VU2 stereo VU buffer kit Build thread

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kings79
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Re: VU2 stereo VU buffer kit Build thread

Post by kings79 »

Joe Malone wrote:
Tue Mar 16, 2021 2:52 pm
Just try them on the buffer output with diodes fitted on buffer to see if they work and do 1dB steps to see if the lineup to the scale or not and let me know what you find.

But the meter should work on the audio line as that is what they were designed to do but they add distortion so a buffer is the best way to isolate the distortion.
Hey Joe, finally found tine to build. All done. All works. Even put 2 variable resistors and a switch so I can switch between 2 dB levels.

But I did 1dB steps as you suggested and it doesn't line up to the scale.
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Re: VU2 stereo VU buffer kit Build thread

Post by Joe Malone »

kings79 wrote:
Sun Mar 21, 2021 3:22 pm
Joe Malone wrote:
Tue Mar 16, 2021 2:52 pm
Just try them on the buffer output with diodes fitted on buffer to see if they work and do 1dB steps to see if the lineup to the scale or not and let me know what you find.

But the meter should work on the audio line as that is what they were designed to do but they add distortion so a buffer is the best way to isolate the distortion.
Hey Joe, finally found tine to build. All done. All works. Even put 2 variable resistors and a switch so I can switch between 2 dB levels.

But I did 1dB steps as you suggested and it doesn't line up to the scale.
OK good to hear you got it working. If it is one of the old type ebay etc meters with old 12v lamp the scale isn't correct or it just doesn't need the VU2 buffer rectifier. As you go down 1dB steps is the needle showing more or less dB?

Moved your posts from our Stereo VU meter build thread to correct Vu2 Build thread.
Joe :-)
JLM Audio
Capturing Audio without Injury

kings79
Posts: 14
Joined: Sun Mar 14, 2021 9:41 am
Location: Sydney

Re: VU2 stereo VU buffer kit Build thread

Post by kings79 »

Joe Malone wrote:
Mon Mar 22, 2021 9:33 am
kings79 wrote:
Sun Mar 21, 2021 3:22 pm
Joe Malone wrote:
Tue Mar 16, 2021 2:52 pm
Just try them on the buffer output with diodes fitted on buffer to see if they work and do 1dB steps to see if the lineup to the scale or not and let me know what you find.

But the meter should work on the audio line as that is what they were designed to do but they add distortion so a buffer is the best way to isolate the distortion.
Hey Joe, finally found tine to build. All done. All works. Even put 2 variable resistors and a switch so I can switch between 2 dB levels.

But I did 1dB steps as you suggested and it doesn't line up to the scale.
OK good to hear you got it working. If it is one of the old type ebay etc meters with old 12v lamp the scale isn't correct or it just doesn't need the VU2 buffer rectifier. As you go down 1dB steps is the needle showing more or less dB?

Moved your posts from our Stereo VU meter build thread to correct Vu2 Build thread.
Its from Amazon. I mentioned that.
https://www.amazon.com.au/Amplifiers-He ... 060&sr=8-1

Image

It shows less of course as you go down. But it isn't correct.
Didn't you say it may not need the diodes? Perhaps this is the problem?
Joe Malone wrote:
Tue Mar 16, 2021 2:52 pm
Just try them on the buffer output with diodes fitted on buffer to see if they work and do 1dB steps to see if the lineup to the scale or not and let me know what you find.
------------------------------------------
knob tweaker

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Re: VU2 stereo VU buffer kit Build thread

Post by Joe Malone »

kings79 wrote:
Mon Mar 22, 2021 3:41 pm
Joe Malone wrote:
Mon Mar 22, 2021 9:33 am
kings79 wrote:
Sun Mar 21, 2021 3:22 pm


Hey Joe, finally found tine to build. All done. All works. Even put 2 variable resistors and a switch so I can switch between 2 dB levels.

But I did 1dB steps as you suggested and it doesn't line up to the scale.
OK good to hear you got it working. If it is one of the old type ebay etc meters with old 12v lamp the scale isn't correct or it just doesn't need the VU2 buffer rectifier. As you go down 1dB steps is the needle showing more or less dB?

Moved your posts from our Stereo VU meter build thread to correct Vu2 Build thread.
Its from Amazon. I mentioned that.
https://www.amazon.com.au/Amplifiers-He ... 060&sr=8-1

Image

It shows less of course as you go down. But it isn't correct.
Didn't you say it may not need the diodes? Perhaps this is the problem?
Joe Malone wrote:
Tue Mar 16, 2021 2:52 pm
Just try them on the buffer output with diodes fitted on buffer to see if they work and do 1dB steps to see if the lineup to the scale or not and let me know what you find.
Yes try one side with no rectifier mod and see if it track better.
Joe :-)
JLM Audio
Capturing Audio without Injury

kings79
Posts: 14
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Location: Sydney

Re: VU2 stereo VU buffer kit Build thread

Post by kings79 »

Ok, pulled off all 4 diodes and put 2 jumpers on D1 & D4.
Now the VU's don'e work at all...
Im only getting 0.8mV across the + & - of the 'M' terminals.
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Re: VU2 stereo VU buffer kit Build thread

Post by Joe Malone »

kings79 wrote:
Tue Mar 23, 2021 10:12 am
Ok, pulled off all 4 diodes and put 2 jumpers on D1 & D4.
Now the VU's don'e work at all...
Im only getting 0.8mV across the + & - of the 'M' terminals.
OK your meters do not have any rectifier in them then. The closest you will get is to what you had with diodes on the VU2 before you removed the them as the scale is not calibrated to the meter coil in your meters.
Joe :-)
JLM Audio
Capturing Audio without Injury

kings79
Posts: 14
Joined: Sun Mar 14, 2021 9:41 am
Location: Sydney

Re: VU2 stereo VU buffer kit Build thread

Post by kings79 »

Joe Malone wrote:
Tue Mar 23, 2021 11:42 am
kings79 wrote:
Tue Mar 23, 2021 10:12 am
Ok, pulled off all 4 diodes and put 2 jumpers on D1 & D4.
Now the VU's don'e work at all...
Im only getting 0.8mV across the + & - of the 'M' terminals.
OK your meters do not have any rectifier in them then. The closest you will get is to what you had with diodes on the VU2 before you removed the them as the scale is not calibrated to the meter coil in your meters.
But there is no voltage coming from the 'M' + & - now though. Is this how it's supposed to be?
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Joe Malone
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Re: VU2 stereo VU buffer kit Build thread

Post by Joe Malone »

kings79 wrote:
Tue Mar 23, 2021 11:55 am
Joe Malone wrote:
Tue Mar 23, 2021 11:42 am
kings79 wrote:
Tue Mar 23, 2021 10:12 am
Ok, pulled off all 4 diodes and put 2 jumpers on D1 & D4.
Now the VU's don'e work at all...
Im only getting 0.8mV across the + & - of the 'M' terminals.
OK your meters do not have any rectifier in them then. The closest you will get is to what you had with diodes on the VU2 before you removed the them as the scale is not calibrated to the meter coil in your meters.
But there is no voltage coming from the 'M' + & - now though. Is this how it's supposed to be?
Yes without the rectifier it will be AC volts going to the meter. With rectifier on VU2 then the meter will get DC.
Joe :-)
JLM Audio
Capturing Audio without Injury

kings79
Posts: 14
Joined: Sun Mar 14, 2021 9:41 am
Location: Sydney

Re: VU2 stereo VU buffer kit Build thread

Post by kings79 »

Joe Malone wrote:
Tue Mar 23, 2021 12:59 pm
kings79 wrote:
Tue Mar 23, 2021 11:55 am
Joe Malone wrote:
Tue Mar 23, 2021 11:42 am


OK your meters do not have any rectifier in them then. The closest you will get is to what you had with diodes on the VU2 before you removed the them as the scale is not calibrated to the meter coil in your meters.
But there is no voltage coming from the 'M' + & - now though. Is this how it's supposed to be?
Yes without the rectifier it will be AC volts going to the meter. With rectifier on VU2 then the meter will get DC.
Ok. That makes sense.

I've just done a test on my SEW ST-475's with your original mono VU buffers and they don't scale to 1dB increments exactly either.
Ive been mixing TV shows with Pro Tools for about 9 years on these and they are fine. I'm wondering if properly scaled ones will make a difference.
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Joe Malone
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Re: VU2 stereo VU buffer kit Build thread

Post by Joe Malone »

kings79 wrote:
Tue Mar 23, 2021 1:52 pm
Joe Malone wrote:
Tue Mar 23, 2021 12:59 pm
kings79 wrote:
Tue Mar 23, 2021 11:55 am


But there is no voltage coming from the 'M' + & - now though. Is this how it's supposed to be?
Yes without the rectifier it will be AC volts going to the meter. With rectifier on VU2 then the meter will get DC.
Ok. That makes sense.

I've just done a test on my SEW ST-475's with your original mono VU buffers and they don't scale to 1dB increments exactly either.
Ive been mixing TV shows with Pro Tools for about 9 years on these and they are fine. I'm wondering if properly scaled ones will make a difference.
Unless you are using the meters for calibrating system it doesn't make any difference.
Joe :-)
JLM Audio
Capturing Audio without Injury

kings79
Posts: 14
Joined: Sun Mar 14, 2021 9:41 am
Location: Sydney

Re: VU2 stereo VU buffer kit Build thread

Post by kings79 »

Joe Malone wrote:
Thu Mar 25, 2021 11:13 am
kings79 wrote:
Tue Mar 23, 2021 1:52 pm
Joe Malone wrote:
Tue Mar 23, 2021 12:59 pm


Yes without the rectifier it will be AC volts going to the meter. With rectifier on VU2 then the meter will get DC.
Ok. That makes sense.

I've just done a test on my SEW ST-475's with your original mono VU buffers and they don't scale to 1dB increments exactly either.
Ive been mixing TV shows with Pro Tools for about 9 years on these and they are fine. I'm wondering if properly scaled ones will make a difference.
Unless you are using the meters for calibrating system it doesn't make any difference.
Yeah cool.

I mixed the Perth A League last night from NEP's HUB and used the VU's. They went well. Mixing a TV show today for Amazon from my home studio. Will see how it goes...

I did notice that the right meter doesn't have same scale as the left. 1dB increments are ok and mostly to scale on the left but not the right. Would that be component tolerances?
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Joe Malone
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Re: VU2 stereo VU buffer kit Build thread

Post by Joe Malone »

kings79 wrote:
Thu Mar 25, 2021 11:28 am
Joe Malone wrote:
Thu Mar 25, 2021 11:13 am
kings79 wrote:
Tue Mar 23, 2021 1:52 pm


Ok. That makes sense.

I've just done a test on my SEW ST-475's with your original mono VU buffers and they don't scale to 1dB increments exactly either.
Ive been mixing TV shows with Pro Tools for about 9 years on these and they are fine. I'm wondering if properly scaled ones will make a difference.
Unless you are using the meters for calibrating system it doesn't make any difference.
Yeah cool.

I mixed the Perth A League last night from NEP's HUB and used the VU's. They went well. Mixing a TV show today for Amazon from my home studio. Will see how it goes...

I did notice that the right meter doesn't have same scale as the left. 1dB increments are ok and mostly to scale on the left but not the right. Would that be component tolerances?
The buffers once set to a gain are perfect amps and we never see difference between even cheap meters left to right.

The only tolerance would be the meters or if one of the BAT85 has gone open circuit so not fully rectifying.

Easiest way to prove were the problem is. Swap the meter plugs over on the VU2 pcb and see if fault stays with meter or VU2 channel.
Joe :-)
JLM Audio
Capturing Audio without Injury

kings79
Posts: 14
Joined: Sun Mar 14, 2021 9:41 am
Location: Sydney

Re: VU2 stereo VU buffer kit Build thread

Post by kings79 »

Joe Malone wrote:
Thu Mar 25, 2021 1:43 pm
The buffers once set to a gain are perfect amps and we never see difference between even cheap meters left to right.

The only tolerance would be the meters or if one of the BAT85 has gone open circuit so not fully rectifying.

Easiest way to prove were the problem is. Swap the meter plugs over on the VU2 pcb and see if fault stays with meter or VU2 channel.
I tested all the Diodes before placing them.

Yeah that's a good idea. After I finished this job first...
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Supablake
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Joined: Tue May 25, 2021 7:10 am

Re: VU2 stereo VU buffer kit Build thread

Post by Supablake »

Hi,

I’ve just finished the assembly of the VU2 kit,
Meter lights work, meters move very slightly on turn on,
But,
No response to input signal.
I’m using balanced inputs driven for testing with a Neutrik Minirator.

+4 DB gives nothing, I’ve adjusted the trim pots and still nothing.

Any suggestions on where to start trouble shooting?

Also what sort of voltage would I expect to measure from the meter outputs ?

Thanks,

Blake

kings79
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Joined: Sun Mar 14, 2021 9:41 am
Location: Sydney

Re: VU2 stereo VU buffer kit Build thread

Post by kings79 »

I had that.

Diodes or no Diodes. That is the question....
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