Gear Porn - A*P*I* 553

Hi all,

They're off to their new home, so I thought I'd take some pix before I packed them up. Sorry for the fuzziness - I was too lazy to get out the tripod and by the time I realized they were already boxed up.

Wow, quite a difference in mechanical/PCB complexity when compared to the pics of the other A*P*I EQ in the forum. That's how I like it, simple and easy to build/troubleshoot, *cough* reverse-eng *cough*...

hehe

Ian

30 components or so? I want to make one.

If you want the original, much larger pics (sorry Ethan, I thought I made them small enough) let me know and I'll send them to you.

:thumb:

if someone were to do these, and it became a group thing, would the board still be the same as the original, to be able to fit into the lunchbox?

I have some 550's but i have some open slots in my lunchbox.


I love all you guys...

It looks cool, but I recently compared those 550 with 550b type:
for my taste the 550 is not a good EQ while 550b rocks!
peace.
Mik.

[quote author="mik"]It looks cool, but I recently compared those 550 with 550b type:
for my taste the 550 is not a good EQ while 550b rocks!
peace.
Mik.[/quote]

The 550a and 550b have proportional Q that narrows with boost while the 550 does not. I don't know about the 553, but it's pretty wide...sounds great on electric guitars, drums etc.

It does have major DIY potential!
Who made the inductors?

Is that factual? I thought the narrowing Q was a byproduct of the filter and not something that was designed in there as an improvement. The drawings for a 550 and a 550a look pretty much identical to me. In use, I have more 550's than anything else but they dont sound significantly different than the 550a or b's I have. When comparing my 550's to b's they sound mostly identical with the exception that you have to go an extra gain step on the 550 to match the 550b (+4 on the b sounds like +6 on the 550) but I always wrote that off to drift from aging components.

Is there a technical explanation to support that statement? Would love to know if there is.

thanks

dave

Trying out this new enlarger thingy, which rocks by the way.

Is there a schemo floatin around for that thing?




different color inductor;

[quote author="soundguy"]Is that factual? I thought the narrowing Q was a byproduct of the filter and not something that was designed in there as an improvement. The drawings for a 550 and a 550a look pretty much identical to me. In use, I have more 550's than anything else but they dont sound significantly different than the 550a or b's I have. When comparing my 550's to b's they sound mostly identical with the exception that you have to go an extra gain step on the 550 to match the 550b (+4 on the b sounds like +6 on the 550) but I always wrote that off to drift from aging components.

Is there a technical explanation to support that statement? Would love to know if there is.

thanks

dave[/quote]

Wait.........I screwed up.
I think it was the 550A-1(Datatronix) that was constant Q, and the 550 and 550A were proportional Q.
Sorry.

Looks nice to DIY.
Maybe Dan Alexander can have some info on this that's not in his site?

cheers!
Fabio