FFBE-32-02-242 (Famous Four Band Eq)

[pahstah]

Hi Guys,

This is my 500 version of "3 2 ", "232" and "02" equalizers, designed to be very cheap or little more expensive in the in out part of the circuit.
a part for some minor mistakers the proto is working nicely in the eq part. About the input output part i've tested it only with that 1246 in that 1646 out and it works great.

I have tested both the 325 style output and the transistor based input, they are set to give -6dB on input and +6dB for output. they both work great and i am really satisfied with the outcome.
If interested PM me.

Paolo

Mouser Carts:

EQ pcbs:

FBE-02    https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=e06f22df13
FBE-32    https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=3af6a1dc04
FBE-242 https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=5DDFBCC759

IN/OUT pcb options:

1246 input:    https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=8642e4c00f
1646 output:  https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=b3c6d5f768

325 output:    https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=9ca08c20ed
IMPORTANT: this cart does not include the DOA and the transformer! the DOA needed is in 2520 format and the transformer is EA-2503 with can be found at capigear

-6dB transistor Input (2 carts ):
https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=e3e191a46f
and
https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=64d6ea18e8


Building Guides:

FBE-02 Building Manual: https://drive.google.com/open?id=1YqNCwoKYRI3x5gFCGs_JK_hgpDjKW5uw

FBE-32 Bulding Guide:  https://drive.google.com/open?id=1FbdyEmJFojiQRXzKJ-qn-FiEtOAZfHxo

IN/OUT Guide https://drive.google.com/open?id=1HGkCRVqqohazD0V1JZVQ8n6Rm_TvAUgN

Front Panel Pdf and Fpd:

FBE-32: 
https://drive.google.com/open?id=1ihwGrwnm2xNx0Xe62cUPmRchKAD89z3T
https://drive.google.com/open?id=1kyni85Q2z53IFUJ2M2zFhSrSnOnl8vSk

 

[fragletrollet]

Nice, interested!

 

[Meyer]

Wow looks great, cool that you included the filters. I'm interested!

 

[Rocinante]

Paolo,
Awesome. The i/o pcb seperated  from the filters is great. Id be curious as to what other circuits one could use with the '32'.  So the only connections between filter pcb and io  are power, audio i/o and ov?

 

[pahstah]

Paolo,
Awesome. The i/o pcb seperated  from the filters is great. Id be curious as to what other circuits one could use with the '32'.  So the only connections between filter pcb and io  are power, audio i/o and ov?

Hi Rocinante,

when I started designing the pcb i soon realized that i would have a lot of pcb space unused so i decided to go a little further and design an i/o pcb so that i could later adopt it for other types of eq without the need to deisgn a input output pcb again. then i thought that it would have been a good idea to put a connection for a trimpot. so the connections between the pcbs are in, out, power snd 0v, and also a connection for a trim. but be aware that this trim only works with the DOA output wich is basically an a p i 325 output.

 

[ruffrecords]

How do you squeeze ten controls onto a 500 series front panel?  Is is even possible to get adult fingers between the controls?

Cheers

Ian

 

[pahstah]

How do you squeeze ten controls onto a 500 series front panel?  Is is even possible to get adult fingers between the controls?

Cheers

Ian

Ian,
you're right:that's a big problem and one of the major downsides of 500 series format. with this configuration however it is possible for adult fingers to set the pots by manipulate them by the tip. the problem arise with the pushbuttons, that's one of my mistakes: they're too deep. one of the changes i will make is to move them forward on the pcb so they stand a little taller, and i will move the hpf and lpf pots further away from the other pots.
ideally i should have chosen pots with 4mm shaft, so i could use narrower knobs but 50k rev log stereo are difficult to find.

 

[fragletrollet]

Tx footprint for 2622?

 

[pahstah]

Tx footprint for 2622?

tx input footprint is for neutrik ntl1, then you have the choice of ne5534, or transistor circuit as in studer line in.
tx out is for 2503, DOA is for 2520 style opamp

 

[fragletrollet]

Anticipating your thoughts om the different IO configurations when youve tried them out!

 

[beatnik]

ideally i should have chosen pots with 4mm shaft, so i could use narrower knobs but 50k rev log stereo are difficult to find.

try ask Omeg UK, they can make custom parts

 

[pahstah]

try ask Omeg UK, they can make custom parts

Thank you beatnik, but i think that with some minor trick i can fix the issue

 

[pahstah]

at this point i haven't tested the alternative in and out but i have worked out the mockup for the frontplatm, what do you think? i've also found some smaller knobs so it is easier to press the button between the knobs. but in the final pcb design i will have the knobs slightly farther apart and the pushbuttons will poke out more.

Paolo

 

[fragletrollet]

Nice, but id prefer white text on black aluminium  8)

 

[mdmitch2]

I'm interested!

 

[pahstah]

Nice, but id prefer white text on black aluminium  8)

Yeah, me too. What about a printed plastic self adhesive sheet to stick on the front panel? It isn't as cool as a powder coated and silkscreened front panel but not bad either, and it is surely cheaper. 

 

[fragletrollet]

Id rather pay for the silkscreened one tbh; i appreciate good looking modules, and this looks like a module i could need 4-6 of i havent seen such a flexible 4 band eq with sweepable filters in a single slot format, kudos!

 

[pahstah]

Id rather pay for the silkscreened one tbh; i appreciate good looking modules, and this looks like a module i could need 4-6 of i havent seen such a flexible 4 band eq with sweepable filters in a single slot format, kudos!

maybe white silkscreen on black anodized front panel could be a solution

 

[fragletrollet]

Yes. Not sure how anodized compares to powdercoated: capi frontplates are anodized and silkscreened while soundskulptor modules are powdercoated and silkscreened? Just to compare with some modules i own.

I did a panel through schaeffer/fpe and it turned out gorgeous; powdercoated black (no silkscreen as all fonts are engraved, leaving a nice gray contrast to the black powdercoat, no infill needed)

 

[zamproject]

Hello Paolo

Nice work as usual !

I like the separated I/O pcb option too, because by removing it I should fit this eq in my modular Studer desk, I have spare room /blank modules.
Is it possible to only use eq pcb, unbalanced I/O with 22v rail (or +/-11v), nominal level around -15dBu ?

Best
Zam