3D "AIR" EQ - "Night EQ" PCB's Complete!

[clintrubber]

[quote author="khstudio"]But I'd rather do the Metalwork any day... I sit behind a computer enough.[/quote]
I see your point, it's sometimes refreshing to drill & file for excercising some other muscles.

I was also missing 2 items & had 1 bag labled correctly with the wrong shit in it. I like Mouser but come on. This scares me when it comes to resistors.

Hmm, that's bad! So far I've only used a few www-part-sources but so far they've always been spot on except for one mislabeled bag. RS has been perfect so far.

When going to town here for a bag of parts I could always be sure at least something was wrong, so www-ordering was quite an improvement.

 

[khstudio]

*I need advise* -

I'm ordering parts & decided to go with Metalized Poly BOX caps & would like to get the WIMA's but damn they're expensive...
Are they REALLY that good at about $1.00 each (1uf) as opposed to about .50cents each for other brands? I guess for the 20k & 40k settings I could go for it but I'm not even sure that they're as noticeable because of they're function in the circuit (just coupling to GND)??? Help me out here if you can.
The Panasonic stacked metal films aren't bad - at about $3.50 for 10 (they are what I had laying around & used)

Kevin

 

[khstudio]

BTW, I'm concerned about cost a LITTLE because I'm building about 6-8 channels of the Shelves only version & the 1uf's at $1.00 each adds up :shock:

kevin

 

[clintrubber]

[quote author="khstudio"]BTW, I'm concerned about cost a LITTLE because I'm building about 6-8 channels of the Shelves only version & the 1uf's at $1.00 each adds up :shock:

kevin[/quote]
I think to have seen there are max. four of those 1uF caps in use at a time for one air-band. So for the cost/hassle of some more switching-complexity it could be arranged that you only need 4 i.s.o. 7 of the 1uF caps. I'm not sure it'll be cheaper & as enjoyable in the end, maybe just keep it like it's now.
So what I mean here is that you switch in such a fashion that once you need to go from say 2 to 4 caps of the 1uF-value you don't jump to four 'new' ones but keep two and add another two.

Or try to make other ways of realizing those values. 4uF = 3.9uF + 100nF (but 3.9 might be hard to get). OK, 4uF is also close enough to 3.3uF + 680nF + 22nF. But hey, if there's some saving at all it'll just be a few $$ per band, hardly worth the hassle I'd say.

 

[Harpo]

[quote author="khstudio"]BTW, I'm concerned about cost a LITTLE because I'm building about 6-8 channels of the Shelves only version & the 1uf's at $1.00 each adds up :shock: kevin[/quote]

have a look at www.Reichelt.de
http://www.reichelt.de/?SID=281TT@jH8AAAIAAEwGKLI28a39ce3c5e3a38cdc7ec306c7a127aa;ACTION=3;LA=2;GROUP=B326;GROUPID=3155;ARTICLE=12376;START=0;SORT=artnr;OFFSET=16
MKS-4-100 1,0µ - 0.28 EUR a piece

100Vdc/63Vac is enough, you don't need the 250, 400, 630 or 1000V rated caps.

Don't know about the panasonics, but if the sound is ok, stick with them.

 

[khstudio]

x

 

[clintrubber]

For some real costsavings it might be good to reconsider the R & C dimensioning. I mean, using as high as 220 nF & as low as 20 Ohms for a 40kHz filter-frequency (36.2kHz) looks quite wasteful w.r.t. capacitor-costs.
Even more so for the 2.5 kHz frequency: 4uF & 20 Ohms (1/(2*pi*RC) = 2kHz)

I can imagine though you wouldn't want to go that route since it might 'lose/change the magic'; but from a technical point of view this is the obvious way to go when looking for reducing component-costs.

I might be overlooking things, but as long as noise isn't a problem the 200 & 20 Ohms could be increased in value & the caps lowered (=cheaper) by the same factor.
But as said, maybe they're like this for noise-reasons, too lazy now to check if that could be the reason.

Bye,

Peter

 

[khstudio]

You are exactly correct... I DO NOT want to reinvent the wheel... it's already turning. I have also read about using several smaller caps in parallel instead of one BIG one for many reasons... one I THINK is the speed or responce to higher frequency's but don't quote me on that.

Who know's, it could be fine & everyone is welcome to build how they want but I will stick to how it was for my builds as much as I can... even if just for piece of mind :wink:

BTW, those caps are not available at Mouser or Digikey

Kevin

 

[khstudio]

While on the subject of caps (SORRY)

Harpo mention something about Elna's but I have no experience with them :?:

I usually go with Nichicon PW's in the signal path & can hear the diference between them & Pan FC's (Brighter & not as smooth)

Wondering about going with the Elna's for a change. Opinions welcome... please don't give me the CAp Lecture :wink:

There are only a few 470uf's in the S path.

Kevin

 

[cannikin]

Hey Kevin,

Here is another resource for you in regards to Elnas ... They are in PA so you will get things in about a day

https://www.hndme.com/productcart/pc/viewCategories.asp?idCategory=72

I plan on using Elna and Nichicon Wimas (just for the hell of it), Won't happen in the immediate future but sometime this spring.

About the PCB layout PDF -- Version 2 is the latest for just the AIR EQ (Correct?). Is the View of the PCB traces needs to be changed to mirror to etch the PCB?

thanks
David

 

[Harpo]

[quote author="clintrubber"]I'm not sure which inductors are under discussion here, but if it's indeed those at the audio-output (L1,2 in the schematic on page 1) then it's not related to the kind of supply but because of the reasons I quoted from the Jensen-datasheet of the load isolator.[/quote]

Good point Peter and thanks for the link :thumb: , but these JT-OLI-3 are specced 39R||3uH as equivalent circuit, giving increasing impedance above 200kHz and according Kevin's post the 3d-EQ has fitted 47.5R||100uH, a 33times off to not affect the audible band, so there might be another reason going on.

Bye,

Harpo

 

[khstudio]

[quote author="cannikin"]Hey Kevin,

Here is another resource for you in regards to Elnas ... They are in PA so you will get things in about a day

https://www.hndme.com/productcart/pc/viewCategories.asp?idCategory=72

I plan on using Elna and Nichicon Wimas (just for the hell of it), Won't happen in the immediate future but sometime this spring.

About the PCB layout PDF -- Version 2 is the latest for just the AIR EQ (Correct?). Is the View of the PCB traces needs to be changed to mirror to etch the PCB?

thanks
David[/quote]

Very cool :thumb:
But know creates more choices... decisions decisions. All those flavors they metioned sound good... damnit. I wonder what the "General" choice is on these?

I used vers 2 for my prototype & it works great but I WILL be making a few adjustments before etching again... what, I think the one with the BIG 150 ohm resistor removed is the V2 I resent out & has already been adjusted (spacings) so I think you fine.

I will post any updates here.

It's really not a hard project (at least not now :green
I think you'll be surprised at how useful it can be.

Kevin

 

[khstudio]

[quote author="Harpo"][quote author="clintrubber"]I'm not sure which inductors are under discussion here, but if it's indeed those at the audio-output (L1,2 in the schematic on page 1) then it's not related to the kind of supply but because of the reasons I quoted from the Jensen-datasheet of the load isolator.[/quote]

Good point Peter and thanks for the link :thumb: , but these JT-OLI-3 are specced 39R||3uH as equivalent circuit, giving increasing impedance above 200kHz and according Kevin's post the 3d-EQ has fitted 47.5R||100uH, a 33times off to not affect the audible band, so there might be another reason going on.

Bye,

Harpo[/quote]

Well hopfully the link I posted for the inductor at Digikey is OK because I'll be ordering them so I have them... what can it hurt to put them in?

K

 

[Harpo]

[quote author="khstudio"]While on the subject of caps (SORRY)

Harpo mention something about Elna's but I have no experience with them :?: [/quote]
Don't know Elna's :?: eighter, but like the WIMA's for their sound an look, but don't expect to many audible colour differences between brands in this frequency range. You may have another opinion on this subject.

 

[khstudio]

[quote author="Harpo"][quote author="khstudio"]While on the subject of caps (SORRY)

Harpo mention something about Elna's but I have no experience with them :?: [/quote]
Don't know Elna's :?: eighter, but like the WIMA's for their sound an look, but don't expect to many audible colour differences between brands in this frequency range. You may have another opinion on this subject.[/quote]

Fair enough... I must have mis-understood or confussed another email.

So your saying the WIMA's are good but maybe not as important... maybe because of the job they're performing isn't as critical :? ???

Thanks again for hanging in there thru all my questions :thumb:

kevin

 

[Harpo]

My opinion on this may be off, but I think, you recognize to tolerances of the caps and not their brand. These elcos and polys are for usual specced 20%, so for your calculated 2kHz filter a 4uF cap which is 20% above it's labeling and with a resistor 20R f=1/(2*pi()*R*C) set your -3dB point to 1.9kHz. Exchanging this cap with another wich is 20% below it's labeling will set your filter to 2.1kHz, meaning until you don't measure the real value of caps, you cannot compare brands.

 

[clintrubber]

[quote author="Harpo"]My opinion on this may be off, but I think, you recognize to tolerances of the caps and not their brand. These elcos and polys are for usual specced 20%, so for your calculated 2kHz filter a 4uF cap which is 20% above it's labeling and with a resistor 20R f=1/(2*pi()*R*C) set your -3dB point to 1.9kHz. Exchanging this cap with another wich is 20% below it's labeling will set your filter to 2.1kHz, meaning until you don't measure the real value of caps, you cannot compare brands.[/quote]
Indeed ! Good reminder !
As most people here found out when measuring caps, you won't find a 20% tol Wima etc being much closer than that to the stamped value. There's definitely 'a hole in the middle', and guess what happened to those... these were obviously stamped 10%... and so on...
It's a cruel world... which is just another way of saying that you get what you pay for.

 

[enthalpystudios]

http://www.mouser.com/search/ProductDetail.aspx?R=MKS2-1.0%2f63%2f5virtualkey50520000virtualkey505-MKS21.0%2f63%2f5

i would get those. 5%, keeps the bands real nice and close. with full boards available, it's probably what I'd get. i mean, you just can't beat the price of this stuff.

the power supply, a parmetal case, and a frontpanel are easily 2/3 the cost of a project like this.

why not go the little extra?

i've been learning to not pinch pennies on parts, but instead pinch pennies on time, and pinch pennies on everything else in life ;]

for all the hard work and dedication, we owe it to ourselves not sell ourselves short.

it's such a tiny little detail, that it seems the only real answer to the question is to answer it your self by picking up 10 of each and building two channels.

i have some extra 1uf wimas if you want to try em out, i'll send em to you... i have 6 leftover from an order... not having the schematic handy, if thats enough to test out an air or 2.5khz channel, i'll send em your way... just pm me.

 

[Purusha]

Kevin, I recommend you to buy some extra caps and match them.
This is what I did for my stereo Pultecs and I have a lot of spare
ones now in order to come really close to 1% difference per ch.
Specially if you plan to use the EQ on the stereo buss.

Regarding those files you sent to us, they are just for the high AIR section, yes?

Why is everyone using the same avatar? :shock: Who is this guy anyway?

 

[Harpo]

[quote author="Purusha"]Kevin, I recommend you to buy some extra caps and match them.
This is what I did for my stereo Pultecs and I have a lot of spare
ones now in order to come really close to 1% difference per ch.
Specially if you plan to use the EQ on the stereo buss.

Regarding those files you sent to us, they are just for the high AIR section, yes?

Why is everyone using the same avatar? :shock: Who is this guy anyway?[/quote]
this tread http://www.groupdiy.com/index.php?topic=20560