gar381

API eq kits???? New
« Reply #160 on: November 19, 2007, 09:30:21 PM »
This one is based 99.9% on peterc's PCB but using Wilco Inductors and adding a third LF freq.





Using Cinemag Transformer and Melcor DOA
Front Panel Express front panel with Re'an collett knobs.

I still need to bend an L shaped bracket for holding the front panel
to the PCB like peter purpose uses on his 525.

I will be making more 553s when peterc has his PCB offering.  I'm
just not shure what Inductors i'll be using yet.  I have never tried
winding my own and may give it a try.  These are Wonderful EQs.

This guy sounds BIG, FAT and SMOOOOOOTH!! I Love it!!

GARY
« Last Edit: December 30, 2009, 07:33:57 PM by gar381 »
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html


API eq kits????
« Reply #161 on: November 20, 2007, 05:39:13 AM »
V.nice Gary... :thumb:
http://www.lazpro.com
I reserve the right to not sell to idiots

peterc

API eq kits????
« Reply #162 on: December 15, 2007, 04:49:19 AM »
Hi All

I have been fine tuning the design for this board, looking good.

Just to get an idea, how many would be interested in PCB's for this project?

I will start a thread in the Black Market, please let me know there.

http://www.groupdiy.com/index.php?topic=304534#304534

Peter
If opportunity doesn't knock, build a door.

codered

API eq kits????
« Reply #163 on: December 18, 2007, 04:22:22 PM »
Quote from: "gar381"
something I'm working on..



based on peterc's 553 design but using opamp labs 87-1 and 87-2 inductors.
http://www.opamplabs.com/87.htm
LF and MF have 6 freqs each plus off and HF 2 freqs with center off.

More later when I get a chance to hear this guy... Looks great on my
scope.

GARY


Gary,

Where did you purchase this 500 series type breadboard ?

thanks
you're a nut ... this is the internet..we're all nuts

gar381

API eq kits????
« Reply #164 on: December 18, 2007, 10:54:52 PM »
This is standard 3662 (4.5" x 6.5"  22/44 .156pitch) vector plugboard.

You can get this at digikey, mouser and other large supply houses.

I cut it to 4.5" x 5 7/8" with a dremel cutting tool and left the center
15 pins to give 15/30  .156 pitch connector. :wink:

Then the FUN BEGINS!!! :thumb:

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

codered

API eq kits????
« Reply #165 on: December 20, 2007, 02:11:43 AM »
Brilliant :thumb:
you're a nut ... this is the internet..we're all nuts

jensenmann

API eq kits????
« Reply #166 on: April 17, 2008, 06:54:16 AM »
Could someone measure the DC resistance of the original 553 inductors for me, please? Or has this been done before and I missed it?
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort

gar381

API eq kits????
« Reply #167 on: April 17, 2008, 09:57:28 AM »
Quote from: "jensenmann"
Could someone measure the DC resistance of the original 553 inductors for me, please? Or has this been done before and I missed it?


Thanks for bringing this up Jens...would love to know the samething.

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

peterc

API eq kits????
« Reply #168 on: April 17, 2008, 10:35:31 AM »
In one of the pics, I wrote down the DC resistance of the coils on top of the cores, the .1H ws 3 ohms & the 1H was 37 ohms (even though it says 3.7 in the pic, this was a mistake.)

I used .22 mm wire for the .1H & .15mm for the 1H

It would be very interesting to see the original specs.

Peter
If opportunity doesn't knock, build a door.

jensenmann

API eq kits????
« Reply #169 on: April 17, 2008, 12:53:03 PM »
Thanks, Peter. Good to have a housenumber at least. You said they sound nice?
Indeed, it would be interesting to see the original values. This would make the inductor choice less trial-and-error.
Jens
Quote from: PRR
The tubes of course don't care what frequency they distort


gar381

API eq kits????
« Reply #170 on: April 17, 2008, 10:27:50 PM »
Thanks peter :thumb:

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

peterc

API eq kits????
« Reply #171 on: April 18, 2008, 01:43:12 AM »
The 553 is the only piece of DIY gear where I have seen peoples' jaws drop when hearing the sound.

Lots of people have said "wow, that sounds great" or "definitely use that" but this was a "my fvck" kind of reaction. The inductors really work well.

Peter
If opportunity doesn't knock, build a door.

API eq kits????
« Reply #172 on: June 14, 2008, 09:40:30 AM »
Peter, or anyone else who have tried to build this eq. What kind of pots did you use? Are Bourns log conductive plastic fine?

I also have some thoughts on the inductors. I never tried to wound an inductor myself, but I have found the RS core part that Peter used. Could this be pulled of even without an LCR meter?

API eq kits????
« Reply #173 on: July 23, 2008, 08:41:39 AM »
What do you guys think, would it be possible to get some more gain out of the op amp in this circuit, and add an extra pot for gain past unity?

gar381

API eq kits????
« Reply #174 on: July 23, 2008, 01:26:48 PM »
Use any 10k lin pot will work fine.  
Don't use a log pot.

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

API eq kits????
« Reply #175 on: July 23, 2008, 03:02:39 PM »
Ok, thanks Gary. What are the cap values used in the filter section? I have a hard time reading it from the schematic, other than the 3Khz cap which looks like 27µF.

Edit:

I did some calculations on the cap values. This is what I got, does it look right?

MF

3Khz      2,7nF
2,5Khz   3,9nF
2Khz      6,3nF

LF

150Hz    1µF
220Hz    0,5µF

HF

10Khz    370pF
12Khz    300pF

gar381

API eq kits????
« Reply #176 on: July 23, 2008, 03:55:10 PM »
Fredric

Use this :

http://www.opamplabs.com/cfl.htm

BTW.. the low shelf is really a BELL centered about 23hz
(around 47uf)

check your dec. points.  some of your values look off

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

API eq kits????
« Reply #177 on: July 23, 2008, 05:07:34 PM »
I actually did use that calculator, but did some random rounding just to get a rough estimate.

I just used the frequencies on the schemo posted in this thread.


 

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