I searched EVERYWHERE looking for the manual/s on this "extinct" amp. Owner-Manuals.com made it available and for nearly nothing. Thanx to them, I can decipher the unknown cables and sort them out. Thanx, Owner-Manuals.com!!
Great manual...really saved me. The only problem is that I thought I would be able to download it directly when I paid for it but never received the download instructions until the next morning. The board trace pages were somewhat light also: really need to turn up the contrast on the printer before printing them. The schematic page was great; very clear! Well worth the money.
I've been in the electronic business for a long time. I used to buy Sam's Photofact for my needs which intailed having to go to the store and paying about $20 for a package of 3 different units so I was forced to buy more than I needed just to get one.
Owner manual is just at your keyboard and the information is almost instantansouly and the cost is very reasonable. Easy to print out if needed or simply read off of the screen. The larger the screen the better for obvious reasons.
Text excerpt from page 3 (click to view)
HTA-DD3
Check that exposed parts are acceptably insulated from the supply circuit before returning the repaired instrument to the customer.
INSTRUMENT (Exposed part)
� Checking method
Measure the resistance value between the both poles of attachment cup (Power supply plug) and the exposed parts (Parts such as Knob, Cover, etc. where the customer is easy to touch.) and check that the resistance value is 500 kohms or more.
Insulation tester (DC 500V)
SAFETY PRECAUTIONS
The following precautions should be observed when servicing. 1. Since many parts in the unit have special safety-related characteristics, always use genuine Hitachi�s replacement parts. Especially critical parts in the power circuit block should not be replaced with other makers. Critical parts are marked with _ in the circuit diagram and printed wiring board. 2. Before returning a repaired unit to the customer, the service technician must thoroughly test the unit to ascertain that it is completely safe to operate without danger of electrical shock.
