Orthodynamic Roundup

[bluemonkeyflyer]

I have a dead HP-1 driver. No reading on Ohm meter with wires disconnected. De-soldered and cleaned the driver's solder tabs...No Joy.
 
How do I open it to inspect the internal connections?
 
Thanks for any help.

 

[DefectiveAudioComponent]

It's a bit silent here - where's team PMB today?
 
(For that HP-1 see http://wiki.faust3d.com/wiki/index.php?title=Yamaha_HP-1 
It looks like you have to remove that piece in the middle (the rivet) that holds the driver together... the tricky part appears to get it back together again...)
 
(The LCD-2 is still better than the old Magnat - but costs a fair bit more of course)

 

[mypasswordis]

  I have a dead HP-1 driver. No reading on Ohm meter with wires disconnected. De-soldered and cleaned the driver's solder tabs...No Joy.
 
How do I open it to inspect the internal connections?
 
Thanks for any help.

 
If the above ^ doesn't help, dBel84 is the king of ortho driver repairs, search through his posts on it or PM him.
 

  It's a bit silent here - where's team PMB today?
 
(For that HP-1 see http://wiki.faust3d.com/wiki/index.php?title=Yamaha_HP-1 
It looks like you have to remove that piece in the middle (the rivet) that holds the driver together... the tricky part appears to get it back together again...)
 
(The LCD-2 is still better than the old Magnat - but costs a fair bit more of course)

 
Hey DAC and everyone else, hope everything's been well with you. I don't have any PMBs but still occasionally listen to my Fostex T10, T20v2, and T40v1, and am pleasantly surprised at their sound every time. The T20v1 is listenable as well in stock form, haven't gotten around to modding it yet.

 

[nick n]

mypasswordis :  what have you got going on in the T-10?
 
 
I still regret passing up the Magnat I saw up over a year ago. It's on the must get list.
 
Guess I am a TEAM PMB member. Actually took these for a walk last night.

 
A bit of a biotch to drive portably. But it gets done. Using Gary's PA2V2 amp actually does the trick well ( I adjusted the 2 gain screws ). And these are 90 db sensitivity rated

. I read somewhere this has a high current output which would make sense I guess. 200 mw max output likely lower, but it did so better than the C&C BH amp that was 600 total Both have to be near maxxed ). Turns out it had a bad battery but still... I guess that means do your research before portably amping older orthotics.
 
This set has the last iteration of the driver with the extra row of holes right out to the magnet edges.
 
 
 Had a driver repair to do during the build- both actually-, not sure if that was mentioned in my earlier post.
 
 After removing all the tacky/ sticky crumbled foam and needing to open the drivers to do it, a few lines of traces were ruined, as well as the center contact points. So to repair that I took some MG Chemicals Silver Conductive Epoxy and applied that paper thin in exactly those spots and bingo perfect functionality again. Resistance even the same on each side ( ~160 ohm ) afterwards. Not sure how I managed that but I was very careful during the repair. They were both botched in the exact same places luckily.
 
These had the sort of floating driver also but not to the same extent as the Magnat. Stock they rest apart from the baffle face on a couple tabs that make it rest up a few mm ( further inwards from the plane of the baffle fronts )
 Pretty close though. I can recall looking when I got it and could not understand why when I pushed the drivers they pushed back into the cups a bit each press. Pressure fit in there only from the foam I think in stock form.
 
Sealed the driver to baffle area and those are soft HM5 pads.
Very capable bass. Nice air.
= fantastic.
 
Where is all this old stuff, not like they made a handful, or is it?  Wonder if folks just tossed them over time after pads wore out, which is what i think may have happened to many of the HOK80.
There was that Dual 330 up the other day with channel imbalance, willing to bet that was crappy foam. Someone has some work ahead of them.

 
Rambling over.
 
 
TEAM PMB OUT
 
 
 
Wish I had used strips and rings of Dynamat or Fatmat instead to to all that sealing. Not enthusiastic about redoing it all. Newplasted it.

 

[mypasswordis]

The T10, T20v1, and T20v2 are completely stock. I have discovered awhile back, from owning 4 different pairs of T20v2s over the years, that the T20v2 with bold text (which is what I have now) has less bass/more balanced sound than T20v2 with skinny text on the cups. T10 and T20v2 (bass light version) sound good stock, the T20v1 needs some work. IIRC it sounds like a radio, very little above 12kHz or so. The T40v1 has one layer of Moorbrook felt damping and I ripped out the foam pucks.

 

[nick n]

wow:  I never realized there were slight variations in the t-20 v2,
thanks very much for that. Burned into my memory
 
JOE LUNCHPAIL PUBLIC reading this, you will forget everything you read.
 
Any thoughts on why this is the case?

 

[DefectiveAudioComponent]

   
If the above ^ doesn't help, dBel84 is the king of ortho driver repairs, search through his posts on it or PM him.
 
 
Hey DAC and everyone else, hope everything's been well with you. I don't have any PMBs but still occasionally listen to my Fostex T10, T20v2, and T40v1, and am pleasantly surprised at their sound every time. The T20v1 is listenable as well in stock form, haven't gotten around to modding it yet.

 
Hi! I recommend a listen to a PMB, if you get the opportunity  They are usually very nice after repairs- but they are never listenable in stock form, since there is always that crumbling foam and the ruined ear pads.... A bit of driver trouble is not uncommon either....
 

  mypasswordis :  what have you got going on in the T-10?
 
 
I still regret passing up the Magnat I saw up over a year ago. It's on the must get list.
 
Guess I am a TEAM PMB member. Actually took these for a walk last night.

 
A bit of a biotch to drive portably. But it gets done. Using Gary's PA2V2 amp actually does the trick well ( I adjusted the 2 gain screws ). And these are 90 db sensitivity rated

. I read somewhere this has a high current output which would make sense I guess. 200 mw max output likely lower, but it did so better than the C&C BH amp that was 600 total Both have to be near maxxed ). Turns out it had a bad battery but still... I guess that means do your research before portably amping older orthotics.
 
This set has the last iteration of the driver with the extra row of holes right out to the magnet edges.
 
 
 Had a driver repair to do during the build- both actually-, not sure if that was mentioned in my earlier post.
 
 After removing all the tacky/ sticky crumbled foam and needing to open the drivers to do it, a few lines of traces were ruined, as well as the center contact points. So to repair that I took some MG Chemicals Silver Conductive Epoxy and applied that paper thin in exactly those spots and bingo perfect functionality again. Resistance even the same on each side ( ~160 ohm ) afterwards. Not sure how I managed that but I was very careful during the repair. They were both botched in the exact same places luckily.
 
These had the sort of floating driver also but not to the same extent as the Magnat. Stock they rest apart from the baffle face on a couple tabs that make it rest up a few mm ( further inwards from the plane of the baffle fronts )
 Pretty close though. I can recall looking when I got it and could not understand why when I pushed the drivers they pushed back into the cups a bit each press. Pressure fit in there only from the foam I think in stock form.
 
Sealed the driver to baffle area and those are soft HM5 pads.
Very capable bass. Nice air.
= fantastic.
 
Where is all this old stuff, not like they made a handful, or is it?  Wonder if folks just tossed them over time after pads wore out, which is what i think may have happened to many of the HOK80.
There was that Dual 330 up the other day with channel imbalance, willing to bet that was crappy foam. Someone has some work ahead of them.

 
Rambling over.
 
 
TEAM PMB OUT
 
 
 
Wish I had used strips and rings of Dynamat or Fatmat instead to to all that sealing. Not enthusiastic about redoing it all. Newplasted it.

 
That's an impressive repair  I never managed to get my hands on the large Dual, only the smaller on-ear Dual (the 720).
How did you get the epoxy right on the traces rather than all over the driver? 
 
I need to experiment with different amplification as well - I have an xcanv3 hybrid tube amp, but I have been thinking for a while that those old orthodynamics may work better with a solid state amp. I also have a small O2 amp, and together with my laptop soundcard, it has deeper bass than my DAC/XCAN combo.

 

[Kabeer]

  I have a dead HP-1 driver. No reading on Ohm meter with wires disconnected. De-soldered and cleaned the driver's solder tabs...No Joy.
 
How do I open it to inspect the internal connections?
 
Thanks for any help.

The 'hour hand' looking soldering tab, does it have a slight movement to it?
ie can you rotate it slightly,even 1/4 of a degree?
 
I have come across two drivers which had bad connections (mind you they were a HP50 and something else) which when you slightly rotated the tab the connection came back again.
 
Of course you shouldnt rotate too much as you can torque the diaphragm, or if the tab is rock solid then this is likely not the cause of your issue.
You can keep the tabs connected to an ohmeter whilst attempted to slightly move the tab and see if it comes alive. Or just have it plugged in playing music whilst doing the same.
 
Opening the driver is tricky, as you need to remove that rivet as defectiveaudiocomponent says (and i dont think its a replaceable once removed). And then dissolve the glue holding the magnets together.
Try the tab movement test before ortho surgeons have a go .

 

[bluemonkeyflyer]

   
If the above ^ doesn't help, dBel84 is the king of ortho driver repairs, search through his posts on it or PM him.
 
 
Hey DAC and everyone else, hope everything's been well with you. I don't have any PMBs but still occasionally listen to my Fostex T10, T20v2, and T40v1, and am pleasantly surprised at their sound every time. The T20v1 is listenable as well in stock form, haven't gotten around to modding it yet.

 
 

  The 'hour hand' looking soldering tab, does it have a slight movement to it?
ie can you rotate it slightly,even 1/4 of a degree?
 
I have come across two drivers which had bad connections (mind you they were a HP50 and something else) which when you slightly rotated the tab the connection came back again.
 
Of course you shouldnt rotate too much as you can torque the diaphragm, or if the tab is rock solid then this is likely not the cause of your issue.
You can keep the tabs connected to an ohmeter whilst attempted to slightly move the tab and see if it comes alive. Or just have it plugged in playing music whilst doing the same.
 
Opening the driver is tricky, as you need to remove that rivet as defectiveaudiocomponent says (and i dont think its a replaceable once removed). And then dissolve the glue holding the magnets together.
Try the tab movement test before ortho surgeons have a go .

 
Thanks for the tips, guys.
 
I was afraid that's what I'd hear about needing to remove the rivet and then the difficulty getting the driver halves back together.
 
I tried my Ohm meter and moved the tab a little bit one way and a little bit the other way. I get only 2.5 ohms on the bad driver and 138 on the good one, but no sound while playing music. I also checked continuity from the TRS Ring to the side solder pad on the driver as well as from the Sleeve to the grounding tab on the driver. Each proved to have good electrical continuity....odd about the resistance being so low and no sound considering the connections are good.

 

[Armaegis]

I had measurements like that on an old driver and it wound up being a perforation in the diaphgram and one side near the outside making contact with the other.

 

[DefectiveAudioComponent]

Just an extra picture of the RT-10. Because it sounds so good
 

 

[nick n]

DAC:  first, thanks for rubbing it in they are gorgeous. Nice colour  scheme very classy.
 
 You asked about the Silver Conductive Epoxy. I mixed up a lot more than needed to make sure it was the right 50/50 amounts. Put this on a piece of cardstock and used a pin to sparingly apply it. The traces were insanely close so in those spots I very thinly opted to fill them in, so the edge of the pin also was used to make it that thin there. Probably more than paper thin actually thinking about it now
 
Hey waitaminnit, I recognize that stand...that's an 890 stand isn't it..  My 890 died on one side the other day, and people still want a ton for them it seems.

 

[mypasswordis]

   
Hi! I recommend a listen to a PMB, if you get the opportunity  They are usually very nice after repairs- but they are never listenable in stock form, since there is always that crumbling foam and the ruined ear pads.... A bit of driver trouble is not uncommon either....

 
PMBs and their OEM versions seem to be much rarer on this side of the pond, I'll keep a lookout but not expecting to find a pair with 55mm drivers anytime soon. I am about to buy some other rare vintage headphones anyway, so the headphone fund is empty now. The RT10 looks very beautiful, you seem to have a knack for finding beautiful vintage orthos.

 

[DefectiveAudioComponent]

The modified RT-10 is like being in a cozy intimate club, on the stage, or in the front row.
There is a well-defined stage with natural sounding instruments, that both meld together into a nice whole, and can be picked out individually on the stage. On fine classical recordings, it's possible to point in the direction of individual instruments.
Bass is just slightly rolled off compared to the bass heavy new orthodyamics out there. 
 
Over and out from team PMB.

 

[nick n]

Quick question do you find them "glassy" sounding? I saw that posted in a description of some Duals and it sort of made sense. Nothing bad, on the contrary.