Vintage Audio
this section covers some restoration work that I did on my vintage HI-FI gear
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Article #1 | 06:43 PM Saturday 11/11/2017

AKAI GX-630D: Introduction

When I bought this tape deck it was partly defect. I never had the chance to enjoy it fully because almost every time I wanted to load a tape I encountered various problems. There were speed problems, logic control problems, overheating -- although I think this is normal -- audio dropouts, bad frequency reproduction. Not to mention the mechanical issues such as bad pinch roller.

Over 8 years ago I said this was going to be a big project. So the unit just waited patiently for the moment to come.

This is going to be a big project. I can already sense that. I will attack one small step at a time. Unfortunately there are only two extra-large printed circuit boards in this machine. They both require service. And a wire forest is connecting these boards to various circuits inside the unit. So I will be patiently working my way through.

Article #2 | 10:03 AM Tuesday 13/11/2018

AKAI GX-635D: Technical Data

This reel to reel tape machine has the following technical characteristics.

TECHNICAL PARAMETERS
ParameterValue
N/AN/A

Article #3 | 12:00 PM Tuesday 13/11/2018

AKAI GX-635D: Parts List

This is a typical 1970s AKAI reel to reel tape deck with two large printed circuit boards crowded with parts. This unit comes from an era when these were state of the art. However the internal construction is highly not serviceable. At least not up until you remove a lot of wires and screws. Then it is perfectly doable.

I decided to use high quality capacitors for the digital system board and audio grade capacitors for the analog audio board. All from Nichicon. The tantalum capacitors were replaced all with Kemet parts.

Descriptions and Parts Listings

The SYSCON board is coded XXX and is located in the top section of the tape machine.

SYSCON Board (XXX)
IdentifierSchematicRecommendedMouser Number
C12200 uF / 35 V647-UPW1V222MHD6
C2220 uF / 35 V647-UPW1V221MPD1TD
C322 uF / 25 V647-UPW1E220MDD1TA
C41000 uF / 25 V647-UPW1E102MHD
C52200 uF / 16 V647-UPW1C222MHD
C610 uF / 16 V10 uF / 25 V TC80-T350E106M025AT
C71000 uF / 10 V1000 uF / 16 V647-UPW1C102MPD
C8100 uF / 16 V647-UPW1C101MED1TD
C1110 uF / 16 V10 uF / 25 V TC80-T350E106M025AT
C121 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C151 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C1710 uF / 16 V10 uF / 25 V TC80-T350E106M025AT
C181 uF / 100 V647-UPJ2A010MDD
C211 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C221 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C231 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C241 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C251 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C261 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C27220 uF / 10 V220 uF / 16 V647-UPW1C221MPD
C28220 uF / 10 V220 uF / 16 V647-UPW1C221MPD
C2947 uF / 25 V647-UPW1E470MDD
C30220 uF / 10 V220 uF / 16 V647-UPW1C221MPD
C31100 uF / 10 V100 uF / 16 V647-UPW1C101MED1TD
C32100 uF / 10 V100 uF / 16 V647-UPW1C101MED1TD
C33100 uF / 10 V100 uF / 16 V647-UPW1C101MED1TD
C3410 uF / 16 V10 uF / 25 V TC80-T350E106M025AT
C3547 uF / 6.3 V47 uF / 6.3 V TC80-T350F476K006AT
C3647 uF / 6.3 V47 uF / 6.3 V TC80-T350F476K006AT
C3747 uF / 6.3 V47 uF / 6.3 V TC80-T350F476K006AT
C381 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C3910 uF / 16 V10 uF / 25 V TC80-T350E106M025AT
C4010 uF / 16 V10 uF / 25 V TC80-T350E106M025AT
C411 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C4222 uF / 10 V22 uF / 25 V647-UPW1E220MDD1TA
C431 uF / 25 V1uF / 35 V TC80-T350A105K035AT
C4610 uF / 6.3 V10 uF / 25 V TC80-T350E106M025AT
C4710 uF / 6.3 V10 uF / 25 V TC80-T350E106M025AT
C48470 uF / 160 V647-UPW2C471MRD
C49100 uF / 100 V647-UPW2A101MHD
C53100 uF / 3.15 V100 uF / 6.3 V80-T350H107K006AT
C5622 uF / 25 V647-UPW1E220MDD1TA

For simplicity of the parts order, I have centralized the parts below.

SYSCON Board (XXX)
How ManyValueTypeMouser Number
121 uF / 35 VTantalum Capacitor80-T350A105K035AT
810 uF / 25 VTantalum Capacitor80-T350E106M025AT
1100 uF / 6.3 VTantalum Capacitor80-T350H107K006AT
4100 uF / 16 VElectrolytic Capacitor647-UPW1C101MED1TD
1100 uF / 100 VElectrolytic Capacitor647-UPW2A101MHD
11000 uF / 16 VElectrolytic Capacitor647-UPW1C102MPD
11000 uF / 25 VElectrolytic Capacitor647-UPW1E102MHD
322 uF / 25 VTantalum Capacitor647-UPW1E220MDD1TA
3220 uF / 16 VElectrolytic Capacitor647-UPW1C221MPD
1220 uF / 35 VElectrolytic Capacitor647-UPW1V221MPD1TD
12200 uF / 16 VElectrolytic Capacitor647-UPW1C222MHD
12200 uF / 35 VElectrolytic Capacitor647-UPW1V222MHD6
347 uF / 6.3 VTantalum Capacitor80-T350F476K006AT
147 uF / 25 VElectrolytic Capacitor647-UPW1E470MDD
1470 uF / 160 VElectrolytic Capacitor647-UPW2C471MRD

The AMP board is coded XXX and is located in the bottom section of the tape machine.

AMP Board (XXX)
IdentifierSchematicRecommended
C1a10 uF / 16 V
C1b10 uF / 16 V
C5a2.2 uF / 50 V
C5b2.2 uF / 50 V
C6a47 uF / 25 V
C6b47 uF / 25 V
C7a10 uF / 10 V
C7b10 uF / 10 V
C10a100 uF / 10 V
C10b100 uF / 10 V
C11a10 uF / 16 V
C11b10 uF / 16 V
C13a10 uF / 16 V
C13b10 uF / 16 V
C14a10 uF / 16 V
C14b10 uF / 16 V
C15a22 uF / 25 V
C15b22 uF / 25 V
C22a10 uF / 16 V
C22b10 uF / 16 V
C24a47 uF / 16 V
C24b47 uF / 16 V
C27a47 uF / 10 V
C27b47 uF / 10 V
C33a10 uF / 16 V
C33b10 uF / 16 V
C35a100 uF / 10 V
C35b100 uF / 10 V
C37a10 uF / 25 V
C37b10 uF / 25 V
C39a10 uF / 25 V
C39b10 uF / 25 V
C40a10 uF / 16 V
C40b10 uF / 16 V
C41a10 uF / 16 V
C41b10 uF / 16 V
C42a4.7 uF / 25 V
C42b4.7 uF / 25 V
C44a4.7 uF / 25 V
C44b4.7 uF / 25 V
C45a22 uF / 25 V
C4910 uF / 16 V
C5010 uF / 25 V
C51220 uF / 25 V
C52a4.7 uF / 25 V
C52b4.7 uF / 25 V
C5333 uF / 10 V
C54a47 uF / 10 V
C54b47 uF / 10 V
C5610 uF / 25 V
C57100 uF / 25 V
C5822 uF / 25 V
C5910 uF / 25 V
C61100 uF / 25 V

For simplicity of the parts order, I have centralized the parts below.

AMP Board (XXX)
How ManyValueType
2610 uF / 50 VElectrolytic Capacitor
4100 uF / 16 VElectrolytic Capacitor
2100 uF / 25 VElectrolytic Capacitor
22.2 uF / 50 VElectrolytic Capacitor
422 uF / 25 VElectrolytic Capacitor
133 uF / 16 VElectrolytic Capacitor
64.7 uF / 50 VElectrolytic Capacitor
847 uF / 25 VElectrolytic Capacitor

...

Article #4 | XX:XX PM XXX XX/XX/2017

AKAI GX-635D: Restoration

I am still working on it.

If you will

Please note that all the work presented herein this site is non-commercial. This is my hobby and I am doing this in my spare time. Through this page I freely share my knowledge with you. But if you like my work, please consider helping me buy a transistor or a capacitor for my projects.

Thank you!

Copyright © 1998- Alexandru Groza