[zachslc]

Has anyone installed level meters on the faceplate of an amp?  (ala vintage macintosh)  I have been poking around the net and I cannot find these for the audio DIYer, but surely they exist, no?  Any experience?  Thanks.

[Tinker]

Has anyone installed level meters on the faceplate of an amp?  (ala vintage macintosh)  I have been poking around the net and I cannot find these for the audio DIYer, but surely they exist, no?  Any experience?  Thanks.

In a word yes, and they look great, although I must confess my current AKSA setup does not have any.
The expensive part is the swinging-needle galvanic movement. I bought a pair a few years back and they were over $100 each. I imagine this is probably the price of precision. However, you can build a respectable one with a 50uA movement galvanomoter which should only cost about $20 from any electronics store. All you need then is a rectifier and driver circuit, and also an integrator if you want a "peak hold" function. Rod Elliot's circuit is most excellent for this and quite cheaps and easy to build
http://sound.westhost.com/project55.htm


You can also build an LED based one using one of the many driver chips, like this
http://home.maine.rr.com/randylinscott/oct98.htm
I've seen these chips with up to 15 outputs. These chips are about $5-$25 and can be got at local electronics stores like DSE and Jaycar. But you can save a lot of bother by buying one of the many kits available. Do a web search for "VU meter LED kit" etc and you will quickly find something.

To calibrate the thing is quite straightforward. You can use your PC to make a test CD with some sine tones of different volumes from 0dBFS to about -40dBFS in say 3dB steps and play this through your CD player.

At this risk of sounding like a motivational speaker: have fun with it.

Cheers,
   T.

[soitstarts]

Oh yeah, analog VU meters look nice.

http://www.flashstar.com.tw/showroom.html


 Found this LED kit as well

http://electronickits.com/kit/complete/ligh/ck1005.htm

Bit over my head, unfortunatly..

[Tinker]

Oh yeah, analog VU meters look nice.

http://www.flashstar.com.tw/showroom.html

Jaycar sells these flashstars for about $23. I've used them and they work well.

The LM3915 is used a lot in these LED-level applications and Farnell sell them for $10. However, for the price of the kit it's worth it for the boards and miscellany that comes with them. I think Jaycar used to have a silicon chip kit for about the $10 mark. You'd need two: one for each channel.

Cheers,
      T.

[PJ]

I don't know if this is of any help to you guys, but my DJ mixer (Allen & Heath) uses a LB1412 to drive a 12 LED array. I can send the schematic to anyone that is interested, but it looks similar to those already mentioned.

[Tinker]

I don't know if this is of any help to you guys, but my DJ mixer (Allen & Heath) uses a LB1412 to drive a 12 LED array. I can send the schematic to anyone that is interested, but it looks similar to those already mentioned.

Excellent choice! If you can find these, they are very cheap. They are probably a better choice than the 3915 I mentioned, although again, if you can buy a complete kit it saves a lot of hassle with a PCB and troubleshooting.

T.

[SamL]

SIFAM have some 'retro" style VU meters that is really nice but they are expensive too.  http://www.sifam.com/vuppm.lasso

[Tinker]

SIFAM have some 'retro" style VU meters that is really nice but they are expensive too.  http://www.sifam.com/vuppm.lasso

Radioparts also sell nice meters like this (although not as nice as the retro ones). If cost is no object these certainly look great. However, a lot of what you pay for is the precision of the meter "ballistics." Ifyou don't need BBC, AES, K-20 or one of the other standards then the flashstar meter with a home-brew dB scale is pretty good. It may also be possible to scrounge a retro meter from surplus or antique stores.

Another 2c worth.
T.