VU2 stereo VU buffer kit Build thread

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Re: VU2 stereo VU buffer kit Build thread

Postby Joe Malone » Sat Sep 27, 2014 9:14 am

steenhart wrote:Hi Joe,

on the coil there is a little mirror and it will reflect the light beam to the front.
Because there is no needle this is a very quick system fasten than every normal Vu-meter.
Normally you need the vintage TAB U70 amplifier.
Have lot of these meters so will try your board once.

regards Ronald


Ok I had a look at the U70 and it does the rectifying and attack and release setting and runs the meter on about 150v rail so looks like there is just a coil of wire in meter.

Does the light run separately? Does it have any voltage current of wattage markings on the lamp?

If you had a couple of photos inside would give me a clue and if you could measure the ohms between the 2 coil wires this would give me an idea on how to get these running on the VU buffer?
Joe :-)
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steenhart
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Re: VU2 stereo VU buffer kit Build thread

Postby steenhart » Tue Sep 30, 2014 5:42 am

Hi Joe

Here some pictures as you can see the meter is from 1959

https://www.dropbox.com/sh/12bhjwbwa7op ... rhfWa?dl=0


The resistance of the coil is around 95 ohm.
The lamp is a 12V 15Watt and is powered separate.


I have an other set brand unknow but there is the resistance 300 ohm.
https://www.dropbox.com/sh/jd1sdnjv9wc8 ... i2Xxa?dl=0


I like you Led vumeter also.

Can I order parts ? I'm in the Netherlands

Regrads Ronald

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Re: VU2 stereo VU buffer kit Build thread

Postby Joe Malone » Tue Sep 30, 2014 11:41 am

steenhart wrote:Hi Joe

Here some pictures as you can see the meter is from 1959

https://www.dropbox.com/sh/12bhjwbwa7op ... rhfWa?dl=0


The resistance of the coil is around 95 ohm.
The lamp is a 12V 15Watt and is powered separate.


I have an other set brand unknow but there is the resistance 300 ohm.
https://www.dropbox.com/sh/jd1sdnjv9wc8 ... i2Xxa?dl=0


I like you Led vumeter also.

Can I order parts ? I'm in the Netherlands

Regrads Ronald


OK the photo shows the meter movement is just a normal 1mA one so the VU Buffer will drive it fine.

You should be able to run the VU buffer kit or VU2 kit off the same 12v rail that will run the lamp to keep it simple

We ship anything on our website worldwide. We usually have at least one or two parcels a week going to Netherlands.
Joe :-)

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steenhart
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Re: VU2 stereo VU buffer kit Build thread

Postby steenhart » Tue Sep 30, 2014 4:46 pm

Thanks Joe,

Will make an order.

regards Ronald

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Re: VU2 stereo VU buffer kit Build thread

Postby steenhart » Wed Oct 08, 2014 10:32 pm

Hi Joe ,

Already received the package that's reaqlly quick.
Think it will not work because 0db = 1,445ma and -50db = 3,345ma is will see.
Else buy two normal Vu-meters.

Regards Ronald

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Re: VU2 stereo VU buffer kit Build thread

Postby Joe Malone » Thu Oct 09, 2014 10:20 am

steenhart wrote:Hi Joe ,

Already received the package that's reaqlly quick.
Think it will not work because 0db = 1,445ma and -50db = 3,345ma is will see.
Else buy two normal Vu-meters.

Regards Ronald


OK I see you think the meter drive is actually reversed?

Let me know if this is the case as there is probably a way around this by adding a dc bias resistor to pull the meter down to -50dB.

If your currents are current a 3.3k resistor in series with a 1k trim pot wired to +12vdc should allow you to set the meter to -50dB (actually best to set to the 0% marker) without the VU2 connected.

Then the VU2 output would be wired reversed to cancel this current so the meter would work like a normal meter.
Joe :-)

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thakava
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Re: VU2 stereo VU buffer kit Build thread

Postby thakava » Fri Mar 18, 2016 11:56 pm

Hi,

I got the kit, but am wondering re. using it with a vintage Weston Vu meter... it needs to be fed 6V for the lamps, not 12V.
What to do?

Thanks!
Tom

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Re: VU2 stereo VU buffer kit Build thread

Postby Joe Malone » Mon Mar 21, 2016 12:24 pm

thakava wrote:Hi,

I got the kit, but am wondering re. using it with a vintage Weston Vu meter... it needs to be fed 6V for the lamps, not 12V.
What to do?

Thanks!
Tom


HI Tom for 6v lamps that cannot be changed easily. Run the 2 x 6v lamps in series from 12v.

So 0v to one meter lamp and 12v to other meter lamp and connect the spare terminal on each meter together.

This makes one 12v lamp as long the 2 bulbs are the same mA.

Best to run these directly from the 12v power supply due to the high current and just cut off the extra wires on the 4 pin wired plugs that are not used
Joe :-)

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Re: VU2 stereo VU buffer kit Build thread

Postby thakava » Tue Apr 05, 2016 9:55 pm

Hi,


So I could just change the lamps to 12V, easy...
What mA and Watt should they be?

Thanks!

Tom

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Re: VU2 stereo VU buffer kit Build thread

Postby Joe Malone » Wed Apr 06, 2016 11:29 am

thakava wrote:Hi,


So I could just change the lamps to 12V, easy...
What mA and Watt should they be?

Thanks!

Tom


Yes you can but running 2 x 6v in series is fine as well if they are the same bulb type.

12v lamp mA or wattage depends on what 6v type is in there? The 12v should have the same wattage so will be half the current.

If you give me the details written on the 6v bulb base I can advice a 12v replacement.
Joe :-)

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thakava
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Re: VU2 stereo VU buffer kit Build thread

Postby thakava » Fri Apr 08, 2016 7:45 pm

Hi,

I won´t be usuing the said vu meters, so I designed a new panel with new lampholders behind the meters, they are just like the Fender amps, so 12V lamps are avail...
The question is what mA / watt is suitable for the bufferkit...


Best,
Tom

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Re: VU2 stereo VU buffer kit Build thread

Postby Joe Malone » Sun Apr 10, 2016 6:18 pm

thakava wrote:Hi,

I won´t be usuing the said vu meters, so I designed a new panel with new lampholders behind the meters, they are just like the Fender amps, so 12V lamps are avail...
The question is what mA / watt is suitable for the bufferkit...


Best,
Tom


The VU2 kit just passes the lamp power via the RLAMP resistor so if you fit 0ohm links the VU2 doesn't care what wattage you use.

We usually fit 10R for RLamp to give the lamps soft start for longer life. What ever the recommended bulbs are for the meters should be fine.
Joe :-)

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Re: VU2 stereo VU buffer kit Build thread

Postby Abszero » Sat Jul 02, 2016 12:05 pm

Hi,
I connected the unbalanced input to the speaker. The amp goes to max 15Vrms.
How do I decrease input sensitivity? Right now at lowest input sensitivity I measure -2dB for an input of about 5.6Vrms
Thanks,
Radu

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Re: VU2 stereo VU buffer kit Build thread

Postby Joe Malone » Mon Jul 04, 2016 12:17 pm

Abszero wrote:Hi,
I connected the unbalanced input to the speaker. The amp goes to max 15Vrms.
How do I decrease input sensitivity? Right now at lowest input sensitivity I measure -2dB for an input of about 5.6Vrms
Thanks,
Radu


Have you turned the 25 turn trim pot fully down as 15vrms should not be a problem?

Also if is often easier to link the VU buffer across the amp input as once calibrated it is no different to connecting to the amp output.

If running very high levels into the VU buffer then all that is needed is a series resistor from the amp output to the VU Buffer input like 100k etc
or wire 10k trim pot as a volume pot to the input of the VU Buffer.
Joe :-)

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Re: VU2 stereo VU buffer kit Build thread

Postby thakava » Wed Nov 02, 2016 4:57 am

Hi,

Does a 12V 500mA power source work?

Best,
Tom

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