[bregez]

The LED is located behind a few tubes and is hard to see if the linestage is on a high shelf or is located in a cabinet.  I was wondering can I add two more LED's (total of three parallel) without any issues.   I machined some brass/rubber feet  ( 1 1/2" diameter ) for the linestage but was thinking about sandwiching in a 1/8" clear piece of clear acrylic and lighting it in the front to add some "bling".  If there is a possibility of burning out the traces on the board I will not do this.  Poty? Jim?
Thanks in advance.
Brad

[poty]

I don't think you burn something. There are two thing you should tune really:
- the R104 (lower to around 220-240 Ohm)
- the R313 (to save 6.3V for heating).

[hagtech]

You can't very well run LEDs in parallel.  But you can add another LED in series with a 1k resistor to the 6.3V heater supply.  That will work fine.  You can add a bunch that way to light up whatever glowing panel you want. 

jh

[poty]

You can't very well run LEDs in parallel.

In fact the feelings about the parallel-connected LEDs are from some "voltage stabilization" effect of LEDs. The reality shows that most of the modern LEDs have very wide voltage margins and the only effect that could be disappointing - some difference in brightness. The difference could be easily mitigated by connecting a resistor in serial with every LED (in this case - around 100 Ohm). For external LEDs it is easily doable.
For myself I'd use widely available LED-drivers (guaranteed current and as a result - brightness) and use not the circuit from the Clarinet, but just every voltage "indication" by its own circuit.

[bregez]

Thanks for the replys, I have decided to just use a single power indicator LED on the front panel using the heater supply.

Brad