RFSiesta
Well-known member
We use either V672 and V672/2 (slightly less coloured) as summing amps in our Trident 80 for years now, with huge success - and remember someone mentioning the V72a to be a great summing amp, too: I understood he meant active (current) summing, because they also have a trident console.
(we have two racked ones as mic pres, but they are not the same league as a V72 or V76, so they don't get too much use) - I studied the manual and they say it's a "voltage amplifier", with a 4kΩ input impedance :/
Is configuration as low-Ω amplifier possible, by wiring or change in circuit? The 672 are completely different, they have an inverting stage with feedback and 2,5-4Ω input impedance. So wiring as summing amps is good, for use as mic preamps they need surrounding circuit with changeable serial resistance, that inevitably leads to decreasing input impedance at high gain, so use as preamps is compromised, while summing currents is not.
Someone told me to use the V72a in this exact application, but I can not imagine how.
Did anyone actually do it?
Schematics are at http://audio.kubarth.com/rundfunk/index.cgi, search "V72a". Can't directly link those docs here.
cheers
(we have two racked ones as mic pres, but they are not the same league as a V72 or V76, so they don't get too much use) - I studied the manual and they say it's a "voltage amplifier", with a 4kΩ input impedance :/
Is configuration as low-Ω amplifier possible, by wiring or change in circuit? The 672 are completely different, they have an inverting stage with feedback and 2,5-4Ω input impedance. So wiring as summing amps is good, for use as mic preamps they need surrounding circuit with changeable serial resistance, that inevitably leads to decreasing input impedance at high gain, so use as preamps is compromised, while summing currents is not.
Someone told me to use the V72a in this exact application, but I can not imagine how.
Did anyone actually do it?
Schematics are at http://audio.kubarth.com/rundfunk/index.cgi, search "V72a". Can't directly link those docs here.
cheers