Need schematic for SL260

[Froggenhoffen]

Hello all,
 I have a SL 260 that makes a horrid noise when I turn it on. I think that it might be a transformer, I was wondering if anyone has a schematic for it.

 I am also looking for an owners manual for a SR 4100, or if someone can explain what all the inputs are on the back.
 Thanks

[loudthud]

I don't have any info on the SL160. I do have a schematic on the SR4100 and will attempt to describe the functions of the jacks.

The SR4100 internally has three busses, Main, Monitor and Effects/Reverb. Each channel has a high and lo impedance input and a level control to each buss.

There is a line level input to the Main buss and a line level Main output after the Main gain control. The line level Main output also feeds the Equalizer input such that when a plug is inserted in the Equalizer input jack, the Main output is disconnected from the Equalizer input. The output from the Equalizer is connected to the Equalizer Out jack and also to the Power Amp Input jack such that the Equalizer is disconnected from the power amp when a plug is inserted into the Power Amp Input jack. The Speaker Jacks are fed from the power amp's output.

The Monitor Input jack is a line level input to the Monitor buss. The Monitor Output jack comes from the Monitor buss through the Monitor Master gain control.

The Effects/Reverb buss feeds the input to the reverb tank and also the Effects Buffer. The output of the reverb tank feeds the Master Reverb control, it can be muted by a standard footswitch connected to the Reverb Foorswitch jack and is fed back to the Main buss. The Effects Input feeds the input to the Effects Buffer, the signal goes through the Effects gain control and goes to the Effects Output jack.

[loudthud]

I found a schematic for the SB160. Insert a plug into the Power Amp In jack. If the noise goes away, the problem is in the preamp. On the power amp board there are two 3 amp fuses. Check them. The fuse the +/- 45V supplys. There are also two 3300uF 50V caps. These are your main filters, check them. There is a +/- 15V regulator circuit on the power amp board and a dual op-amp (IC202) that makes +/- 4V for the CMOS IC's. On the opamp check for +15 on pin 8, -15 on pin 4, +4 on pin 7 and -4 on pin1.

[smellygoatllama]

Recently aquired a SL160 at auction.   It works well, reasonably quiet but it appears that someone has removed the reverb pot and  wiring. The spring pan is in place under the amp with an in and out RCA jack.  A schematic would useful as would a wiring diagram.