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Studer A807 VU bulbs replacement Recorders, Players & Tape Machines
Old 1st March 2018
  #1
Gear Head
 

Studer A807 VU bulbs replacement

Hi

Could anyone please give me tips, or info on how to replace the VU bulbs on my Studer 1/4". (A807)

thanks
David
Old 1st March 2018
  #2
Lives for gear
 

Quote:
Originally Posted by david L View Post
Hi

Could anyone please give me tips, or info on how to replace the VU bulbs on my Studer 1/4". (A807)

thanks
David
The service manuals (and tons of other documents) are here, Studer Public FTP:
ftp://ftp.studer.ch/Public/

Or directly here:
A807 Mk I:
ftp://ftp.studer.ch/Public/Products/...alog/A807_MkI/

A807 Mk II:
ftp://ftp.studer.ch/Public/Products/...log/A807_MkII/

I'll download the manuals later.
Old 1st March 2018
  #3
Lives for gear
 

Could be a 6 V 30 mA T1 1/2 bulb (also written T1-1/2).

Studer Part #:
51.02.0144

10 pces (about USD 15 for 10 pieces):
51.02.0144-V

It's a common industrial pilot light bulb, don't remember if there are 6 V DC LED drop-in replacements.
In the serious industry since years pilot light bulbs are systematically replaced by LED equivalents where possible. Unfortunately there a lots of different bulbs/LEDs in use.

You should be able to find such bulbs everywhere.


As additional comment not applicable here as it's about VU-meter lighting, if LEDs are used to replace pilot lamps with colored lens (i.e. the transparent or translucent part giving the color) or with a clear lens and colored diffuser it can be useful to chose the right LED color (even if the original bulbs don't have any color). There are either recommendations issued by the manufacturers or general rules can be applied if no manufacturer data is available.
Old 1st March 2018
  #4
Gear Head
 

Thanks Schoeller

for those links. Heaps of interesting Studer info here.

I should have mentioned that I have the original manuals etc from when I purchased this machine new in 1990!

My problem is that I cant find clear instructions on how to get to the Bulbs.

Taking the front face plate off exposes the VUs, but I'm not sure how to proceed from here.

Any thoughts would be greatly appreciated.

David
Old 2nd March 2018
  #5
Lives for gear
 

I can't imagine it to be complicated. Studer means first class engineering, not some crappy Chinese-designed stuff with plastic clips which break when you try to remove a cover.

If there's nothing mentioned in the manuals (I didn't check as I don't know excactly which model and options you're referring to) it's simply because there's nothing special. As spare parts are listed, and especially bulbs which are known to fail at some point, it must be user-replaceable.

The Studer service manuals are very comprehensive, like for industrial equipment. If only SSL, Amek, A&H, D&R, Harrison, Neve, Mitsubishi and others, would made available such detailed manuals to freely download after some time.

If you can post a pic or the exact model information some could have a closer look at the service manuals. But as said, I really don't expect it to be difficult to replace these VU-meter bulbs.
Personally I'd replace them by T1-1/2 socketed single-chip LEDs, bulbs will fail agail after some time. Though check the voltage as 6 V DC is not a standard industrial control voltage.

BTW it's also written T1.5.
Old 3rd March 2018
  #6
Gear Head
 

Thanks again Schoeller for your input!

My model is the A807-2 TC VU HS (VU meters integrated into the control panel interface)

I've scoured the manuals looking for the procedure to get to the bulbs, but cant see anything.

Like you say, maybe its too obvious to mention!

Has anyone got any ideas?

David L
Old 3rd March 2018
  #7
Lives for gear
 

A807-2 TC VU

STUDER A807 MKII Operating and Service Instructions
Manual Order no.: 10.27.1421 (Ed. 0697)
PDF manual (588 pages): A807_MkII_Op_Serv_E.pdf (freely downloadable at the Studer FTP, see some post above).

Can you please check if the manual Order # and edition correspond as there are several ones available to download.

Other manuals (will check them later):
Operating instruction manual MKII: 10.27.3071
Operating and service instruction manual MKII: 10.27.1421

"VU-meter with input level potentiometer and channel control as well as output level potentiometer built into the operator panel" (see page E1/6)

Instructions to replace VU-meter illumination lamp:
Page E3/13 (PDF page 133/588): Cover removal
Page E3/16 (PDF page 136/588): VU-meter illumination lamp replacement

I don't expect it to be difficult to perform, Studer's designs are well thought. Just make sure to respect ESD (electrostatic discharge safety rules) and of course disconnect mains cable. ESD is pointless for the lamp bulbs but there are PCB boards and also LEDs are ESD sensitive (if you replace the bulbs by LEDs, if so replace all VU-meter bulbs even if intact but as said, IIRC the VU-meter illumination lamp voltage is not common for T1.5 single-chip LED drop-in replacement parts.

I wonder how Studer studio consoles would have been, unfortunately they focused on other domains. As I was a kid a relative of mine had a Studer Revox HiFi reel-to-reel recorder, don't remember which model but it was very well built.

HTH
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