[sdiy] Op-amp to boost VC signal with +5V/GND?

[Thomas Strathmann]

Am 7/28/10 08:11 , schrieb mikas:
> 1. Could You recommend me an op-amp to boost VC signal with single
> +5V/GND power supply? I don't want to make PSU with +12V/gnd/-12V (or
> 15V) just for boosting VC signal. I've made simple +5V with 7805 to
> use with external +8V PSU. I want to keep it simple.

I'm not really sure, but substituting ground connections for connections 
to 2.5V should work, although I wouldn't expect wonders.
Have not tried something like that, but I've seen similar in guitar 
effects circuits (with use a single 9V supply with gives you a little 
more "headroom" than 5V).

> Can I use TLC27? Or other recomendations. My local shops are a bit
> limited, ex: http://www.rcl.lt/index.php?id=2&lang=en&acc=show&fid=644

Any general purpose op amp should be fine, but I'll leave the definitive 
answer to someone who's tried something like this instead of just 
looking at schematics.

> 2. Also, can I drive GATE with two 40106 as shown in schematics? Idea
> taken from MFOS.

Depends on what you mean by gate (i.e. which synthesizer you want to 
drive). Many modern modulars including Doepfer and other Euros take 
something like 5V or maybe even less, but certainly more than line 
level. Others may need upwards up 10V. If you drive the 40106 from a 5V 
supply you'll get max. 5V at the output which as said before might be 
enough for your purposes.

	Thomas