Anyone interested in some API 500 format projects??

[Family Hoof]

So what do we do about inductors and output trafo for this 553? What are you using, strangeandbouncy?

As I already told Miko, I think I can make a PCB layout for this very easily once a BOM and measurements have been presented. Unfortunately I don't have access to a 2520 or any of these parts right now, but maybe next month. If someone wants to lend me one for a week I can copy the board almost exactly. Gerbers and etch-your-own pdf to be posted here upon completion.

 

[drpat]

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[Sammas]

...I like the idea of the 553 as first project :thumb:

I'll continue the working on the layout for a mono GSSL... it'll be a few weeks though.

 

[drpat]

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[Sammas]

[quote author="drpat"][quote author="Sammas"]...I like the idea of the 553 as first project :thumb: [/quote]

For sure, minimal components, 2520 boards already available, schematic available, good transformer subs available, sounds like the PCB will be the most difficult part. Anybody else want in?

Shucks, I guess my dreams of having another 4 of the pres just got shot dowm by myself![/quote]


I'd be happy to work up some PCB layouts, but it would be handy if someone could source exact parts (well, none R & C parts). DOA pinouts are pretty straight forward, as too are the 10K pots (i think they are 10K, i haven't looked at the schem since yesterday) but i've never used inductors before so if someone could point me to an appropriate data sheet with pin out dimensions i'd be happy to get to work...

The switch looks like a 4P2T switch which i can probably put in pin placements for a couple of different types.

The Transformer... there is the Profile version, and i assume lundahl might have one that does the same. Joe from JLM has one too. He might be willing to give us a group discount if we can get a few people in for a purchase...

 

[drpat]

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[peterc]

Hi all

On the 533 EQ:

Can anyone tell me what the components should be that go between points 6 & 7 (marked Gain Trim) ?

Many thanks
Peter

 

[drpat]

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[fum]

man, I can't jump in on this as I'll be on a boat for a week starting tonight, but looks like I'll have some cool stuff to look forward to.

On the inductors, you may want to leave a somewhat widely spaced pair fo pads to mount the two wires of the inductor to. something on the 15mm range.

In this fashion, people can wind their own inductors, or if you can find a stocked part somewhere for the inductors, that could be cool too.

Regards

ju

 

[drpat]

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[Sammas]

[quote author="drpat"][quote author="fum"]man, I can't jump in on this as I'll be on a boat for a week starting tonight, but looks like I'll have some cool stuff to look forward to.

On the inductors, you may want to leave a somewhat widely spaced pair fo pads to mount the two wires of the inductor to. something on the 15mm range.

In this fashion, people can wind their own inductors, or if you can find a stocked part somewhere for the inductors, that could be cool too.

Regards

ju[/quote]


Fukem (oops, did I just say that) let's wind our own! Is this DIY or DIT (do it themselves)? Personally, I like bragging about making my own components! Even if it's just a 0? resistor. HaHa![/quote]


:shock:

Thats probably a little more than im willing to do... but i can leave the space needed... Anyone know where there is a data sheet or pin dimensions for the inductors we need?

 

[TomWaterman]

Hey guys - good idea for the bucket modules.

Peter, according to some datasheets for the API5xx eq modules at danalexander, pins 6 & 7 marked gain trim (I guess on all eq modules) are NC = not connected.....

Anyways just thought I'd mention it. Not been with it lately.

Does anyone know if the 553 will accept an unbalanced input to the Hi connection with the Lo in grounded? I'm trying to cook up a 312/553 hybrid...

Cheers Tom

 

[thestudio]

Nobody build 312 pcb's for 500 series rack?????? :idea:

 

[Family Hoof]

[EDIT] Didn't materialize

 

[Sammas]

Ok, i just measure my OSA's. Probably the biggest PCB that you'll fit into a 500 series rack. Its 115mm high and 150mm from the faceplate to the end of the edge pins.


drpat... regarding input transformers on the 553... I was under the assumsion that they'd be 10K:10K?

I've got the rough layout down, bar the different variations for input/output trannys and the inductors but i've left plenty of room to play so i'll add it in when i get an idea of what people would like...

 

[drpat]

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[strangeandbouncy]

Sorry, Guys,

I somehow missed your comments/questions. i used empty 325 line amp cards, Fabio's 2520RC, Profile tx's, Paxolin board for front panel(!), and fastened it into my Lunchbox with Stickytape!!! THAT's why i don't wanna show! I have only built the HF part so far, with switched caps to vary freq from @10kHz up to @24kHz. Inductors for LF, I have looked at a Sowter multitapped to give variable Freq, but too pricey for me right now!. Cheapest option seems to be a Cinemag 2H at @20$. This would give @80-100Hz shelf, and I was going to try making a 1xFreq Shelf/Switchable Bell(by adding different caps in series). At the mo, I cannot affrod either the inductor, or to take them out of the rack for completion, since they ROCK on the top end of vocals, drum bus, or mix.
I don't know why you would want to add extra cost/reduced space by adding an input tranny. sounds amazing to me as is, and I have never had a noise problem. You should be giving 'em a hefty old level in my book!

Keepin' it Real for da peepul . . .


ANdyP

 

[drpat]

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[TomWaterman]

Andy duuuuude are you running yours unbalanced or balanced in?
I'd like to see your botch job anyway - I'm sure its coolios.

If peeps were going to turn this into a full-blown project what would be the preference for inductors....wilco, cinemag or sowter?

-Tom

 

[Sammas]

[quote author="TomWaterman"]Andy duuuuude are you running yours unbalanced or balanced in?
I'd like to see your botch job anyway - I'm sure its coolios.

If peeps were going to turn this into a full-blown project what would be the preference for inductors....wilco, cinemag or sowter?

-Tom[/quote]

Yeah! I'd still like to see photos too! Everyone has a "black sheep" in there studio...



Tom, I've got the PCB layout pretty much done except for the inductors and some tranny options. What do you want to use?

It would be cool to get some tapped inductors for switchable frequencies... Is it as simple as i think it is? just put a single pole multiple position switch between the seperate "tappings"... so each time you turn the switch it shortens the length of wire windings in the inductor that are being used?? :?: Strangeandbouncy? maybe you can clue me in?

I'm actually swinging towards tapped cinemags... or if not... maybe we could try and organise a group order for cinemag trannies and inductors. They might be able to give us a deal.

regarding transformers...

here is a small list i've put together but im not sure if they are all appropriate for our purposes.

- OEP Z3002E (optional input)
- Jensen Jt-11p-1 (optional input)
- Lundahl LL1540 (optional input)
- Profile 4804 (output)
- Sowter 9825 (output)
- API 2503 (output), Dan Alexander has 20 for sale...
- Cinemag CMOB-2S (output) (SCA are using this instead of the 4804).

any others?