Headroom Module Archive thread
Sep 8, 2005 at 8:23 PM Thread Starter Post #1 of 111


Headphoneus Supremus
Aug 3, 2005
With all the versions of headroom amps, and the changes in naming for their modules, I would find it very useful to have an archive of the different modules that were used, including opamps used etc. Headroom amps seem to be quite a good buy on the used market, and knowing which module is which would make buying easier.

I have a 2003 Supreme and just picked up a 2004 Cosmic Reference (before the module change), and have no idea what the modules have on them, which are in class A, etc. The sound is very different between the 2, and compared with the new desktop portable, but it's still possible they use the same opamp.

Any insights appreciated!

Edit, March 19th 2006: The actual archive begins at post no. 16. Things sure have come a long way since September...
Sep 8, 2005 at 11:56 PM Post #2 of 111
I reckon I should be able to help here. I'll get Mike (our service guy) to work on this a bit. Maybe we can come up with some pictures to reference things. But it sure won't happen overnight. FWIW I would guess there's about 12-18 different modules out there.
Sep 9, 2005 at 8:45 AM Post #3 of 111
I think this is a great idea!!!!!!!!!!!

I see these old school H.R. amps in old copies of stereopile and what not But that was before my time and I get confused with the new (not the new new but the new before new new) and old school's

Tyll Its great you and the boys and girls are doing this! take your time and do it with panache!

cant wait but I will live until.hehehehe
Sep 9, 2005 at 1:57 PM Post #4 of 111

Originally Posted by TheSloth
Thanks Tyll, super helpful as always.

Sort of related, am I nuts to prefer the sound of the old reference module (in a cosmic (opa627)) to the new home module in the desktop portable? And it still gets 20 hours on batteries... It's a shame you don't offer it any more!

I'd love to give you a chance to hear it again with the Desktop Module in it, I find it significantly superior to the old modules. YGPM.
Sep 22, 2005 at 5:28 AM Post #9 of 111
sounding real good. enjoy your new toy. im feelin the itch! keep the impressions coming. how does it perform regarding diffferent souces, i.e. computer USB (lossless) and decent CDP? if using dedicated CDP, im assuming you are bypassing the CDP DAC and using optical input? i really want that amp
Sep 22, 2005 at 4:24 PM Post #10 of 111

TheSloth, I'm glad you're diggin' your amp.

I just wanted to try and clarify the Module thing a bit.

The 04' Standard Module used multi-layer ceramic caps and ceramic resistors with 2x OPA2134 and 1x HA5002 on a two layer circuit board.

The Micro and Desktop Module both use .1% film resistors and 2% film caps throughout the audio path. These are manufactured on a 4 layer circuit board. This is a bit of an upgrade from the Standard module.

There is no equivalent to the Premium module.

The only difference between the 04 Reference and the new Home module is that the Home Module is on a 4 layer circuit board allowing better signal routing. It's difficult to hear any difference but it measures a tad bit better. For all practical purposes, they're identical.

The Max is well, the MAX. Our attempt at something better sounding than the 04 Reference. It's certainly more expensive. I'll leave the comments about sonics to others.

Hope this helps,
Sep 27, 2005 at 2:45 PM Post #14 of 111
Looks like I never bothered to make space for the lower power modules, so here is my first attempt:

'04 low power module for Coda:
OPA2137U, HA-5002, Ceramic Caps/Resistors, 2 Layer Circuit Board.

'05 Micro Module:
AD822, HA-5002, Metal Film Caps/Resistors, 4 Layer Circuit Board.

Both modules get 20 hours battery life on 2 9v Cells.

Note I've been updating the earlier post with details about the other modules. (edit: now removed, information integrated into later posts)

There will be much more interesting things to come in this thread soon, but I'll let you know about that in due course...

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