Headroom Module Archive thread

[RasmusseN]

Originally Posted by TheSloth

From post 21...


In other words, don't hold your breath...

Originally Posted by TheSloth

Are you being facetious, or did you simply not understand what has been said very clearly already?

There will be no more modules of this type, EVER. The replacements, involving a complete top to bottom redesign of the entire amplifier line will not be arriving for at least 2 years, and that is a conservative estimate. I have no information on this, nor is any information available or going to be available until nearer that time.

From your post before you made it sound like there wouldn't be anymore modules with that pin count and they will be designing something newer than you started talking about upgrading your existing amp and not waiting because there will be no new modules with the current pin counts.

I ment different modules with different pin counts which you failed to understand clearly but your a smart guy so you will clearly miss this just like you did before.

Have fun being all the time

[TheSloth]

After some very pleasant interludes by the member above, I have a small adjunct to the module archive, which is a comparison of the old (200x - 2007) wallwart with the new wall wart that is gradually rolling out on an 'as needed' basis in the Desktop line. I have no details as yet on when, if ever, the low end Desktop and Micro Amps will come with this PSU as standard.

Basics:

The old 'brick' is a simple linear regulated PSU, with a maximum current output of 240mA per rail. The new 'brick' is a larger, switching PSU, with a maximum current output of well over 1A per rail. The original PSU is set to a specific input voltage, whereas the new switcher is universal. The new switcher is a fair bit larger and heavier than the brick - something to be considered for those wanting to take two with them along with a Micro Stack.

Conventional PSU wisdom suggests that, within its current limitations, the old linear regulated PSU will be better than the new switcher, but as always with audio electronics, knowing the technology at the heart of a design does not tell you for certain how well it will actually sound in a given circuit/system.

My first comparison is with Max '06 Modules, using analogue inputs. In this configuration, the power consumption is getting towards the top end of the 'brick' output, but still within it. Headphones are HD 650's, with stock cable. I can't imagine anyone will have this configuration, as I would assume anyone with Max Modules will have a DPS, but it makes a good comparison at the upper limit of the old PSU.

This isn't a subtle difference in this config. Switching back and forth between the two, there seems to be reduced channel seperation and rolled off frequency extremes with the old brick, as well as slow and muddy bass. The new switcher seems to improve on all of these issues - the top end opens up significantly, and the bass is definitely cleaner. The high end is the most major area of improvement, where ambient details in the high harmonics fall into place where they seem to be simply absent with the old PSU. The switcher might err a hair too far in that direction, with the sound at least from my first impressions being slightly edgy where the old one was rolled off. Even with that caveat, given the choice, I'd go for the new PSU in this instance.

As a final test, running the amp at high gain with no source, and the volume control set to maximum yields a slightly lower noise floor with the new supply.

This is a worst case scenario for the old supply, as it is at the top of its ouptut range and has little or no dynamic headroom available. The next installment will deal with an 'absolute quality' situation, where the old PSU will be operating well within its output capability.

[applegd]

TheSloth,
What transformer is in this new switching PSU? Is it toroidal? Just curious, if it is possible that you can post a picture of the inside of this PSU will be very helpful. Any way it is too late for me as I am building "super" PSU by using amb's sigma22 board now.

P.S. Finally I finished the upgrade of my '04 Premium Module to '05 Max Module level (Why I don't say it is '05 Max now is I will replace 2134s with 627(maybe 827) later) by myself, it is amazing to see $50 parts can make this kind of sound quality difference.

[TheSloth]

Originally Posted by applegd

P.S. Finally I finished the upgrade of my '04 Premium Module to '05 Max Module level (Why I don't say it is '05 Max now is I will replace 2134s with 627(maybe 827) later) by myself, it is amazing to see $50 parts can make this kind of sound quality difference.

That's very impressive Applegd, and I'm pleased I was able to help you out along the way.

Please take some pictures and post them here when you change the opamps - it is after all a new module, albeit one of a kind. The folks at HeadRoom would enjoy it also.

From the size of the PSU I'd say no it is not toroidal. I am assuming it is actually very similar to the one in the original brick. I have some shots of the old brick innards that I'll post - the new brick didn't look as simple to take apart, but I'll take a look anyway.

[applegd]

Originally Posted by TheSloth

That's very impressive Applegd, and I'm pleased I was able to help you out along the way.

Please take some pictures and post them here when you change the opamps - it is after all a new module, albeit one of a kind. The folks at HeadRoom would enjoy it also.

I will post the hi-def picture of my module when I upgrade 2134 to 2827, but I will shield all resistors' value to avoid any potential leakage of Headroom's intellectual property info although no one from Headroom told me what is the value of each resistor.

[Tyll Hertsens]

Don't bother to spend the time blotting everything out, you can publish your photos as is.

[applegd]

Originally Posted by Tyll Hertsens

Don't bother to spend the time blotting everything out, you can publish your photos as is.

I have to say sorry, it is my personality that I have to do all things both legally and ethically.

The bottom line is I am one of the Headroom fans, I always think Headroom people are very nice and its product&service are very good.

Some people might say, Oh, it is just about $50 parts cost for the module upgrade, so the total cost is just about $50. I will say No. There are a lot other things as pre-conditions such as very good (SMD) soldering skill/experience, good soldering tools/equipments, electronic circuit design background, PCB layout design background etc, plus tens hours to understand the Headroom module design, order parts, finally desolder/solder the SMD parts. As a audiophile, I treat all these pre-conditions as FREE as it is my hobby. But if someone add all these stuffs together, it costs much much more money beyond $500 which someone can use to upgrade '04 Premium to '06 Max module. (Actually the cost of involved tools/equipments might beyound $500 depends on how smart he/she is.) So the upgrade cost of Headroom modules that Headroom charges still seems very reasonable to me.

[applegd]

This is one of my little project as SUPER HEADROOM FAN at least one year ago.

Before upgrade, stock '04 Premium Module.



Then I upgraded it to '05 Max module level by myself, the changes are all 0.1% tolerance Vishay Dale metal Thin film resistors throughout the circuit board, deep and full(including output buffer stage) class A biasing as '05 Max module, two layers of best tiny caps for power rail decoupling ......... The only thing I can change at any time but not change is the 2134s. I still haven't upgrade them to OPA627 yet as I think it is not cost effective to me any way and my MOH's sounding is damn good already(Couple months later after I did this upgrade, I got chance to compared it "side by side" with stock '05 MAX module, I trust my ears.).



Side Note #1: This is not the picture of the final module board, I did not even clean up the module board yet. I am lazy, I don't want to open up my MOH again.

Side Note #2: The resolution of above photos are intentionally reduced. Sorry if you see little bit illegibility.

To me this upgrade is for fun. Some challenges at implementation stage are soldering temperature control when dealing with certain type of caps, also developed my own procedure for desoldering whole module board off from the main AMP board(Trade secret)......