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I have a model 2000 that I have been working onm replacing caps and checking resistors erc, getting rid of 2sc458 transistors. On the main amps I also replaced the 4 diodes with 1n4148...After getting the thing together I find that the center voltage can only be brought up to apprx 21 volts. The...

I am working on another 555a main amp board, the board is recapped, all resistors are in spec, transistors are ztx795, ztx694b, 2n3904, for t05's there are mj15003's. Initially I could not get the center voltage below around 33 volts, and the bias would not go below 18mV, the B+ is 58V. I...

I have been working on a 555A and finally got the main amp to show good voltages, no fuse blowing and correct bias. I currently have another 555A that I rebuilt and which plays very well. The amp with the problems, I have coupled with the good amp in the following ways: Pre out on the good amp...

Hello I have been working on a 555A for sometime now, this included a recap of all boards and on the main amp replacement of the transistors using ztx 694 (8002-1) and 795 (9002-1), ksa 992 (xa495g) and 2n3904 (2sc281). Output transistors and TR815 are original and test good on an Atlas. All...

The switch on the AU517 which separates the pre amp from the power amp has 2 options, direct coupled and capacitor coupled. I have tried to find an owners manual which would explain this option, but have had no luck. What is the significance of this option?

AU519 F-2915 power supply and protector circuit problems. Initially I powered up this 519 without the output boards in place, after recapping and checking all components. The protector circuit worked fine and I was able to make the flat amp and equalizer board adjustments with no problem. I then...

Hello all, I have been working on an AU-505 and discovered some variations between the amplifier and the schematic. I am as certain as one can get that no one was ever inside this this, and thus certain this was a configuration delivered to customers, or at least one customer. First there is no...

I picked up one of these for less than shipping costs on fleabay. First off I have downloaded a service manual but it has no alignment instructions, so I was wondering does anyone know the bias current value, or alternatively the voltage across R843? Second issue is the output TO3 transistors...

Anyone know where I can find a service manual?

I haven't seen many posts about the 519. I purchased last winter a number of Sansui integrated amps intending to rebuild them when I became redundant..So I have now rebuilt 2 555A's, am working on a 317 and have finished a 517. A lack of parts lead me to finally open up the 519 and begin the...

I reassembled my 517 for the second time, this time after replacing all the diodes, the transistor which drives the relay, and all fuse resistors and resistors out of spec. The amp is also completely re capped. When I turned it in I was able adjust both output boards to correct vales, and the...

The amplifier is now working, replacement of TR805 and 806 did it. I want to thanks all that provided support technical and moral, this is a great place. Listening to this amp I find it particularly good with saxaphone and upright bass, much more to these sounds than the amp I removed (a Music...

The main amp board is now configured with tr801 and 803 xa495g's are now ksa992fbu the 8002-1 are now ztx649b tr 805 and 806 2sc281 are original tr 809 and 810 9002-1 are now ztx795a tr 815 original The amp was able to be aligned using the voltage drop across r843. The main voltage is 61.6...

I checked the smaller fuse in the meter and it was blown. I guess from now on I will start in the 20A range. The bias current reads 1.4A and the pots have no effect. I guess for me the real question is why would it be so high? Would TR801, 802 809 810 and TR 803 804 807 808 cause this if they...

I am close to giving up on this amplifier. The main board alignment is not possible. I can set the voltage, currently I have 51V, so I adjusted the voltage to 24V, slightly less than half (using the ratio of 57V to 27V I assume the voltage adjustment should be a bit less the 1/2). However I have...

I finally got back to the 555a after John advised me to set the center voltage to 27V, since I do not have a scope or signal generator. There was a problem which caused the right channel fuse to go incandescent. After looking at the main board I discovered I had a dyslexic transistor placement...

I am working on a 317 now and am wondering about the advisability of replacing the 2 10,000uF caps with 2 12,000 uF caps that I happen to have left from another project. Some of the posts I have read have mentioned replacing the 12,000 uF caps in the 517 with 15,000 uF. In the case of the 317...

I have replaced all the transistors except the drivers and the outputs which tested good on the Atlas tester that I have. All suspect resistors and all electrolytics have been replaced. All switches cleaned and treated with deoxit. I have powered up the amp with no inputs and the volume all the...

What type of capacitor are the orange wafer caps? Also the polystyrene caps, which are available in limited values, is there a cap that can be substituted for them that is of a different type?

Hello Replacing the transistors on an AU555A main board, I came up with the following replacements CDC-90021A BY ZTX553 CDC8002-1A BY ZTX694B XA 495C BY 863-2N5087RLRAG (MOUSER #) 2SC 627 BY 512 BC546ATA (MOUSER) 2SC281 BY 512 BC547CTA (MOUSER) My method of choice was to first match Ic...

Continuing the effort to rebuild my 517 I discover that both driver boards were never fitted with D03, both slots are empty and it looks like the wave solder just soldered all 4 pads, so it is unlikely they were removed at a later date. The schematic does call for a diode in these positions. Is...

I ordered a complete set of AL electrolytic caps for a Sansui 517. Afetr getting into the job, my first, I see that some of the electrolytic caps are bi polar and are not marked for polarity. My question is are these caps suitable for a polar application or should I re order and specify polar...

I am working on the equalizer board and have found that the schematic calls for R31 and R32 to be 10ohm resistors. When checking these resistors I come up with 1.5Kohm for each. The color codes on the resistors is correct for 1.5Kohm 5% tolerance. Are these resistors the wrong value or is the...

In an earlier post I asked about these caps, the ones I ordered from mouser are chemi-con 63v 12000uF snap in package. There are 2 short leads and no indication of polarity on the package, although the can has a stripe on one side corresponding to the location of one of the leads, this same lead...

I have received all the electrolytic caps from Mouser and have some problems. First when I removed the caps I did not take note of the locations and corresponding cap values. I assumed I would be able to get that information from the Hi Fi engine manual that I downloaded. Unfortunately the...