Can one make a Quad Eight 310 500 EQ clone if the schematics are available?

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I like the discrete transistor 312 better than the 310 with the AM4 but they are fabulous sounding EQ’s. There aren’t too many active LCR EQ’s out there. I used an MM312S in my mastering rig for over 20 years.
 
the nickel sized, hybrid/thick-film/whatever AM4 is allegedly the same circuit as the discrete version and notoriously unreliable.  note the kludged array of discrete amps in the 310 eq.
of interest is Sphere's rendition of the AM4.
 

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In the over 20 years I used the MM312's I never had a problem with them. The discrete version is the same as half a 712. They have been nothing but reliable. The switches they used are still silent and overall build quality was excellent. The PCB's could be better quality. The traces lift easily.
 
Whoops said:
With limited electronic knowledge you will not be able to do this.

Your questions are also so basic that you should be thinking in something else to do that would fit better your present knowledge.

There's a lot of EQ's already in 500 series format and normal rack format, you should try one of the projects that is already developed here in the forum and has an help thread already.

EQ's in 500 series format theres, helios 69, SSL 4k E, Neve 1084, API 550, Neumann W491, and much more...

I already did. It worked great but I want to make my own designs and also give back to the community.

fazer said:
The dual stacked 11 pole switches will be a hard source but not impossible.

Have you played or Listened to this EQ?  Just wondering what drew your attention to it.

I've heard clips of them and some engineers swear by them and say they are on the same level as 1073 Eqs. I trust them. The electrodyne 511s have different frequencies and only 2 bands
 
Gold said:
I like the discrete transistor 312 better than the 310 with the AM4 but they are fabulous sounding EQ’s. There aren’t too many active LCR EQ’s out there. I used an MM312S in my mastering rig for over 20 years.

I can't find what the difference between the 310 and the 312 is. I thought one has a pre included and one doesn't. You say the 310 doesn't have a transistor? I only have a lo res schematic of the 312 unfortunately
 
PhilipMarlowe said:
I can't find what the difference between the 310 and the 312 is. I thought one has a pre included and one doesn't. You say the 310 doesn't have a transistor? I only have a lo res schematic of the 312 unfortunately

The 310 uses a discrete transistor gain block. Look at the 712. The 712 has two of those amp blocks.

I like them better than 80 series Neve or API or anything else.
 
PhilipMarlowe said:
I can't find what the difference between the 310 and the 312 is. I thought one has a pre included and one doesn't.
the 312 has two discrete gain blocks.  one for the eq, the other for optional line gain.
 

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The QE’s were made to order. Mine are called MM312S. They have a mic pre which is a transformer and discrete gain block that is different from the EQ gain block. They also have an active HPF/LPF. Mine doesn’t have a line transformer like the one in the picture above. I had UTC LS30’s at the line input.

The 310’s and 312’s were made at the same time. The 310 designates the AM4 and the 312 is the discrete transistor version.
 
It basically looks like an API 553 with three peaking bands and switches instead of pots, no? Swinging gate RLC filters?
 

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