API inspired channel strip and stereo EQ.

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Zebra_PD

Well-known member
Joined
Nov 7, 2017
Messages
196
Location
Umea, Sweden
Hi,
I got about 6-8 original API 2520, a bunch of vintage API output transformers, two API 2500 frontplates n a API TCS frontplate.

My plan was originally to try to clone 4+1 550, 4+1 312 and a 527 circuits on two PCBs and build my self a kick ass 3U unit.

But covid, a baby n a total rebuild of the studio have forced me to revaluat the project since I don't have time to design custom PCBs for it all. :(

So asking you for some advice/hints on different PCB designs or premade boards out there that make use of the 2520 op-amp and has a nice API flavour that would be suitable to combine together for my project.

The 212/312/512 is a piece of cake. But the still looking for a suitable EQ n compressor.

Anyone have some thoughts or ideas for me?

Also if anyone in the EU have some PCBs or projects that fits the build they are willing to sell send me a DM :)
 

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Got a great deal on a Fredenstein Artistic Leveler, with a few mods I think it will be a suitable 517 substitute.

So now I just need a suitable substitute for the 550. Is there any ones out there besides the CAPI BT50 (rather expensive to buy since I live in Europe and only need the board more or less...)
 
Must admit I'm not aware of one that's current. The complex and expensive switching is the main deterrent there.

Of course, if you're just looking for API-style EQ and not wedded to the 550 models, a 553 would be a lot easier to build from scratch - even with some switchable frequencies. There was a post about API "Be-All" posts recently on one of the Markets I think, which might perhaps be adapted to a 553 without too much effort.

Watching with interest!
 
Thx for your advice!

I think I sow that post in BM... Yeah a 553 would be fine as well. Will try to study the schematic of that and see if it's possible to use a "be-all-board"
 
You Can Combine them in 500 series from CAPI Gear. He has all of them... 312/550/527
Other way there is several DIY 312 design around, like the ML12, Access312 or AVD in 500 series...
I don't know others than Jeff who have DIY 550 or 527...
 
I think this is a great advice, just do a small 500 series rack and combine 3 modules, a preamp an EQ and a compressor.
Like oran.outan said you can get all this modules from CAPI
Well I all ready have the hardware for a 19" unit n no more space in the API 500 lunchbox. But using 500 series PCB for the EQ n comp is the idea.

Jeff was the first to clone the 550 I think but both the 527 n 525 was cloned before CAPI started selling them.

But I think u are right that CAPI is the only company that sell anything but 212/312/512 today. Besides Fredenstein Artistic series that is more inspired by API units and using 2520 type OP-AMP.

I think I need to buy CAPI BT50 after all. The price nowdays is really expensive with the US vs EU trade war...

But for the two 5500 units I will do some type of hybrid ones with API 535 type line amps but one with Neumann type EQ section from PCB Grinder and the other one with a set of SSL 4000 EQ card I have over.
 
I understand your already have the hardware for 19' but you can still sell it or used it later for another project... and use a 19' 1U 3 slot rack like the BAE R53 or Radial powerstrip... and fill it With 500 unit.
In my opinion, that will save you a lot of time...
You still built the unit but Drill front/back panel (or pay for a pro one) is always a question to think... As it's often not so easy... and take time...

I'm in EU too and yes, cutom, shipping, fees are to consider but in your case, for the unit you're looking for, I don't see (or mostly know) other option, in DIY...

"But I think u are right that CAPI is the only company that sell anything but 212/312/512 today."
I think Capi is the closer and keep going to the vintage original one, other way there is others... depend on format and 'flavor' your looking for...
 

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