Grado "slam" at 600 Ohms?

Original AKG K240 Sextett (1975) - it's 600 Ohm.

 

Heya,

 

No.

 

But what you can do, is take a short cable and add a few 150ohm or 250ohm resistors to it ($1 each from parts express), and make any headphone into a high impedance load to couple with an OTL amp (I assume this is why you're looking for high impedance specifically).

 

As for other headphones that have energy like Grados do, the Ultrasone HFI 780 or PRO750 could be considered. An ortho might be interesting to look at here too (HE400). Maybe the DT880 even. You can also look at the HD598 or Sony MA900. And again, just get an adapter with some resistance soldered to it to bring up the impedance load for use with an amp that needs higher impedance (like an OTL or speaker amp with high gain).

 

Very best,

Edited by MalVeauX - 1/25/13 at 9:32am

Might I ask what the importance is of having a 300-600Ω headphone?

 

Btw HD700 has a good amount of energy at 100hz and 6-7khz.  I've never heard a Grado but I assume the HD700 would have some similar qualities.  I personally can't stand the HD700.

I'm glad my name choice distorts your facial expression!  for better or worse!!

 

the sextett isn't quite the same flavour as any Grado, but the 'slam' is pretty close.

There is A LOT more bass in a sextett (especially the very earliest production models), which the higher end Grados like the GS1000i gets close to, but the sextett will never have the resolving power of even the RS225i. 

 

It's just amazing considering it was born in 1975. 

I'm pretty hard-pressed to think of any cans that even sound like Grados AT ALL, much less high impedance. The closest I can come is the AD2000 but that's just as low impedance as Grado. The Sextett is nice but closer to the K501 than a Grado IMO. They have good mid energy like most AKGs I've heard but Grado energy is a little different. I'll be receiving the HD700 in a couple days so I can report on that soon, although I haven't owned a Grado in a year or so so I can't do a DIRECT comparison.

 

I agree with the idea to add resistors to a short cable. Grado's have a pretty flat impedance by frequency curve, which is a good sign that they would work with an adapter like this. I believe that headphones with large differences in impedance at different frequencies have the potential for their frequency response to change if resistors are added.

Koss MV1 - 250R and probably as close as you will get to the same level of punchiness (without being overly harsh or clashy, or cold); closed too. Still "flatter" overall, not as intimate (wider SS), etc - they're kind of like a "Grado Lite" (except for being harder to drive (higher impedance + lower sensitivity)). Otherwise I got nothing. Comfort/fit is equally quirky - they're softer on the ears, but very much "seal" to your head, and weigh relatively a lot (but you don't notice it that much - Jude made a comment about headband design and weight distribution about a year ago that I agree with 100% here; the MV1 are an example of that). Note that afaik, they were recently discontinued as well (Amazon still has them, but for how long I do not know (I don't think they're terribly popular, so you don't have to run out and rush)).

Now, as far as MV1 versus Grado overall - it depends on which Grado you want to talk about. The RS-1, GS-1000, etc are superior headphones in terms of comfort, detail, refinement, etc. The MV1 will be more on-par with the Prestige series, like the SR-225 and SR-325 (better staging though, which is an edge) - just something to keep in mind (basically, I don't think these will replace your RS-1, but they should give the SR-225 a solid run for their money (and they are closed and actually provide isolation)).

This is 100% correct. Remember that adding resistors will provide attenuation, and you won't remove the power requirements of the headphones (you'll just translate them "up" - if the amplifier can deliver that, it'll be fine); it's inefficient but if the amplifier requires it for stability/noise/etc reasons it isn't a bad fix. I think that's probably the best overall answer here; just throw a few hundred ohms in-line and you should be good to go (as Mal suggested). Make sure the resistors' ratings exceed whatever you're likely to put across them, just to be safe.
Edited by obobskivich - 1/25/13 at 4:50pm