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Grado HPA-1

post #1 of 20
Thread Starter 
I just found out that Grado made this amp and I was curious to its sound qualities with Grados. If anyone has pics that would be sweet too.
post #2 of 20
I got one of these. I have never had time to hear it. I lent it to Zanth. Also I lent it to GSferrari for a short while.

It's old very old.
post #3 of 20
Joseph Grado Signature Products HPA-1 Headphone Amplifier



Designed by the legendary Sidney Stockton Smith of Marantz fame, this amplifier uses custom-made capacitors and a volume control specially-made to Joe Grado's requirements. A one-of-a-kind symmetrical copper conductor is used in all of the amp's point-to-point wiring, and custom-designed RCA connectors are also employed. This amp was made in extremely small quantities before being discontinued because it was too expensive to make.



The HPA-1 is one of the best compact headamps around and was made/tested by Joseph Grado himself. The HPA-1 has a special synergy with the HP-1000 headphones. The original retail of this headphone amplifier was US $795.



Here’s the power supply:



It’s built like the proverbial chit house. I believe it has an Alps Black Beauty volume pott.

There seem to be 2 types out there. 1 is built with perf. Board on some areas and not as finished inside as the other type which is probably the full blown production run.






Mitch
post #4 of 20
Is it kind of similar sounding to the Ra-1?
post #5 of 20
“Is it kind of similar sounding to the Ra-1?”

I don’t know I’ve never heard the RA-1. I believe it’s along the lines of the synergy thing HP1000’s + HPA-1 and the RA-1 + RS-1. While the RA-1 is often disparaged for its simple design it’s supposed to sound really nice with the RS-1’s.

The build quality of the production HPA-1 is staggering but then it sold for $795 more than 10 years ago- there’s a reason Grado Labs was in the red and losing money in those years = engineering without compromise.


The electronics are potted in place under a metal shield and I don’t know of anyone who’s opened it to see what the design is.

I liked it enough that I regretted selling it and tried to buy another but that one was destroyed in by UPS.


Mitch
post #6 of 20
I asked John Grado about the HPA-1 vs. the RA-1. Quote: "It's the same circuit." Whether or not that translates into similar sound, I couldn't tell you. I heard the HPA-1 briefly, but did not do a head-to-head with the RA-1. The thing that struck me about the HPA-1 was its size.......it's small! Much smaller than the pics had led me to believe.
post #7 of 20
From the pictures it looks quite substantial.
post #8 of 20
Quote:
Originally Posted by GoRedwings19
From the pictures it looks quite substantial.
Substantial in build quality? yes.
Large in size? Most definitely not.

EDIT: Maybe my impressions of its size has something to do with the larger amps it sat next to at Bozebutton's house, because I just looked up the specs, and according to Hirsch, it is approxiamtely 6" X 3" X 8"......not large, but it doesn't seem to be as small as I remember. But I do recall remarking that it seemed a lot smaller than the pictures I had seen of it.

In comparison, the RA-1 is 5" X 1 1/2" X 5 1/2".
Sorry for any confusion, but I guess size is relative.
post #9 of 20
I don’t have one so I can’t show a picture with something to compare the size of it to but when looking at the picture (for perspective) keep in mind the:

¼ inch headphone jack on the front
RCA’s on the back
9 volt batteries inside

Yes it is small but not tiny. As a form factor it was just about perfect to me- not too wide – not too deep - not too tall. But large enough for easy operation – stability and gorgeous to look at. You weren’t going to drag it around the table by the headphone cord with out a fight.


Mitch
post #10 of 20
"Is it bigger than a Breadbox?"

Actually, I think it's exactly the size of a breadbox. It takes up the air of two Solos stacked on top of each other, if that gives you an idea, Red. Compared to the Solo (and the RA-1) the HPA-1 is a mellow fellow. Alot smoother than the RA-1 - some folks think it's because of rolloff, but I didn't feel that. It's not as impactful as the Solo, not as much slam. It's gentle and observant for a Solid State - doesn't color like the Earmax does. Pleasant, but matched with the HP series this might be the first Solid State Amp to put me to sleep lol. These are my impressions from the NYC fall meet.
post #11 of 20
The sound is similar to the RA-1, but in close comparison HPA-1 is smoother with noticeably less grain. The regulated power supply was a $125 option, and allows selection between AC and battery power (note the use of the Ultra-Wide Bandwidth Reference cable). It uses two 9v batteries, same as RA-1, but there's room in the battery compartment to carry a spare set. I got approx 25-30 hr on a pair of Plainviews.

There was never a production run, per se. All mechanical work was done by Joe Grado himself. All electrical work was done by an engineer who originally worked on QC for Marantz (I've forgotten his name, unfortunately). Those two people built all of the HPA-1's by hand.

It's a fairly warm sounding amp. The weak spot, compared to today's battery-powered amps, is the low end. There's less bass extension and definition than the best of the battery-powered amps (Headroom Cosmic, Gilmore AE-1, Ray Samuels SR-71 are some that I've heard with better bottom ends).
post #12 of 20
Quote:
Originally Posted by Hirsch
The sound is similar to the RA-1, but in close comparison HPA-1 is smoother with noticeably less grain. The regulated power supply was a $125 option, and allows selection between AC and battery power (note the use of the Ultra-Wide Bandwidth Reference cable). It uses two 9v batteries, same as RA-1, but there's room in the battery compartment to carry a spare set. I got approx 25-30 hr on a pair of Plainviews.

There was never a production run, per se. All mechanical work was done by Joe Grado himself. All electrical work was done by an engineer who originally worked on QC for Marantz (I've forgotten his name, unfortunately). Those two people built all of the HPA-1's by hand.

It's a fairly warm sounding amp. The weak spot, compared to today's battery-powered amps, is the low end. There's less bass extension and definition than the best of the battery-powered amps (Headroom Cosmic, Gilmore AE-1, Ray Samuels SR-71 are some that I've heard with better bottom ends).
Actually the weak spot might suit some Rs-1 owners given that some of them feel the bass is a bit too woolly and nutso. I will have to spend some time with it.
post #13 of 20
Thread Starter 
Wow that is a great looking amp. It looks really well built too. How much do you think it would sell for today?
post #14 of 20
there was one hanging around audiogon forever for around $450 i think. not a hot market for it, so if you see one you should be able to get a decent price.
post #15 of 20
there was also one on thsi site for sale a fiew months back.
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