TEAC A-430 auto bias operation

[Gertjan90]

Hi guys,

A friend of mine brought in a TEAC A-430 for servicing, as it needed new belts.
While the new belts are on their way, I installed a temp replacement to check the other functions.

I'm especially intrigued by the auto-bias function and it's motor driven knob. Unfortunately, I'm unable to find an owners manual for the A-430, so I don't know how this is supposed to work.
You can dial in the bias manually with the knob for metal, chrome or normal tapes, but I'd like to test the auto-bias.

So far I've got this going on:
When recording a tape, not paused, when pressing the auto-bias button, the knob will start turning round and round and the bias light starts blinking. But as soon as I let go the knob stops and the light goes out.
It's a three head deck so while I press the button, I can hear a high pitched tone being recorded on the tape. I assume the machine then listens back to the tone and determines the correct bias.
However, the biasing goes on for however long I press the button, stopping whenever I let go at any position the knob happens to be at.

Can anyone tell me what is supposed to happen when using auto-bias? Am I missing some steps?
I'm looking to see if something is broken or if I'm just not doing it right.
It might be worth mentioning that the auto-bias button is labeled as on/off, but it's not captive, as in it wont stay in the on position when pressed. It just pops right out.

Any help is appreciated.

 

[xelablan]

Hi.Hope this will serve. What´s your opinion about its sound quality? I´ve just bought one but it´s not here yet. Best regards.

 

[Gertjan90]

Hi,

Thanks for the info!
I eventually figued out how to use the auto-bias. The machine has been back to it's owner for a while now, but I still have some tapes I recorded with it.
Now, I haven't listened to a lot of high end tape decks before, in fact the A-430 is probably the most expensive (when new) deck I ever serviced.
That said, I loved the quality of the recordings I made. Way better than any decks I own myself.
The owner is considering selling the A-430, and if I wasn,t downsizing my collection, I would buy it for sure.
Build quality and easy of maintenance is great as well.

You wont regret your purchase.

 

[xelablan]

Hi,

Thanks for the info!
I eventually figued out how to use the auto-bias. The machine has been back to it's owner for a while now, but I still have some tapes I recorded with it.
Now, I haven't listened to a lot of high end tape decks before, in fact the A-430 is probably the most expensive (when new) deck I ever serviced.
That said, I loved the quality of the recordings I made. Way better than any decks I own myself.
The owner is considering selling the A-430, and if I wasn,t downsizing my collection, I would buy it for sure.
Build quality and easy of maintenance is great as well.

You wont regret your purchase.

Thanks for your answer. There´s no much information of this deck and not User Manual anywhere, only Service Manual but, with understanding of how AutoBias work, it´s very easy to use. And, fortunately, there are belt kits and pinch roller made new for this machine, so it is easy to maintain. I think its construction is very good, so it will be a reliable, good sounding and long lasting deck. I followed advise from David Haney, an English tech who recommended me to buy a deck from the 70´s or 80´s instead of more modern machines with more complicated electronics and, overall, a lot of plastic parts. Best wishes for you and your family.

 

[xelablan]

Hi,

Thanks for the info!
I eventually figued out how to use the auto-bias. The machine has been back to it's owner for a while now, but I still have some tapes I recorded with it.
Now, I haven't listened to a lot of high end tape decks before, in fact the A-430 is probably the most expensive (when new) deck I ever serviced.
That said, I loved the quality of the recordings I made. Way better than any decks I own myself.
The owner is considering selling the A-430, and if I wasn,t downsizing my collection, I would buy it for sure.
Build quality and easy of maintenance is great as well.

You wont regret your purchase.

Hi. Teac A-430 arrived three days ago. I cleaned and desmagnetized heads, captan and guides .At first there was too much wow and flutter and I got very worried about it. After oiling motor and capstan bearings the thing changed completely and sound was very good. With memory buttom pressed, tape stops perfectly at Zero but I still didn´t get Autostop to work at FF, REW or when a tape comes at the end on playback. Don´t know why. But main problem is that I tried Autobiass with a Normal tape. The Autobiass knob started to spin, LED didn´t iluminate or flashed and the knob didn´t stop though I left pressing the buttom, more I switched off ower and when I switched ON again, the knob followed spinning inmediately without doing nothing. Can you tell me what it´s happening? I´d thank your answer about this. Thanks and best regards.