Marcocet

Harrison Ford Filter Feeler
« on: November 02, 2011, 12:14:35 AM »
It looks like 12afael, Jens and I finally have a production version of this PCB ready and we're about to place an order for ourselves. Essentially it's a clone of the classic Harrison sweepable filters. The board runs on +/- 15v, has extremely few parts, and is tiny enough to fit a bunch in a rack case. It could also easily be built into a 500 series module. The hardest parts to source are the 47k Rev Log pots, which are available at Audio Maintenance (thanks Colin!).

I'm not trying to run a shop or anything, but if anybody would like a few boards I can figure out a price and add them in to our order. Please feel free to PM me or email me at strangeweathersound @t gmail.



EDIT:

Boards are sold out. Here's the BOM. I've attached an excel copy too for those who are that way inclined.

5   10k           R1, 2, 6, 7, 9   
4   390           R3, 4, 5, 8   

9   0.1u           C1, 2, 6, 7, 11, 12, 13, 15, 16   
1   100p           C3   
1   0.012u   C4   
1   0.047u   C5   
2   100u   C8, 9   electrolytic
1   10u           C10   electrolytic

2   50k Dual Lin   LOPASS, HIPASS   Audiomaintenance.com
1   ESWITCH 2 pole   switch   Audiomaintenance.com

1   INA134P   IC2   
1   TL074P   IC1   
1   DRV134PA   U$1   

http://strangeweatherbrooklyn.com/sales/HarrisonFilterBOM.xls


schematic here
« Last Edit: December 30, 2011, 08:49:08 PM by Marcocet »


tmuikku

Re: Harrison Ford Filter Feeler
« Reply #1 on: November 02, 2011, 03:43:16 AM »
Hi!

which pot it uses, the conductive plastic or this cheaper carbon pot? http://www.audiomaintenance.com/acatalog/om-01-028_extended_info.html

have you prototyped it already? 8) the pushbutton seems to come very close of those potis, is there room for switch cap and knobs? Just kicking the tires since I'm interested!

It seems eight will fit into 1u case?
« Last Edit: November 02, 2011, 03:50:42 AM by tmuikku »

coriolis

Re: Harrison Ford Filter Feeler
« Reply #2 on: November 02, 2011, 04:34:52 AM »
I'm not familiar with these - are they hi/lo shelf filters with selectable freqs? Or? Got a schem or a pic of an original unit?
I'm certainly looking for something simple like this, so might be interested...

C
- more projects than sense...or money...or time...
http://www.hzandbits.com

Re: Harrison Ford Filter Feeler
« Reply #3 on: November 02, 2011, 09:59:18 AM »
tmuikku,

just a guess but switch is probably on one side and pots on the other side of the PCB.  BTW, if it fits Omegs then they are ALL conductive plastic. According to their website, that's all they make.   I've even brought this up to Colin once, but didn't really understand the reason he gave me for selling them as carbon. Anyway, bottom line is that all Omegs are cond plastic.

There was another thread with info about these in the drawing board:

http://www.groupdiy.com/index.php?topic=44444.0

okgb

Re: Harrison Ford Filter Feeler
« Reply #4 on: November 02, 2011, 10:10:49 AM »
Depending on cost , i could speculate on a board set or two
[ knowing i may have a hard time getting to them  ]
GKB Audio / Greg Boboski

Re: Harrison Ford Filter Feeler
« Reply #5 on: November 02, 2011, 01:28:42 PM »
If the price is reasonable I'd love to grab up 8 of them, I can never seem to find enough highpass filters in the studio.

are the 12db/oct filters?

Dubka

Re: Harrison Ford Filter Feeler
« Reply #6 on: November 02, 2011, 05:19:52 PM »
Yep, 8 here as well - depending on price...

Marcocet

Re: Harrison Ford Filter Feeler
« Reply #7 on: November 02, 2011, 08:10:53 PM »
I'm expecting them to land in the $4-5 each territory, but don't hold me to it quite yet. It all depends on how many people are interested.

Yep, they're 12db/octave filters.

Mitsos got it. Switch mounts on the bottom of the board.

I'll get together a BOM but if I remember they weren't more than $25 each in high quality parts, excluding the pots.

minor_glitch

Re: Harrison Ford Filter Feeler
« Reply #8 on: November 02, 2011, 10:36:58 PM »
Hell yes!  If they're $5 a pop I'm in for at least 8.

Re: Harrison Ford Filter Feeler
« Reply #9 on: November 03, 2011, 02:51:46 AM »
What does the switch control, sorry if it's obvious, I just glanced at the PCB, is it a bypass for both filters or just the lowpass?


danijel

Re: Harrison Ford Filter Feeler
« Reply #10 on: November 03, 2011, 05:02:53 AM »
I'm in for 8... :)

Marcocet

Re: Harrison Ford Filter Feeler
« Reply #11 on: November 03, 2011, 12:27:09 PM »
What does the switch control, sorry if it's obvious, I just glanced at the PCB, is it a bypass for both filters or just the lowpass?

Both, but it's not true bypass. If you want that you can wire it up off board.


Denyle Guitars

Re: Harrison Ford Filter Feeler
« Reply #12 on: November 03, 2011, 01:29:56 PM »
In for 8 as well.

Re: Harrison Ford Filter Feeler
« Reply #13 on: November 03, 2011, 02:53:23 PM »
So do we just post here, or have to email you with the desired number of boards?
It's 8 for me btw...
 :D

Marcocet

Re: Harrison Ford Filter Feeler
« Reply #14 on: November 03, 2011, 03:12:51 PM »
So do we just post here, or have to email you with the desired number of boards?
It's 8 for me btw...
 :D

Either one's fine :) You are now on the list. I'll close it in a week or so and contact everybody for payment.
Thanks!
-marc alan


monkey

Re: Harrison Ford Filter Feeler
« Reply #15 on: November 03, 2011, 11:41:21 PM »
Much needed! I'm in for two.

12afael

Re: Harrison Ford Filter Feeler
« Reply #16 on: November 04, 2011, 12:01:57 AM »
I love the name! ;D
heavy metal is the law!!!

detonator

Re: Harrison Ford Filter Feeler
« Reply #17 on: November 04, 2011, 03:59:47 AM »
in for 2 depending on the price

MrZpliff

Re: Harrison Ford Filter Feeler
« Reply #18 on: November 04, 2011, 06:27:54 AM »
4 boards for me please  :)
Thank's !
Peace
Magnus
www.bitterend.se

Marcocet

Re: Harrison Ford Filter Feeler
« Reply #19 on: November 04, 2011, 05:34:50 PM »
I love the name! ;D

And I love Christopher Lloyd.

Good times.