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Poly/EX-800 Delay Time Mod - Success!

Poly/EX-800 Delay Time Mod - Success!

2017-06-05 by ashdot@...

Hi,

I think I found the way to control the delay time of the EX800 chorus.

I removed resistors R67 & R68 and replaced them with a potentiometer wired as a voltage divider between D+ and D-.

My scope shows that the pot changes the frequency of the voltage going into the MN3012 clock.

I placed a 10K resistor between D+ and the pot, as any resistance below about 10K stalls the chorus.

Izhar

Re: Poly/EX-800 Delay Time Mod - Success!

2017-06-05 by jusuf@...

Hi
Hi, yes, you need to cut off input from LFO to lead 7 of MN3102. Then you can control "delay" time with knob between leads 6>7 + capacitor between 5>7. You can see it on my old drawing under group files "Cross Modulation mod" .
By the name "cross modulation" i was not meaning classic cross-osc, but something as semi-modular use of available signals (chorus LFO...)
It is a pitty I have no records from my >time ago-ed< experiments - just one record of chorus feedback ... :

https://xa.yimg.com/df/korgpolyex/Poly800+-+Matrix.jpg?token=iqmfh2coqUuJ9e8iR0sVDdZMG08gEr4ne1aZ5d3vfxnu4g7hhgAvx4dYflbZCk0iRKL-OpPsmnVxA2HFpZvaoWR_6q_559U1Gs9T88e4s4KA9KgbmkxuPc0KTJOKZev-QRNayyWQQZcY65oRjs2v9Wrwzn_tJjZWNxWamCvtWYwzwqU6Ml5EUqlnSIoD-f17lVwlr-Nr&type=download



---In korgpolyex@yahoogroups.com, <ashdot@...> wrote :

Hi,

I think I found the way to control the delay time of the EX800 chorus.

I removed resistors R67 & R68 and replaced them with a potentiometer wired as a voltage divider between D+ and D-.

My scope shows that the pot changes the frequency of the voltage going into the MN3012 clock.

I placed a 10K resistor between D+ and the pot, as any resistance below about 10K stalls the chorus.

Izhar

Re: Poly/EX-800 Delay Time Mod - Success!

2017-06-06 by ashdot@...

Thank you!
Your suggestion to cut off the LFO from pin 7 would make it a "straight" delay.
My goal was to change the MN3102 clock while keeping the LFO oscillation, which I managed by replacing R67 & R68 with a pot and a 10K resistor.
Izhar

Re: [korgpolyex] Poly/EX-800 Delay Time Mod - Success!

2017-06-06 by paulmorison

Well done. Very useful mod! Approx how much does it vary it-what is freq range from one end of the pot to the other Please?

Rgds

P



Sent from my Samsung Galaxy smartphone.

-------- Original message --------
From: "ashdot@ashdot.co.il [korgpolyex]" <korgpolyex@yahoogroups.com>
Date: 05/06/2017 20:44 (GMT+00:00)
To: korgpolyex@yahoogroups.com
Subject: [korgpolyex] Poly/EX-800 Delay Time Mod - Success!

Hi,

I think I found the way to control the delay time of the EX800 chorus.

I removed resistors R67 & R68 and replaced them with a potentiometer wired as a voltage divider between D+ and D-.

My scope shows that the pot changes the frequency of the voltage going into the MN3012 clock.

I placed a 10K resistor between D+ and the pot, as any resistance below about 10K stalls the chorus.

Izhar

Re: [korgpolyex] Re: Poly/EX-800 Delay Time Mod - Success!

2017-06-07 by Michael Hawkins

I think it's time to add LFO modulation of the Chorus as a real mod in the HAWK.
It would be pretty simple to do.
/Mike
Show quoted textHide quoted text
      From: "jusuf@... [korgpolyex]" <korgpolyex@yahoogroups.com>
 To: korgpolyex@yahoogroups.com 
 Sent: Monday, June 5, 2017 6:31 PM
 Subject: [korgpolyex] Re: Poly/EX-800 Delay Time Mod - Success!
   
    HiHi, yes, you need to cut off input from LFO to lead 7 of MN3102. Then you can control "delay" time with knob between leads 6>7 + capacitor between 5>7. You can see it on my old drawing under group files "Cross Modulation mod" .  By the name "cross modulation"  i was not meaning classic cross-osc, but something as semi-modular use of available signals (chorus LFO...)It is a pitty I have no records from my >time ago-ed< experiments - just one record of  chorus feedback ...  :https://groups.yahoo.com/neo/groups/korgpolyex/files/4)%20Modifications/Chorus%20Feedback%20mod/

https://xa.yimg.com/df/korgpolyex/Poly800+-+Matrix.jpg?token=iqmfh2coqUuJ9e8iR0sVDdZMG08gEr4ne1aZ5d3vfxnu4g7hhgAvx4dYflbZCk0iRKL-OpPsmnVxA2HFpZvaoWR_6q_559U1Gs9T88e4s4KA9KgbmkxuPc0KTJOKZev-QRNayyWQQZcY65oRjs2v9Wrwzn_tJjZWNxWamCvtWYwzwqU6Ml5EUqlnSIoD-f17lVwlr-Nr&type=download 
|    |
|    |        |    |       https://xa.yimg.com/df/korgpolyex/Poly800+-+Matrix.jpg?t...     |    |
|      View on xa.yimg.com      |    Preview by Yahoo    |
|    |

   

---In korgpolyex@yahoogroups.com, <ashdot@...> wrote :

Hi,I think I found the way to control the delay time of the EX800 chorus.I removed resistors R67 & R68 and replaced them with a potentiometer wired as a voltage divider between D+ and D-.My scope shows that the pot changes the frequency of the voltage going into the MN3012 clock.
I placed a 10K resistor between D+ and the pot, as any resistance below about 10K stalls the chorus.Izhar   #yiv7486255067 #yiv7486255067 -- #yiv7486255067ygrp-mkp {border:1px solid #d8d8d8;font-family:Arial;margin:10px 0;padding:0 10px;}#yiv7486255067 #yiv7486255067ygrp-mkp hr {border:1px solid #d8d8d8;}#yiv7486255067 #yiv7486255067ygrp-mkp #yiv7486255067hd {color:#628c2a;font-size:85%;font-weight:700;line-height:122%;margin:10px 0;}#yiv7486255067 #yiv7486255067ygrp-mkp #yiv7486255067ads {margin-bottom:10px;}#yiv7486255067 #yiv7486255067ygrp-mkp .yiv7486255067ad {padding:0 0;}#yiv7486255067 #yiv7486255067ygrp-mkp .yiv7486255067ad p {margin:0;}#yiv7486255067 #yiv7486255067ygrp-mkp .yiv7486255067ad a {color:#0000ff;text-decoration:none;}#yiv7486255067 #yiv7486255067ygrp-sponsor #yiv7486255067ygrp-lc {font-family:Arial;}#yiv7486255067 #yiv7486255067ygrp-sponsor #yiv7486255067ygrp-lc #yiv7486255067hd {margin:10px 0px;font-weight:700;font-size:78%;line-height:122%;}#yiv7486255067 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