Passive EQ - DIY

[Futureman]

Now that I've DIY'd one kick arse compressor, and taking my time on the second, I thought I'd make something else.

I'm thinking about making a passive EQ with inductors etc..

I like the idea of this
http://www.gyraf.dk/gy_pd/pultec/pultech.gif
http://www.recproaudio.com/diy_pro_audi ... ematic.jpg
(Same deal, different values)

minus the gain make up stage.. just transformers on the input and the output... keep it simple.

Sowter sell the inductors, and I do believe Cinemag do too.
http://www.sowter.co.uk/acatalog/SOWTER ... ORS_6.html
http://www.cinemag.biz/inductors/CML-15 ... matic.html

Anyone here ventured into making EQ's? Any thoughts?

Kind regards
Mike

[rob]

passive EQs are nice.

thoughts about building one.... layout, layout and shielding

[waitup]

I am slowly getting around to building the Gyraf Pultec style project. I've ordered the boards from Gustav and I've got the input and output iron (thanks Rick ;)). I've drilled and painted my front panel, so I think it will come together pretty quickly once my boards and caps/resistors arrive. I'm still undecided about which road to take regarding inductors... I'm going to use some cheap ones from Altronics first and have a listen, then I might order some cinemag or sowter.

If you decide to go down the route of the Gyraf project, I have a front panel designer file of the front panel with the hole designations that you could use for a drill template (all the pots and switches mount to the board). I also have a PDF of a front panel design that I'll use for Lazertran, you could have that too if you go down that route.

There's also a guy on the Lab that sells crazy replica panels and knobs and stuff, if you want to go authentic looking.

One thing to think about when you're laying out your enclosure, is that this project uses not one but two power transformers, so try to keep your audio boards away from them as much as possible.

Best of luck with the build, I'll see you on the other side hehe.

Nick.

[Futureman]

I was actually thinking of keeping the whole thing passive, so no power in the thing at all.

Im planning on using input and output transformers, then using different pre's for the gain make up.

..also decided to place an order from cinemag for the inductor. around $34US + $13 postage.

I like the idea of a pultec style layout, but I want to experiment a bit, so I'm even thinking of putting it in a 1 RU case.. maybe go ghetto style until I get it right.

Layout and Shielding eh? I hear ya. duly noted.

Regards
Mike.

[mylesgm]

I have a pair of the g-pultec's and they are excellent. Not sure how similar they are to a pultec cause I've never had one but I do like mine. They can sparkle, they can warm or they can be edgy (not harsh) or they can be fat. I find that gentle use is best. I've lundahls on the i/o and mullards in the sockets.

myles

[Chris H]

Did you build them yourself Myles?

[mylesgm]

Hi Chris, No I didn't, they were built for me. Often just dont have the time to do the diy I'd like to...

m