Deepdark
Well-known member
Hi there
I'm analysing both the original and the Gyraf schematic and had some questions about it. I plan making my own board of it, for my own pleasure haha. And no, I don't want to rip-off the work of Gyraf and Gustav.
First, the input. It's quiet straight foward, input is a simple differentiel amplifier and uses an NE5534. Would it be possible to think replacing it with a API2520, or melcor, or even a 990? And, if so, would I'd be better off to changed the values of the résistors from 22K to 10K? If all the resistor has the same value, then I guess we're set to unity gain, right? R1/Rf = R2/Rg, right?
The output section (right after the DBX202). We have a balancing circuit made with a NE5532, in an inverting configuration. First, why using the inverting input? I'm not quiet sure how this one work. Is it possible to think replacing this with an THAT Corp 1606/1646 module? With a bit of decoupling. It could be feed wth +/-15v.
Side chain VCA: Originally, T3, was an LF315N (single opamp JFET) on the Gyraf one, it's replaced by one half of a TL072.
Audio VCA originally used 1/4 of a CA324 (didn't find much about it), now we use the second half of the TL072, and since Jakob flushed all the fader related circuit, then we don't need anymore the second 1/4 of the CA324, so this ease the layout. Just like the opamp right after the attack/relase switch (T1 originnaly). We use now 1/4 of the TL074 instead of a single LF351. I guess it was to. again, ease the layout as well as the the current consumption?
Any other alternative to the TL072-074, or they are pretty robust and great replacement candidate?
Why using tantalum in the release circuit? Does it brings something to the sound?
The sidechain circuit uses now an TL074 instead of using TL081. Any reason why changing it? The TL081 looks to be still available?
Thanks Guys! It's a really fun schematic to studying at!
I'm analysing both the original and the Gyraf schematic and had some questions about it. I plan making my own board of it, for my own pleasure haha. And no, I don't want to rip-off the work of Gyraf and Gustav.
First, the input. It's quiet straight foward, input is a simple differentiel amplifier and uses an NE5534. Would it be possible to think replacing it with a API2520, or melcor, or even a 990? And, if so, would I'd be better off to changed the values of the résistors from 22K to 10K? If all the resistor has the same value, then I guess we're set to unity gain, right? R1/Rf = R2/Rg, right?
The output section (right after the DBX202). We have a balancing circuit made with a NE5532, in an inverting configuration. First, why using the inverting input? I'm not quiet sure how this one work. Is it possible to think replacing this with an THAT Corp 1606/1646 module? With a bit of decoupling. It could be feed wth +/-15v.
Side chain VCA: Originally, T3, was an LF315N (single opamp JFET) on the Gyraf one, it's replaced by one half of a TL072.
Audio VCA originally used 1/4 of a CA324 (didn't find much about it), now we use the second half of the TL072, and since Jakob flushed all the fader related circuit, then we don't need anymore the second 1/4 of the CA324, so this ease the layout. Just like the opamp right after the attack/relase switch (T1 originnaly). We use now 1/4 of the TL074 instead of a single LF351. I guess it was to. again, ease the layout as well as the the current consumption?
Any other alternative to the TL072-074, or they are pretty robust and great replacement candidate?
Why using tantalum in the release circuit? Does it brings something to the sound?
The sidechain circuit uses now an TL074 instead of using TL081. Any reason why changing it? The TL081 looks to be still available?
Thanks Guys! It's a really fun schematic to studying at!
