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Intonation on DX7

 

I've been reading about the "Railsback curve". Is there a way to implement this on a DX7?

For those not familiar, this refers to deviations to the mathematically pure 2:1 ratio for octaves that are often implemented by piano tuners. I'm curious about this, in part because of intonation issues when playing my oboe along with recorded DX7 parts. The higher notes of the DX7 sound progressively flatter compared to what I'm naturally playing on my acoustic instrument. I've been working to adjust my acoustic instrument's pitch to accommodate, but from what I've recently been reading about "subjective octaves" (that for orchestral instruments, they may in fact have a stretch-octave curve similar to the piano's Railsback curve), I'd like to experiment with having the DX7 accommodate my acoustic instrument, instead.

Reference links:
Re: Assistance needed

 

I had a similar problem with mine. The memory would get corrupted when switched off, even with a fresh battery.

In the end I found the fault was ZD1 (a 6.2V Zener diode) on the power supply board. This is used in the circuit that detects the power being switched off and puts the RAM into a safe reset state before the main power goes off. Without this happening properly the RAM can get spurious writes as the unit powers down.

Hope this might help.
Re: Assistance needed

 

There are several elements to the battery that need to be correct. Obviously the battery itself must be good and properly connected, then there is the germanium diode which you can test with most DMM's (Digital Multimeter ... not expensive, buy one if you plan to work on your gear), then there is a jumper on the bottom of the board (it can become unsoldered).

You will need to verify the battery voltage right on the RAM ICs with the unit powered off to know if the correct voltage (around 2.5v to 3v) is appearing on the RAM. I wouldn't go by just the built-in battery voltage reading menu.

GB

On 6/29/2021 7:13 AM, david covino via groups.io wrote:
Good morning, all.? I need your help.? My DX7 is one of those from Japan with the lamp cord power cord.? Recently, I've received this display and figured the battery was bad, so I changed it out, and reloaded the sounds from the cartridge to internal memory.? My problem is that the memory does hold the sounds for more than maybe 10 minutes, and internal memory reads as you see here, and it doesn't emanate any sound.
Strangely, in cartridge mode, all sounds are normal and they work fine.
Has anyone seen this before and have any suggestions?? Battery voltage reads 4.6 volts with a new battery.? (As I recall, these models normally read more than the 3.3 volts for the CR2032)
Thanks very much in advance!
Kind regards,
L. David Covino
**
**//___^
-----Original Message-----
From: David Covino <ldcbox@...>
To: ldcovino@... <ldcovino@...>
Sent: Tue, Jun 29, 2021 10:02 am
Subject: Fwd: kB
-----Original Message-----
From: DAVID COVINO <ldcbox@...>
To: ldcbox@...
Sent: Tue, Jun 29, 2021 9:58 am
Subject: kB
Re: Assistance needed

Bruce Wahler
 

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Hi David,

I'm not a DX7 owner (TX802 here), but here are some general comments:

  • The battery is 3.1-3.3 volts.? If you are reading 4.6V, and you are certain that you are reading only the voltage across the battery, it sounds like the power is on.? You want to read the battery with the power off.? It should read 3.{something}. and the voltage going to the memory chips should be something around 2.7V, because of a blocking diode in the battery path.
  • If the battery is actually reading 4.6V when power is on, I suspect that the blocking diode has shorted, causing the 5V power to feed the battery.? This is not a good situation for the battery, as it is attempting to take a charge.? Best case, the battery will be damaged over time.? Worst case, it could explode!
Regards,

-BW

Bruce Wahler
Halfmoon-Switch.com?
bw@...

978.597.7008

PLEASE NOTE: ?The AshbySolutions.com domain will be closed soon. ?Please use the new (wahler.us) email for all future correspondence. ?Thank you for your understanding.
?
?
On 6/29/2021 10:13 AM, david covino via groups.io wrote:

Good morning, all.? I need your help.? My DX7 is one of those from Japan with the lamp cord power cord.? Recently, I've received this display and figured the battery was bad, so I changed it out, and reloaded the sounds from the cartridge to internal memory.? My problem is that the memory does hold the sounds for more than maybe 10 minutes, and internal memory reads as you see here, and it doesn't emanate any sound.?

Strangely, in cartridge mode, all sounds are normal and they work fine.

Has anyone seen this before and have any suggestions?? Battery voltage reads 4.6 volts with a new battery.? (As I recall, these models normally read more than the 3.3 volts for the CR2032)

Thanks very much in advance!

Kind regards,?

L. David Covino?





-----Original Message-----
From: David Covino <ldcbox@...>
To: ldcovino@... <ldcovino@...>
Sent: Tue, Jun 29, 2021 10:02 am
Subject: Fwd: kB




-----Original Message-----
From: DAVID COVINO <ldcbox@...>
To: ldcbox@...
Sent: Tue, Jun 29, 2021 9:58 am
Subject: kB

Re: Assistance needed

 

re cap your power supply , or check
voltages at main and follow first
Assistance needed

david covino
 

Good morning, all.? I need your help.? My DX7 is one of those from Japan with the lamp cord power cord.? Recently, I've received this display and figured the battery was bad, so I changed it out, and reloaded the sounds from the cartridge to internal memory.? My problem is that the memory does hold the sounds for more than maybe 10 minutes, and internal memory reads as you see here, and it doesn't emanate any sound.?

Strangely, in cartridge mode, all sounds are normal and they work fine.

Has anyone seen this before and have any suggestions?? Battery voltage reads 4.6 volts with a new battery.? (As I recall, these models normally read more than the 3.3 volts for the CR2032)

Thanks very much in advance!

Kind regards,?

L. David Covino?





-----Original Message-----
From: David Covino <ldcbox@...>
To: ldcovino@... <ldcovino@...>
Sent: Tue, Jun 29, 2021 10:02 am
Subject: Fwd: kB




-----Original Message-----
From: DAVID COVINO <ldcbox@...>
To: ldcbox@...
Sent: Tue, Jun 29, 2021 9:58 am
Subject: kB











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Re: DX21 and DX27S chorus effect

 

On Fri, 18 Jun 2021, Co Da via groups.io wrote:

That's interesting, I wouldn't describe that as a chorus at all, to my ears
that's actually tremelo.
Maybe because it's a testttone, only a sinewave?
If you look at it in a wave editor you will see a type of irregularity that you will not see with a tremolo effect.

--

MT
Re: DX21 and DX27S chorus effect

 

That's interesting, I wouldn't describe that as a chorus at all, to my ears that's actually tremelo.
On Thursday, 17 June 2021, 21:56:31 BST, Florian Heer <yamahadx@...> wrote:


And here is the recording.

INIT Voice without chorus and with chorus as well as just one operator without and with chorus.

Hope it helps.


Best, Florian


On 17/06/2021 21:07, Florian Heer wrote:

I overlooked your question about the hardware, sorry.

DX21 uses a Panasonic MN 3209 as a chorus (256 stages), the DX27s? a MN 3204 (512 stages).

I had done a quick comparison in the past, I couldn't really hear a difference in the chorus. Of course it's a bit difficult, as the DX21 has the chorus on the mono output whereas the DX27s uses the chorus to produce a stereo-effect.

Try to get to recording in a few minutes.

Cheers, Florian

On 17/06/2021 12:21, Florian Heer wrote:

If noone comes through faster, I can record a DX21 in ~8 hours.



On 17/06/2021 12:05, Martin Tarenskeen wrote:

Hi,

The DX21 and DX27s have a very basic Stereo Chorus effect with only one parameter: On/Off. I am looking for someone owning one of these keyboards, who can record a simple single note testtone - for example an INITVOICE with the Chorus switched on - and share a WAV or MP3 with me. I need it to try to find the most accurate speed/depth setting when converting this effect for use in my Reface DX Legacy Project. The V50 that I own myself has much more FX - but no chorus ...

BTW: Is the DX21 chorus identical to the DX27S chorus? Can someone tell from the schematics in the service manuals maybe?

Thanks for any info and help, 




    
  


                            

					


				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

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This is a different instrument. I can't find Service manual or schematics for DX27S.

Daniel Forró



				
					
					

					


On Jun 18, 2021, at 3:13, star9gem <gmercanti@...> wrote:

Might these be the schematics you need?.... :



Gus



					


				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: DX21 and DX27S chorus effect
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
On 18/06/2021 00:26, Martin Tarenskeen wrote:
On Thu, 17 Jun 2021, Florian Heer wrote:

One question from my side: the DX100 is powered by an external power brick, right? Do you know if the DX27 is powered like that as well? Just curious, as the DX27s and the DX21 are very different beasts, the DX27s has an old fashioned linear PSU and the DX21 has a switching power supply, although their built largely at the same time. I would have assumed Yamaha would probably try to reuse parts..
It was very long ago that I owned a DX100. But looking my collection of PDF scanned manuals might give an answer.

Ah, don't bother. It's fine.

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: DX21 and DX27S chorus effect
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				

  
  




开云体育

    

    On 17/06/2021 23:06, Martin Tarenskeen wrote:
    

    
On Thu, 17 Jun 2021,
      Florian Heer wrote:
      

      

      
INIT Voice without
        chorus and with chorus as well as just one operator without and
        with chorus.
        

      

      

      Seems something is wrong with your INIT VOICE? The standard INIT
      VOICE should be only one operator without modulation. Don't know
      if it's like that on your DX27S, but it was like that on my DX100,
      FB01, YS200, and V50.
      

      

      Your INIT VOICE - even without chorus - doesn't sound like a clean
      sine wave at all. No worry, the second part of your recording
      fixes this and is completely usable for my purpose.
      

    

    

    

    I was wondering myself, but I hadn't used the DX21 for a while, so
    didn't give it another thought. Just wondered why you wanted that
    sound - for good measure I threw in the other sound 
    

    

    Well, turns out the potentiometer on the modulation wheel is a bit
    scratchy. So the first recording apparently had some modulation from
    there. I probably moved it while changing parameters - that's how we
    got an unmodulated signal.
    

    

    I did want to prove that my DX21 does not work like DX27(s)/DX100
    (all 3 share the same mainboard), FB01 - which comes from a
    different division after all, YS200 - which I like most of them all
    (not only because you can't program it with its own user
    interface)...
    

    

    Anyways, thanks for the complaint, this way I got to repair that
    part.
    

    

    One question from my side: the DX100 is powered by an external power
    brick, right? Do you know if the DX27 is powered like that as well?
    Just curious, as the DX27s and the DX21 are very different beasts,
    the DX27s has an old fashioned linear PSU and the DX21 has a
    switching power supply, although their built largely at the same
    time. I would have assumed Yamaha would probably try to reuse
    parts..
    

    

    

    Cheers, Florian
    

  


				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: DX21 and DX27S chorus effect
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
On Thu, 17 Jun 2021, Florian Heer wrote:

And here is the recording.
INIT Voice without chorus and with chorus as well as just one operator without and with chorus.
Hi Florian,

Seems something is wrong with your INIT VOICE? The standard INIT VOICE should be only one operator without modulation. Don't know if it's like that on your DX27S, but it was like that on my DX100, FB01, YS200, and V50.

Your INIT VOICE - even without chorus - doesn't sound like a clean sine wave at all. No worry, the second part of your recording fixes this and is completely usable for my purpose.

-- 

MT

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: DX21 and DX27S chorus effect
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				

  
  




开云体育

    
And here is the recording.

    
INIT Voice without chorus and with chorus as well as just one
      operator without and with chorus.

    
Hope it helps.

    


    

    
Best, Florian

    


    

    
On 17/06/2021 21:07, Florian Heer
      wrote:

    

    

				
					
					

					



      
      
I overlooked your question about the hardware, sorry.

      
DX21 uses a Panasonic MN 3209 as a chorus (256 stages), the
        DX27s? a MN 3204 (512 stages). 

      

      
I had done a quick comparison in the past, I couldn't really
        hear a difference in the chorus. Of course it's a bit difficult,
        as the DX21 has the chorus on the mono output whereas the DX27s
        uses the chorus to produce a stereo-effect.

      
Try to get to recording in a few minutes.

      
Cheers, Florian

      

      
On 17/06/2021 12:21, Florian Heer
        wrote:

      

      

        
        
If noone comes through faster, I can record a DX21 in ~8
          hours.

        


        

        


        

        
On 17/06/2021 12:05, Martin
          Tarenskeen wrote:

        

        
 

          Hi, 

          

          The DX21 and DX27s have a very basic Stereo Chorus effect with
          only one parameter: On/Off. I am looking for someone owning
          one of these keyboards, who can record a simple single note
          testtone - for example an INITVOICE with the Chorus switched
          on - and share a WAV or MP3 with me. I need it to try to find
          the most accurate speed/depth setting when converting this
          effect for use in my Reface DX Legacy Project. The V50 that I
          own myself has much more FX - but no chorus ... 

          

          BTW: Is the DX21 chorus identical to the DX27S chorus? Can
          someone tell from the schematics in the service manuals maybe?
          

          

          Thanks for any info and help, 

          

          

          
        

        

        
      

      

      
      




    

  


					


				
				
				
			

			
				

				

					
						
	
		
			
				
			
		
		

			
				
			
			
				
DX21 with and without chorus.mp3

			
			

				
					DX21 with and without chorus.mp3
				
			

			
		

		
			
		
	

					
				

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: DX21 and DX27S chorus effect
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
On Thu, 17 Jun 2021, Florian Heer wrote:

And here is the recording.
INIT Voice without chorus and with chorus as well as just one operator without and with chorus.
Hope it helps.
Thank you!

MT

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: DX21 and DX27S chorus effect
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				

  
  




开云体育

    
I overlooked your question about the hardware, sorry.

    
DX21 uses a Panasonic MN 3209 as a chorus (256 stages), the
      DX27s? a MN 3204 (512 stages). 

    

    
I had done a quick comparison in the past, I couldn't really hear
      a difference in the chorus. Of course it's a bit difficult, as the
      DX21 has the chorus on the mono output whereas the DX27s uses the
      chorus to produce a stereo-effect.

    
Try to get to recording in a few minutes.

    
Cheers, Florian

    

    
On 17/06/2021 12:21, Florian Heer
      wrote:

    

    

				
					
					

					



      
      
If noone comes through faster, I can record a DX21 in ~8 hours.

      


      

      


      

      
On 17/06/2021 12:05, Martin
        Tarenskeen wrote:

      

      
 

        Hi, 

        

        The DX21 and DX27s have a very basic Stereo Chorus effect with
        only one parameter: On/Off. I am looking for someone owning one
        of these keyboards, who can record a simple single note testtone
        - for example an INITVOICE with the Chorus switched on - and
        share a WAV or MP3 with me. I need it to try to find the most
        accurate speed/depth setting when converting this effect for use
        in my Reface DX Legacy Project. The V50 that I own myself has
        much more FX - but no chorus ... 

        

        BTW: Is the DX21 chorus identical to the DX27S chorus? Can
        someone tell from the schematics in the service manuals maybe? 

        

        Thanks for any info and help, 

        

        

        
      

      

      
      




    

  


					


				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: DX21 and DX27S chorus effect
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
Might these be the schematics you need?.... :



Gus

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: DX21 and DX27S chorus effect
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
I could compare schematics if only DX27S Service manual or schematics is available. Unfortunately it isn’t.

Daniel Forró

				
					
					

					


On Jun 17, 2021, at 19:05, Martin Tarenskeen <m.tarenskeen@...> wrote:


Hi,

The DX21 and DX27s have a very basic Stereo Chorus effect with only one parameter: On/Off. I am looking for someone owning one of these keyboards, who can record a simple single note testtone - for example an INITVOICE with the Chorus switched on - and share a WAV or MP3 with me. I need it to try to find the most accurate speed/depth setting when converting this effect for use in my Reface DX Legacy Project. The V50 that I own myself has much more FX - but no chorus ...

BTW: Is the DX21 chorus identical to the DX27S chorus? Can someone tell from the schematics in the service manuals maybe?

Thanks for any info and help,

-- 

MT




					


				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: DX21 and DX27S chorus effect
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				

  
  




开云体育

    
If noone comes through faster, I can record a DX21 in ~8 hours.

    


    

    


    

    
On 17/06/2021 12:05, Martin Tarenskeen
      wrote:

    

    

				
					
					

					



      

      Hi,
      

      

      The DX21 and DX27s have a very basic Stereo Chorus effect with
      only one parameter: On/Off. I am looking for someone owning one of
      these keyboards, who can record a simple single note testtone -
      for example an INITVOICE with the Chorus switched on - and share a
      WAV or MP3 with me. I need it to try to find the most accurate
      speed/depth setting when converting this effect for use in my
      Reface DX Legacy Project. The V50 that I own myself has much more
      FX - but no chorus ...
      

      

      BTW: Is the DX21 chorus identical to the DX27S chorus? Can someone
      tell from the schematics in the service manuals maybe?
      

      

      Thanks for any info and help,
      

      

      

      
      




    

  


					


				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							DX21 and DX27S chorus effect
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
Hi,

The DX21 and DX27s have a very basic Stereo Chorus effect with only one parameter: On/Off. I am looking for someone owning one of these keyboards, who can record a simple single note testtone - for example an INITVOICE with the Chorus switched on - and share a WAV or MP3 with me. I need it to try to find the most accurate speed/depth setting when converting this effect for use in my Reface DX Legacy Project. The V50 that I own myself has much more FX - but no chorus ...

BTW: Is the DX21 chorus identical to the DX27S chorus? Can someone tell from the schematics in the service manuals maybe?

Thanks for any info and help,

-- 

MT

				
				
				
			

			
			

	

	
			

			

				
					

				
				
			

			

				

					

				

			

			
			
			

			


				
	



		
			
		
			
				
	
		
	

		
			

			
			

			
			
				
				

					

						
							
							

							Re: The 4OP to DX7 Conversion Project
							
						
					

				

				

			
			

				

					


						
							

								
								
							

						
					

					

						
							


						
						 
						
							
							
						
						
					

				

			

			

			

				
That?s? why? I hope for a 1HU MODX rack since Yammi came ut w/ the
keyboard versions.
Unfortunately, these keyboard actions aren?t the holy grail too.

Am 15.06.2021 um 22:25 schrieb Martin Tarenskeen:


On Tue, 15 Jun 2021, LarryS wrote:

Multi wave forms.? 8 (or more) operators.? Adaptable, even
dynamically assignable algorithms. ?Real time parameter changes.
Sounds like a Yamaha Montage or MODX to me.

MT

--
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