Hi all,

I have a quaestion for the experts:

I have picked up a repaired walkman from a near technical service, on which they have changed all capacitors and cleaned acid on the circuit.
Now it sounds very good! It's an AIWA. Well, in fact I have more than one model that suffers from the same problem.

But it seems the high frecuencies doesn't sound as good as other models I have, specially SONY's DD series. Yes, I know, DD series sounds so good, but this time it's a azimuth matter.
So I telephoned to the technician and we talked about this problem. I don't have so much skills in this area, but as I studied enginery at university, I can understand this kind of things.
He explained me that in some walkmans it's possible to adjust but using a special recorded tape, with 1khz and 3khz frecuencies.
So I proposed him that I record this frecuencies on a good tape (Maxell XL-II S) using my SONY D6C (calibrated for Maxell XL-II); this way he will adjust azimuth on them for my recordings.
How can I record this tape? Or, better said: is there any software that produces that frecuencies so I can play them with my PC, using a good sound card?

Regards,

What model Aiwa is it? The later Aiwa models do not have adjustable azimuth. If it is a recording model, you could "create a tape" from the Aiwa to use as a baseline for a better tape recorder to make tapes for it to listen on.

Also check for tape head wear. Aggressive tape head wear can cause the high end frequencies to sound duller.

There are a number of free frequency generators out there. I use TrueRTA myself. It also doubles as an oscilloscope frequency analyser.

quote:

Originally posted by plop:
What model Aiwa is it? The later Aiwa models do not have adjustable azimuth.

Well, I have this feeling with some models, like the PX303 but specially with some JX707. I know the PX303 and JX303 have some kind of auto adjustable azimuth, but is it possible with JX707s?

quote:

If it is a recording model, you could "create a tape" from the Aiwa to use as a baseline for a better tape recorder to make tapes for it to listen on.

But I prefer to record on a different deck, well known for having a good quality. I don't think quality recordings of those full-deatured walkmans is top-end, right?

quote:

Also check for tape head wear. Aggressive tape head wear can cause the high end frequencies to sound duller.

Ok, thanks for the point. I don't think this is a problem, as most of them are in very good condition, near to mint (I checked it)

quote:

There are a number of free frequency generators out there. I use TrueRTA myself. It also doubles as an oscilloscope frequency analyser.

Oh, thanks. Could help me a bit? Which one of the two hundred buttons is the one I have to click on? :-)
O better: can you tell me ho do I set two frecuencies at the same time?

Regards,

Hugo,

Unfortunately the JX707 azimuth is not adjustable. This is confirmed in the service manual and also having having taken a fair few of these apart myself. The earlier JX505 does have an adjustable azimuth. From photos it appears the PX303 shares the same tape mechanism as the JX505 and therefore should also have an adjustable azimuth. The PC202 series also has adjustable azimuth.

When I suggested creating a tape recording from the Aiwa recorder with the fixed tape head, I meant to use it to record an azimuth correction tape using a frequency generator such as TrueRTA. From this tape, then adjust a much better tape recorder such as a WM-D6C using the azimuth correction tape created from the Aiwa. This would mean that your Sony now has the same azimuth adjustment as the fixed head on your Aiwa. Record about 3 minutes at 1KHz and another 3 minutes at 10KHz. NOTE: If you want to return to the Sony's previous azimuth setting, be sure to create a recording on tape from the tone generating for it before you do any azimuth adjustment to match the Aiwa.

Before using TrueRTA, please read the help section concerning calibration of the Line Input and and Line Output of your PC sound card. This will ensure that you get sensible readings on TrueRTA.

Using TrueRTA to generate test tones is quite simple. When you run TrueRTA, there are a number of buttons on lefthand side. These are the ones that you need. 'Freq.' sets the frequency. Set this to 1000 for the 1KHz test tone. Set the 'Ampl.' at -10dBu. Set the wave to 'Sine'. Press the 'On/Off' button to start the tone. When you are finished press 'On/Off' again. You can now repeat the process again for the 10KHz, by entering 10000 into the 'Freq'

Hi Plop,

I've bought the necessary cable so I can do the autocalibration of my sound card and now it's done. Interesting process :-)

But I have a problem: the technician told me I have to record both frecuencies at the same time. Can this be done with TrueRTA?

regards,

I did a mistake.

What the technician does mean is that the frecuency gets recorded on both channels...
well, so let's see how good sounds after this.

regards,

im not clued up on any of this but would like to be anyone shed light on a thread or link onto what this is regarding playing a tape to retune cassette player in intrested cheers daz

@Plop
"Unfortunately the JX707 azimuth is not adjustable. This is confirmed in the service manual and also having having taken a fair few of these apart myself. The earlier JX505 does have an adjustable azimuth. From photos it appears the PX303 shares the same tape mechanism as the JX505 and therefore should also have an adjustable azimuth. The PC202 series also has adjustable azimuth"



Well, it is not quiet accurate, All Heads has Azimuth adjust-ability, most are manual, some are kind of automatic like Aiwa PX/JX303 and some of JX50. some are set heads with plastic housing. exception to that is the JX707 which has 2 adjustable points but it is still in a plastic housing and can be removed by an expert for best sound results. another thing to consider is to clean the heads with fine 95% alcohol.



BTW: Plop, thanks for your Help with the Bad caps, I have succeeded with replacing my PX303 bad caps after almost a year. :-)


Cheers.
TheLion

@TheLion

I am intrigued to know how this would be achieved easily. There are two screws that attach the bi-azimuth head to the armature (which in turn swings out to the tape and pressure pad). The purpose for these screws it would appear is to hold the head in the armature only. Adjustment probably might be possible by adding a shim under one of the screw positions, but to go to such tortuous trouble may not effect a successful recalibration and may require numerous disassembly and reassembly attempts before the desired effect is achieved. Certainly not a simple task by any means!

On earlier bi-azimuth Aiwa HS the head is attached with two screws, but crucially one end of the head is pivoted against a back plate. Through adjustment of this backplate azimuth correction is achieved. This is not the case in the later bi-azimuth Aiwa HS anymore.

Cleaning and demagentizing tape heads will only get you so far on a misaligned head, in any case as tape listeners routine maintence is something we should be doing as a matter of course. If not to maintain audio fidelity, but certainly to minimise tape head wear.

Well all this is more theoretical then practical.
But it is still possible in extreme cases. when Sony started to buy shares of AIWA the whole manufacturing became very much cheaper and less quality. AIWA was always bragging of it's head design and of it's high quality class. they were one of the first to introduce special features head developing and extending sound features to them. note the changes that took place when Sony stepped in and the new plastic housing style. the JX707 was the last AIWA attempt to maintain that quality, there for you will notice JX707 with old logo and new logo. AIWA style was never about titanium style like the flashy Sony WM701S & EX. even the head in the PX1000 is a Sony head (blue/green reading head PX).


As I said earlier the only one to support a Bi-Azimuth is the PX303, PL35, RL30 and some of JX3000/2000/50... Later models didn't have that Bi-Azimuth, Just a small piece of metal reminder to move the head forward, but certainly not an bi-azimuth. most of the JX505 have this special Bi-Azimuth plate and holes for the screws but that was about it just a reminder for a budget cut on the Sony part. yes, sad enough.... cause eventually look what happened to AIWA today after all their glory days....


Your right, cleaning is only a minor issue. it is more for wow & flutter or unclear sound, it is no answer for alignment or crystal clear sound. but head wear is not a common issue. tape heads are very durable, I have never seen a worn out head except for the old answering machines. or when using metal tapes without the metal switch on.
Cheers
 TheLion

I have a few examples of varying degrees of tape head wear on a number of JX707. In one case the tape head wear is so bad on one example that even using it to record a DIY alignment tape and adjusting a recorder with known good heads such as D6C, Playback of recording from adjusted D6C was lousy on JX707 with worn out head and perfect on D6C and other JX707 with good head.

Head wear does occur, Yes you are right especially with metal type, but cheap ferric tapes which drop out more particles more frequently used by most people can be even worse than a good metal tape with anti-shedding properties..