CLX-VU Build Thread (DBX 160VU ) UPDATE: REV 3

[Spencerleehorton]

Ah ok, my version doesn’t work but it’s all round the wrong way as per the other pic. Will try reversing and hopefully will sort!!

 

[Spencerleehorton]

Is there a way of using a 0.5ma Vu meter for this?
What would the resistor config be?

 

[Spencerleehorton]

Looking at R107 it says 3.3k for 1ma meter and 10k for 0.1ma so if I replaced R107 for 10k trimmer I should be able to set about 5-6k and that should be 0.5ma?

 

[Spencerleehorton]

Well I’m not sure the other wiring image works or not!! As I didn’t have the plug in the correct way and then changed it!!
Getting compression but having difficulty setting up correctly.

 

[BerndVP]

So, where can I find 'CA3083 or NTE929' ?

 

[BerndVP]

So, the IC I found now,

I see we need a 1.29M Ohm resistor, that doesn't exist off-coarse, so how did you guys fixed this ?

 

[JMan]

So, the IC I found now,

I see we need a 1.29M Ohm resistor, that doesn't exist off-coarse, so how did you guys fixed this ?

I would just use a 1.3 Meg instead (readily available).  That’s still within tolerance — heck, your 1.29 M might have shown up on your doorstep measuring 1.3 anyway.

If you’re truly set on getting 1.29 precisely, I guess you could connect two smaller value resistors in series to get it, but I don’t really think it’s worth the hassle here.

 

[BerndVP]

Ok! Thanks for the tip!

For all other components.
Has are their some tips?
I see people using some Orange Drops in some builds.

 

[JMan]

I guess you could use orange drops and see what they sound like, but I think what you’ve probably noticed are actually the big poly caps that sit in some of the larger footprints.  They are kind of reddish-brown in color and they are fat, and look a bit like orange drops.  The build guide recommends polypropylene caps in the audio path, I believe, so that’s the place to start, but there’s nothing wrong with trying out different flavors and seeing what you like.

 

[BerndVP]

Ok, thanks for the info,
When I look at mouser, the brownish are Panasonic ones.
But what are the things I have to look at when selecting ones ?

 

[JMan]

I'd say don't overcomplicate it for yourself.  The only things you really need to pay attention to are the following:

-the type of capacitor (e.g. film, ceramic, electrolytic, tantalum) -- these are specified in the BOM
-the capacitance value -- in pF, nF, uF - use an online converter tool if you need it, as sometimes you will be looking, for example, for a 100nF cap and only finding 0.1uF, and you need to know that these are the same value
-the voltage rating -- this is pretty simple, whatever the DC voltage is at a given point in the circuit, you'll want the cap to have a voltage rating that is equal or higher than that.  It's likely that any cap you buy that will go into the audio path will have a sufficient rating (though it doesn't hurt to check), but make sure that you pay attention to the voltage ratings in the power supply section.

If you want to go a little deeper, you can look in to the ways that different dielectric materials impact the sound of the audio in the circuit (although this is always a bit subjective and can get a little tricky depending on the cap's role in the circuit).  Really, I don't think you're going to go wrong using the recommendations in the build guide.

 

[Bowie]

Ok! Thanks for the tip!

For all other components.
Has are their some tips?
I see people using some Orange Drops in some builds.

When it comes to component selection, you get familiar with the sound of certain components by doing comparisons. If you don't want to do that then I recommend going for parts with good specs (which tend to be more linear/transparent). I personally wouldn't see the point of going with orange drops here but maybe that sound works for you. Most of all, you're going to need to go with components that fit the PCB so the opportunity to experiment will be somewhat limited.

 

[JMan]

When it comes to component selection, you get familiar with the sound of certain components by doing comparisons. If you don't want to do that then I recommend going for parts with good specs (which tend to be more linear/transparent). I personally wouldn't see the point of going with orange drops here but maybe that sound works for you. Most of all, you're going to need to go with components that fit the PCB so the opportunity to experiment will be somewhat limited.

I agree with Bowie. 

I will say that the PCB does offer quite a few footprint options on a number of key capacitors, so if one were so inclined, this might actually make experimentation easier than some other boards. 

I'm not sure I see the point of orange drops either, but who knows, maybe that's the secret sauce.  You could always try sticking some sockets in and swapping out different caps until you find what you like, but truly, if I'm reading your questions correctly -- and perhaps I'm not -- you might be trying to run before you can walk.  I'd say build it as it is intended first, and then if you feel like a new cap will really be the thing to take it over the top, go for it.  (I say that having a stereo unit sitting built-but-uncalibrated on my bench waiting for my attention for the last 6 months now, so take my advice with a grain of salt).

 

[BerndVP]

Hi,
thanks both for replying, it's not I want to go for Orange Drops, but on a not so sharp picture I thought it was them.

I ordered the PCBs first an then will source the components for it.

 

[JMan]

Ah, understood.  Have fun with your build!

 

[BerndVP]

@JMan, thanks!
@Bowie: are you willing to share you're components list so I can compare with mine ?

 

[Bowie]

@JMan, thanks!
@Bowie: are you willing to share you're components list so I can compare with mine ?

I looked up my Mouser BOM from over 6 years ago and most of the caps are no longer made. I won't share the resistors because I recall a lot of the Vishays I got were over-sized and did not fit so I don't want to recommend parts that don't fit. Here are some of the series types of caps I used;
https://www.mouser.com/Panasonic/Film-Capacitors/ECQEB-Series/_/N-1yzvjj0Z9x371Z1yzn81f
https://www.mouser.com/Cornell-Dubilier/Film-Capacitors/160-Series/_/N-1z0zlgfZ9x371Z1z0seay
https://www.mouser.com/Murata/Multilayer-Ceramic-Capacitors-MLCC-Leaded/RPE-Series/_/N-1z0zlftZbkrdjZ1z0yn0i
https://www.mouser.com/Vishay/Film-Capacitors/MKP419-Series/_/N-1z0zls5Z9x371Z1yzumc1
https://www.mouser.com/Nichicon/Aluminum-Electrolytic-Capacitors-Radial-Leaded/UKL-Series/_/N-1z0zlbmZ75hqwZ1yi2vyo

 

[BerndVP]

So, another question, the NTE929 I can't find it here in Europe.
In the US, it's $45 shipping costs, and that for 2 chips.

Is there an alternative for this chip ?

 

[JMan]

The NTE929 is offered in the BOM as an alternative to the CA3083.  Look around the web for those — Mouser and the usual suspects won’t have it, but you’ll surely be able to find some.  Here’s one auction currently available on eBay (it’s a US seller, but you can look for sellers more local to you):

https://www.ebay.com/itm/4-PC-RCA-CA3083-GENERAL-PURPOSE-HIGH-CURRENT-NPN-US-SELLER-FREE-SHIPPING/254579703994?epid=1500558920&hash=item3b462200ba:gbEAAOSw3adepJP5

 

[BerndVP]

Thanks for the tip, I ordered them from you're link