5003 eq building and help.

[technut]

no you can see them! i had to make them look a little worse so i could bridge them. I will get pics to you on wednesday when i can take the bridges off peter. im slammed with work out in the field right now. The way i figured it out was my led wasnt working. they are the 2 lines near the bottom of the board. Other than that i had no problems with my boards. They work great

 

[evilcat]

A nice thing with this project is that there is a lot of posibilities to experiment with different caps/freq. If there was space enough I would like a rotary for the mid eq. But it isnt that hard to implement a toggle with midle stop to add three frequensis. Take a look at the quad8 or Opamp labs schems, and this http://www.opamplabs.com/cfl.htm
Any news on the pots?
j

Does anyone have tried another freq ? I'm planning to put these EQ in a non-500 rack and rotary switches for every bands. Weird thing : I tried different values on the link @ opamplabs but it doesn't seems to work. Even with the original values of this project, I get other freq than what they're supposed to be (I don't know if I'm clear ).
Anyway, I definetly want to try others caps values. First, built it as it supposed to be, make it works. Then with the aid of sockets, tried other caps... I'll let you know of course.

Ben

 

[Denyle Guitars]

Here's a possible source for cheap pots in the US:
http://www.mouser.com/ProductDetail/BI-Technologies/P160KNPD-4FC20B10K/?qs=%252bUYXD5bnyXo7nCLwbZeBWQ%3d%3d

The spec sheet says it's 41 detent, conductive plastic substrate, 5mm pin spacing, 16mm body.
I ordered a few so we'll see next week. I didn't get Peter's metal work so I can't verify they'll work for everyone.
You'll need to bend the pins to make it side adjust, very tough DIY.  ;D

 

[kazper]

Here's a possible source for cheap pots in the US:
http://www.mouser.com/ProductDetail/BI-Technologies/P160KNPD-4FC20B10K/?qs=%252bUYXD5bnyXo7nCLwbZeBWQ%3d%3d

The spec sheet says it's 41 detent, conductive plastic substrate, 5mm pin spacing, 16mm body.
I ordered a few so we'll see next week. I didn't get Peter's metal work so I can't verify they'll work for everyone.
You'll need to bend the pins to make it side adjust, very tough DIY.  ;D

They would probably work for your own metal work, mounting bushing is about 4mm to small for the provided metal work (11mm hole) so a work around will have to happen. Since the mechanical design of this project is using the pots and switches to hold the front and metal work together as well as holding the front part of the pcb, I'd recommend that one using the metalwork use the right parts.

I called Laura at Taw yesterday about there stocked Omeg pots. She quoted me a $3 per pot price for the ones they stock for the W492 EQ project. These parts are the 4mm shafted version but will work perfectly in the space. If you got this route get 4mm knobs or buy the 1/8 shafted knobs from classic API pull out the set screws and carefully ream them out with a 4 mm drill bit. I'd recommend using the inserts, in case you go all the way out.

As far as ordering these in a group, Rapid electronics in the UK has a excellent price on these items in 1/4" shaft (6.3m) . Unless we ordered 200+ pots there was no way we could group buy them for less.

 

[evilcat]

Also if anyone needs a BOM I put this together quickly this afternoon.

http://www.benlindell.com/diy/5003-BOM.pdf

Hey guys ! Is this BOM is correct ? There is some blank on it (R11, C8, C13, D2), is it normal ? Or, does Peter post a BOM somewhere, I can't find it.
Thanks.

Ben

 

[kazper]

This is by far the simplest DIY project for parts sourcing I have seen, all you need is the schematic or PCB and the silkscreen tells you every part you need.

Take the BOM you have and figure out what your missing and create one.... don't know why you guys are having such a tough time with this.

 

[evilcat]

This is by far the simplest DIY project for parts sourcing I have seen, all you need is the schematic or PCB and the silkscreen tells you every part you need.

Take the BOM you have and figure out what your missing and create one...

I don't have the PCB yet, it was for moving on my shopping list while I'm waiting for them. I'll start with benlindell BOM and do some corrections (if needed !) when I will have my boards.

 

[kazper]

I think I posted the top side of the PCB in the order thread... The schematic is on the first couple pages of this thread. This is a really low parts count project.

I try to not order stuff for a project till I have PCB's in hand, and most people end up with a few extra components here and there and I try to use them up.

 

[pjdiy]

I hooked up my 15 pin connector from my preamp to the 5003eq's connector.
Pins 2 and 4 to ouput/xlr,
Pins 8 and 10 to input/xlr,  
V+ to pin 12, V- to pin 14, pin 13 to com from the psu adjusted to 16vdc,
pin 5 is audio grd for both input and output xlrs.

1st problem) My 2520 opamp was bad so I replaced it with the one from the preamp which I know is good.

2nd problem) LED did not light. Technut mentioned problems with some traces and I did a visual check and did not see anything obvious. I'm waiting for his pics to see the problem area. I will order some new leds.

3rd problem) With good 2520 in, I plug into an amp to check the EQ. Turning the knobs all the way in either direction gave a slight hissing noise. Pushing the bypass button in gives a slight buzzing noise. Since I am new to this EQ I am not sure how it operates and assume it works like any regular eq. I could not notice any difference in eq when rotating the knobs and flipping the toggles. I was using a vocal microphone to listen to the eq with.



Ignore missing caps in this pic below  they are in since I took this pic.


Someone mentioned reverse polarity with the brown and red wires. From left to right in this old photo I fixed the polarity wires to red 1st, brown 2nd. Hope this helps.

 

[pjdiy]

OK I switched the red and brown wires and got the volume up and the eq is working. Out of phase huh?
Still no led light.
Doesn't the cathode side of the led go into the square pad on the pcb???

Getting some buzz noise maybe coming from the proximity to my psu.

 

[kazper]

On the LED , check polarity and use a DMM to verify if you have power. Radio shack may have something to cover you.

Look at how peter laid out the PCB, check out the caps polarity and what he used for the square there will be the same on the LED.. I think square is the + side, but it's really up to the designer.

I think this is the second time someone mentioned the issue with the noise. I haven't finished mine simply because I need to order pots.

Do you think it's one of the op amps going into oscillation that your hearing?

I twisted the Inductors wires together tightly and separated them away from each other, trimming them with just a little extra. I pair up the outputs wires and trim the wires back as well. I try to keep a little extra just incase, but not to much.

 

[pjdiy]

Thanks kazper for the led info.

With all 3 pots when I turn the knob fully on either way the buzz gets louder.
When set to the middle of the pot is when it is the quietest. Will twisting the wires resolve this?

Another thing since I don't have the eq board bolted in, when moving the whole board assembly around
it is quieter in certain positions. Are the inductors that sensitive?

Thanks PJ
see ya tommorrow...

 

[peterc]

Pj

Try with another preamp if you can for a reference.

Kazper is correct, the LED pos is a square (as are the electrolytic caps as well) on the PCB

Peter

 

[dmp]

With all 3 pots when I turn the knob fully on either way the buzz gets louder.
When set to the middle of the pot is when it is the quietest.

I have the same thing and haven't figured it out yet. It is 60Hz  w/ harmonics. Any induced current in the inductors will be amplified the most when the pot is turned all the way, either direction, since it only shows up on one input of the opamp and will thus get amplified at the output.
I'm building a 51x rack with external psu, which I hope is a solution.

 

[fazeka]

In reading this thread and others, I see that some are experiencing noise/buzzing.

In prepping for my build, I noticed something that I should check on and haven't seen made mention here.

Does this pic show what I think it shows? A jumper on the PCB?

If so, it is kinda easy to overlook. Wondering if those with noise issues connected that jumper?

Thanks,
Chris

 

[peterc]

Chris

It is a jumper. If it is not connected, the EQ will be in bypass all the time.

Peter

 

[pjdiy]

If so, it is kinda easy to overlook. Wondering if those with noise issues connected that jumper?

Thanks,
Chris

Thanks Chris  ??? this jumper I missed. I will report back this eve.

PJ


Dudes I have a working EQ . Yeehah ;D ;D ;D
LED is working too!

 

[pjdiy]

Hi Jeff,

On my 2nd opamp that I assembled, I looked over for solder bridges, cold joints, and diode orientation.
I did not find anything under the magnifying glass. Only problem could be the transistors which I cannot
see and verify because of the close proximity of the components. My next step is to remove some of the transistors to make sure of the right transisitor placement/orientation.

Thanks guys for all your help.

Edited...
Jeff found my problem was the 2 power trasistors DB139 and DB140 were switched.
Thanks PJ

 

[fazeka]

Hey all,

Finally got time this weekend to start the build on my 5003s. Yes, I ordered custom panels for these. I have yet to finish my GDIY 51X power supply, so for now here are some pics (with and without flash):

Yeah, the knobs are too small in that they don't conceal the nuts of the pot. Shoulda went with the 1/2"...

 

[peterc]

Nice panels...