Nikko Preamp question
Spike_L
Posts: 17
Hi all, I recently picked up (from a local Buy/Sell site) a Nikko Beta 50 II preamp to replace a Hitachi 6500 I had controlling my Hafler DH-200. The unit showed up in near new condition and sounds great when hooked up, the one issue I have encountered is that the headphone jack doesn't seem to function properly. The main speakers don't cut out when the headphone jack is inserted and only a very faint sound comes through the headphones. I've tested the headphones themselves, which check out fine, and I've read the manual to see if there's a control that needs to be activated (or de-activated re: speaker monitor etc.) in order for the headphones to function properly. I lifted the cover briefly thinking it may be the output redirect spring on the headphone jack that's malfunctioning, but it's a sealed jack and the connector springs are hidden. I really want to keep the unit because it's in such spectacular shape otherwise, but the headphone function is one of the main reasons for my upgrade, and I don't want to spend big bucks just to make the jack function. Any suggestions or leads on a replacement part (it appears very proprietary though), would be greatly appreciated. Thanks,
Mike
Mike
Post edited by Spike_L on
Comments
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It might be a relay problem.Some pre's use a relay to mute the main output's when the phones are plugged in.Testing
Testing
Testing -
Mike,Hi all, I recently picked up (from a local Buy/Sell site) a Nikko Beta 50 II preamp to replace a Hitachi 6500 I had controlling my Hafler DH-200. The unit showed up in near new condition and sounds great when hooked up, the one issue I have encountered is that the headphone jack doesn't seem to function properly. The main speakers don't cut out when the headphone jack is inserted and only a very faint sound comes through the headphones. I've tested the headphones themselves, which check out fine, and I've read the manual to see if there's a control that needs to be activated (or de-activated re: speaker monitor etc.) in order for the headphones to function properly. I lifted the cover briefly thinking it may be the output redirect spring on the headphone jack that's malfunctioning, but it's a sealed jack and the connector springs are hidden. I really want to keep the unit because it's in such spectacular shape otherwise, but the headphone function is one of the main reasons for my upgrade, and I don't want to spend big bucks just to make the jack function. Any suggestions or leads on a replacement part (it appears very proprietary though), would be greatly appreciated. Thanks,
Mike
I've got a Beta 40 that the headphone jack is not being used. It's a "test" preamp and rough and if you need the jack I'll trade you. Send me yours and I'll send you mine. mine does work although I never use it and doubt I ever will.
Harry -
Mike,
I've got a Beta 40 that the headphone jack is not being used. It's a "test" preamp and rough and if you need the jack I'll trade you. Send me yours and I'll send you mine. mine does work although I never use it and doubt I ever will.
Harry
Hi Harry, thanks for the most generous offer. I'd very much appreciate being able to swap the parts. I'd like to remove the one from the 50 here, send you some pics to ensure they appear compatible before I put you through the effort though. Won't get a chance to tinker with it until the weekend. Why don't I PM you with the details after that. Thank you very much again for the offer.
Mike -
Mike,Hi Harry, thanks for the most generous offer. I'd very much appreciate being able to swap the parts. I'd like to remove the one from the 50 here, send you some pics to ensure they appear compatible before I put you through the effort though. Won't get a chance to tinker with it until the weekend. Why don't I PM you with the details after that. Thank you very much again for the offer.
Mike
Timewise the weekend would work out better for me also.
My 8 year old son has his last day of school thursday and I'm going to take him out to get ripped on candy and milkshakes etc.
He needs to unwind after a long school year. LOL.
I'll pm my email address and exchange some pics and see if I can find schematics to see if anything else could be your problem. It's not a problem I've run into before. I've run into a couple of bad headphone jacks over the years with the plastic sockets but what you're describing leads me to think it's something else.
If you're using a mini to 1/4" adapter plug like some newer headphones take I'd make sure it's the right plug adapter before I go switching out parts on the pre.
Just guesswork at this point without "hands-on".
Harry -
Mike,
Timewise the weekend would work out better for me also.
My 8 year old son has his last day of school thursday and I'm going to take him out to get ripped on candy and milkshakes etc.
He needs to unwind after a long school year. LOL.
I'll pm my email address and exchange some pics and see if I can find schematics to see if anything else could be your problem. It's not a problem I've run into before. I've run into a couple of bad headphone jacks over the years with the plastic sockets but what you're describing leads me to think it's something else.
If you're using a mini to 1/4" adapter plug like some newer headphones take I'd make sure it's the right plug adapter before I go switching out parts on the pre.
Just guesswork at this point without "hands-on".
Harry
Hi Harry, received your PM, thanks. Candy and Milkshakes....mmmmm. My 4 year old expects that after a long 1/2 day at pre-school! Must....not...give...in! In regards to the preamp, I'm using my vintage Sennheiser 430's, no adapter required. MP3 players weren't even a twinkle in anyone's eye when I got them. The headphone jack in the Beta 50 is a plastic sealed unit, which I will try and source here at our commercial electronics suppliers before we do the long distance thing. I have tried all the basic troubleshooting methods so far, from the jiggle the wires to using all the input/output options, and taking the power amp out of the equation. I have yet to put a meter on anything though. Will when I have it apart though. Have fun on Thursday.
Mike
p.s. I wonder if you could clear something up for a newbie? What the heck does "bump" refer to when used in the replies on this forum?? -
Hi Harry, received your PM, thanks. Candy and Milkshakes....mmmmm. My 4 year old expects that after a long 1/2 day at pre-school! Must....not...give...in! In regards to the preamp, I'm using my vintage Sennheiser 430's, no adapter required. MP3 players weren't even a twinkle in anyone's eye when I got them. The headphone jack in the Beta 50 is a plastic sealed unit, which I will try and source here at our commercial electronics suppliers before we do the long distance thing. I have tried all the basic troubleshooting methods so far, from the jiggle the wires to using all the input/output options, and taking the power amp out of the equation. I have yet to put a meter on anything though. Will when I have it apart though. Have fun on Thursday.
Mike
p.s. I wonder if you could clear something up for a newbie? What the heck does "bump" refer to when used in the replies on this forum??
"Bump" is getting your post back to the top to be noticed. -
Thanks GV for your suggestion, and Harry for your generous offer, but it appears after some tinkering and a generous swab of contact cleaner the jack appears to be fully functional. Big relief. Thanks again for the response.
Mike -
Glad it all worked out. A good cleaning can bring gear back to life.
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Thanks GV for your suggestion, and Harry for your generous offer, but it appears after some tinkering and a generous swab of contact cleaner the jack appears to be fully functional. Big relief. Thanks again for the response.
Mike
I'd look into finding that part anyways, as it will get dirty again and eventually fail. I guess it depends on how much you enjoy it.CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.

