7: Speaker Load / Impedance
FX-4: stereo speakers 2Ω or 4Ω; 4-8Ω when bridged. Full power table at 2Ω/4Ω/8Ω already in ``. Other Amplifier SKUs: see `impedance` field per SKU (many marked PENDING or 'supports multi-level load, see channel_count').
**Exercise:** Using the real data above, explain speaker load / impedance behavior for the SKU(s) cited.
**Certification question:** What speaker impedance range does FX-4 require in bridged mode? (Answer: 4-8Ω.)
### Module 8: Common Mistakes
FX-4 Troubleshooting : 'No Stereo Sound And A Weak Bass: Speaker cables (+) and are mixed up, unit wired out of phase' — polarity/phase mixing is a documented real installation mistake. 'Poor Sound Quality (Distortions): speakers are overloaded, turn down the volume level.' Other Amplifier SKUs: PENDING VERIFICATION.
**Exercise:** Using the real data above, explain common mistakes behavior for the SKU(s) cited.
**Certification question:** A customer reports weak bass and no stereo sound on an FX-4 installation. What is the documented likely cause? (Answer: speaker (+)/ leads mixed up / unit wired out of phase.)
### Module 9: Noise Diagnosis
FX-4 Interference page : power and RCA audio cables are most prone to interference; remote cables less so. Guidelines: (1) use only a proper source cable between amp 'low level in' and radio RCA/DIN output; (2) keep signal, speaker, and power cables physically separated; ground/serial cables may run together, but audio/speaker cable should stay far from them; REM cable may run with signal cables; (3) add an interference-suppression choke to the power wiring if electronic-noise interference occurs; (4) use thicker or additional ground cables if humming noise occurs.
**Exercise:** Using the real data above, explain noise diagnosis behavior for the SKU(s) cited.
**Certification question:** Per FX-4's Interference page, what should you add to the power wiring if electronic noise persists? (Answer: an interference-suppression choke.)
### Module 10: Installation
FX-4 real wiring procedure (ground, power, REM, speaker, fuse placement) — see `` and ``. Note two AWG figures exist in the same manual for different contexts: Wiring Instructions page gives a general '#10 gauge or thicker' minimum for the main battery run; the Operation page gives a distance-based table (3m → min. 8 AWG, 6m → min. 6 AWG) — both are presented here rather than silently reconciled, since the manual itself does not explain the discrepancy.
**Exercise:** Using the real data above, explain installation behavior for the SKU(s) cited.
**Certification question:** PENDING VERIFICATION — draft one using the cited real values above once reviewed by a Technical Engineer.
### Module 11: Testing
FX-4 Fuse Replacement : 'If the fuse blows, check the power connection and replace the fuse. If the fuse blows again after replacement, there may be an internal malfunction — consult your dealer.' No formal bench-test procedure documented. Other Amplifier SKUs: PENDING VERIFICATION.
**Exercise:** Using the real data above, explain testing behavior for the SKU(s) cited.
**Certification question:** If FX-4's replacement fuse blows again immediately, what does the manual recommend? (Answer: consult your dealer — likely internal malfunction.)
### Module 12: Protection Circuit
FX-4 : 'This amplifier is provided with a protection circuit which operates in the following cases when: the unit is overheated; the speaker terminals are short circuited.' Troubleshooting symptom: 'No Sound/Red LED Protection Shines' → plus/minus speaker wires shorted, or overloaded (2Ω speaker in stereo mode, or 4Ω in bridge/tri-mode) — turn gain to minimum until resolved.
**Exercise:** Using the real data above, explain protection circuit behavior for the SKU(s) cited.
**Certification question:** What two conditions trigger FX-4's protection circuit? (Answer: overheating, or short-circuited speaker terminals.)
### Module 13: Fuse Placement
FX-4: fuse must be placed no more than 30cm from the battery on the power cable. _(Source: .)_
**Exercise:** Using the real data above, explain fuse placement behavior for the SKU(s) cited.
**Certification question:** How far from the battery must FX-4's fuse be placed? (Answer: no more than 30cm.)
### Module 14: Negative Ground
FX-4 operates on 12V DC negative ground only. _(Source: .)_
**Exercise:** Using the real data above, explain negative ground behavior for the SKU(s) cited.
**Certification question:** What ground polarity does FX-4 require? (Answer: negative ground, 12V DC only.)
### Module 15: Dealer Tips
PENDING VERIFICATION — no dedicated dealer-tips document exists for Amplifiers beyond what's already folded into Common Mistakes / Noise Diagnosis above.
**Exercise / Certification question:** PENDING VERIFICATION — no real content exists for this topic yet; do not quiz on invented facts.
### Module 16: Remote Turn-On (REM)
FX-4 Noise Diagnosis guidance: REM cable may be run together with signal cables (unlike power/speaker cables, which must stay separated). _(Source: .)_
**Exercise:** Using the real data above, explain remote turn-on (rem) behavior for the SKU(s) cited.
**Certification question:** Can FX-4's REM cable be run alongside signal cables? (Answer: yes, per the Interference page — unlike power/speaker cables.)
### Module 17: Class AB vs Class D Selection
PENDING VERIFICATION — no dealer-facing decision guide exists comparing when to recommend Class AB (FX-4/FM-1/FS-6) vs Class D for a given customer scenario.
**Exercise / Certification question:** PENDING VERIFICATION — no real content exists for this topic yet; do not quiz on invented facts.Amplifier Master Course
Intermediate · ACADEMY