stage 1.5 schematic+pcb amek2500eq+harrison filters

I was looking over my schematics for the M3000 EQ over the weekend and in my search for a better version (mine are hand drawn and pretty beat up). Aside from how hard they were to read, there was actually a few values missing. The M2500 EQ is very close to the M3000, they are different.

Once i actually get is finished drawn up,. i will post it. How did your project end up?

mmm the Nemek (amek with linear pots instead of revlogs) is working well, I did a pcb with rev logs pots to compare but I haven't had an enclousure for it so still is not finished(after years I must admit  :'( ). I`m not completly happy with the PCB I should use a concentric pot as the original, that is the reason why I didn`t release the PCB. I was toying with the idea of a 500 format eq but I haven't had the time to do it.

I am currently rebuilding/some redesign of an M3000 console. the basis of which the M2500 was derived from.

go here for details on the project

http://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=6&t=578&p=6638#p6638

I like the idea of the harrison filters though and may implement that idea in the console.

Would be interested in seeing what you had ended up with

joel

this is how it end up. it look very DIY isn`t haha I had to add two 1k resistor for each band in the nemek mode that is the only difference with the schematic at the first page of this thread.

I did a PCB for the harrison filter you can search for harrison ford filter here at the forum. it is tested.

I will be launching an updated version of this design in 500 format in a couple of days. Stay tuned.

Are you sure you want to replace the TDA1034 with a TL072? the TLA1034 is supposed to be a NE5534....

you might get away with an LME49720 if you want to use a more modern dual opamp package.

- cheers,

Michael

You caught me being a little lazzy, I am not building this example, it was an attempt to represent the original design. I am aware that the TLA was an early 5534. Could use a 5532 package for that location. Half 5532 for each stage. I plan to build it close to the above with high quality components. IE: wins caps, high quality resistors. With a solid foundation I will begin the IC rolling to see/hear what works best over the aforementioned IC's. TL072/5532 are cheap. When you are building 48 channels, that speeds the process. With IC sockets, once completed it is easier to modify. Also I will being using relays not switchs. I know. Expensive. But would rather spend the money now on the " foundation" the play with what ever is hot now IC's once built. I will post my build schematics once completed

the eq in that console is a daughter board? or it is in the channel board?
or you will build the complete console channel?

Sahib, I will be waiting your design!

In the original design it's in the channel pcb, in the new design it will be a daughter card

To be clear, I am rebuilding/ redesigning a m3000 console from ground up.

The 10Ks R22,38,56,72 probably will better connect to opamp-output.

my respect, you are a brave man, that is a looooot of work.
you will add the bell/shelving switch?

Yes it is allot of work, but nothing that has not been done before. I guess it's time for full disclosure, I do this for a living, I repair high-end pro audio.

My approach in questioning the basics stems from a self taught point of view as well as to hear other peoples perspective on the topic. There is a vast amount of talent here and in the pro audio design forum. the basics, IE: what cap should i use at x y z, metal film, or carbon resistors, Conductive plastic or carbon pots... etc, can have a profound effect on the result. The design, is made or broken in the fine details. As i am sure that most here are aware, what defines a piece of equipment to be high-end, is the mere fact that the details were carefully managed.

I will upload, the modified version of the EQ, (the one i will actually build) in the next few days.

Did not mean to hi jack your thread, should we start a new topic for this?

For those following this, The project has made a full turn back to, refurbishing the original console. As the history of the particular console I own along with respect to how it sounded began to take light. It became clear that Modifications was not the proper way to go, let alone a redesign.

The EQ Schematic i posted is directly from the hand drawn schematics. However, what is in the actual channels (of my console) is a bit deferent.

For a more detailed story on why I have changed course, rather then re-type.

Look here

http://recording.org/vintage-pro-audio/54489-the-amek-m3000.html

Joel

sahib said:

I will be launching an updated version of this design in 500 format in a couple of days. Stay tuned.

Click to expand...

EQ launched.

http://www.groupdiy.com/index.php?topic=52444.0


Also a new micpre.

http://www.groupdiy.com/index.php?topic=52443.0