Headphone identification?

[jjcha]

Just curious as to why you say these may be "an early prototype"? They are Joseph Grado HP1000 w/Polarity Switches as @megabigeye mentioned. These also are missing the silk screening around the cups/rod bocks, as well as polarity indicators around the switches, and most of the switches went bad and Joseph bypassed them when serviced. I wouldn't exactly say "you just hit the lottery"...not by far due to their condition. These definitely will not bring many thousands of dollars.

Yeah. I had never looked that closely at the HP-1 polarity switches -- but fortunately I have mine right here and I think it's just a cover/cap that can be removed?

 

[joseph69]

Yeah. I had never looked that closely at the HP-1 polarity switches -- but fortunately I have mine right here and I think it's just a cover/cap that can be removed?

Probably glued on like any other button on a Grado grill.

 

[megabigeye]

I wouldn't send a dime of my Money to that site. At those prices, there's definitely something very wrong going on, unless they don't work at all. I didnt look any further into the listings.

Oh yeah. Definitely a scam. I meant that as a joke.

 

[Philimon]

Unfortunately, the price of these headphones have gone down bit.

It might've been because I was promoting the info that these early Grado drivers were modified Nakamichi SP-7 drivers which was also probably a long held secret by greedy bastards.

Lottery is hyperbole, but in Grado audiophile land its as close to winning lottery as you can get.

 

[Philimon]

Nakamichi SP-7 prices are trending way way up!

 

[ESL-1]

They look like prototype HP1000’s to me. Great find if that’s what they are. What are you plugging them into and how do they sound?

The answer may have already been given. This one of three models of Joseph Grado’s (John’s uncle). He designed them for neutrality and as a tool with the design of some top line recording microphones.

The one shown is the HP1 with the phase switches. Its retail in the day was $595. Next version is the HP2. Same tight tolerance matched drivers with a retail of $495. The last was the HP3 @ $395 retail and not as tight a tolerance in driver matching. The HP2 is my own favorite as the phase switches often caused issue as they got older and the switches taken out of the circuit.

There were a limited number made so finding one for sale is not easy especially if it is near perfect condition, around $2000. The red stenciled letters are very delicate. I have a pair I got from another head fi buddy who was worried to use them. They are now near perfect with a few small spots missing. They sound great with my Melos SHA-1 preamp.

Working ones that are not so clean or perfect would be hundreds of dollars less in cost but still not easy to come by. A special bit of Grado history.

 

[Strat1117]

The answer may have already been given. This one of three models of Joseph Grado’s (John’s uncle). He designed them for neutrality and as a tool with the design of some top line recording microphones.

The one shown is the HP1 with the phase switches. Its retail in the day was $595. Next version is the HP2. Same tight tolerance matched drivers with a retail of $495. The last was the HP3 @ $395 retail and not as tight a tolerance in driver matching. The HP2 is my own favorite as the phase switches often caused issue as they got older and the switches taken out of the circuit.

There were a limited number made so finding one for sale is not easy especially if it is near perfect condition, around $2000. The red stenciled letters are very delicate. I have a pair I got from another head fi buddy who was worried to use them. They are now near perfect with a few small spots missing. They sound great with my Melos SHA-1 preamp.

Working ones that are not so clean or perfect would be hundreds of dollars less in cost but still not easy to come by. A special bit of Grado history.

Although it might no longer be perfectly ‘stock’, paintfill on metal is an easy fix, if my limited experience in restoring vintage putters is any indication. I’ve done it a dozen times on both stainless and carbon steel. All you need is a paint pen and an acetone soaked (but not dripping wet) q-tip. Fill in the letters with the paint pen, then carefully wipe away the excess around the edges with the q-tip before the paint dries - all that will be left is your perfectly restored lettering. Just be certain the raw metal finish metal isn’t sensitive to acetone (idk about aluminum, for example), and do not let any paint or acetone drip onto the drivers!!

 

[joseph69]

Although it might no longer be perfectly ‘stock’, paintfill on metal is an easy fix, if my limited experience in restoring vintage putters is any indication. I’ve done it a dozen times on both stainless and carbon steel. All you need is a paint pen and an acetone soaked (but not dripping wet) q-tip. Fill in the letters with the paint pen, then carefully wipe away the excess around the edges with the q-tip before the paint dries - all that will be left is your perfectly restored lettering. Just be certain the raw metal finish metal isn’t sensitive to acetone (idk about aluminum, for example), and do not let any paint or acetone drip onto the drivers!!

There is no recess in the aluminum cup for the lettering...it's directly on the surface of the cup.

 

[Strat1117]

There is no recess in the aluminum cup for the lettering...it's directly on the surface of the cup.

Ahh …. Then never mind.