| jackinnj |
I am thinking to implement this VU Amplifier circuit, have PCB's made -- L1 and C2 adjust the Attack and Delay (and can be changed as needed.) The circuit is from a design by Jon Munson in EDN in 2005, and I have simmed it with good results. Probably around $5 or $6 for a 2-channel board using through-hole devices:
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| Tony |
| will that include the meter movements too? i am interested.:D |
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| rpapps |
| quote: | Originally posted by Tony
will that include the meter movements too? i am interested.:D |
2 channel Board + components + meter movement for $6.
You are without doubt an optimist.
:)
Cheers
Rob |
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| Tony |
| quote: | Originally posted by rpapps
2 channel Board + components + meter movement for $6.
You are certainly an optimist.
:)
Cheers
Rob |
that's not what i have in mind, i know that meter movements cost more than $6, i was wondering if we can have the meter movement also together with the boards...i hope i made mysself clear this time...
:D |
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| jackinnj |
| quote: | Originally posted by rpapps
2 channel Board + components + meter movement for $6.
You are without doubt an optimist.
:)
Cheers
Rob |
As we say in the States "Read the prospectus carefully before you invest". I typed PCB.
At any rate, I have sold many hundreds of amplifier PCB's -- if I can panelize the boards and cut them here in my shop the price will be lower.
I also thinking of adding a simple logarithmic converter so that you don't have to screw around with the meter face. |
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| ChrioN |
| This could definitely be interresting. I could sure need a bunch |
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| Dominick22 |
| I am interested. |
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| azerty34 |
| I'm interested too |
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| Flodstroem |
Hello jackinnj :wave:
Maybe you will find further informations to your VU-project here:
http://www.ethanwiner.com/meters.html
Also, one of the finest VU-meter companies are the Sifam. Home-site here:
http://www.sifam.com/vuppm.lasso (I have bought VU´s from them)
If you could make PCBs I will order at least 4-6 boards from you
Regards :cool: |
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| tommak |
I'm also interested!
Does anyone know if this will work well with the Corning pH meter Model 7 meters you can buy on eBay?
I searched the EDN site and found Jon Munson's article on the above design. ( Then I saw that jackinnj also linked to this in another thread. )
http://www.edn.com/contents/images/6280030.pdf
Thanks,
Tom |
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| Ed Lafontaine |
I'm interested.
Jack, will you have any of the parts available? |
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| jackinnj |
Ed -- I have a bunch of Nat Semi SMT "rail-rail" opamps -- these should work very well -- but I would imagine that most folks are most comfortable working with "through-hole" devices. For the rectifier to work properly you really need rail-rail devices.
What I will do is configure two boards -- one for surface mount, the other for through-hole devices. This isn't that difficult since my software will change them on the fly.
Jack |
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| ChrioN |
Cool!
Keep us updated :) |
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| samsagaz |
| yes, im interested too |
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| audio-kraut |
| count me in as well. |
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| PhrazeMaster |
Hi, I read the linked article and I'm interested in a board too if possible, it sounds great!
mike |
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| tommak |
Dear "jackinnj",
Are you still planning to build these boards and offer them to diyAudio members? If so, what time frame were you expecting this might happen?
In comparing your schematic in Post #1 above to the schematic in the article, the "bottom" of diode D1 and capacitor C6 from your schematic are connected directly to the negative input of the opamp in the article.
Regards,
Tom |
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| jackinnj |
OK -- I made the correction (appears in first post) -- here's a recent purchase on EBay -- was listed in the wrong category -- it's a attenuator with a pair of VU Meters:
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| cowanrg |
im very interested. im still trying to find a pair of meters and circuits for my cases.
what kind of time frame are we looking at? |
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| Nordic |
| I'd be interested if you can help me with a method to test VU meter rateings... I have a few sets pirated from miscelaneous pieces of amps and tapedecks... |
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| jackinnj |
| quote: | Originally posted by tommak
I'm also interested!
Does anyone know if this will work well with the Corning pH meter Model 7 meters you can buy on eBay?
I searched the EDN site and found Jon Munson's article on the above design. ( Then I saw that jackinnj also linked to this in another thread. )
http://www.edn.com/contents/images/6280030.pdf
Thanks,
Tom |
I have a couple of those Corning meters -- they use tubes -- they are exactly the type I used when doing analytical and quantitative chemistry over 30 years ago. |
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| jackinnj |
| quote: | Originally posted by Nordic
I'd be interested if you can help me with a method to test VU meter rateings... I have a few sets pirated from miscelaneous pieces of amps and tapedecks... |
The meter movement is driven by the current flowing in its coil -- you have to determine the amount of current which drives the meter to full scale -- as shown in the attached, choose a potentiometer whose value is twice that necessary to cause the meter to deflect to full scale. In the case of a 50uA meter and 1.5V battery a 100k potentiometer will work. The shunt potentiometer should be about 1k -- this method is described in the ARRL handbook. |
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| Nordic |
| ah ok, small voltage + ohms law and observe swing on needle.... it is a DC voltage though that I need to apply? |
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| jackinnj |
ok, here's a 3D image of what the board looks like -- two channels -- 5" x 2" -- I am going to make a proto to make sure that they work. You can make your own 10mH inductors or purchase from Mouser:
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| Flodstroem |
Only one comment to your layout: why do you have so much space/air round components ? This board could be halves the size to what it looks to be now by placing the on board components tight and closer together. This will make the board more flexible to use in amps where there is not much space to fit a board including one VU-meter (mono block amp), or worth, one board and two VU-meters (stereo amp). If using this board in a pre-amp or in a mixer, ok, there is usually space enough for this, but seldom in a power amp due to the "big" VU-meters you had to mount if visibility should be good enough. Also there should be a power supply to feed this VU-board, an extra placing issue.
Just some thoughts
Otherwise it looks great.
Regards :cool: |
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| jackinnj |
If I had "Autoplace" I could probably fit it into 3/4's the space -- bur my poor addled brain can't take the strain.
I like to site the mounting holes at least 0.200 inch from the periphery and try my best to keep everything which is defined by their centers into a tight rectangle. I allow for R0207R10 resistors which are a little big for a tiny project. My fingers aren't quite as nimble as they used to be, but I agree -- it could be perhaps 25% smaller.
Jack |
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| Nordic |
Come on Jack, you know you want to make is smaller... small is the new black.
So how long before we can start ordering? |
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| eapavant |
| I am interested. Looks good. |
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| bushroot |
| Interested in a board as well. |
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| Cobra2 |
I am interested in a couple...maybe more...
Arne K |
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| peterpan188 |
I am interested for some.
Peter |
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| Nordic |
Jack, I need to borrow your brain...
This circuit is for a 3500ohm movement, mine is only 650 ohm.
The instructions says to change R6, 7 & 8. to accommodate other meter resistances. I am at a total loss. My meter moves but is only deflecting the needle a tiny bit, (about one numbered unit) on the scale.
Can you offer guidance my learned solderer. |
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| sklimek |
Hi, Interested in a board as well.
Stan |
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| Minion |
I might be off bace here but wouldn"t a LED VU meter be cheaper and easier to implement??
There are quite a few designs available for a LED VU meter and there are many IC"s available for controlling The LED"s based on the DB of the input signal....
i know there is a Project and Boards availabel at the Prodigy pro forum and the Boards were only $4 and the Parts weren"t much more expensive......
Cheers |
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| acenovelty |
| But they are not nearly so cool as these. |
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| Minion |
I guess if your Going for the Retro Look then the standard Analogue meters are the way to go but i personally like LED VU meters better as you can arrange the LED"s in cool Patterns to say Spell something or make a Cool design.....
Cheers |
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| acenovelty |
Then you should buy the other meter driver boards. Folks that want moving needle meters are not much impressed with dancing LEDs.
Might be swimming against the tide on this thread. |
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| jackinnj |
| quote: | Originally posted by Minion
I guess if your Going for the Retro Look then the standard Analogue meters are the way to go but i personally like LED VU meters better as you can arrange the LED"s in cool Patterns to say Spell something or make a Cool design.....
Cheers |
I wouldn't dissuade you from using the LED Drivers from National -- the schematic I described (with full credit to the folks at LinearTech who thought it up) provides something close to the right attack and delay times with pretty good dynamic range -- see the original EDN article.
I haved been really jammed up with my real job so haven't been able to get the prototypes done. |
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| AR2 |
Hello Jackinnj,
great idea for the project. I will be interested as well in getting a few boards. I hope they are going to be available soon.
I would like to know what type of meters we should be looking for? Volt meters, amp meters or specificly VU meters? I made some calls and learned that VU meters are built differently from lets say voltmeter or amp meter in the terms of ballistic - the way needle moves and speed. Logically VU meters would be best, but I would conclude many people will try to use what they have or eBay where not soo many VU meters are available, so it will be very helpfull to know what to look for. If voltmeter or amp meter is OK what maximum Voltage or Amps they should be made for?
I also would like to know if it is possible to convert or use your boards as a Wattmeter, as I am planning in using it on the amp. In my mind VU meter and peak meter are much more usefull in the preamp area so in the amp wattmeter would be great.
Here is a good resource for new meters in US:
http://www.meterdistributor.com/index.htm
I spoke with tech support and they are great to deal with.
I am lookingg for BIG meter, something like 6" wide, so all that I am finding are meters for hunreds of Volts or Amps. I would appreciate your guidance on this subject very much.
Thank you
AR2 |
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| AR2 |
| Here is the meter for serious analog meter lovers. |
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| Nordic |
| If I understood correctly that circuit would use a 10V meter.... as it could provide an improved scale compared to a UV meter. |
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| sts9fan |
| i would like some of these as well |
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| davidlzimmer |
I much prefer an analog meter as oppossed to a digital or LED indicator. Mainly becuase of the natural damping.
But, I'm old and slow. :D |
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| AR2 |
I hope Jackinnj is out of his jam at work. Jack I sent you email with some questions, and I do not know if you have received it.
I decided to go ahead and order parts so I could do assembly point to point. I will order smaller meter just for testing and than if it works well I will go for big one.
In submitted article, it is mentioned that this volume meter is meant to be used with typical 100 W amp. What if amp is much bigger? Do we need to add some voltage divider or that could be done through the circuit, or meter should be changed for higher voltage.
Does anyone knows what replacement diodes to use instead of ones in schematics:
D1 MBR0520 and D2 CMPD6263S? These are surface mount and I would like to substitute them for through hole for point to point wiring.
This would be a really good project for surface mount devices, as the size of board could be much smaller, and there are really not too many parts.
AR2 |
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| AR2 |
| Sorry disregard my question on various amp power. Jackinnj explained it on first page. :cannotbe: |
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| AR2 |
Unfortunately not too much activity in this tread.
I completed this circuit by doing point to point wireing on small proto board. I got small 10V AC Voltmeter just for testing purpose. The circuit works well, but I am not sure that meter is the right choice. I still have to calibrate meter for the max and min movement as explained earlier by Jacinnj. The movement is what I am not too happy about. Niedle moves rapidly, and is very sensitive (easily reaches max) but has a lot of inertion. That results in the niedle rocking left and rigt with no signal until it setles. I do not know if the problem is that voltmeters are not made to have a fast movenmet and maybe I would need VU meter to test.
If anyone else made a test please post your experience, partcularly on meter movement.
Thank you
AR2 |
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| jackinnj |
| quote: | Originally posted by AR2
Niedle moves rapidly, and is very sensitive (easily reaches max) but has a lot of inertion. That results in the niedle rocking left and rigt with no signal until it setles. AR2 |
Are you using the value of inductor specified.
The logjam at work is now managed.
Jack |
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| jackinnj |
ok, I am sending out for some prototypes -- i.e. without silkscreen to make sure that they work as planned -- the footprint is 4" x 2" ( x y ) -- the dual comparator is an LM319 -- the final will have silkscreen.
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| AR2 |
| Great news! Looking forward. |
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| jackinnj |
this is one of the protos I got back -- i think that it can be dimensioned to about 3 inches on the X-Axis -- I am still not done checking them out -- apologies to Linear Tech -- but I used an LM319 dual comparator for two channels. Two of the linear devices would fit in about the same space.
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| sklimek |
I designed my first two sided board from the schematic by Jon Munson and Jackinni at the beginning of this thread.
I was hoping that someone who is familiar with Eagle could give it a look-over for accuracy, clearances, etc., also a little help on setting up the Gerber files as well before I send it out for a prototype. I pretty much followed the components as illustrated at the beginning of this thread and created a new package/device for the IHSM-7832 SMD inductor. The MBR0520 (D3 and D4) diodes are a sod-123 package zener; I just didn’t want to design a new component for this (borrowed the correct config. from the library) and the CPMD6263S (which reads as a BAS 40-04) is correct as well. The board measures 4” X 3 1/4”.
Here is the .brd file and some pics…
Stan |
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| sklimek |
| Eagle .brd file... |
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| sklimek |
Knock, knock, I slimed the board down to the best of my abilities. It now measures 2 5/8" X 3 1/4". I've checked and dbl checked, guess I'll send it out to see if it can fly. Here is new pic and can send .brd if anyone is interested.
Stan |
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| ppcblaster |
| quote: | Originally posted by jackinnj
ok, I am sending out for some prototypes -- i.e. without silkscreen to make sure that they work as planned -- the footprint is 4" x 2" ( x y ) -- the dual comparator is an LM319 -- the final will have silkscreen.
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I am also interested
With blue leds |
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| jackinnj |
well, I don't know if you will be happy with LED's -- the capacitor C6 has to discharge -- the discharge time depends upon the "ohms per volt" of the meter -- here's what the charge/discharge time looks like with a 1k resistor on C6 -- this is simmed -- i am havin a little difficulty getting the real protos of the boards to work:
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| ppcblaster |
I would like to have an affordable pair of the old meter faces
and needle with a dim blue LED. for my BrianGT stereo amp. |
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| ckwong99 |
Hi Jackinnj
Not sure this VU-Meter cct. PCB still available or not ?
If yes , i want to order the full set (PCB+components) ship to HongKong. So what will be the price should be charged.
CK |
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| jackinnj |
for a meter face you can redimension the face plate using a program like power point, and it is quite easy to slip in a string of blue surface mount leds.
i am sorry that i can't supply a kit of parts -- but everything should be readily available almost anywhere on the planet. |
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| ppcblaster |
| quote: | Originally posted by jackinnj
for a meter face you can redimension the face plate using a program like power point, and it is quite easy to slip in a string of blue surface mount leds.
i am sorry that i can't supply a kit of parts -- but everything should be readily available almost anywhere on the planet. |
What exactly does this board do? confused. |
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| jackinnj |
| if you go back to the first post or so -- the board implements the attack and decay specified for a VU meter -- (but remember that the original standards were abandoned when modern recording equipment pushed the telco standards out of the way). It has broader dynamic range due to the use of two rail to rail opamps set up as a precision rectifier. The original circuit used a Linear Tech comparator -- but these might be a bit inconvenient for some folks to obtain so I used a garden variety bipolar unit. The circuit appeared in EDN a year ago or so, and I thought I would just make some boards for my own use and knock down the unit cost by doing a GB, offering them out at cost. |
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| ckwong99 |
Hi Jackinnj,
Can you give me advice about the substitution of LT1011 and LT1469 ?
CK |
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| jackinnj |
In deference to Linear Tech who came up with the idea I showed their parts in the schematic.
I've used another dual comparator -- the LM339 -- the LT1011 is a single, bipolar comparator -- both can sense near ground potential.
I have also used other opamps -- but the LT1469 is very fast, low noise and very acurate (16 bits).
Remember that the point of the device is to change the attack and decay of a VU meter circuit in order to be useful. |
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| markgall |
Hello,
Are PCB's available for purchase yet or are you still in the prototype stage?
Mark |
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| ckwong99 |
| THrough a month of work , just finish a board (single-sided PCB replace with through hole 8-pin OPAMP sockets) use same components like an original introduced. However, my result is out of my thinking that is not work properly. So here seek your comment about this circuit whether anyone can succeed on building that with a good performance result ? |
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| sklimek |
| I finally got this finished but haven't the time yet to test it yet. I pretty much followed the posted schematic and parts. |
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| ckwong99 |
Hi Sklimek,
It's very wonderful thing but if it had passed your test will be fantastic.
Can you share the PCB layout with me ?
Or, if you have a more, how about sell one for me.
I have a pair of lager meter from Japan , not sure who have interest ?
CK |
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| sklimek |
Hi CK, I did a quick hook up to the output of a of a CD player and and watched very small meter movement, the output was only .5 volt though. I need to wire it up correctly to see if it works correctly, I also need to figure out what my meters are and how to calibrate it as well. I'll try to get to it this later this week.
I made the circuit w/ Eagle, here is a revised .sch and board layout, keep us posted, thanks - Stan |
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| sklimek |
Screenshot of the schematic, let me know if you can use the eagle files.
Stan |
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| ckwong99 |
The passage claimed the first stage gain factors is 6. In general speaking CD player can deliver 0.5-1v rms output for this circuit. So that it can be operated in a larger scale.
http://www.edn.com/contents/images/6280030.pdf
From the passage said IC2 which monitors the difference between the incoming signal's amplitude and the peak-detected output. What is the meaning to this statement ? What the function of the IC2 ?
If you can find what the problem of your case, please update to me. Later, I will try to make one of this prototype.
SCH & PCB I am using Protel SE 99 , it really a good thing but eagle i can try. Can you post the PCB brd layout file here ? |
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| sklimek |
| quote: | Originally posted by ckwong99
The passage claimed the first stage gain factors is 6. In general speaking CD player can deliver 0.5-1v rms output for this circuit. So that it can be operated in a larger scale.
http://www.edn.com/contents/images/6280030.pdf
From the passage said IC2 which monitors the difference between the incoming signal's amplitude and the peak-detected output. What is the meaning to this statement ? What the function of the IC2 ?
If you can find what the problem of your case, please update to me. Later, I will try to make one of this prototype.
SCH & PCB I am using Protel SE 99 , it really a good thing but eagle i can try. Can you post the PCB brd layout file here ? |
Here's the Eagle .brd file. |
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| comicrcc |
I am interested in your VU meter board also.
:cannotbe: |
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