Discussion in 'Pioneer Audio' started by xXColdShotXx, Dec 30, 2018.
rcs16, thanks for the part #'s. Will I have to modify the boards any like drill the holes out?
I am not sure, I made my holes 55 mil in the AWR-154 pcb re-design. You are correct they might be a very tight fit or need a drill mod to work. The part spec says to use 1.4mm finished hole. What are the hole sizes did they used?, I did not measure them on the original AWR-154, which I gave back to the owner, so I can not measure them now. If they are 25mil square posts then the hypotenuse is 35mil, so they might have gone as high as 40-45 mil ( 1-1.1mm)
The posts in the AWH-045 board I want to get rid of measure 1.16mm.
I checked all the solder joints with ones nearest to them on the same copper trace and they all seem fine. They tested right around 1Ω.
Anyone know what kind of reed relay is used on this AWH-045 board I found on the bay? The board looks like the same revision as the ones I'm working on at the moment.
I (think) finally found my problem. I used one 512-1N5247B diode, and (think) I'm supposed to use 2 512-1N5247B diodes in series to get the 34v 1w the board needs.
I was reading markthefixer's post here where he said this "D2 is a 34V 1W zener, and I use a series'd
pair of 17V 500mW zeners to replace, since a 34V 1W zener is an oddball"
I am glad I was reading that thread and realized my mistake. I am going to take the one out and add another to it in series and test it again.
It is a good thing to read all the threads a person can find about whatever it is a person is working on, never know you may find something in one of the threads that helps you figure something out.
I put 2 diodes in series and that fixed the mv issue on the right AWH-045 board.
Now I gotta rebuild the left AWH-045 board, put the 2 relays on the AWR-093 board and rebuild the AWM-081 board. I am getting around 29.5mv on both board from pin 13 and 26. When I test the speakers terminals in DC mV, left has around -28mv and right has -1 or -2mv.
And you are getting good at searching for answers.
Knowing the right search words goes a long way to getting the answers.
One key word: Audiokarma
zebulon1, you think this oscilloscope would be ok for working on vintage audio equipment?
I don't like it. Leader has some good equipment but this is too questionable and expensive.
Too far a drive for this scope?
It works and comes with a probe.
The seller might give you a quick lesson as well.
See what else he has? Maybe some nice door prizes
Still need a dummy load.
Anything I can use to get scratches off the Spec 2 faceplate and knobs? I used a magic eraser to clean it, but I'd like to get the scratches off if possible.
I don't know of any other site quite like AK. I've gotten a lot of info from this site that has helped me fix some stuff I'd never gotten fixed by local techs.
Just got the left AWH-045 rebuilt. I'll test it tomorrow and put the results on here afterwards.
Got the spec 2 playing with 30mv on both left and right AWH-045 VR1's. VR2's and VR3's on both boards are turned all the way down. It sounds good and it's not even adjusted for 4Ω/8Ω loads or input sensitivity. I still need to rebuild the meter board also, may do that later today/tonight.
Like I said the limiters if not messed with should be close. I should of made notes on the adjustments. A guy could just move them up out of the way and run at his own risk.
I guess you could look at the circuit and figure it out.
I changed all the VR1's, VR2's and VR3's on the AWH-045 boards., I just turned them all the way down except the VR1's on both boards. It sounds pretty damn good the way it is. I can imagine it'll sound even better once it's tuned to spec.
The limit pots/circuit protect the amp by knocking the output down when the amp reaches near its limit. It has nothing to do with dynamics.
If it/they were set to low the amp would clip early and cause distortion. That would cause some dynamic issues.
I haven't been getting crazy with it, just around 10/50 watt on the meters, if the meters are accurate. I haven't rebuilt the meter board yet.
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