Steve48 Posted November 6, 2014 Share Posted November 6, 2014 Hi Guys, Has anyone ever replaced the VU bulb on a Ashdown MAG 300 head. Mine stopped working a few weeks back and I want to sell the amp but would like to get the VU backlight working again before I advertise it. If so is it easy enough to do and what bulb do I require. Thanks in advance. Quote Link to comment Share on other sites More sharing options...
thefyst Posted November 6, 2014 Share Posted November 6, 2014 as far as i know they're relatively unique. will probably have to get one from Ashdown...they will probably tell you how to change it too! Quote Link to comment Share on other sites More sharing options...
remibass Posted February 19, 2017 Share Posted February 19, 2017 Hi, mine has also ffailed. I decided to replace the bulb par 3 leds. To access to the bulb, disconnect the mains, open the Mag 300 head, take care to the radiators where ther some high residual voltage. To acces to the Vu meter, you have to remove all rotative knobs, remove all screws for the potienmeters and the jack plugs, and to remove the 2 small screws on the DI plug. Then it is possible to remove the front panel Quote Link to comment Share on other sites More sharing options...
remibass Posted February 19, 2017 Share Posted February 19, 2017 Following - Then it is possible to remove the front panel PCB from the front panel. I had to push on the Vu meter glass and to move it with a screwdriver, because the vu meter is attached via double face tape both on the PCB and on the front panel. Once the PCB is removed, the bulb can be seen on the PCB, behind the Vu meter. The bulb is horizontal, soldered on the PCB and is not fixed on the Vu meter. Anyhow, it seems (very) difficult to replace the bulb without removing the Vumeter from the PCB. I removed the Wumeter ( unsoldering it, it was soldered by 2 large plots of solder). Then I removed the bulb. The bulb is supplied by something like 15,5 V DC ( I measured on mine 15,7 V DC). I replaced the original by 3 leds in serial. Each Led receive 18 mA, through 3 resistors 180 Ohms in serial. I have build a small PCB for the 3 leds and the resistors. The PCB have been fitted beteween the Vu meter and the main PCB, and I have added 2 plots of mastic to avoid vibration or displacement. Its works now, with the same color (amber) as original. Nevertheless, I was not having blue or white leds, which I sgould have prefered. It took me around 3 hours to do it ( including test and measurement of leds that were in my spares box, and the building of the small PCB, Good luck, Remi The Leds lights the Vu meter by transparency, but it still possible to distinguish 3 spots of light . Quote Link to comment Share on other sites More sharing options...
MoonBassAlpha Posted February 22, 2017 Share Posted February 22, 2017 I'm amazed Ashdown don't use LEDs these days. Incandescent bulbs are sooo last century. Then again, V.U. meters? Quote Link to comment Share on other sites More sharing options...
Bassman Rich Posted March 20, 2017 Share Posted March 20, 2017 When mine went, all Ashdown wanted was the money to cover an envelope and the postage, they sent me one out for a few pence (well 3 or 4 quid I think). Its pretty easy to do, just phone them up or look on their website. Quote Link to comment Share on other sites More sharing options...
LewisK1975 Posted March 29, 2017 Share Posted March 29, 2017 Ashdown sell em for a quid through their website: http://ashdownmusic.com/shop/product.php?id=2515 There's a dropdown box on that page where you can select which VU meter you want to buy, at the bottom of the list you'll see the bulb. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.