[Hirsch]

Seven of us gathered at my place on Saturday to listen mainly to the Orpheus headphone. We had three HE90's and an HE60:

However, the star of the show was the prototype of a new amp by Headamp.com based on the HEV90. Here, Thrice listens to the new amp (the circuit seems to be complete, but the amp does not yet have a case):

This is a two-box design, with power supply in one box and amplifier in another:

Here's the power supply:

And here's the amplification section. Note that this amp uses the same tube complement as the HEV90 (2 12AX7's and 4 ECL86's):

One of the objectives of the meet was to compare the prototype to my Stax SRM-007t, which included the resistor in the bias line:

But I've got to admit that the prototype amp was the one that got me dancing (particularly to gpalmer's Bob Marley disc

):

I'll post a bit more about the sonic differences in a bit.

 

[Guss2]

Very,very cool Hirsch.I can't wait for my cans and amp to arrive

,any impressions would be appreciated.Did you experience any of the arcing problems with the new amp?That clone has one hell of a power supply,doesn't it?Gary

EDIT Isn't this amp gonna have balanced inputs?

 

[CD44hi]

Good to see the usual suspects again!

I had previously heard the HE-90 at a NYC meet (the last at Grado Labs to be specific). So it has been a while since that ocassion, but I do remember how dynamic and fast they were from the Meitner DAC/phillips combo.

From what I heard yesterday though, I believe that the guys which are getting the Headamp amplifier taylored for the HE-90 are in for a treat! To my ears the presentation was rather effortless and more vivid compared to the 007T stax amp. It is hard to come back to my rig after hearing such excellent sound. I would not even try to make any comparisons with the HE-90/Gilmore/Meitner/Phillips, since it has been such a long time. I can confidently say though, that to my ears, the Headamp/He-90 is a better combination than the 007T/HE-90 with the associated gear that was present at the meet yesterday.

On other notes, the AE-1 portable amp has quite the good synergy with the HF-1 cans (bowl pads). Dynamic and punchy. It sounds pretty good with a pair of Headphile modded SR200s as well. Nice little amplifier.
[edit] I'll post more in the AE-1 in a couple of weeks as I am listening to this amplifier for an extended period now.

 

[Teerawit]

Is the headamp prototype in GS-1 chasses?

 

[gpalmer]

Quote:

Originally Posted by Guss2 Did you experience any of the arcing problems with the new amp?

Not while I was there and I don't think it happened at all, though we did run into it with the 007t (In spite of the 5M resistor mod having been applied). It was within about 15 minutes of plugging in my set of brand new HE-90s for the first time!

Not a good experience!

Quote:

Originally Posted by Guss2 EDIT Isn't this amp gonna have balanced inputs?

It's sort of an homage to a past great so I think not...

 

[gpalmer]

Quote:

Originally Posted by Teerawit Is the headamp prototype in GS-1 chasses?

I think it's a little larger though I didn't have the GS-1 there to compare against. It's a deceptively heavy little sucker though!

 

[Teerawit]

Quote:

Originally Posted by gpalmer I think it's a little larger though I didn't have the GS-1 there to compare against. It's a deceptively heavy little sucker though!

I bet! That's one huge toroid!

 

[Canman]

Nice work Justin!

Did anyone compare the HE-60 from the 007t and Justin's amp?

 

[Guss2]

Thanks Gpalmer,all this time and I never realized the HEV90 didn't have balanced inputs.No big deal,sounds like this is a real winner.Keep the impressions coming guys.Gary.

 

[jjcha]

Looks like a load of fun. I count three HE90 - I know one's gpalmer's and the other's is Hirsch's - who's the lucky third person? Steveo didn't break down did he?!

Best,

-Jason

 

[bozebuttons]

Vrey Nice looking amp, can't wait to get a ear on it.
Nice dance moves Hirsch

 

[kevin gilmore]

For a size reference both circuit boards are 9 inches deep and 10.5 inches
wide.

 

[Tyll Hertsens]

Very nice, Justin.

 

[eric343]

That's a lot of Orpheus headphones in one place.

If not for the 9 hour trip from Boston, it would have been one more and a KGSS.

 

[Hirsch]

The Headamp amp (as yet unnamed) does not have balanced inputs. It is based on the HEV90 circuit, which is a single-ended circuit. Balanced inputs are not an option (they'd have to be converted to single-ended to work in the circuit anyway).

The base chassis is the same as the GS-1. However, the full chassis design is not yet done. I saw some of the material that's going to be used cosmetically in the final chassis. This amp is going to look sweet.

I noticed immediately that Justin's amp had a more "organic" sound than the 007t. There is a sense of ease and natural flow that is the hallmark of the HE90. The HEV90 is the best amp I've heard to bring that sound out of the headphone, and this amp may match it (I last heard the HEV90 with a Meitner source, and the Meridian G08 simply isn't as good, so I have no real way to compare even in memory). The Stax amp can let the bass get away from it, and start to bloat a bit. The Headamp offering has complete control all the way down. The Headamp amp also has a wonderful sense of space. It was immediately clear to me that Justin had accomplished his goal, which was to catch the magic of the HE90/HEV90 combination in a modern amp based on the HEV90. Bias voltage was dead on at 500v when we measured it.

While Justin's amp is designed for the HE90, it performs equally well with the HE60. I think the differences between the amp and the 007t were more subtle with the HE60, but still present. The HE60 does not go as deep as the HE90, and the deep bass was one area that the differences were large (at least to me). In any event, this amp can make Sennheisers sing.

This amp needs a name. Perhaps Eurydice? That's seems to be a natural pairing with Orpheus. Get one (and never look back)

Other notes from the meet. Thrice, the R10 that you listened to was the older "low bass" model. I had it hooked to an MPX-Slam demo. The current output of the MPX pushed some good bass out of the older R10. My suspicion is that the R10 is simply a current hog. When they aren't fed enough, the bass goes away. An amp that can put decent current into low impedances will bring out the bass in the R10 very nicely, even the older one.

The HF-1 headphone surprised me. Caught me flatfooted, actually. I hadn't planned on getting this, on the theory that I have enough headphones already. Oh well, wrong again. This headphone sounded absolutely wonderful driven by a Headamp AE-1. Excellent synergy there, with a very fast and clean sound. There's no way that headphone had any right to sound that good. I want one.