In most if not many cases, the collector is the case. Since the emitter and collector should never read except in the case of a short, it should be easy to identify the emitter with an ohm meter set to x1000 or higher. IMHO. From given info one can establish the relationship between emitter and base and collector and base.
The substitute transistors did not bring the mixer to life.
Plan D is to exists without a mixer since I don't actually do any mix sessions.
However, the line input to the computer sound system throws a wrench into patch planning because there is no true line input... as a cheap way of cutting-corners this system only has a mic level input serving both the mic input and what they Gigabyte/Realtek) falsely label a line input, therefore I need to use pads (attenuators) when inputting line level, which was something I built onto the mixer so it would serve all purposes.
I'm trying to think of a quick fix to get this ship sailing again... not prepeared to declare a building project....
I'll sign off here. Thank you.
I can't leave it alone.
Why have I assumed the electrolytics are good in this Radio Shack Mixer? A shorted electrolytic would explain everything.
Now you know where the evening is going.
I was going to suggest that you check the caps for a short, but I figured you didn't need encouragement.
If it were me, I would have a cool adult drink. Perhaps a stogy..(I know, I am not politically, healthfully or whatever correct), and enjoy the evening poking at electronics before I had a rant about my inabilities to repair the device. The rant would possibly rival those of another member on this site...
Pabst Blue Ribbon and a Muriel cigar comes to mind. I like neither, but I heard a vintage commercial for each on my local station............................
Good luck, may you restore the electrons to the proper direction of flow!
Thank you for the pep talk craigF.
This mixer outage is a useful experience... we learn the value of a spare tire when one suddenly goes flat. "But it's never gone flat before!"
Ya, I'm looking at three electrolytics closest to the input power section.
First is the housewide search for the patch cables that fit the capacitor checker.
Ultimately this facility will be completely recoverable no matter what happens... unless the International Space Station falls out of the sky and flattens everything.
Maybe we can name our studios the International Earth Station.
I have one, maybe two. The one I remember best is either an old B/W or Heathkit. I I will need to dig and see if I can find it. That way it can collect dust in front of me before I hide it again from lack of use.
I must admit, I have had an urge of late to repair some old radios...the ones that glow in the dark.
The FCC has changed the regs for tower lighting, now shorter towers also need lighting, not sure how short. Certainly not 3-meter towers.
It would be neat though if our 3-meter outdoor tower could be a light-stick.
Well, the 3 capacitors checked out alright in circuit, except that a 220 uF read above 600 uF so I don't know what that means. It was in circuit so probably other components got swept up in the reading.
I wired up an XLR to unbalanced stereo-miniplug patch cord so I could input the mic directly to the computer, but the level is far too low.
Yet when I proof out the input jack with a line level signal I need to roll the level down just above cutoff because it's so loud. There's a lot of gain there, but not enough to amplify a microphone.
That other older mixer got tried... fresh battery, but no signal.
Maybe instead of a new mixer I need a decent sound card.
This morning we took a tour of the large audio vendors to shop for a simple 4-input microphone mixer at under $100.
There are many mixers out there but their features are either too little or too much for our taste.
Of course there are the room-filling mixers the size of small cars with 100 channels and EQ, etc.
There are small economical "line" mixers which require sparate mic preamps, which raises the cost significantly and junks up the small studio.
We'll keep looking on the liklihood that some small company offers a plain mixer like the old Radio Shack mixers were.
Yes, we visited Shure's website... the mixers they have now aren't the war-horses that their older designs were, way over-priced.
a used Shure Mixer from eBay would be too much of a risk.
Next on the agenda is a tour of modern sound cards which could replace the old fashioned hardware mixer.
Carl, you might look over at Amazon. I have perused some there at a range of prices. Seems like may of the Behringer products are USB devices now. That might be an option to look at for additional sound input strategies.
I did scroll Amazon and kept seeing "used, used, used, used, used".
All my broken equipment is also used.
Which does not guarantee that "new" will not break.
In the fever of this quest to become operational I have found a mixer that fills every wish (except the under $100 one)...
But turning the subject to "USB" mixers... at first I figured they simply drew power from the USB port, and maybe that's true. But now I'm thinking maybe they also provide a digital audio input through the USB? Gosh.
I am not an expert on these devices, nor anything for that matter. But, yes, some models are capable of being a Digital Input Device. They would be loaded like a soundcard. Beware, that processing sound and USB has its own set of flaws/weaknesses. But it is very common these days in the sound world. I am considering adding a very basic unit to my stable for voice audio processing.
Huh. Interesting about USB and audio.
The Direct Sound Audio Output (Winamp) has a choice between usual analog mini-plug output or USB Audio output.
And I meant to add this above regarding "Behringer"...
Some talk in these threads have claimed that Behringer audio gear is known for having poor caps and premature failures because of it.
The Behringer mixers look well designed but have more doo-dads than desired.
You can't be prejudiced on the social scene but it's ok to have judgements about equipment.
MINUTES LATER...
Here is a lovely PDF Sheet on the RDS MX4 Mixer
My justification for purchasing is building...
1.) Buy my time back so I can stop tackling this problem;
2.) Pay for the satisfaction of being satisfied with the product;
3.) Save the time of building one;
4.) Selling out on the vow to DIY.
The story about poor caps may have been true in the past. But I am running a very nice processor from the comapny of the same name on our LPFM. It sounds great and is well built.
I think the price point is enough to usually not worry about the caps. But, as WDCX said, it was more prevalent in the past. Also, keep in mind, we are a disposable society. Five years use is pushing the design limits these days for electronics. Most are 2-3 years for the end user, and even that is sketchy at times.
And, yet, I am from the school, where I drag things out of the closet every few years and expect it to work. My part 15 is using a Tascam M-06st that has literally been in the trunk of my old Mercedes for 10 years, and prior to that in a closet. All the lights work, and the pots aren't even scratchy..just stiff from not being used. I didn't even wipe the dust off of it..
Regardless, your decision is a good one. As an official endorser, I endorse your decision to make your decision.
Haven't placed an order yet... in fact I'm back inspecting the Radio Shack mixer with the notion that with a brain my size I should be able to spot whatever tiny part is bad.
It's become a kind of game in which I think the universe is out-foxing me and I need to think like a fox to come out on top.
With all the electronic equipment I have there should be a fast way to get a microphone into the computer without using a credit card.
I rarely feel stupid and this gives me an opportunity to see what it's like.