I am planing on building a tubelabs simple se, and think it would be cool to incorporate a couple vu meters. I cant seem to find out how they are hooked up. Is it as simple as rectifying the input or output signal and feeding it into the meter? maybe adjusting it abit? or is it really complicated?
A real VU meter, as used on professional sound equipment, has a movement built to ballistic specifictions. It is intended to be used across a terminated 600 ohm source with a 3600 ohm series resistor. The rectifier is built in.
For all the other types on home or semi pro equipment, it's a 1 mA (or less) movement that may or may not have any special ballistics with a "suitable" series resistor. If your meter has no internal rectifier, build a small bridge with fast recovery diodes (to get the response) and connect it across the speaker output with a series resistor to make it read as needed. But remember it's just for looks since the varying speaker impedance will affect calibration.
For all the other types on home or semi pro equipment, it's a 1 mA (or less) movement that may or may not have any special ballistics with a "suitable" series resistor. If your meter has no internal rectifier, build a small bridge with fast recovery diodes (to get the response) and connect it across the speaker output with a series resistor to make it read as needed. But remember it's just for looks since the varying speaker impedance will affect calibration.
Trick VU meters
Weston:
Have you considered tube VU indicaters??
Quite possibly THE most spectacular looking meters on the planet...yes you will have to come up with some high voltage to run it as it is another tube....but the support circuitry is simple....do a search you will be astounded!
__________________________________Rick.........
Weston:
Have you considered tube VU indicaters??
Quite possibly THE most spectacular looking meters on the planet...yes you will have to come up with some high voltage to run it as it is another tube....but the support circuitry is simple....do a search you will be astounded!
__________________________________Rick.........
Attachments
I'm currently putting moving coil "VU" meters in an amp too.
(the end result intended to match cosmetically my revox stuff: "wannabe" pic here... Amp Plan
The problem with VU meters, or any linearly driven moving coil meter used as an output level device is that at normal listening levels, it barely reads at all. Most of it's scale covers only the really loud peaks.
So I'm creating a non-linear (somewhat like a logarithmic) driver that will give a scale that rather more related to loudness.
This puts full scale at 150W and the halfway point at around 10-15W - or even lower if it looks better when experimenting. (Halfway on a VU meter would only be at -6dB)
I'll post results as I create them.
(the end result intended to match cosmetically my revox stuff: "wannabe" pic here... Amp Plan
The problem with VU meters, or any linearly driven moving coil meter used as an output level device is that at normal listening levels, it barely reads at all. Most of it's scale covers only the really loud peaks.
So I'm creating a non-linear (somewhat like a logarithmic) driver that will give a scale that rather more related to loudness.
This puts full scale at 150W and the halfway point at around 10-15W - or even lower if it looks better when experimenting. (Halfway on a VU meter would only be at -6dB)
I'll post results as I create them.
Variac said:
It was from an EDN article written by a guy from Linear Technologies -- 60dB of dynamic range. I had some prototype boards burned...problem was that my pulse generator died and I just replaced it about 2 weeks ago with a beautiful vintage Genrad unit.
Here's a link to the article:
http://www.edn.com/article/CA6280030.html
For these archived articles EDN's server can be slow, so reload the webpage.
Apologies..
Tom...My apologies for posting your circuit without your permission/authorization. Your noting the origin of said circuit has me thinking of this subject worthy of a new thread. I myself have posted several circuits & diagrams here...& I consider it an honor for someone else to refer to them or post pictures of them. A commercial endeavor is quite another thing of course. My interpretation is one of ..If you don't want it to "appear" later , do not submit it into cyberspace.
Have you seen the movie some years ago called "Fat man, little boy"? , the story of the Manhatten Project.
The character playing Robert Oppenhiemer in the movie remarked that his scientists could not function at their best by compartmentalizing the various departments...that a free flow of information was vital thruout all members of the project.
In this day and age the free flow of information has created a collective intelligence unheard of in all of human history......and we here, right now, are a part of it.
___________________________________________Rick.........
Tom...My apologies for posting your circuit without your permission/authorization. Your noting the origin of said circuit has me thinking of this subject worthy of a new thread. I myself have posted several circuits & diagrams here...& I consider it an honor for someone else to refer to them or post pictures of them. A commercial endeavor is quite another thing of course. My interpretation is one of ..If you don't want it to "appear" later , do not submit it into cyberspace.
Have you seen the movie some years ago called "Fat man, little boy"? , the story of the Manhatten Project.
The character playing Robert Oppenhiemer in the movie remarked that his scientists could not function at their best by compartmentalizing the various departments...that a free flow of information was vital thruout all members of the project.
In this day and age the free flow of information has created a collective intelligence unheard of in all of human history......and we here, right now, are a part of it.
___________________________________________Rick.........
> By the way, half power is -3dB.
True, but on a VU meter, 50% deflection is -6dB.
A PPM may be very useful for seeing how much headroom is left, but it doesn't give a good indication of the subjective loudness of the music. Depends I guess on what one actually wants the meter to tell you, which one you pick.
Or have both - with a switch to select the response characteristic.
True, but on a VU meter, 50% deflection is -6dB.
A PPM may be very useful for seeing how much headroom is left, but it doesn't give a good indication of the subjective loudness of the music. Depends I guess on what one actually wants the meter to tell you, which one you pick.
Or have both - with a switch to select the response characteristic.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.