Orion HCCA 250 Digital Reference resistor identification

[Chopperbuilder]

Does any know the value of the resistor that goes in the location I have circled in the attached photo? The photo's I have found are not clear enough to me 100% be sure of the color of the bands. Best I can tell from those photos the bands are: green, brown, black and gold... a 51 ohm 5%. I attached the best photo I could find.

 

[Perry Babin]

Does one end connect between the collectors of the NPN driver transistors and B+?

What do you measure across it?

This is a 2150. It's 68 ohms, like most other Orion amps of this time.

 

[Chopperbuilder]

One end connects to collector of the 2N6488 the other end to B+.


The resistor is missing on my board so I have no way to measure it.

 

[Perry Babin]

I would think it's a 68 ohm.

 

[Chopperbuilder]

Thank you for the photo Perry. A definite help! I'm sure you are right.

 

[Chopperbuilder]

While we are on the subject of this amp and most other Orion amps of that time...
Do you happen to know a part number for the switches and LED's I circled in the attached photo?

 

[Perry Babin]

I don't but the LEDs should be easy to find. The attached image is for the newer amps. I don't think they will work on your amp. Use a dial caliper and measure the spacing for the pins to find something that will fit the board.

 

[Chopperbuilder]

The LED's I picked up at the local electronics store didn't work. I'm guessing they require a higher voltage than what is in these amps.



I'll do that on the switches.

 

[Perry Babin]

The LEDs are polarity sensitive.

The LEDs are driven through a resistor from the 15v supply. As long as the forward voltage of the LED isn't more than about 10v (very rare for a small LED), they should work.

 

[Chopperbuilder]

I'm aware that they are polarity sensitive. I pulled some off a parts board I have and those worked fine. Unsure as to why the ones I bought don't work. I'll dig around and find some other ones.