The quartz locked control IC is made by Toshiba and I bought it from eBay. I have used high quality components such as precision metal film resistors, quality film capacitors, C0G MLCC parts, and Texas Instruments integrated circuits. Here is a close range picture of the quartz servo tape speed circuit. This operation is not mandatory, but I like to work in a clean fashion. First of all, I used a combination of isopropyl alcohol and high purity acetone to clean the lacquer from the circuit board zones that I worked on. The solder side of these AKAI PCBs are coated with some kind of flux lacquer that emits some stinky fumes while heated. Then I removed all FG servo related components and populated the quartz servo circuit section with the expected parts. The FG servo control circuit is left of the unpopulated quartz servo section. But with some care and a good vacuum pump I removed every connection point in less than ten minutes. The difficulty at this step was to unsolder all command and control wire ribbons. Since the system control printed circuit board in this cassette deck has provisions for the quartz locked servo tape speed control circuit, the conversion from FG servo to quartz servo is straightforward.įirst, I completely removed the system control PCB from the machine. While this is pretty much bulletproof, a quartz locked tape speed control is still a desirable feature. This unit comes from the factory with an adjustable FG servo tape speed control. And do it well.ĪKAI GX-95: Quartz Locked Tape Speed Control Board (CB-5002)Īs always, do not hurry, take your time and do the job once. The quartz locked control circuit is located on the System Controller (SYSCON) printed circuit board, in the upper-mid section, just right of the FG servo section. The parts list was obtained from reverse engineering with the help of a member of the Tapeheads community that added some pictures of the SYSCON PCB assembly from an AKAI GX-Z9100EV unit. This functionality is not part of the original implementation and nor is it specified in the service manual. Let's start with a parts list for the quartz locked servo tape speed control circuit. I have assembled a partial parts list for this cassette deck. TECHNICAL PARAMETERSġ x direct-drive linear torque BSL motor for capstan driveġ54 mm (H), 460 mm (W), 350 mm (D) / 10.2 kg This cassette deck has the following technical characteristics. The entire documentation is just a reflection of my work and I cannot be held responsible if you damage your unit, or even harm yourself in the process. But you can consider this whole content as a general guideline, should you decide to launch into such an adventure. The following articles are not to be treated as do-it-yourself tutorials on how to fix, restore, rebuild, or improve the unit in cause. In my opinion the standard AKAI GX-95 unit is a good unit for everyday use, both in terms of recording and playback.Įnough talking and let's see what I can do to this machine in order to improve its characteristics. I excluded A&D Japan-only units from the start due to scarcity and price tag. ![]() More on this, later on.įor a few reasons, I specifically wanted the first generation GX-95 unit, and not the MK2. Unfortunately, at the time I did the mechanical block swap, I haven't had the Vintage Audio site and I didn't document anything.įrom the start I had this idea to convert this machine to quartz locked tape speed control. I replaced it and finally I could listen to cassettes. I ended up buying a complete low mileage mechanical block from eBay. And it had some other issues with the mechanical block especially in the tape path. It was previously tampered with by somebody that somehow managed to misalign the preamplifier output level of the tape head left reproduce channel. I have this cassette deck since 2006 or so but I have never had the chance to enjoy it fully. ![]() This section covers some restoration work that I did on my vintage HI-FI gear
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