[003]

I would really like to know, what is the impedance of the Grado HP-1000?

I have spoken with two people who OWN HP1000s and they didn't know for sure what it was

Would anybody happen to know this random bit of information off the top of their head?

 

[iPatcH]

My guess is 32 Ohms, like all Grados...

 

[Jahn]

Yeah, impedance is low (40? dunno if it's 32 but it's definitely not over 100! Koss clips are 60, and i know the HP2 is lower than that) but these cans are INEFFICIENT. So you'll still need a beefy amp with lotsa current to power these guys up.

 

[003]

Thanks for the info. Now I'm also curious, does anybody know the sensitivity (dB per mW)?

EDIT:
And I still get the same kind of response from more people that own them (I think, I guess, I assume)

It seems like some kind highly kept secret!

 

[adamse]

Maybe you could contact Grado and ask them?

 

[robm321]

I've tried them with a lot of different amps. Tube and SS and the Melos was the only one that made them next level. So, find specs that match the kind of current the Melos can give.

I didn't try the super expensive high end amps for obvious reasons... I don't own them.

 

[003]

Quote:

Originally Posted by robm321 /img/forum/go_quote.gif So, find specs that match the kind of current the Melos can give.

Err, what about a Singlepower MPX3 SLAM with 6bl7gta output tubes?

 

[daveDerek]

Quote:

Originally Posted by robm321 /img/forum/go_quote.gif I've tried them with a lot of different amps. Tube and SS and the Melos was the only one that made them next level. So, find specs that match the kind of current the Melos can give. I didn't try the super expensive high end amps for obvious reasons... I don't own them.

did you try any grado (joe or john) amps, mad amps, or singlepower amps? an expansion of your original statement would be appreciated. tia.

 

[slwiser]

I don't know the source of this info but take it with a grain of salt:

http://en.wikipedia.org/wiki/Grado_Labs

40 ohms as shown there.

Add this to your reading about the "HP-1" Grado Signature

http://www.positive-feedback.com/Issue15/rkv.htm

Talks about the HP-1 having a 40 ohm impedance.

 

[003]

Yes and it's also listed as 40ohm on headphonereviews.org...

I think 40 is the closest to being true at this point.

Now what is the sensitivity and driver matched dB for the HP1, 2 & 3? (well 1 & 2 have the same drivers, so..)

 

[Rise To The Top]

32 is my guess. Probably slightly more though.

 

[recstar24]

40 ohms impedance

I have the number somewhere written down when I spoke to Joe Grado last time we had a chance to chat. I will try to find it.

 

[003]

I just found this:
http://www.head-fi.org/forums/showthread.php?t=1139

I have no idea where the info came from or how credible it is, though.

 

[jpelg]

[size=xx-small]Not necessarily from Joe Grado himself, but still pretty credible, imo...[/size]

This Stereophile article from 1992 reviewing the Melos SHA-1, mentions the Grado headphones it is designed to drive are 40-ohms.

Also, in this Positive Feedback article reviewing the RKV amp, former Maestrobating guru Carlo Flores mentions his HP-1's are 40-ohms.

 

[robm321]

Quote:

Originally Posted by daveDerek /img/forum/go_quote.gif did you try any grado (joe or john) amps, mad amps, or singlepower amps? an expansion of your original statement would be appreciated. tia.

I tried them with the Singlepower MPX3 briefly. They sounded pretty good. I think you could find the "right" tubes which would tailor them to what you like.

I heard them with Joe's amp HPA-1? at a meet and was not impressed. It sounded ok but didn't have the impact/dynamics of the Melos.