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I'm working on a HH Scott R36S receiver. The output of the tone amp are JFET's. When I hook my scope up to them all I get is 26 volts, no signal even though I hear the tone on the speaker. I am putting in 1000 hertz. What am I doing wrong. Thanks

I pick up a Yamaha AST-A10 with a AST-KS1 cartridge in it. Can I test this amp with 8 ohm dummy loads? From what I have read, I can't just hook any old speakers to it, they must be Yamaha speakers made for the matching cartridge. Thanks

I think this is kind of funny. I listed two 200 disc CD changers on Ebay. One is a Nikamichi and the other is a Sony. Both are made by Sony. The Nikamichi is a very basic changer, it just changes disc. The Sony has all of the bells and whistles a much better machine. The Nikamichi has lots of...

Hi. I just pick up a Teac 1500U reel to reel that is missing its dummy plug. I got the service manual for the 1500 but the 1500U is a little different. The 1500 has a 4 pin socket and the 1500U has a 8 pin socket. I do have a Teac A-4010 that I took the dummy plug out of and tried it in the...

I am working on a JVC R-S33 super A receiver. When testing I put an input signal in starting with 40hz. When working the slide control on the equalizer section only one channel would change on the scope. On the 250hz slide just one channel change. On 1Khz and 5Khz both channels change and in...

I just finish a recap and transistor replacement on this Pioneer SX-9000. It does sound great but it wouldn't reach rated output before clipping. It started clipping at about 17 volts AC, reading across my dummy loads. Which is about 36 WPC. This stereo is rated at 50 WPC, which should be 20...

My latest project is a Pioneer SG-9500 equalizer. What should I expect to see when I put a signal in and look at it on a scope? And what about a square wave. Will the shape of the square wave change as it does when turning the tone controls on a stereo. I do plan on recapping this EQ and there...

Hi, I am recapping a Teac A-4010S reel to reel tape deck. There are two odd caps on the playback board. They are mark TICAP-L 10uF 10WV. It has three leads, two that seems to be what an electrolytic would be and measure out at 14 uF. the third which comes out the top appears to go to common...

Hi, I am recapping a old Teac reel too reel. The board has no silk screen or markings. I started pulling the caps one by one replacing them as I went. After about a dozen was done I took a closer look at the caps that I was pulling. Instead of marking the negative side of the caps they had the...

Hi, I am working on a Pioneer SX-9000 that has capacitor coupled outputs. Could someone give me a basic idea of how this works? I don't understand how it gets an AC voltage across the speakers. I do have a knowledge of electronics. I can change out the parts and hook up my test equipment and it...

Hi, I just want to see if my line of thinking is right about this. This is on a Pioneer SX-9000, the line voltage selector was set at 110 volts when I got this unit. I measure 120 V on my outlets. I want to move the selector to 117 V. When doing this, will it tap into the transformer so that it...

I pick this up at an auction the other day for $35. The front was in good but the wood cast was rough. I took the cover off and there was 47 years of dust in it. I blew out the dust and clean the pots. I check the DC offset at the speakers outputs and had about 700mV. A bit high but I hook up...

Hi, I pick up a Teac A-4010S reel to reel deck. It was made in 1967 and it does work quite well. I would like to recap it. Many of the caps are 50uF ranging from 6 volts to 25 volts. 50 uF isn't a common size, can I go down to 47 uF or jump up to a higher value cap? Thanks

I picked up this little amp, only 15 WPC. I took a look at the inside before I power it on and found this 10 ohm resistor in series with the positive side of the right speaker output. Does anyone know why someone would do this? I don't know how this amp was used, on the outside it was mark "...

I pick up this KR-3010 at an auction for $20. The outside was mint. The inside was a little dusty. I recapped everything but this board which I believe is the phono board. There is a little empty board by it that is connected to it. Any ideas what it is there for? And there are two pots on...

A surprising find when I took apart a bad power switch. It is reversible, all I need to do is flip it over and reconnect the wires and of course find out why it did burn out in the first place. One gets lucky sometimes.

This chip came out of a Sony RTR TC-440. It is for the servo amp board that drives the motor. I can't find a data sheet on it. I take it that pin one is on the lower right side of the pic below. The one on the left is the old one and the one on the right is the new one. I tested all of the...

While rebuilding the transport on this deck I found that the pulley for the auto shut off wasn't turning to well. How stiff is this pullet suppose to be. The belt is hardly turning it. I got pics below.

This board is from a Onkyo cassette deck model TA-2060. When I press down on the board the VU meters would peak all the way up and at other times the VU meters just didn't work. The deck does play. So when looking for bad solder joints this is what I found. There are no solder pads at these...

Hi, this is the first Sansui that I have work on. When I got this receiver it was sounding and working bad. With a 2 channel input, in quad, I had no left rear speaker output. That I believe I fix with just cleaning the controls. The FM only work with the FM muting button push in, I haven't look...

Hi, while working on stereos I deal with the tiny input and output wires that lead to the pre out and mains in jumpers. I was wondering why they use such big jumpers and is there something better that I could use. I don't know what kind of metal that is used but noticed that a magnet won't...

Hi, this is my first Sansui that I have work on. When I tested it out it sounded really bad, noisy controls and lack of bass. There was no AM and the FM only work with the muting off. When driving all 4 channels, one channel didn't work but when only driving 2 channels that one channel did work...

When I got this tape deck it had a broken belt. I replaced the belt and it was playing fine for a short while. Then the solenoid would kick in and shut it off. This deck is dual capstan. It has two sensors, one for the supply reel and one for the take up reel. Both seems to be turning fine...

I was working on a Pioneer SX-780 and I killed one of the output IC. I do have a pair of STK-0080 but from what I have read I am not sure if it a good idea.

I just finish recapping this stereo and replace the three transistors in the power supply. It does play but my problem is with the DC offset adjustments. With my meters connected to the test points for the offset, at first power up they read high, at 1 volt+. then they slowly drop till the relay...