[devouringone3]

They do that:
 
+ ()()() ^_^ ()()() +

- )()()( ^_^ )()()( -
 
+ ()()() o_0 )()()( -
 
- )()()( 0_o ()()() +
 
 


 
From Tyll's review on an out-of-polarity headphone (http://www.innerfidelity.com/content/headphones-united-airlines-flight-962), in which he did describe the sound repercussion of such a mistake in wiring.

 

[Mortalcoil]

Sorry if I'm in the wrong thread but I'm very curious what that polarity switch does on this pair of headphones, does it change the sound signature in any way? I'm not quite sure what it means but it's so unique

 As far as I know the polarity switches were intended mainly for the Pro audio sector, used in some cases by sound engineers. 

 

[devouringone3]

As of May 2014 tamahome77 received his pair from Joseph Grado and he put for sale: http://www.head-fi.org/t/717257/fs-grado-hp1000i-hp2i-upgraded-hp1000-with-improved-earpads
 
Total price of the upgrade: USD 2000$ excluding shipping.

 

[Mortalcoil]

Good to hear he finally got them back.

 

[abhinit90]

Glad to know he got it, especially after undergoing that harrowing ordeal.

 

[BoogieWoogie]

And it looks like isn't worth the upgrade..

 

[mulveling]

I feel awful for the guy. Shame on you, Joe Grado -- what was done is criminal. Even if he gets asking price, the net result of the mod is that he only gets $600 back from his (probably wonderful) stock HP-2. They were worth a LOT more than that.

 

[jonbmet]

  To be fair the HPA-1/2 uses significantly, not slightly, better components and more of them (separate power supplies for battery and PSU)
I'm not sure you realize the the op-amp and circuits are hidden underneath the black metal shield in the pics you posted above.
 
The RA-1 looks pretty cheap in comparison.
 
Just for example the HPA-2 uses a $50 pot (Alps RK40) and boutique "film & foil" caps ; the RA-1 uses a $2 pot and Solen caps.
 
 
I don't think the RA-1 looks nearly as good inside:
 
 
Joe built the HPA-2 to be the best battery powered headphone amp he could build.
John designed the RA-1 to be an inexpensive replacement.
I've owned both and the HPA-1/2 is much better, especially with the HP-1000
Just my experience...
 
 

I own the HPA-2 and RA1 battery powered version. I've never tried the HPA-2 on batteries...and maybe this is why, but I prefer the sound of the RA1. This probably is the reason why since I don't have very "clean" power where I live.

 

[Sherwood]

I've been really enjoying a set of HP2i I recently picked up. I can't imagine anyone sending anything to Joe now, given what has happened to Tamahome and others, but the modified HP1000 are really a superlative headphone in every way. I don't know that I have ever heard anything quite like them, in terms of tonal accuracy. They sound astonishingly, unflinchingly real.

I would love to get some backup pads, just in case, but I can't imagine dealing with Joe over the phone. I'm off to convince myself that Todd's flats are just as good

Edit: deautocorrected some words (bumper lattice?) that slipped past me posting from my phone at night.

 

[stacker45]

I've been really enjoying a set of HP2i I recently picked up. I can't imagine anyone sending anything to Joe now, given what has happened to Tamahome and others, but the modified HP1000 are really a bumper lattice headphone. I don't know that I have ever heard anything Quite like them, in terms of tonal accuracy. They sound astonishingly, unflinchingly real.

I would love to get some backup pads, just in case, but I can't imagine dealing with Joe over the phone. I'm off to convince myself that Todd's flats are just as good

I"m glad you like your HP1000i, and regarding the fact that TTVJ"s pads are," just as good", Joe's flats have been specially treated, (dipped), with a secret substance, (olive oïl), this explain the funny, (and I do not mean funny Ha! Ha! here), smell, and also the greasy texture.
 
Seriously, I do not know what Joe does to his flats, but since Grados are so sensitive to different ear pads, I have no doubt that they sound different, than TTVJ's.
 
 For many reasons, I do not want to send my precious HP1000 to Joe, first, he is very old, and he takes a very long time to do the job, so, what if he expires, after finishing one side. They could also get damaged in transit, or worse, they could get lost in the mail. And the mother of all those reasons, what if I end up hating the way they sound after the mods.
 
I bought the HP1000, because I liked the way they sounded, and at $350,  they were very cheap, (poor person didn"t know the value of what he had).

 

[Sherwood]

  For many reasons, I do not want to send my precious HP1000 to Joe, first, he is very old, and he takes a very long time to do the job, so, what if he expires, after finishing one side. They could also get damaged in transit, or worse, they could get lost in the mail. And the mother of all those reasons, what if I end up hating the way they sound after the mods.

 
You've mentioned that before in this thread -- I suspect that some part of you really wants to send them, but you haven't talked yourself into it all the way.  If it were still 2011 and he was turning them around in a few weeks, I'd say go for it.  With the trouble folks have been having lately, though, I don't blame you.  With any luck, you'll have the chance to hear Devouringone3's pair at some point.  
 
That said, I don't think it's possible to not like the sound.  The thing that distinguishes the HP1000 is neutrality and timbre, and this mod brings them a little closer to true life.
 
Of course, you prefer your PS1000, so this might be in the complete wrong direction for your tastes.  
 
As to getting lost in the mail, I'd say to just insure them well.  If they get lost, they were a good investment  

 

[devouringone3]

Yes, one day I might send my pair on a world tour, mainly to promote my lovely “sunflower” pads:

(Mini-tutorial)
 (you can do without the plastic toothpicks, the principle is the same; it's faster using your fingers, though maybe less accurate)
 

 

 

 

 

 

 


Apply the strip along the edge...

...proceed to add another “petal”

 


Repeat in an overlapping pattern...[...]

Trim excess Scotch-tape with scissors and voilà / behold:

 

 

 
You have the bass conducive (lows are extended), sealed yet airy foam pad which entirely supplanted Joe's improved flats for me. I have been using these pads exclusively for more than a year, going back to my old taped flats only to be rebuked*.

*My recurring problem (ultimately with all Grado pads other than comfies) is that they do not sound the same throughout the entire volume range; they sound muffled at low intensity, highs are next to absent. Their variable foam density (the stiffer layer on the rear especially) makes them incoherent/muddy/echo-y sounding and leaves much to be desired in terms of clarity, something that I noticed when upgrading from TTVJ's to Joe's flats. The HD414 as the base pad for the above demonstrated sunflower mod solves the volume related-sound uniformity and clarity issues while increasing comfort.

 

[Neal]

I had my HP-1s repaired by Joe in 2010. Both drivers and the Ultra High Bandwidth cable were replaced. However, in order to have Joe repair the phones he insisted on bypassing the phase switches. There was no wiggle room; I had to bypass the fully functioning switches or forego the repair. So on they went to Joe who did the repair, bypassed the switches, and sent the phones back. I have to say I was never happy about the bypassed switches. Yes the phones sound great but I always felt since then that my HP-1s were revised, not restored and lacked their original character. Fast forward to a few weeks ago I found a store on ebay called Amplifier_Surgery that offers upgrade amplifier packages and does limited repairs on a variety of headphones including Grado. So I contacted them and inquired about wiring the phase switches back in. Hamad said it was very do-able providing Joe left the switches intact. The charge was nominal, including insured shipping. The phones are home and are fully functional and sound great.

 

[ruthieandjohn]

  I had my HP-1s repaired by Joe in 2010. Both drivers and the Ultra High Bandwidth cable were replaced. However, in order to have Joe repair the phones he insisted on bypassing the phase switches. There was no wiggle room; I had to bypass the fully functioning switches or forego the repair. So on they went to Joe who did the repair, bypassed the switches, and sent the phones back. I have to say I was never happy about the bypassed switches. Yes the phones sound great but I always felt since then that my HP-1s were revised, not restored and lacked their original character. Fast forward to a few weeks ago I found a store on ebay called Amplifier_Surgery that offers upgrade amplifier packages and does limited repairs on a variety of headphones including Grado. So I contacted them and inquired about wiring the phase switches back in. Hamad said it was very do-able providing Joe left the switches intact. The charge was nominal, including insured shipping. The phones are home and are fully functional and sound great.

Congratulations!  I'm pleased!  Even though I don't know why those switches were there in the first place, they render the headphone unique and I would hate to see them go!
 
Did you think the headphones sounded BETTER, or DIFFERENT, or THE SAME after Joe Grado's upgrade (just curious... would never have it done to mine).

 

[Neal]

That's how I felt about the loss of functionality of the switches. According to Joe, phasing between components wasn't standardized at the time hence the phase switches. He wanted audio engineers to be able to compensate for components being out of phase. Insofar as how the phones sounded after the repair, I sent them to him because one of the drivers completely failed. They sounded better after the repair than before the failure with the new drivers and cable in that they are now even more detailed than before. Whether that had to do with one of the drivers failing or about to fail I can't say. I read some time ago that others experienced the mandatory switch bypass so I wanted to get the word out that Amplifier_Surgery was a safe answer to the issue for me. I hope this answers your question kayandjohn.