Serviced Fostex X-14 1990s 4-track cassette recorder with original box, manual, and vintage tape

We have completed servicing, calibrating, and testing this Fostex X-14. It's a nice little unit with basic functionality (easy to use). It has one instrument input, one microphone input, and a built-in mic. Only 1 channel can be recorded at a time. A great cassette sketchbook. This unit is in near-mint condition, and has been fully disassembled and washed in the sink with soap and water. It comes with the original box, manual and power supply. We are also included an erased vintage tape.

Repairs:

These were need to bring the item back to functioning condition, before performing maintenance.

• A common problem on vintage 4-tracks of the pause function is broken. The little cap that holds the pause spring down will often crack and lose its hold. We have developed a custom 3d-printed replacement that can be adapted for different models. We created a custom replacement for this unit to fix the pause.

• The solder joints on the main out RCA jacks have been resoldered

Maintenance: 

With many vintage 4-track recorders approaching 40 years of age, they need to be maintained to continue to work properly. First and foremost the rubber belts need to be replaced, but there are many other things that can keep the 4-track running well.

• Clean and demagnetize tape heads

• Replace belts with low wow/flutter belts

• Oil capstan bearing with high quality German oil. It greatly improves wow/flutter

• Clean all input and output jacks with Deoxit on a cue tip. No messy spraying.

• Clean all potentiometers and faders with contact cleaner

• Check for and fix broken or weak solder joints. It is common for 1/4" input jacks, RCA jacks, and power jacks to have their solder crack from strain. We check for this and fix it when needed.

Calibration:

Aside from calibrating the tape speed which is required after changing belts, often the rest of the calibrations are fine from the factory, but we check them and make tweaks when necessary.

• Calibrate tape speed

• Check the playback level for even playback

• Check the record level for even recording

Cleaning:

We also take pride in restoring the cosmetic condition of the units we work on. Note that in some cases there are stubborn marks that we leave. Rather than scrub them away with a harsh cleaner which can damage the original finish or patina and leave the unit looking spotty.

• All knob and fader caps were cleaned with an ultrasonic cleaner.

• In some cases when the faceplate is removed we clean it in the sink with soap and water and dry it completely before reassembly.

Quality Assurance:


We also do a thorough QA of all our units. This process includes hooking the unit up to a vintage Hammond drum machine, Nord organ, and various other gear. We then record music on all 4 channels, and test all the functionality that would be used when recording music. It only gets listed once it has been tested this way. If any issues are found, we fix the issues before listing. This ensures that the unit is functioning as it should without a doubt! 

Other notes:

• It comes with a new power supply and bulk-erased vintage tape. Vintage tapes are the best in our experience.

• Free USPS ground shipping. Will usually ship same day.

Need your 4-track serviced? Reach out to us via direct message or our website for availability and rates. We are located in San Francisco, CA. See our website functional.fyi for more info.

Internal Id: G335
Listing Date: July 1, 2026