Anyone know what RAFI light bulb this is?

[salomonander]

Anyone know what kind of bulb this is? Comes from a neumann signal light. I need to know the appropriate form/socket. Its from RAFI.

Thanks a lot!

 

[Khron]

Is there a photo that didn't get attached (properly)?

 

[salomonander]

Thanks for reminding me about the missing picture

 

[Evertide]

RAFI F9

 

[salomonander]

Thanks a lot everide! In case you know where to get a led replacement, please let me know. Best

 

[Evertide]

Sorry, use the old fitting to make your own...

 

[jensenmann]

https://shop.griederbauteile.ch/product_info.php?currency=EUR&products_id=19462&language=en

 

[Tubetec]

Ive seen these types on Studer as well ,
its possible to remove the old bulb by heating the solder either side .

 

[salomonander]

Im kinda irritated that these are fitted in a Neumann light unit that is called b-f 24 and yet all the bulbs are 12v not 24v….

 

[zamproject]

Ive seen these types on Studer as well

Studer use T5.5 bulb, at least in the 70' 80' product I know (EAO switches)

its possible to remove the old bulb by heating the solder either side

Yes that also what I do, those bulb are expensive so now when one broke on my console, I separate the socket from the bulb and solder a led/resisor combo on the socket, it also relax the signaling PSU as a single bulb is rated at 40mA...

Once I get important failure rate in a relative short time, thinking all bulb get old, but then I accidentally notice (not affecting audio) my signalling rail get unregulated and at 30V...

 

[Evertide]

signalling rail get unregulated and at 30V...

Missing lamps / inserted LEDs makes the higher voltage , a side-affect of LEDs , making more lamps pop...

 

[zamproject]

Missing lamps / inserted LEDs makes the higher voltage , a side-affect of LEDs , making more lamps pop...

Nope... not in my use case, it append before I partially replace by LED, just the old uA723 that finally blow out...
The one of the three 24V regulator unit/card that handle the signalling rail (relay, light, etc...)

 

[salomonander]

One more question: if i decide to go with the replacement bulbs ill have to convert my 24v to 12v. Guess id just use some of these small traco or murata dc/dc converters. How would i dimension them in terms of power rating? Do i want to buy something with more power than needed, or something close to the 120mA that the bulb daws. What will give better efficiency? I would use one converter per bulb as each button (four in total) is in a separat module. Thanks

 

[zamproject]

120mA for just signalling light on a push button ? it's a lot of lost power...
Are you sure you can't trick this wit a led and 2k2 or 3k3 resistor on the 24V rail ?

Just to be clear, it's a small light signalling feedback on a panel for operator ? or a -big- light that everyone need to see on a studio like -on air- or -REC- ?

 

[salomonander]

well the 120mA version is the only one still available. These bulbs do not sit in a frontpanel but in a neumann signaling light. So it will be placed in the live room and needs to be clearly seen by everyone. I doubt that it will look good with leds that most likely have a sharp beam angle. Please correct me if im wrong. Is 120mA very bright? I lack the reference.

In case i do opt for leds… what power rating should i look for? I find them from 20mA up to 120mA.

 

[zamproject]

Ok now it's clear !!!
Forget what I say about small led, for this you need more power for sure, I just catch that the Rafi is way bigger than the T5.5 !
I was thinking of a push-button light...

Hard so say about lux/lumens, I don't find datasheet for this, but 1.4W filament should probably be ok to see the light tree when ON from anywhere in the room. IIRC pilot light typically used on tube amp is about 1W, if that help

If filament is not enough for you, have a look a led COB. Maybe you'll find something that fit in the tree ?