Doepfer

Hey all, whats the longest a cv/gate cable can be without problems?
I have gear on opposite sides of studio now and need to buy cables to reach, want to be sure before I buy.

Cheer John.

hi John,

i use 2 meter cables without problems....

Bakis Sirros - Parallel Worlds / Interconnected / Memory Geist

[Doepfer_a100] group owner

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--- On Sat, 5/28/11, john m <jmaddocks1975@yahoo.co.uk> wrote:

From: john m <jmaddocks1975@yahoo.co.uk>
Subject: [Doepfer_a100] Whats the longest a cv/gate cable be?
To: Doepfer_a100@yahoogroups.com
Date: Saturday, May 28, 2011, 5:53 PM







 



  


    
      
      
      Hey all, whats the longest a cv/gate cable can be without problems?

I have gear on opposite sides of studio now and need to buy cables to reach, want to be sure before I buy.



Cheer John.





    
     

    
    


 



  





[Non-text portions of this message have been removed]

Hi,

What Florian says is spot on; from a theoretical point of view (for anyone interested) the key things are output and input impedance, cable capacitance and resistance. If you take a relatively standard low-cost coax cable of say 380pF/m and 128 Ohms/km this will not cause any noticeable loss in audio top-end from a 1k Ohm output impedance until you exceed 20m or so but you are more likely to get increased noise and interference. From a CV point of view the cable resistance is a more important parameter (if your CV is controlling VCOs that is) but even 20m is only 2.6 Ohms so this can be ignored compared to the high input impedance of most VCO CV inputs** (see my note below); again long lengths are more prone to pickup so 50Hz mains can modulate the CV (you may also experience hum loops by just connecting gear together that is powered from different power outlets across the room).

** One thing I've noticed using my Doepfer to drive the Roland 100M is that CV from the Doepfer via the Roland's 191-J CV input drives all the CV bus connected modules (e.g. 112 dual VCO & 121 dual VCF) which presents 4 x 50k pots in parallel - and when the CV I/P wipers are at max the next stage input impedances are also paralleled - my Roland 100m standard D set has a CV input impedance of just 12k Ohms - little wonder it gets flatter the higher the CV - therefore I now use my A-185 (very low o/p impedance) to drive the Roland CVs which helps a lot.

Hope that's of interest.

Cheers
Tony
(Synovatron Electronic Music at synovatron.blogspot.com)


--- In Doepfer_a100@yahoogroups.com, Florian Anwander <fanwander@...> wrote:

>
> Hello john
> 
> > Hey all, whats the longest a cv/gate cable can be without problems?
> > I have gear on opposite sides of studio now and need to buy cables to reach, want to be sure before I buy.
> Gate cables even longer than 10 meters usually are no problem.
> 
> CV-Cables of this length may(!) have a slight loss depending on the 
> electrical characteristics of the input and the output. I use 10m cables 
> between my Doepfer and the Roland System 100. It is very difficult to 
> judge whether the not completely clean octave tracking is caused by the 
> cable or the System 100.
> 
> Real loss of signal quality starts with asymmetric audio cables at such 
> a length.
> 
> And you have always to keep in mind that electromagentic and 
> electrostatic influences (humm and sizzle) can affect longer cables more 
> than shorter cables.
> 
> Florian
>

Hello john

> Hey all, whats the longest a cv/gate cable can be without problems?
> I have gear on opposite sides of studio now and need to buy cables to reach, want to be sure before I buy.
Gate cables even longer than 10 meters usually are no problem.

CV-Cables of this length may(!) have a slight loss depending on the 
electrical characteristics of the input and the output. I use 10m cables 
between my Doepfer and the Roland System 100. It is very difficult to 
judge whether the not completely clean octave tracking is caused by the 
cable or the System 100.

Real loss of signal quality starts with asymmetric audio cables at such 
a length.

And you have always to keep in mind that electromagentic and 
electrostatic influences (humm and sizzle) can affect longer cables more 
than shorter cables.

Florian