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

[waner]

Hi

Almost finished with my CLX-VU. I have two questions:
1. I have a Led for "above" that is brighter than "below". Could I put a resistor in series to ground (of that Led) or will it affect the compressor in any way?
2. Is the XLR:s grounded to the chassi? If yes: Booth IN and OUT?

Thanks
Mattias

 

[abechap024]

Hi

Almost finished with my CLX-VU. I have two questions:
1. I have a Led for "above" that is brighter than "below". Could I put a resistor in series to ground (of that Led) or will it affect the compressor in any way?
2. Is the XLR:s grounded to the chassi? If yes: Booth IN and OUT?

Thanks
Mattias

Hello
1)You safest bet is to just get similar LEDs or just stick with one brighter than another, I really don't have any Idea if it will mess with the circuit.
2) Its common practice to only link the Input XLR to the chassis.

 

[waner]

Thanks Abe

I have two more questions

1. I`m using Hairball VU`s with LEDs. From the schematics it seems that the LEDs are connected straight from the secondary of the transformer (via R125) and to the LEDs of the VU. That meens that the LEDs get AC. Is that correct? I saw that you use Hairball VU. What value of R125 do you use. From the BOM it`s 260k or 10k for brighter LEDs.

2. I have grounded the input XLR to the chassi. Do I need any more ground connections to the board?

Regards
Mattias

 

[abechap024]

Thanks Abe

I have two more questions

1. I`m using Hairball VU`s with LEDs. From the schematics it seems that the LEDs are connected straight from the secondary of the transformer (via R125) and to the LEDs of the VU. That meens that the LEDs get AC. Is that correct? I saw that you use Hairball VU. What value of R125 do you use. From the BOM it`s 260k or 10k for brighter LEDs.

yes 10k works fine.

2. I have grounded the input XLR to the chassi. Do I need any more ground connections to the board?

Regards
Mattias

nope

enjoy!

 

[waner]

Thank you!

Mattias

 

[redmojosteve]

Hi Abe
Got my boards last week and there are plenty of components packed in! The build manual looks excellent too. I'll start building very soon and let you know how I get on with it.
Cheers
Steve

 

[redmojosteve]

Spent a very wet afternoon here happily soldering the resistors in place. Perhaps I've misread something but my BoM shows 10k or 260K for R125 (LEDs) but the Rev 3 board silkscreen shows 4.7K. Have I missed something?
Thanks for all the hard work you guys put in with these projects, my home studio has benefitted greatly as has my electronics knowledge (I am a Mech Eng by profession and my electronics circuit theory can be a bit rusty!).
regards
Steve

 

[abechap024]

Spent a very wet afternoon here happily soldering the resistors in place. Perhaps I've misread something but my BoM shows 10k or 260K for R125 (LEDs) but the Rev 3 board silkscreen shows 4.7K. Have I missed something?
Thanks for all the hard work you guys put in with these projects, my home studio has benefitted greatly as has my electronics knowledge (I am a Mech Eng by profession and my electronics circuit theory can be a bit rusty!).
regards
Steve

Hi Steve,
Sorry I didn't include the updated REV 3 BOM in this latest version of the build manual! Thanks for pointing that out. Fixing it right now.

Abe

 

[warpie]

Hi Abe,

On a similar note the BOM I have specifies 1N004 for CR1-CR4, CR20-CR23 where on the rev.3 PCB are marked as 1N007.
Shall I trust the PCB and use 1N007s?

thanks
Michael

 

[abechap024]

Hi Abe,

On a similar note the BOM I have specifies 1N004 for CR1-CR4, CR20-CR23 where on the rev.3 PCB are marked as 1N007.
Shall I trust the PCB and use 1N007s?

thanks
Michael

1n4001, 1n4002, 1n4003 etc up to 1n4007 are all fine just that 1n4001 is only rated at 50v and then 1n4007 is rated at 1000v. when you figure the price difference (almost none) it makes sense to use the highest rated diodes in all your projects wether they specifically ask for 1n4007 or not. usually 1n4001 will be perfectly fin, but always nice to have more robust parts.

http://www.diodes.com/datasheets/ds28002.pdf

Have a good one.

 

[warpie]

Thanks abe, that makes sesne

I hope I'm not asking too much but is there a BOM for rev3? The current BOM I have (5/2/2011) makes it a bit harder to source the exact components and values I need (especially on the film caps). One example is that I can see many 100nf on the PCB but the BOM calls only for one (C100)...

Also, has anyone sourced (in UK or Europe) any VU meter that would fit in 1U rack ?

 

[Rob Flinn]

Also, has anyone sourced (in UK or Europe) any VU meter that would fit in 1U rack ?

Thanks again for your help.
Mike

Hi Mike I used some meters from HAirball that were really cheap, I can't remember the model number but I think Mike at Hairball told me which one to use, & they fitted Danderloo's case to, which I bought so I could wrap the project up quickly.

 

[warpie]

Hi Rob,

Did you have to pay any import taxes? Do you remember (roughly) the total cost?

 

[abechap024]

Hello,
here is the rev 3 bom/manual

http://www.acsoundstudio.com/manuals/clx_manual_rev3.pdf

the meters are on hairball audios site. they are the 1ma ones that mount behind the faceplate.

Cheers!

 

[warpie]

great thanks! I had the manual but I was missing the page with the bom. All good now 

 

[warpie]

Hey Abe,

I have a couple of more questions if you don't mind 

1) C1 and C4 (100nF). Do these need to be installed? (they're not in the BOM)

2) What's that above C4 (labeled as +24V and G). Is it just a test point where you can measure your voltage? I assume no component need to be installed there (?)

 

[abechap024]

Hey Abe,

I have a couple of more questions if you don't mind 

1) C1 and C4 (100nF). Do these need to be installed? (they're not in the BOM)

Yes. Thanks for pointing that out. you should install them.

2) What's that above C4 (labeled as +24V and G). Is it just a test point where you can measure your voltage? I assume no component need to be installed there (?)

Thats for if anyone wants to use a lamp instead of leds in their meter.

 

[warpie]

Hey Abe, still here with more questions! (i know, i know... :)

I powered it up and it looks to function OK. I haven't connected the meter and the switches yet (I haven't received them), and neither I have calibrated the unit. It passes audio and it compresses though.

However, the voltage regulators are getting hot! I can't really touch them. Is this normal? I'm using a 2x18V 30VAC trasformer for a single unit, which should be fine.

In the power rails, I measure +/-15V and +/-28...

 

[abechap024]

However, the voltage regulators are getting hot! I can't really touch them. Is this normal?

Hello,
Questions are good! Hmmm on my builds the regulators don't get especially hot...I don't know if I could touch them though, I haven't tried! I'm powering on a set, so I'll try and touch the regulators. It could be that you don't have the switches hooked up. All in all i wouldn't worry about it too much, maybe try touching other components (after you wire up the switches) and see if any opamps or chips are getting hot. If not, then your ok, I'd say.

Have a Good one!

 

[warpie]

Thanks Abe,

It'll be interesting to see how hot your regulators are. I'll try with the switches once I get them. Opamps and chips seem to be OK at the moment (not hot at all).

Is there any chance this is cause from the high voltage I get in the 24V rails (I measure +/-28V)?
In fact, is it normal/OK to have 28V in these rails?

I was thinking of using a relay connected to the +/-24V for bypassing the signal but I don't know if that's a good idea.