Studiomaster 300 8.2 Powerhouse. Powers up fine but no sound from output.

[marmaladesoup]

Hi there i recently aquired a Studiomaster 300 8.2 powerhouse mixer. All seemed to be well when i got it home, Powers fine all the lights etc even tried the headphone socket and can hear everything fine. But alas when i try to plug my speakers into the outputs in the back i am greeted with silence ???
Does anybody have any ideas how this could be resolved and even what may have happened. Many thanks Ross
I have looked at it again and i can report sound is coming out of the outputs but it is really weak like the amps not doing anything . I only have one speaker lead so i can't test the right and left channel together, Im wondering if this may be the problem ?? Or perhaps the amps just had it !!

[djboo1234]

Hi there i recently aquired a Studiomaster 300 8.2 powerhouse mixer. All seemed to be well when i got it home, Powers fine all the lights etc even tried the headphone socket and can hear everything fine. But alas when i try to plug my speakers into the outputs in the back i am greeted with silence ???
Does anybody have any ideas how this could be resolved and even what may have happened. Many thanks Ross
I have looked at it again and i can report sound is coming out of the outputs but it is really weak like the amps not doing anything . I only have one speaker lead so i can't test the right and left channel together, Im wondering if this may be the problem ?? Or perhaps the amps just had it !!

i have the exact same amp and had the exact same problem, there are a few things to try...
1 make sure your gains are up.
2 check that the +48 volt switch at the top right is pushed in
3 check the to amp switch on the right second up from the bottom! to make sure this is turned up!
4 check that the button under the to amp knob is not pushed in as this means all sound is redirected via the rev to mon slider next to the reverb slider!!

if still nothing check channel fuses inside the amp this requires a small amount of skill and quite a bit of electrical knowlege lol not that difficult if you know how though!
let me know how it goes!

[marmaladesoup]

Hi thanks for the info : I have just tyied your suggestions I'll have to have a look at the fuses you mentioned because its still playing up . I have updated info on the fault tho, Its baffeling me :S. Firstly my speakers are both hooked up, (I mentioned in this post i thought the fault maybie caused because my speakers were not both hooked up) That turned out to be right, as soon as i plugged both speakers in it seemed to work fine. I was relived i thought that was problem solved that was of course until i start messing with the controls. I plugged in a mic, (Everything ok) I looked at the pan control on that channel its was panned fully to the left ! Yet sound was comming out of both speakers ??? i started to move the pan pot and the signal got weaker and weaker the more a got to the cental position i carryed on panning around from the centaer to the right the signal got stronger and stronger untill perfect again out of both speakers. I dont know much about amps but i deduce from this the because the desk has two amps 300+300 I.e two 300 watt amps one must have blown and power is being redirected. I dont know i might be barking up the wrong tree ! Does your desk work with one speaker unplugged ? If it does this may confirm my suspicions. Anyway thats for the info again Any help would be a god send cheers Regards -Ross-

[lekyspain]

Have similar problem - output gone down - do you have schematics for this unit?

[djboo1234]

i do apoligise for the length of time it has taken me to reply........ i unfortunately do not have the plans for this amp i have no problems powering 1 or 2 speakers from my unit on either channel another thing to check would be that the gain knobs arent old and dammaged as this also could result in the phantom panning problem also be sure there is nothing plugged into the amplifier inserts at the back as shorting these would give you the same issue if you wanted you could transfer all power to for example the left channel and daisychain your 2 speakers together this would give you mono sound from both speakers but please bear in mind when daisychaining that 2 8ohm speakers together =4ohm therefore 2 4ohm speakers=2ohms these amplifiers should not be run any lower than 2ohm even though it says between (4ohm-16 on the back) message me bk if anything works lol!!!!!!

[lekyspain]

Power Output solved

i do apoligise for the length of time it has taken me to reply........ i unfortunately do not have the plans for this amp i have no problems powering 1 or 2 speakers from my unit on either channel another thing to check would be that the gain knobs arent old and dammaged as this also could result in the phantom panning problem also be sure there is nothing plugged into the amplifier inserts at the back as shorting these would give you the same issue if you wanted you could transfer all power to for example the left channel and daisychain your 2 speakers together this would give you mono sound from both speakers but please bear in mind when daisychaining that 2 8ohm speakers together =4ohm therefore 2 4ohm speakers=2ohms these amplifiers should not be run any lower than 2ohm even though it says between (4ohm-16 on the back) message me bk if anything works lol!!!!!!

This was a long time ago, but if I remember correctly, I traced the fault to the power pre-amp board. On this board is an 8pin DIL chip which sits in an 8 pin holder. These holders corrode with time and cause high resistance to the pins. Solution - push hard on the top of the chip to force it into the holder just a fraction more. This causes the contacts to be wiped clean. Simple once the fault has been traced, but ti's the tracing that takes time. If no luck, do the opposite - prise the chip out of the holder and then replace - the action wipes the contact points. Make sure the chip goes in the same way around - it will be marked with a dot or a cut-out towards pin 1,8 end.