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Servicing a SONY DAT machine (Pictorial)

hdrobien said:
A few tips for adjusting the tracking without a dedicated tracking tape.

First, get a tape recorded on a properly tuned deck.

Connect the oscilloscope with channel 1 on the RF signal and channel 2 on the SWP signal. Set the trigger to channel 2 SWP.

You only need to visualize the RF signal without DC component (AC mode).

Set the deck to XTEST SERVO test mode (short circuit of the XTEST SERVO terminal with ground) and cancel ATF auto-tracking (REC MODE Switched to STANDARD).

Play the tape and adjust the oscilloscope to view a single frame as shown in the following image (vertical 1 div = 50 mV).

View attachment 2815781

Note that the left guide S1 (S for supply) will act on the left part, and the right guide T1 (T for tape-up) will act on the right part.

Turn the left guide so that the part circled in red is clearly visible. If you turn clockwise too much, this part will shrink. If you turn in the opposite direction, this part will widen to a certain point and then stop increasing (about 1 and a half turns / 2 turns from the fully screwed guide).

Stop turning S1 just after the part circled in red no longer widens.


Then turn the right guide T1 so that the RF signal is as rectangular and symmetrical as possible (both vertically and horizontally). Adjust the right guide T1 to the middle position between the positions where the signal is no longer rectangular.

Then you'll have to fine-tune the setting by ear.

Listen to the tape in play mode: is it clean without digital noise?

If so, listen to the tape in accelerated playback mode (by pressing the >> button during playback): is the sound jerky without digital noise ? Congrats, you're done !

If you can ear jerky sound with digital noise, adjust the right guide T1 by very small actions (1/16 1/32 of a turn at a time) in one direction and in the other, until obtaining the jerky but clean sound.
Click to expand...

Hello,

What's the best option in order to proceed without an official test tape ?
I have 2 "trusted" machines. Would it be better to create a test tape with a sinusoidal signal of, for exemple, 12Khz at 0db or would any audio tape be as good ?

Tx!
 
Hi

It would be to record something (anything) on a trusted deck, then play it on the deck to adjust.

Adjust S1 to display the full left part of the signal, then adjust T1 to have a symmetrical signal.

Finally, you need to fine adjust T1 in order to have a clean chopped sound in fast play, without digital artifacts.
 
Thank you for all your answers.
I found the problem, one of the wires from the head is broken on the drum PCB. I don't know how this happened, I never disassembled the drum assembly from the mechanism. The wire is in this position because I, very carefully, moved it to be sure that is really brocken.
 

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I'm going to investigate if i've a similar problem. I suddenly had no sound after recording. I can't actually tell in your picture which wire is broken :D Did you manage to repair it?
 
Good morning, a greeting to all of you, sorry if I disturb ... I have a DTC 670 to which I replaced the condensators of the preamp module, but now when it is in play every 30/60 seconds the audio stops and I hear a click from a Blue relè on the mother board. Does any of you have any solution? Thank you
 
Hi

It could be anything from dirty heads to failed capacitor replacements.

Also check the condition of the 6800 µF capacitor on the power board.
 
From my experience, only 2 places are prone to fail : the 6800 µF on the power board and the smd on the RF amp (both 22 and 4,7 µF).
 
Good morning everyone...I replaced the capacitor but the problem remained...when I start the play the tape turns but after a few seconds the relay in the photo starts to click click and the playback stops for milliseconds and restart soon. Do you have any other suggestions? Could it be the motor that needs replacing? Has anyone already done it? Thanks everyone and sorry for my bad English.
1000014867.jpg
 
This relay clicks when the signal is not good enough.

Have you cleaned te drum ?

Have you tried messing with the guides ?

It could also be a bad solder on a connector.
 
The 2 guides that wrap the tape around the drum.

They set the position of the tape precisely against the heads (~azimut or tracking).
 
You mean the White guides? Yes i clean it and i clean the heads and i dismantle the capstan and clean the pinch roller and everything but... The problem persists ‍♂️... I don't know how can I make now...i am thinking to put in the junk this dtc 670 ‍♂️
 
vallentin said:
Ofcourse there are other options cheaper than eBay :) I have some copyprocessors to part ways with. Some of them are NOS.
You also have the DYI no.2 option ~20-30EUR a sample.
I successfully modded my 55-ES and 60-ES using the latest development ATTiny modules.
In every situation I get the ID6 00 on my tapes (No copy protection) :
ID6 00 Optical
ID6 00 Coaxial
ID6 00 Analog
ID6 00 AES/EBU
Click to expand...
Hi Valentin.
I'm writing from Hungary.
I would like to have an ATTiny module like this too.
I have DTC-60, 690, 55, and PCM-R500.
Which one is good for and how much is it?
julacika@gmail.com
 
Same question here about the Attiny SCMS remover.
I cannot find any valid source of information about it...and I guess those only work for DAT equipped with the CXD2601 or CXD2605 processor.

Any information would be welcome.
 
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