AIWA AD-F350

[stoppz]

Just picked up a recently serviced AIWA AD-F350.
I was born and raised listening to my dad's AIWA F660 which was then sold by him after years of non-use in 2009. I remember well the mechanics and sound of these AIWA decks.



I'm looking for the instructions/owner's manual, but in the meantime I was wondering the logic behind the bias adjustment, with the 4-position knob. On the front there is a table with a list of cassette tapes and the recommended bias adjustment, but I would like to understand how it works in order to manage recording with other cassettes.
Dad's old F660 had a different bias knob, with the (easy to understand for me) ±20.
I'm wondering if anyone knows this bias adjustment system and can help me understand, thanks!

 

[oldvinyldude]

I can't state with certainty, but my educated guess is the 4 bias levels are simply a simplified version of the bias pot on your dad's machine. If bias is set too low for the tape, the recording will be overly bright, and Dolby tracking will be adversely affected. (Honestly, I avoid Dolby now, as most decks have drifted quite a bit over time, and I lack the tools to realign it). If the sound is lacking highs, then bias is set too high.

Bottom line, test record a familiar track, and adjust the bias through the 4 positions. Play back and choose whatever sounds best to you. Make a note of this whenever you use that tape brand\type. Do this for all brands\types you have. Then just click into the position your tests told you were best, for recording,

 

[stoppz]

Thank you so much oldvinyldude!
I have finally found the owners manual, and I see you were right: the bias pot is the same as the ±20 on other models!

 

[WernerO]

these Aiwa tables were notoriously inaccurate

 

[oldvinyldude]

these Aiwa tables were notoriously inaccurate

Yes-with all the various formulations produced, it’s likely that one setting will be pretty good, while others are not. Just pick what sounds best to the user and call it good.

I will say that my ADF810 sounds great on Chrome setting, with Bias fine tune at 12 o’clock, using Maxell UDXLII. My hunch is this was the formulation that they used to set Bias and equalization for the Type 2 setting.

 

[stoppz]

The deck was not-so-well-serviced. We have problems!
There's a good technician working near me, but he's busy until March. In the meantime, I'd like to try to understand if it's worth taking the deck to him for service, or it's not worth it.

1. During playback and recording, the left channel plays at a much lower volume than the right, and it also lacks high frequencies, perhaps a problem with head alignment and azimuth? The head is noticeably crooked, I hope it's not damaged.

2. The deck does not understand what type of cassette has been inserted, the "Metal" LED remains lit regardless of the type of cassette inserted. The "Normal" and "CrO2" LEDs never light up, probably an issue with the switches located at the top of the deck.

3. The F.FWD> works regularly but there is a cyclic noise, while the <REW works only a few times and when it works it stops after a few seconds, as if it had no torque to pull the tape.

Do you think I can do something at home while waiting for the technician?

 

[oldvinyldude]

Yes-that head sure looks twisted. It’s a decent deck, but only you can decide whether it’s worth repair. With multiple issues, it will likely cost the value of the deck, for repair. While you wait, you could look around for any other physical distortions. Perhaps you can find where the cyclic noise is coming from. You might determine what button/switch lever when depressed will allow the REW and FFD to run with no tape is loaded. Maybe you can observe slipping of a belt, or an idler, by grabbing the driven spindle while running. Careful observation might assist the technician.

 

[stoppz]

Thanks so much for your help, I found which lever when depressed will allow the REW and FFD to run with no tape is loaded.
Surely the idler slips and is unable to rewind the tape, however without the cassette inserted it runs well.
I didn't understand how the deck recognizes the type of tape, not even from the service manual.

 

[dhnash]

The service manual shows that leaf switches S904 and S905 are used to detect whether tapes of type other than ferric are installed in the cassette bay. They do this by detecting the presence or absence of notches on the top side of the cassette.

 

[stoppz]

I really appreciate your help, with which I will at least be able to direct the technician!
In the meantime I can order a new idler, new belts and pinch roller. I hope to get it working again in full efficiency, or it will always be a "poor" unit.

 

[Okke 70s]

Without the "monitor" function of a three-head deck I suppose you would have to rely on a pre-set bias menu. I guess it could work, basically like the tape-type selector switch. It might be a bit crude. I see for instance TDK type D, SA and SA-X all under the same setting, while they definitely respond differently, and require (minor) adjustments between them on my deck. But it is still better then nothing right? Which is the standard for two-head decks.

As for the repairs, well it is not going to be economical. In the sense that you will not increase the market value of the machine with it, to a point that offsets the costs of repairs. So spend what you are willing to burn on it.

Once the head is realigned you might have full sound back on both channels without farther work done. If nothing is bent, but just misaligned, you could give it a try by tightening that little screw with the spring around it a bit, right under the head. Be careful not to use a magnetised screwdriver in there.

The slipping during winding is probably caused by a bad idler-wheel rubber. And who knows, maybe that is all it needs. Yeah, cassettedecks are either serviced or need servicing. Count on it!

 

[stoppz]

When I turn this deck on, and it is still on the stop position, I can here the "hum" of it quite noticeably. It is coming from the deck itself (not from the speakers). I think it comes from the transformer. Now I don't know whether to throw it away or continue with the repair.

 

[oldvinyldude]

It’s best if you can find the source of the hum. Try using a length of tubing to act as a stethoscope of sorts, moving it to possible sources (motor or transformer).
Humming transformer? Grasp it firmly and see if you can alter the hum. Perhaps it has loose fasteners, or some part of the chassis is in contact with it. It seems to be supplying proper voltages, so it’s likely a mechanical issue.

I have wondered whether the bent head mounting might have been due to an impact. A big impact could have moved other items around.

It’s not uncommon to hear faint motor hum, but not easily heard hum.

 

[stoppz]

Thanks for your patience oldvinyldude, and for your help.
I correct myself, I can hear the hum even when the switch is OFF. When the deck is ON, the capstan spins and a noise is heard, but the hum can be heard (albeit more faintly) even when it is OFF. All of this makes me think of the transformer.

 

[oldvinyldude]

Take the cover off and investigate the mechanical issues.

 

[stoppz]

I took the cover off, inspected the transformer and everything looks OK to my eyes.
However, I found the problem that the deck does not recognize the tape type. The black plastic levers that close the contacts are missing. In fact, by closing the contacts with my fingers, the "CrO2" and "NORMAL" lights light up correctly. I think these types of parts are unobtainable, I will leave aside the maintenance of this unit.

 

[oldvinyldude]

It does seem like this deck just keeps on giving (headaches). Further evidence that it may well have sustained shipping damage at some point.

I think I would move on as well.

 

[Okke 70s]

I agree. This machine might be fun if it runs, or maybe needs one little notch-up, but not much more. And it is starting to look like it's full of surprises..

 

[stoppz]

I found another AD-F350 deck in better condition, I think I'll keep this one for spare parts!

 

[oldvinyldude]

There ya go!