5003 eq building and help.

[Denyle Guitars]

also, was there a definitive answer the phase as to which way round the red/brown wires go?

I've only got one probe on my scope, and no studio either! if any one has the definitive polarity of these wire id be much obliged.

cheers

Pete

I only scoped one of two but:
Brown= primary + (closest to the bottom)
Red= primary -

Here's the first 2 of 4. One with Ed's OT, the other with Peter's.

Initial testing done in a A Designs 500HR with Fabio 2520 & OPA627 opamps. LF was noisy with extreme settings at first. Rotating the power transformer in the 500HR fixed that issue.

I don't remember who suggested on-off-on switches but thanks for the idea. Works great. All in all, this was a very simple project with the only minor snag being the holes for my pushbutton switch needed to be enlarged.

I made these metal plates to hold the inductors in place, mainly for looks. I also mounted them leads down, allowing for shorter leads. Having the extra steel and wires between the pcb & L bracket may or may not help with noise but it doesn't hurt either.

I just need to finish up the metal work now.

 

[user 10827]

Hey thats very good idea on the inductor holdings.

We fired mine up in the studio today, and two very good engineers were there and gave it a good test, they loved it,

they described it as fun! at first they thought the frequencies for each band were too close to each other, but after using it for a day they liked it allot..FWIW..


Best
Pete

 

[Andre]

A couple of notes about this build...

1)  I noticed that there is no direct connection between the metalwork and the chassis ground pin.  So i added a connection between pin 1 (at R6) and the PCB mounting bolt near the transformer.  The white powder coating of the metalwork is rubbed away on the inside of the recessed screw hole, so you'll be able to get good contact here if a flat head screw is used.

2)  For many of the inexpensive pots available for this build, it just so happens that their mounting nut acts a perfect shim to fit the metalwork.  So you can mount the pot quite well by using two nuts and a washer.  Run the first mounting nut all the way flush against the pot.  And then push the pot in the mounting holes, and it will kind of snap in place.  On the outside, use the washer and a second nut to secure it.  The washer will have just enough diameter to not go through the hole.  Of course there is the problem that you'll need to either buy additional mounting nuts, or buy twice as many pots in order to poach the hardware.  For reference, I used Mouser part #313-2000F-10K, which has solder tabs instead of PCB pins.  By accident this was a good idea because it allowed easier mounting of the pots and PCB separately with just using wires to hook them up.

Hope this helps.
- Andre

 

[pjdiy]

I am still having trouble getting my 5003eq quiet at the extreme settings for the pots. Since I have it in a 1u rack with the psu I rotated the psu toroid till it got a little bit quieter but not quiet enough. I removed the toroid outside the case and it removes all the buzzing completely. So I guess I will have to build a seperate psu enclosure for my eq. In the photo below Jeff's classic audio preamp is dead quiet in the same enclosure.

Also one note when I bypass the eq the volume drops. Does this mean I have the red and brown incorrect? ???
I have the xfmr that Peter supplied with the kit.




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.

 

[peterc]

PJ

Try mounting the toroid using a plastic screw & isolating it so that the toroid does not touch the case.

Also one note when I bypass the eq the volume drops. Does this mean I have the red and brown incorrect? Huh
I have the xfmr that Peter supplied with the kit.

The output stage is always in circuit, so the Red/Brown will not make a difference. If you put the pots on the centre (i.e. flat) & hit bypass, is there still a level difference?

Regards
Peter

 

[dmp]

If you are externally bypassing the EQ, I think the gain is slightly different than unity, by about a dB.
Btw, with my 51x rack with external psu, the buzzing went away on mine. I think the inductors are just very sensitive to picking up hum.

 

[dmp]

The Gain = 10k/27k * 3, where 3 is the transformer ratio. If you want the gain to be exactly 1, adjust the 27k resistors.

 

[Andre]

I am still having trouble getting my 5003eq quiet at the extreme settings for the pots. Since I have it in a 1u rack with the psu I rotated the psu toroid till it got a little bit quieter but not quiet enough. I removed the toroid outside the case and it removes all the buzzing completely. So I guess I will have to build a seperate psu enclosure for my eq. In the photo below Jeff's classic audio preamp is dead quiet in the same enclosure.

You might try moving the inductors off of the PCB and using a shielded wire to reconnect them.  This way you can play with orientation of the inductors to achieve the least noise.  Also may want to shorten wires between iec socket and fuse.  I like the iec sockets with a built in fuse holder in order to reduce high voltage wire runs.

 

[Denyle Guitars]

Also, try moving the EQ to the left slot, away from the power supply.

 

[pjdiy]

Btw, with my 51x rack with external psu, the buzzing went away on mine. I think the inductors are just very sensitive to picking up hum.

dmp
I put the psu in an old pc psu enclosure and the noise went buh bye. Dead quiet and sounds fantastic!!!
I agree the inductors are sensitive. Great diy EQ ;D

Thanks Peter for the help too with the troubleshooting.
You are right about the volume change with the pots at center detent. No change in volume when bypass is engaged.

 

[janczmok]

Finally got around on finishing my PSU so that i can test (and use) the 5003 along other modules:

However, when placed like this (the 5003 being in Slot 6), i get a real AUDIBLE hum, which is mildly audible in the center positions and
really noticeable on the CCW and CW positions.

How can i rule out if that is coming from the PSU or from the 5003 ? Unfortunately i'm a real beginner on 51X modules and
such.

How much should the PSU be away from the modules to have less interference. ? (as i saw hr-designs 1U design with integrated PSU).
Or shall do do something different on the PSU ?  (Check my Flickr: http://www.flickr.com/photos/jczmok/sets/72157625412420387/ )

Thanks for all support. Besides the hum, everything works like a real charm!

 

[dmp]

However, when placed like this (the 5003 being in Slot 6), i get a real AUDIBLE hum, which is mildly audible in the center positions and
really noticeable on the CCW and CW positions.

Try it in position 11, so it will have shielding on the open side. With it sitting in the middle position without another module next to it, the top has no shielding. Then move it away from the psu as possible, especially so that the axis of the toroid power transformer is not pointing at the inductors. Also, make sure you connected the L bracket to the chassis ground, for proper shielding.

 

[janczmok]

I was sceptical if the moving to Pos.11 was changing a lot, but it really did. That 5003 eq is a badass motherf....   ;D ;D ;D ;D ;D ;D ;D
I feeded the beast with Daft Punk, some Rock stuff and even Royksopp, and (despite) the mixes are great made, this 5003 just gave a small (well... rather HUGE) attenuation or equalization. It isn't comparable to one in a mixer, as those would sound "muffling", but the 5003 is crystal clear and hamming the bass if you ++ on the lower 150 frequency. a big TWO thumbs up for that. Can't await to feed it with my songs and mixes.

 

[evilcat]

Hi Peter !
Still haven't received anything. It's been 3 months now ! You told me 1 month ago that you would send me another set because the 1st should have been lost and since, no news... What's happening ?

Thanks,

Ben.

 

[evilcat]

BBBUUUUMMMMPPPP !!!!!

Peter, 1 month later still no news. What Is Happening ? Please !

Ben.

 

[evilcat]

Hi Peter !

What is happening ? Should I forget it and being refund ? Please, let me know !!! I tried to PM you but your Inbox is full.

Best,

Ben

 

[benlindell]

I'm waiting on my metal work too Does anyone have Peter's email?

 

[okgb]

Hey Peter , not sure if my email is getting through
or you are busy BUT , haven't recievced the tracking
number you were going to send [ and still No eq's ]
let me know what's going on when you have a moment

regards Greg

 

[evilcat]

Peter,

I payed in october for 2x(PCB-inductors) set and I still have nothing in my mailbox. I'm tired of waiting. I want my money back and forget about this project. It's too bad but I can't wait any longer !

paypal adress : [email protected]
amount : 132€

Regards,
Ben

 

[peterc]

Hi Ben

I am sorry about this but I sincerely promise you that your parcel has shipped. I can get you the tracking number (again?) this evening.

If nothing arrives in the next couple of weeks I will gladly refund you your money, but as I say it is on the way.

Regards
Peter