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I once had Q11 (869) on the amp board get "noisy" which caused it to go into protection. The 869 may test good when noisy. Like already mentioned, replace with that 1845.

Mark, Hopefully you can find time to watch the world series. Starts Friday. Bob

Congrats!

Hey Zeb, Have you heard anything more from the op?

I think this turntable needs to be completely set up before any other diagnosis is possible.

Load up on garlic?

R41 and R42 are a voltage divider which controls Q12, which then controls Q13. If these are turned on fully, there will probably be too much current draw through that 150 ohm resistor. This is what I see causing too much current draw through R44 (150 ohm). Any other opinnions!

Unless I'm seeing things, pin #2 should have -49 volts, you have -2 volts, which is the Emitter of Q13. We need to figure out why. Unless Zeb has another idea, I would pull/remove Q13 and test. Bob

For some reason too much current is flowing through R44. I would pull one leg of each component in that area and test. My guess is a component near is causing those transistors to be conducting too much causing one or both to go into saturation. Don't forget to check that zener. Also verify the...

Thoughts are with you.

I wrote this just out of curiosity. Sometimes funny things can happen "acoustically." To answer one person's question, I meant the speakers, not just a driver. One of these days when I have lots of ambition (moving heavy speakers takes ambition) I may give it a try just for the halibut.

Thanks for the responses guys. All my speakers are identical. I do realize the power would be distributed between the two. I never tried it but had wondered how the actual sound would be. Less power going to each speaker but double the amount of speakers so. Now we're talking acoustics...

Has anyone ever hooked up 2 speakers in series? If so, do you have an opinion on sound? In other words, two identical speakers on one channel wired in series vs just one. The reason I have this thought is, my speakers are 4 ohms, my amp is rated to use a minimum of 4 ohm speakers. With two...

Hi all, I was using my Sony wireless headphones on a communications radio, unplugged them, then I lost all audio. After turning the radio off and back on, same problem. Left the radio off for 5 minutes or so, then all is now fine. With the headphone transmitter powered up, I measure 23 mV on...

Glad you found it. Keep us posted on your rebuild.

You guys have probably said this but if there's audio at the headphone jack, the only possibility that I can see is in the switches and/or something in the switch circuit. Solder trace??? Open, shorted?

Some records have several grooves on the lead in. In other words they're closer together so a few more "turns" until the beginning of music. And there's a few that have very few grooves. They're spread far apart so the stylus "slides" down the raised part and slams into the music grooves as you...

I wrote about an experiment with idle current a couple years ago on a 1250. While adjusting the idle current, with a fan blowing toward the work bench, it would affect the idle current. I checked with the fan in different positions etc and the idle current changes followed the fan so to speak...

Watthour, Going through my posts I just noticed I never answered a question you asked. I know 2+ years ago. I did not recheck power supply voltages with the fan. Bob

Have you worked on this 1250 yet?

Your service manual gives voltage readings at several locations.

John, You can Google "resonant frequency calculator" You will get lots of different online calculators that will work for this. Better than math! A whole lot better! Bob

Mark, Could it be a ground problem? I'm not a pro but can think of a couple times in the past where improving grounds (such as a star washer under a screw) has cured strange issues. Bob

Mark, I replaced the two 750's that you suggested for the 992's and success!!! I got all adjustments set etc. All adjustments acted normal etc. Quiet as a mouse. Thank you!

Mark, Thank you. I did one more test to confirm. Scope pattern on the input to AWH-048 power amp board shows a clean signal going in, pin 4, which is the preamp to power amp connection on the back of 1250. Will pull the AWH-048 board and get busy on it. I wish I could get to the other...