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2226B Stereo Lamp

LBPete

LBPete

Rolling Along
Subscriber
I need to replace the stereo indicator lamp in my 2226B. It is a bulb with wires attached not a bi-pin. I don't see a value on the bulb housing and I measure 9.6 volts supplied to it. That's kind of an odd value. An 8v bulb will run hot and a 12v bulb would be dim. Does anyone know the specs for the original bulb?

- Pete
 
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There 'may' be a dropping resistor in series with the lamp that lowers the voltage once current is flowing to accomodate a 8V lamp...speculation, since I don't have a manual for that one.
 
EchoWars said:
There 'may' be a dropping resistor in series with the lamp that lowers the voltage once current is flowing to accomodate a 8V lamp...speculation, since I don't have a manual for that one.
Click to expand...
That's probably it. I didn't think about loading it down. I had a bulb on hand that works perfectly.

- Pete
 
I checked in my 2226B SM and nothing, nada
V001
Part number IN10080340
Description: Lamp, Stereo indi.:thumbsdn:

I aslo checked in the SM of my 2600, there the stereo lamp is rated at 8v 50ma.

In a 2325 the value is 12V 30ma

In the tuner 21xx serie, the lamp is rated at 12v 30ma

The 12v 30ma is a common valule for the Marantz tuner or receiver with a single lamp for the Stereo indicator.

Tony
 
marantzbe said:
I checked in my 2226B SM and nothing, nada
V001
Part number IN10080340
Description: Lamp, Stereo indi.:thumbsdn:

Tony
Click to expand...
That number is on my box of 8v/60ma with metal collar and red & white wire leads, that's also the lamp in my x-ref for that model, Dave. :yes:

marantz_lamps_03.jpg
 
Thanks Dave, I got it handled. The original did have a metal collar and red and white pigtails like the one in your picture.

- Pete
 
LBPete said:
Thanks Dave, I got it handled. The original did have a metal collar and red and white pigtails like the one in your picture.

- Pete
Click to expand...
Pete, Thanks for confirming that's the correct lamps, Dave. :yes:
 
The stereo beacon lamps obviously can be trouble, but I have taken to replacing them with a white LED and dropper resistor due to the fact 9 out of ten are running straight from the MPX IC with no buffer transistors and these IC's are unobtania now when they blow. I have also found that even a 40mA correct voltage bulb can take out an old mpx chip, particularly if the beacon lamp has been out for a while. My theory is this: sometimes when the old stereo beacon bulb died, the filament either broke or fell onto the support guy wires in the bulb itself creating a very low resistance for the mpx chip and actually taking out the beacon driver within the mpx chip. You replace it and it either works for a short time or doesn't work at all. Not only that, the mpx chip often stays in mono and doesn't trip into stereo anymore. The open collector outputs of those mpx chips were marginal at best and only a few manufacuters actually used a buffer transistor as they should have. Take care.:thmbsp: :thmbsp:
 
stereo LED

restorer-john said:
...I have taken to replacing them with a white LED and dropper resistor...
Click to expand...

I like the idea, I would like to apply it to my 2226B. What size LED do you use, and what light intensity will be comparable to the original 8v 60mA wire bulb? Is the viewing angle of any importance? Or should I look for a dull white LED?

Thanks, Michiel
 
John,
This is the ubiquitous HA1156 integrated circuit, correct? I've been unable to locate any data on the permissible lamp driver output current. Would you happen to know a safe level?

Thanks
Tom

restorer-john said:
The stereo beacon lamps obviously can be trouble, but I have taken to replacing them with a white LED and dropper resistor due to the fact 9 out of ten are running straight from the MPX IC with no buffer transistors and these IC's are unobtania now when they blow. I have also found that even a 40mA correct voltage bulb can take out an old mpx chip, particularly if the beacon lamp has been out for a while. My theory is this: sometimes when the old stereo beacon bulb died, the filament either broke or fell onto the support guy wires in the bulb itself creating a very low resistance for the mpx chip and actually taking out the beacon driver within the mpx chip. You replace it and it either works for a short time or doesn't work at all. Not only that, the mpx chip often stays in mono and doesn't trip into stereo anymore. The open collector outputs of those mpx chips were marginal at best and only a few manufacuters actually used a buffer transistor as they should have. Take care.:thmbsp: :thmbsp:
Click to expand...
 
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