SAFETY WARNING: Always disconnect the unit from power before working internally.
High voltages may be present in the power supply even when unplugged. Discharge large capacitors
before handling. If unsure, consult a professional technician.
Introduction
The TEAC A-3300SX is a classic reel-to-reel tape deck that often requires capacitor replacement due to age.
Electrolytic capacitors dry out over time, leading to hum, noise, poor frequency response, or complete failure.
Required Tools and Materials
- Capacitor assortment (see values below)
- Soldering iron (25-40W) with fine tip
- Quality solder (lead-free or 60/40)
- Desoldering pump or wick
- Needle-nose pliers
- Wire cutters
- Isopropyl alcohol and cotton swabs for cleaning
- Service manual for reference
Capacitor Locations and Values
Below are the key capacitors that typically need replacement in the A-3300SX:
Power Supply Board (P-1000 Series)
C101: 2200μF 35V - Main filter capacitor
C102: 2200μF 35V - Main filter capacitor
C103: 100μF 25V - Regulation circuit
C104: 47μF 25V - Regulation circuit
C105: 10μF 25V - Regulation circuit
Playback Amplifier Board (A-700 Series)
C701: 100μF 16V - Coupling capacitor
C702: 100μF 16V - Coupling capacitor
C703: 47μF 16V - Bypass capacitor
C704: 4.7μF 25V - EQ circuit
C705: 1μF 50V - Timing capacitor
Record Amplifier Board (A-800 Series)
C801: 47μF 16V - Bypass capacitor
C802: 10μF 16V - Coupling capacitor
C803: 4.7μF 25V - EQ circuit
C804: 3.3μF 25V - Bias circuit
Replacement Procedure
- Disconnect the unit from power and allow it to discharge for several hours
- Carefully remove the top and bottom covers to access the circuit boards
- Take photos of the boards and capacitor orientations before starting
- Note the polarity of each electrolytic capacitor before removal
- Use desoldering tools to carefully remove old capacitors
- Clean the pad areas with isopropyl alcohol after removal
- Install new capacitors observing correct polarity and values
- Trim leads and ensure no solder bridges between connections
- Double-check all work before applying power
Testing After Replacement
After replacing capacitors:
- Power up the unit without tape and check for abnormal sounds or smoke
- Verify proper voltages in the power supply section
- Check all transport functions (play, record, fast forward, rewind)
- Test audio playback with a known good tape
- If possible, check bias and alignment after capacitor replacement
Additional Tips
- Use high-quality, low-ESR capacitors for longer life
- Consider replacing transistors known to be problematic in these units
- Clean all switches and pots with contact cleaner while unit is open
- Lubricate moving parts with appropriate lubricants
- Demagnetize heads after extensive work
