13 Dollars for an electronic switch ?? (was: 4066's. Eat em up, Yum)

[Tim Cockram]

---------------Included Message---------------



>Ooo Ooo. And another chip I just thought of. Once again on the expensive
>side but these guys are better than OTAs. It's a little 8 pin VCA chip from
>Motorola. Now what's it called? Let me look it up here. MC3340 that's the
>one. Only the VCA stands for Voltage Controlled _Attenuator_. Rather than
>Amplifier. You only get one per package but because they're an attenuator
>rather than an amplifier they're real quiet. I've got 3 of 'em somewhere.
>Back in the days when you could get them.

	........MC3340? these are IMHO shite......
	damn near reduced me to tears until I realised that the control signal
	just pours right thru to the output.....they might be ok for their intended
	application,
	domestic gear with a remote dc control voltage from a pot, but believe me 
	hit the control pin with a frequency above one wrs (wrist thrn /second) and
	it is thump city.

	National make a perfectly good digitally controled attenuator series with mute,
	of course single wire digital serial control, with a clever strategy so you can
	hang a number in series.....helps the layout i suppose. (up to 3 per pack)

	paul perry melbourne australia not florida

 

Your absolutely right Paul.  I built a vca ( from the Practical Electronics Synth Keyboard unit) using the MC3340 
about 25 years ago and it was S**t*.  Even though my understanding of electronics at the time was minimal ( I was a 
presumptuous 12 years old) I managed to get better results out of a longtailed pair made with unmatched 2N2926 
(green spot if anyone remembers them).  Stay clear of this chip unless you want to make a remote volume control.

Regards  

Tim


-------------------------------------
Tim Cockram
E-mail: tim at redragon.demon.co.uk 

Phone:-UK-1222-384041
Fax:-    UK-1222-390326


-------------------------------------