Yamaha HP-1 Modifications Complete

elcoholic

Jet Fuel Genius
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I've had mine since new in '76. A few years ago I re-cabled them with Mogami and damped them with two layers of felt and sealed them up with monkey snot (rope caulk). A huge improvement or so I thought. Recently I picked up a pair of virtually identical YH-1's. In comparing the 2 the originals were much more open and airy, but lacked the bass of the modified pair. Even more recently I bought some Stax which really show the shortcomings of my HP-1's. The detail and high-end was just not as good as it should/could be. Since the re-cabling I've had to open them up and repair broken wires several times. The lack of proper strain relief being the culprit. Said monkey snot making the job a PITA.

This time I hope is the last time I'll have to repair a broken wire. With the drivers removed and the baffles in place and working through my drill index 1 step at a time I was able to enlarge the hole and recenter it as I went to add 3.5mm panel jacks. While I was at it removed all the old monkey snot opening them up again as orthos should be. (Thanks again to Wualta for reminding me of that). I went to just one layer of felt and sealed the baffle with gaskets I cut from a silicone baking pad. I also added treble dots on the back of the drivers. So far I just gave them a quick functional check listening. My receiver has a decidedly meh headphone section so more listening won't tell me much. I'm actually excited to go to work tomorrow so I can try them with my HP amp. Hoping for goodness.

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Thanks boza. It was dicey without a drill press, but they came out where I wanted. I used CA on the plastic parts and backed that up with hot melt on the inside. Whey seem well planted. As I hoped they sound so much better opened up & with far less damping especially driven with the 6 watt Schiit amp. I listed to Bob Marley's Exodus at work and the bass is excellent. I haven't A/B with my Stax, but they are just as pleasing to listen to, different yes, but not necessarily inferior. Mission accomplished me thinks.
 
That's great I like jack sockets on headphones it just seems a better idea as you don't have to worry about pulling the cable so much and if the cable does get damaged it's easy to replace.
Especially when you as clumsy as me.
 
That is a great job with the removable cable mod. Very impressed. Are they 3.5 or 2.5mm?
I just picked up a pair of these, the HP-1's, cheap. One side (right side) is not working. So, have come here researching a 'fix'. Only way to check is to take the pads off and take the drivers out so I can continuity test with a volt metre. (If I'm incorrect please advise.) It's pretty daunting. I really don't want to 'screw them up' but there doesn't appear to be any options.
Seeing the result of what you've accomplished gives me some resolve though. I WILL fix these classic Yamaha headphones. They CAN be saved.
Thank you.
 
Before you crack them open start with the plug end. The most common point of failure is right at the end of the strain relief. There is little to gain by cable upgrading for orthos. They don't provide much feedback for the amp so cabling isn't critical. If you do want to upgrade the cable go for it. The most benefit comes from sealing the driver at the baffle and felt damping. This is know as the "Level 1 Mod" on the internet. If you go to the trouble of opening them up do the Level 1 mod and get some fresh ear pads.

Be warned of the slippery slope you're about to venture on to. Orthos can be addictive. http://audiokarma.org/forums/index....yamaha-hp-1-build-thread.713183/#post-9586776
 
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Before you crack them open start with the plug end. The most common point of failure is right at the end of the strain relief. There is little to gain by cable upgrading for orthos. They don't provide much feedback for the amp so cabling isn't critical. If you do want to upgrade the cable go for it. The most benefit comes from sealing the driver at the baffle and felt damping. This is know as the "Level 1 Mod" on the internet. If you go to the trouble of opening them up do the Level 1 mod and get some fresh ear pads.

This was supposed to be my first port of call. Opening them up. I want to 'see them' a-la-natural and have a look at them. But one of my drivers isn't working and the cable is sealed so I can't do a continuity test without opening the cups up to test end to end on the cable. But I don't have fresh pads. And the pads currently on there are 'original' and pretty tired.

... Be warned of the slippery slope you're about to venture on to. Orthos can be addictive. http://audiokarma.org/forums/index....yamaha-hp-1-build-thread.713183/#post-9586776

I can see why. Those custom cans a pretty cool. But I just want to test them first and get them working. the HP-1's are a pretty good looking set of cans. I'm loath to give up on them. Well, giving up isn't a option. Just hope the drivers are okay and intact without any perforations of the membrane. Better be careful with my soldering iron.

Is there any way I can continuity test the cable without chopping them? So tips would be appreciated.
 
Sure I would think so. You should see approximately the same resistance between tip to common and middle ring to common on the 1/4" stereo plug. You'll know if you have an open circuit on one channel before opening them up.
 
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