EQP-1S5 - 500 series recreation of solid state EQP1A

[wowi]

Yes, this is a marvelous project.
I am in for 2 of 2
Wolfgang

 

[martthie_08]

fantastic project, I would really be interested in some (say four) inductors, if you make them available separately! I bet you could sell loads of these if they sound good :

A stereo unit with one set of controls would be killer too, that's what I am putting together right now, but you probably have enough on your mind with this project anyways ;D

Anyways, great work!
Marten

 

[mitsos]

thanks for the input guys! Much appreciated. This is one of my fav projects so far, testing the iron has been quite fun.

As far as inductors go, I'm leaning towards getting enough for the project only, but, like I said, if I have to meet a minimum with the winders I'll get more and sell the rest individually, or as sets with any extra trafos (those have quite high minimums as well).

RE: the stereo with one set of controls, be careful you don't limit yourself. Something like Igor's might make more sense. It's more faceplate real estate, but you can do dual mono or stereo. If you think the 12T lorlins are limiting in gain, get yourself some of those chinese Uraltone or whatever 24T switches and have a blast!

 

[martthie_08]

ok, that sounds like a good plan.

regarding stereo: As I already have two mono units it won't be a problem really. Of course having two mono units with switches throughout would work as well, but I hardly ever EQ left and right differently on the mix bus, except for when in MS mode. My flatmate has two of the Amtec Pultecs and having 12 steps on gain and bandwidth is not a problem really. I have already ordered 10 Lorlins to convert my mono units to stepped controls...

One thing that comes in handy and is really simple to do is add a high shelving mode, by shorting out the inductor. I have it on my units and it sounds cool.

Speaking of options, another thing I've been meaning to try is switching in inductors after the caps in the high frequency attenuator section of the filter circuit to make the attenuation a bell curve. Jakob put me on to this, I'll need to experiment with finding the right Henries for that.

EDIT: Sorry for getting off topic, will start a new thread on this sometime!

 

[mitsos]

Those are great ideas, I think it would be cool for a rack mount, I don't think any more switches would fit on a 500 series There is supposed to be a bypass switch on the lower right of the front panel, I forgot to put it in the drawing...oops! but any more switches and it would get crowded..). 

the main idea is to make this thing the best way possible, kind of like the way they used to, before toroidal inductors (and trafos to an extent) became too expensive for the accounting department, and trafos were too colored...

Anyway, beyond the scope of this thread I guess, but your thoughts got me interested, send me a PM with some details of your circuit (like if it's based on one of the ones here) and I'll run some calculations for the Hcut inductor.

 

[mitsos]

I got some requests for information which I thought I had included in the first post, so I reformatted the first post (removed fat!) and included a render of the edge connector. The original post is still attached to the first post for whoever might want to read it.

 

[craigmorris74]

I would take two of option number two.

 

[Marcocet]

Awesome. Of course as always it depends on my budget at any given time but I could most likely build a pair.

 

[j_fraser]

I would be very interested in a pair of these kits.  Please count me in.  Depending on price of course...

 

[mitsos]

hey guys, just a little update. All prototype parts are slowly trickling in... I'm waiting any day for the final inductor proto any day and the PCB next week!

Thanks to all who have expressed interest!

 

[Mike D]

This looks great, I'm in for two kits as well.

Mike

 

[kazper]

Those are looking very good, and I'm very interested.

Do you have a ruff idea on what a kit will cost?

Kaz

 

[mitsos]

Those are looking very good, and I'm very interested.

Do you have a ruff idea on what a kit will cost?

Kaz

Kinda hard to tell exact pricing. My initial calculations (somewhere in the first post I think) were between 300-400 US for a complete kit, minus opamp, but it depends a bit on final numbers and what the metal guys tell me (waiting on quotes for faceplates and L-brackets still). 

I guess I can say that there is a member looking into metal work, and an opamp group buy. I'm sure he'll speak up when he has more details.

Stay tuned!

 

[kilmister]

Hi.

I'm in for 2 sets of kit 1 depending final price.

Looks yammy.

-Paavo

 

[mylesgm]

hows this progressing??

 

[mitsos]

moving along    I planned to be done by now, but I had trouble finding someone to do a prototype PCB with a cardedge... most of the proto houses restrict that kind of stuff and the rest are quite pricey or take forever.  I bit the bullet and ordered it anyway, so that's out of the way, had a couple of glitches with metalwork. Having a really hard time finding a silk-screener so I'm almost giving up on paint... I've got a couple of interesting finishing options which I hope to put to vote here in the next few days.

More to come soon!
thanks!

 

[jensenmann]

Our member Frank at http://www.nrgrecording.de and http://www.nrg-cnc.de/html/contact.html is doing silkscreening, too.

 

[mitsos]

I thought of Frank's service at first, and it would be ideal except for the fact that he is in Europe. As it stands  I'm concentrating everything in the US since it will be easier for me to pay for parts and this way I won't have to deal with customs at any point (except for filling out customs forms for anything sent to other countries, but that is the easy part).

Anyway, part of the problem I'm having is that some metal shops will do paint/powdercoat or anodizing but not silkscreen. Some powdercoaters will do silkscreening but not all, and none of the silkscreeners do metal work. This means there is no one-stop-shopping for metal work so I need to have two people involved in the process, which I don't think will cause problems except for the fact that it means one more person/company to deal with, and I'm already dealing with enough.

I am looking at a couple of last paint/silk guys or a non-paint/silk option which looks pretty darn nice and would actually be more resilient than any paint/anodizing option. I should have more details the next few days, and I'll post a pic of the final faceplate art in a next post, now that I've nailed down the High boost frequencies.  

I do welcome any and all suggestions people might have to make this easier/faster, I really would like to start playing with my EQs!

cheers!

 

[Marcocet]

I'm in for a pair of full kits

That said, what I could possibly do is throw in a little IC->2520 pinout adapter board. This would be better for me as I have been wanting one of those for some time...

Also I'd take a crapload of those off your hands. I've been meaning to make my own but I've been too damn busy to learn how to etch pcbs. They'd make great backups and I've been building a lot of stuff with discreet opamps that I bet would run just as well on ICs...

-marc alan

 

[mitsos]

Marc, I'll look into it, probably something simple like a 5534 with a BD139/140 buffer on the output. It should fit into one of the trafo holes so everyone can get one in the kit, since I won't be making a 2520 available with it. Vintage 2520 would be the way to go if you want to stay "authentic."

Anyway as promised, here is a JPG of the face plate, one with bold letters one (mostly) without, since I can't fidn the file with just the one faceplate. The bold only really matters onscreen, the silk or non-silk will look a bit different than either as is always the case. The knobs I have in mind are machined aluminum, silver in color.

Here is a pic of the knob, disregard the blue, it's because of the flash, the top of the knob is the same silver as the sides. Never claimed to be a photographer!  ;D