Schematic needed for Korg DTR-1000 Tuner

[brent]

Well, I eliminated the relays by powering up the board on a couple alligator clips to keep it connected to the chassis. The relays seem to be doing their job based on the schematic and my multimeter.

In thinking about it... really the only difference, or unique variable between input 1 and input 2 is that the 110 comes into the unit within close proximity to input 1 (on KLM_2356 FRONT JACK sheet). It definitely sounds like that 60 cycle hum. Switching to input 2 eliminates the higher voltage side of the tuner. (input 2 comes in and goes out on the +5 volt side of the tranny which is mounted on a separate PCB). Moving the transformer wires around with a chopstick while its powered up seemed to make some slight alterations to the hum....

Aside from the tranny taking in the AC voltage from the wall and putting out the DC voltage to the board... is it possible it might be creating some EMI or injecting some hum on the front input?

Thanks again for reading and offering suggestions. I realize this is probably a lost cause. I've put more time into it than its worth, but throwing it in a box without fixing it or at least knowing what the problem is keeps me up at night

[brent]

Well, I bought another DTR-2000 and it has the same issue. I suppose it's been there all along and I just never noticed it. Weird. I picked up some nylon connectors and pins and nd I'm going to try some shielded cable to see if I can quiet it down some.

[brent]

Here's my handy work. The factory cable is on the left, my cable is on the right. The signal is carried on the orange wire in the left cable. I believe because AC is coming in on this side and this wire is not shielded, that it was introducing some HUM in the signal path which caused input 1 to be noisy, while input 2 was quiet. I replaced my cable with the one I made and both inputs are quiet.

Easy to test for.... Turn amp volume UP high, don't plug in any instruments into the KORG but have the sound out connected to the amp. Switch between input 1 and input 2 and notice the difference.

Anyway, this is more for others who are interested. I appreciate all the help here! I realize there isn't a high demand for upgraded cables in the KORG DTR-1000/2000 but if anyone is interested... here they are!

[ohjustbyteme]

Korg DTR1000 issue

Greetings, I won a dtr1000 on ebay, and its functions seem to work ok as in it will do strobe or tuner, but will not display its output, perhaps its not receiving any signal. as in the first owner may have blown out the input. i'm curious.. i can hear the mute relay work, but again its not displaying output for the signal applied, can i replace the cpu chip ? will that help its issue? i see continuity from tip of input all the way to the cpu input pin.

[Longhair]

Happy New Year

Today I plugged in my guitar into the Korg DTR-2000 - probably the first time in a couple of months - and noticed nothing was happening when I tried to tune the guitar. After trying different cables, I grabbed a practice amp to see if the problem was with the cable or guitar. When I was greated with sound, I took the cable out of the amp and plugged it into the DTR-2000 trying all inputs with the same result - nothing. Frustrated, I plugged the cord back into the practice amp and plugged a 2nd cord from the headphone out to the DTR-2000 input and the tuner worked.

Is this a simple fix (replace a single over the counter component) or will need to be sent in to a service center for replacement parts? I am a basic DIYer.

Thanks

[leadfootdriver]

Yeah, my DTR-1000 was working fine last night, but today the tuner function won't work. The signal will pass for in to out, but there's no tuner action.

Any ideas before I tear into this this?

[leadfootdriver]

I tested the diode bridge, and got about 10.85 vdc at the output, and about 5vdc out of the 78MO5A voltage regulator. So something else bought the farm on it. These are about the only things serviceable in the unit for the most part. The rest is tiny surface mount stuff. I'm bummed. It just sat there, and now it doesn't work.

No more KORG purchases for me. Who make a good rack tuner?

[Longhair]

I am using the tuner out from the Line 6 G90 wireless and it seems to boost the signal to the point I am able to still use the tuner.

[ElectronicTechnician]

Hello, I know this is an old thread.

Nearby lightning strikes can damage any type of equipment unless surge protectors are used....

I am looking for KORG DTR-2 service manual and/or Schematic diagram. ANy help is appreciated.

Thanks.

[g1]

You should start a new thread in the "schematic requests" section: Schematic Requests