Barry Porter "Net EQ"

[petermontg]

Got around to having another look at these boards over the weekend.....

R27 which is 10r was reading 20r on one board. On both boards the 4r7 was reading 5r5 for some reason. Everything else is good. I will change them hopefully later this week. Fingers crossed for me......

 

[Gustav]

Got around to having another look at these boards over the weekend.....

R27 which is 10r was reading 20r on one board. On both boards the 4r7 was reading 5r5 for some reason. Everything else is good. I will change them hopefully later this week. Fingers crossed for me......

"On the board", meaning - in circuit? Cant measure resistance on an individual resistor in circuit, and the difference between 10/20R and 4R7/5R5 would not mess up anything anyway.

Gustav

 

[DAN_000]

Hi,

I really like to use this EQ with broad Q settings.  But there are some limitations with this and noise, like mentioned in Porter doc.
There are some NetEq builds with extended band bandwith. like  20 to 200hz  ---->  20 to 510hz
Is there any benefit of extended bandwith  band vs  Q (broad setting) noise ?
And another question to Harpo,  how you calculate new optimal integrator capacitor values if you change freq bandwith ?

Thanks

 

[petermontg]

Got around to having another look at these boards over the weekend.....

R27 which is 10r was reading 20r on one board. On both boards the 4r7 was reading 5r5 for some reason. Everything else is good. I will change them hopefully later this week. Fingers crossed for me......

"On the board", meaning - in circuit? Cant measure resistance on an individual resistor in circuit, and the difference between 10/20R and 4R7/5R5 would not mess up anything anyway.

Gustav

One leg disconnected. Am going to get PSU board from you in a bit Gus, just to rule that area out. It outputs 18v can never be TOO sure.

 

[frazzman]

Hi,

I really like to use this EQ with broad Q settings.  But there are some limitations with this and noise, like mentioned in Porter doc.

Is this in theory or in practice ? I haven't observed any drastic noise changes with broad Q, also the Q at it's broadest setting actually isn't that broad compared to some other EQs of a similar ilk.... 

 

[vilddyr]

Hi Guys.

I have seen this build around, and I really don't know how to identify the parts. I'm of course not looking to copy, but I do know, that I don't care about switches, but just about getting a great sounding EQ. So this stereo controlled style, with regular pots is much more appealing to me, than using hours and hours soldering cheap switches up with resistors, since I'm not really keen on using 100's of $ on ELMA switches.

Gustav, maybe you can help me out, are these board not more or less identical to yours? So maybe someone could point me in the direction of where to get the pots used here, that fit directly on the PCB?

Is there anyway to get some kind of pcb for metering, like the one in this unit? Any standard stuff, easily implemented?

Great to see people doing this thing.

 

[petermontg]

Hi Guys.

I have seen this build around, and I really don't know how to identify the parts. I'm of course not looking to copy, but I do know, that I don't care about switches, but just about getting a great sounding EQ. So this stereo controlled style, with regular pots is much more appealing to me, than using hours and hours soldering cheap switches up with resistors, since I'm not really keen on using 100's of $ on ELMA switches.

Gustav, maybe you can help me out, are these board not more or less identical to yours? So maybe someone could point me in the direction of where to get the pots used here, that fit directly on the PCB?

Is there anyway to get some kind of pcb for metering, like the one in this unit? Any standard stuff, easily implemented?

Great to see people doing this thing.

There was a document in the folder on pots. Maybe if you find the link somewhere it could be still there. It alludes to...

Model P270/271/272
27mm Rotary Potentiometer
TT Electronics.

 

[vilddyr]

Yeah I looked into it a little more, and the PCB in those units are of course stereo boards, while Gustav's is "dual" mono. So I was kind of way off. And I guess it does need to be switches, if it's to be mastering capable. Not so much for the steppings, but for the lack of accuracy with standard pots.

 

[Gustav]

Not so much for the steppings, but for the lack of accuracy with standard pots.

Exactly.

During the last year or so, I have really come to love the way an EQ can impact the sonics of the program more than any other type of processing, and this EQ is nothing special in that regard.

What it does, in my opinion, is unnoticeable accuracy, which is really pretty boring as a "sound". So ditching the pots would be a bad move.

I saw some prepared switches on ebay recently, but I didn't notice the price, and I can't seem to find a link again.

Gustav

 

[vilddyr]

Yeah, I have seen some of those, with pre installed resistors. I assume these could be useful for the gain switches, since this is just a string of the same resistors (right?), but there's not really any way of avoiding having to make your own frequency switches. Which is of course fine, as this is how to choose your values!

Would you guys recommend ordering the frontpanel as the absolutely last thing on a build? I'm kind of getting ready to order the different parts, but still haven't really figured out what to do about the back panel. Guess it would be best to just have schaeffer make on that could fit on the back of the modu enlosure. It seems modu also does custom panel stuff though, anyone have experience with that?

 

[kante1603]

Would you guys recommend ordering the frontpanel as the absolutely last thing on a build? I'm kind of getting ready to order the different parts, but still haven't really figured out what to do about the back panel. Guess it would be best to just have schaeffer make on that could fit on the back of the modu enlosure. It seems modu also does custom panel stuff though, anyone have experience with that?

Hello,


we don't know where you are located,best to update your profile.
Just in case you're in europe I would highly recommend Frank at NRG (http://www.frontpanels.de),he does all panels for me.Same as Schaeffer,but cheaper and you always get help from him.He's cool!Just create a file with FPD like you would for a Schaeffer order,send it to him and ask if you need any(!) help.He can do a lot of things with frontpanels (I mean that!),he works with aluminium and acrylic.


Check it out and have fun,


Udo.

 

[vilddyr]

Yeah Sorry. I'm in Copenhagen denmark.

I'm doing a little research still. Trying to get a grasp on everything, since I'm pretty much a rookie, who wants to go all in  I'm good with a soldering iron, and have done other stuff, but I have probably zero understanding of what is actually going on. But I am very keen to learn ! The case and back panels from don-audio looks like quality stuff

Does it make sense to go for the more expensive switches? Or will the actual switches have absolutely nothing to say in regards to audio quality, since the resistors soldered to them is pretty much the determining factor? In my head the switches does not pass audio as such, but are only a way of controlling whats going on, on the PCB... As said, I am a total noob, and probably wrong  ???

 

[frazzman]

Yeah Sorry. I'm in Copenhagen denmark.

I'm doing a little research still. Trying to get a grasp on everything, since I'm pretty much a rookie, who wants to go all in  I'm good with a soldering iron, and have done other stuff, but I have probably zero understanding of what is actually going on. But I am very keen to learn ! The case and back panels from don-audio looks like quality stuff

Does it make sense to go for the more expensive switches? Or will the actual switches have absolutely nothing to say in regards to audio quality, since the resistors soldered to them is pretty much the determining factor? In my head the switches does not pass audio as such, but are only a way of controlling whats going on, on the PCB... As said, I am a total noob, and probably wrong  ???

The switching mechanism type is really just for the "feel" - i.e. The ELMA switches feel nicer and smoother than the cheaper Uraltone counter parts. I used cheap uraltone / chinese switches in my build and they worked fine.

Just my 2 cents... I don't think this is a very good beginner project. It's somewhat complicated, there are lots of parts and lots of decisions to make about how to achieve what you need. It isn't nearly as comprehensively documented as say any of the Gyraf projects.

Personally I would start off on a more straightforward build than this.

 

[vilddyr]

Yeah, I see your point. But I'm way too stubborn, so it's not gonna make much of a difference

 

[DAN_000]

Hi,

I really like to use this EQ with broad Q settings.  But there are some limitations with this and noise, like mentioned in Porter doc.

Is this in theory or in practice ? I haven't observed any drastic noise changes with broad Q, also the Q at it's broadest setting actually isn't that broad compared to some other EQs of a similar ilk....

Original Porter broadest Q is 1.    There is no noise issues with this original value.  But things start to change if you modify input and feedback integrator resistors values. 
There are some modified extendend freqs per band builds.    And there is a value of Q=0.3  in this builds (exactly what Im looking for).  Maybe this extended freq range helps noise figure ?

Anyone who builds with modified broad Q range please can give me some help ?

 

[frazzman]

Hi guys,
Almost finished my build so close I can taste it!
Just finished wiring on my right channel. All checks out except for an issue on HF band. Shelf is fine but peak isn't working for boost or cut., just stays at 0  - freq plot is flat.
I'm using stepped switches as per Harpos spreadsheet.
This channel is built identically to my (working) left channel. Any ideas ? If shelf works, where should I focus for peak issue ? I'm reading the right resistance on at the pcb so I'm know switch is wired correctly.
Thanks a lot

 

[biigniick]

hi all,
i'm getting started on my Net Eq build and i was looking for LED illuminated DPDT toggle switches.  i'm having a bit of trouble finding a suitable set.  anyone have any suggestions or what has worked for you guys?  i'd prefer illuminated, circular pushbutton...

thanks in advance,
- nick

 

[Gustav]

Hi guys,
Almost finished my build so close I can taste it!
Just finished wiring on my right channel. All checks out except for an issue on HF band. Shelf is fine but peak isn't working for boost or cut., just stays at 0  - freq plot is flat.
I'm using stepped switches as per Harpos spreadsheet.
This channel is built identically to my (working) left channel. Any ideas ? If shelf works, where should I focus for peak issue ? I'm reading the right resistance on at the pcb so I'm know switch is wired correctly.
Thanks a lot

Did you figure this out?

Gustav

 

[petermontg]

hi all,
i'm getting started on my Net Eq build and i was looking for LED illuminated DPDT toggle switches.  i'm having a bit of trouble finding a suitable set.  anyone have any suggestions or what has worked for you guys?  i'd prefer illuminated, circular pushbutton...

thanks in advance,
- nick

Try Deca if you can find DPDT. I cant see where you would have any problems really.

 

[frazzman]

Hi guys,
Almost finished my build so close I can taste it!
Just finished wiring on my right channel. All checks out except for an issue on HF band. Shelf is fine but peak isn't working for boost or cut., just stays at 0  - freq plot is flat.
I'm using stepped switches as per Harpos spreadsheet.
This channel is built identically to my (working) left channel. Any ideas ? If shelf works, where should I focus for peak issue ? I'm reading the right resistance on at the pcb so I'm know switch is wired correctly.
Thanks a lot

Did you figure this out?

Gustav

Hey Gustav,
Yes I did, thank you mate. Wrong resistor value somewhere.

Everything is pretty much working except for one overall anomaly, affecting both channels - even in bypass.
I'm observing some noise/ripple in the higher frequencies...Very prevalent with a HF boost. The plots from RMAA explain all....

It's quite audible, even though the unit is very quiet and hum free with no audio passing. With audio present  you can hear this 'ripple'.

Did you ground your pcbs ? I haven't done that and I am wondering if that's where my problem is?

Thanks a lot