Search results

Crap, I was afraid of that. The unit I borrowed is from a place I work at and I`ve already had it too long. I just might buy one for this project and sell it afterwards.

If I receive my Q6s and Q10s early enough, and they do in fact remedy the bias issues, would it be time to install a vertical bank of outputs? What would the test procedure(s) look like?? I ask because I need to return the Variac and I would prefer to have it in this next round of testing.

Hold off on that Lee, I`m working on something. Let me get back to you. I already have an LED board, looks great. The 410s have been loaded for a while now.

I`m about to place an order for 2N5088s for Q6 from Digikey, is there anything else I should replace while I`m at it?

Offset is a respectable .09 and .04

That's with the 3403, does that mean they too are FOOBAR?

The lowest bias #`s are: Left R38 .421 Left R39 .430 Right R38 .352 Right R39 .478 Keep in mind this is with trimmers fully counter clockwise (1:00 position) where they originally were just past the halfway (7:00) position

No, original resistor was put back into place.

2N3403`s back in, voltages dropped a little, about 150mv all around, but still cant get below .400 volts anywhere except Right channel R38 which comes in at .352 with trimmer fully counter clockwise. :sad:

OK, I`ll put the 3403s in to see what happens. I don't recall the pinout though (here we go again:) )

Alright, so would that mean that the 2n3415 are the wrong devices? Should I put the original 2n3403s back in? BTW, thanks for your patience :)

TIME OUT :) We are spinning our wheels here. Can we agree on: 1. PCB wire color code, Red>Collector, Black>Base, Brown>Emitter 2. 2N3415 pin out. Looking at FLAT side, pins on the bottom =ECB 3. Looking at picture posted, the Left Channel is wired properly, the Right side is not.

Correct. Left channel is proper, yes?

Correct. See picture of Left channel

That will get me back to the original configuration (like the Left) with the swap taking place at the board rather than transistor..

The Red and Brown wires?

Does this qualify as Bias Hell? This is the kind of stuff I was afraid of.. Now what?

No shit? Take a look at my last post, I hope I didn't f@#ck something up :sad2:

Left channel as it was, Right channel changed. I started to measure upwards of 8volts real quick in that configuration (Right Channel) while bringing up the variac before I shut `er down.

What I did was trace the wire/board termination and came up with the above. Joe`s transistor pinout confirms the one I had on hand but his wire color to pin reverses E and B :confused2: