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I ran the audio to my Audiosource EQ, then to the SA-R430 Receiver and it worked.

With my Technics SA-GX505 and a little $30 Signstek Mini USB DAC that work great together. I recently picked up a SA-R430 slightly older generation Receiver, and when i hook up the DAC I get a low feeback hum, no sound at all. Using the CD input that works with a CD changer fine. I would...

Thanks guys, the speakers sound beautiful. I'm going to just leave it alone.

Hi, I restored a pair of AT-10's and I see the crossovers have the yellow plastic Film capacitors. The capacitors upon measuring were well within tolerance and close to spec. When listening, the tweeter and mid speaker controls don't really seem to do much. There is not much difference. Is...

I decided to buy the service manual.... turns out its a 27V zener Red / purple markings. haha.

I picked up a early 90's SA-R530 receiver for personal use, These and other units of this era of Technics tend to heat up a lot burn out the joints and overheat components, lack of cooling etc, the internal fans not coming on soon enough. Anyways... I found a bad diode next to the driver...

I don't think it will be an issue at all. Its pretty typical to use slightly higher farad capacitors in place of the old ones, partly to get the correct physical size. I have replaced the main caps with larger ratings and had no issues. Maybe someone else can chime in with their thoughts.

I just recently fully restored a 8080DB, it took forever and ever and ever to completely overhaul it. Did a full recap, transistors, DB board re-flowed / pinned, modified the Power supply board with a large heatsink'd resistor, Full LED upgrade, and re vinyled the bonnet cover. It was...

Awesome! The 5000X is a beautiful sounding receiver. I don't know about most people, but I only use Fairchild / onsemi transistors unless I absolutely can't.

From what I remember I had about 83V to 84V both channels and they both about 42V on my 5000X. You're measuring the collector of TR808 and TR810 and ground to get the half voltage? Definitely a component you changed on both boards, if both channels are not half. The easy fix might be to...

The left channel is getting 42V and the right is getting 38V?

Replacing transistors with modern ones can cause issues with DC offset values from my little experience. I have ran into this problem with a Marantz before. I have also rebuilt a 5000X eariler this year and I used the MJE15032 / 15033 combo for TR804/805. Did not have any issues with the half...

Ok I figured it out! I had to have the volume from 80 to 100% to see the clipping. When I set the signal generator to 200mV, that was the best spot. The scope was showing around 20V on the screen when the volume was that high. I was able to adjust it really well, both clipped sides of the...

I checked the AC voltage coming out of the signal generator, and I adjusted it to 150mV and 200mV. I'm not sure how to turn down the sensitivity. I played with it some more but I can't see any clipping, and if there is just a crazy tiny amount on the tips of the wave, it doesn't seem to change...

Here is the video of my setup, maybe this will help figure things out. There's really no voltage on the speaker terminals.

I'm having issues with the DC offset. I bought a pocket oscilloscope and a small signal generator. The sine wave looks good, but I can not get the signal to show any clipping like the SM states. I have a 8ohm 50W resistor for the dummy load. When I adjust VR801 the sine wave moves around on...

First, fiddle with the knobs and see if the distortion changes. Might need some deoxit.

I replaced all the zeners and trimmers during the rebuild. I've been using the KSC3503 / KSA1381 & the KSC2690 / KSA1220 combo's for drivers pretty much all the receivers I work on

OK, you were right, one of the 2SK24's was getting weak, .43V /.64V on the diode test, vs equal voltages with the other channel. I replaced them both with J113 N channel fets I had, and the sound is now equal! I had some BF256's here too, and those probably would have worked also.

Thanks I will check it out! and report back! I may have to buy a scope to do the offset later.

The only FET's in the SM are on the MIC board 2SK24 I probed all the transistors on the Amp driver board and the only thing that was different was Left channel TR810, PNP transistor that was reading .640V on the diode check vs .59V on the right side. All the other transistors left and right...

Hello, I am servicing a 3300 for a friend, and the service manual shows having to use a scope to do the output adjustment. From all my experience this should be 0V on most receivers except a 5000X I worked on. I do not have a scope, originally the Left channel was about 100mv and the Right was...

I would deoxit all the switches well with D5 if you haven't yet. I just recently completely rebuilt a 8080DB and it was in serious need of that. Spray and turn the switches back and fourth a lot. Let it sit for 20 min then use compressed air to dry it out. I also use D100 a lot of the time...

I have Autocad if needed. Heres a couple pictures. No, there were never any resistors or diodes in those spots. The solder on the backside was untouched smooth from the factory. I'm the first person to get into this one. Here are the pictures there are wires routed from the connections...

There are no resistors in R616 or R617, FYI Pad R617 -56V / -32V Pad R616 +56 / +31.5V There are no Diodes either in the board. Pad ZD604 +31.5V / GND Pad ZD605 +56V / GND