[MermaidMan]

I've gone through with deoxit twice pretty thoroughly and yes the left channel has completely stopped working. I also get fairly severe static when unplugging the headphones and other times it is random. I'll go back though after class tonight and see if that fixes it. Thanks for the encouragement!

 

[Skylab]

When you say you have cleaned with deoxit...you disassembled the unit so you can actually get the deoxit inside the switches and controls, yes?

 

[SpeakerBox]

Checked the speaker fuses?

 

[richard51]

i need some help... i had a cable xlr to connect to a speakers amp hitachi sr 904.... The 4 braids at the end  are wriiten right and left but the 2 others are written Eg and GS what that means?  where is the positive and negative ....That is the back of my amp...thanks        L-js L-eg R-js R-eg  how do i connect that ? i interupt some discussion here i realize, and apologize...

 

 

[MermaidMan]

Sooo...I went back through again with Deoxit and it seems to be working fine now. No static, channel loss, nothing. I must have missed something the first couple of times. Think it was the input selector knob...But anyways I am absolutely in LOVE with the synergy of my HE400's and the Pioneer, even on Slacker Radio I haven't skipped a song yet, and Slacker isn't the best quality!

 

[richard51]

i am very happy for you..... I had the he 400 too.....my problem is to connect the xlr cable

 

[richard51]

is there any problem if i connect the positive braid in the negative by mistake ?  my xlr had 4 braids two marked right and 2 marked left ... ?

 

[Skylab]

Sooo...I went back through again with Deoxit and it seems to be working fine now. No static, channel loss, nothing. I must have missed something the first couple of times. Think it was the input selector knob...But anyways I am absolutely in LOVE with the synergy of my HE400's and the Pioneer, even on Slacker Radio I haven't skipped a song yet, and Slacker isn't the best quality!

Not surprised, but glad. The symptoms you described are almost always dirty controls. Good for you for getting them finally really cleaned!

 

[richard51]

is there a danger for the headphone if i connect the positive in the negative out  by error because i try to figure which of the four braids go negative or positive at the  speakers ouput of my hitachi amp ?

 

[TomNC]

@richard51
 
   Why take the risk? If you have a multi-meter, it only takes a couple mins to sort out the fires. Good luck.

 

[Skylab]

If you ONLY mix the positive and negative for the SAME channel, and they wires never touch each other, no risk of damage.

HOWEVER, if you connect the two positives to one channel and the two negatives to another...then there is the possibility you could short the outputs. And in that case, given the age of these vintage amps, you might have killed it for all time.

So I agree...get a multimeter and check to see which is which. Anyone serious about vintage gear should have a multimeter, if for no other reason that to check DC Offset periodically.

 

[PhoenixG]

If you ONLY mix the positive and negative for the SAME channel, and they wires never touch each other, no risk of damage.

HOWEVER, if you connect the two positives to one channel and the two negatives to another...then there is the possibility you could short the outputs. And in that case, given the age of these vintage amps, you might have killed it for all time.

So I agree...get a multimeter and check to see which is which. Anyone serious about vintage gear should have a multimeter, if for no other reason that to check DC Offset periodically.

Yeah, I've shorted an amp by trying to be too clever and it is just the worst. I had to replace like 4 parts to get it working again. Fortunately the PS blew before the outputs were damaged.

 

[captouch]

i need some help... i had a cable xlr to connect to a speakers amp hitachi sr 904.... The 4 braids at the end  are wriiten right and left but the 2 others are written Eg and GS what that means?  where is the positive and negative ....That is the back of my amp...thanks        L-js L-eg R-js R-eg  how do i connect that ? i interupt some discussion here i realize, and apologize...

I suspect the s is for signal and g is for ground, so you have a left signal and ground and right signal and ground.

If that's the case, then L-js would go to the left red speaker out, L-eg would go to the left black speaker out, R-js to the right red speaker out, and R-eg to the right black speaker out.

It may be safer to probe/ohm it out if you have a DMM, but assuming the left and right labels are correct.
, the worst thing you could have is a polarity/phase issue if you connect it wrong between positive and ground and you'd hear it if that happened.

Remember to go easy on the volume know and start at min and increase slowly. You don't want to blow your headphones.

Good luck and let us know how it works out!

 

[richard51]

I suspect the s is for signal and g is for ground, so you have a left signal and ground and right signal and ground.

If that's the case, then L-js would go to the left red speaker out, L-eg would go to the left black speaker out, R-js to the right red speaker out, and R-eg to the right black speaker out.

It may be safer to probe/ohm it out if you have a DMM, but assuming the left and right labels are correct.
, the worst thing you could have is a polarity/phase issue if you connect it wrong between positive and ground and you'd hear it if that happened.

Remember to go easy on the volume know and start at min and increase slowly. You don't want to blow your headphones.

Good luck and let us know how it works out!

thank you very much for your help ... Problem solved 

thanks to all of you and particularly to you 

 

[richard51]

dear vintage receiver lovers.... I am one of your pack now.... the hitachi headphone out was very good but the speakers out is a great progress towards a more 3 body sound....i am glad that i had listen to some of you... Thanks to all ... By the way like you said all the speakers amp out is a notch above most mid tiers

  headphone amp ....