Latest news of Meier-Audio
Jun 27, 2001 at 9:00 AM Thread Starter Post #1 of 60

Jan Meier

King Corda
Member of the Trade: Meier Audio
Joined
Jun 21, 2001
Posts
854
Likes
182
Dear Headwizers and Headfizers,

I must admit, although Jude did a splendid job I do miss the Headwize community. Hopefully Chu will be able to solve his problems soon.

Not only Headwize has his growing-pains. Although still a hobby Meier-Audio has gone to a level that simply goes beyond my powers. I'm therefore very pleased that my friend and Headwizer Harald Graupner has agreed to help me with the construction of the amps. Together with Alexander Derevin (Odeen) who handles all credit card payments, we now have a triumvirate that tries to fulfill your headphone wishes as good as we can.

Nice help was also given by our fellow-headwizer Beni. Since he was tired of typing my rather long home-address he decided to register www.meier-audio.com. This address is directly linked to my home-page. Thanks Beni, one point less on my TO-DO list.

This list is quite long, actually. So many ideas that still need completion.

Chu Moy is presently editing a new article that will be loved by those who like to hear real deep bass but don't have the proper loudspeakers to make them audible. It's a nice technical project, although only suited for experienced DIY-people. I hope he will be able to present it soon. However, he's quite overloaded so be a little patient.

Another article in the pipe-line will present a number of techniques to optimize headphone performance (lowering/increasing output impedance of your amp, changing cables, damping of RF-noise, shielding, proper positioning, acoustic damping, ....). I hope to find some time to finish this one soon.

Also to be finished is my design of a portable headamp. If all goes well it should be available in approximately 6 weeks.

Some other ideas??
Yes, quite a lot. But they have to wait. First things first.

You might have noticed that I presently do not have any sales-actions. I'm not sure every Headwizer has found his way to Head-Fi, and therefore actions are postponed untill the Headwize forums are up again.

Thanks to all that have supported my request to add the CORDA Headamp to the database of AudioReview. I guess the chief-editor will be quite surprised when he looks at the number of positive responses. I'll note as soon as the CORDA amp is on the list.

Happy listenings,

Jan
 
Jun 27, 2001 at 3:55 PM Post #3 of 60
Hey Jan, in your spare time can you work on a tube amp?
biggrin.gif
 
Jun 27, 2001 at 5:21 PM Post #4 of 60
Yo Jan,

I'm glad to hear biz is going well for you! I look forward to reading about your portable amp on Headwize. Though I hope your next sales action is the Corda amp, so I can write a review on audioreview.com.

A few months ago I bought a pair of HD600 from you and appreciate the great service. They are now my best phones and I rarely listen to music with anything else.

Thanks,

Chewy
 
Jul 9, 2001 at 6:07 AM Post #5 of 60
Porta-Corda! Porta-Corda! Porta-Corda!!
smily_headphones1.gif


Jan, we're _very_ curious about the details. Same driving power as Corda 1? 9-volt, or AA's for power? How many? Recharging capability?

Thanks,

Alex
 
Jul 9, 2001 at 7:42 AM Post #6 of 60
** Same driving power as Corda 1?

Are you kidding?
The CORDA HA-1 has +15V and -15V powerlines!

This weekend I finished my first prototype and I'm very pleased with the results.

The amp is driven by a single 9V battery but also can be driven by an external power source that is to be connected to the battery clip. External voltages up to 24V are allowed.

Maximum driving capacity (depending on supply voltage) approximately 100mA per channel!

Maximum gain factor 17dB (7.2 x)

Current consumption approximately 9mA! With a single standard 9V battery (550 mAh) 48 hours of service should be within reach.

The amp has two crossfeed settings: stereo and medium.

By the time it will be available both as a DIY kit as well as assembled.

Size:

6.3 x 12.7 x 2.3 cm.
2.5 x 5.0 x 0.9 inch

The amp comes with a removable belt clip.

The first parts were ordered last week but delivery will take quite a while (custom made potentiometers by ALPS, minimum charge 1000 pieces!!)

Cheers,

Jan
 
Jul 9, 2001 at 11:03 AM Post #8 of 60
** did you use the lm6171 for this one?

Yes, I did. The reason is that even at a +/- 4.5 Volts supply this opamp is still able to throw out a 30 mA per channel. At these low supply voltages only very few opamps are able to do so and I didn't want to use a voltage multiplier (increases effective battery resistance and produces high frequency noise on the power lines).

In contrast to the CORDA HA-1 the opamps are not driven into class A since this would result in an increased current-consumption. However, by using a somewhat unconventional circuitry signal amplitudes are kept at a high level during the whole processing within the amp (and are not reduced by a potentiometer at the entrance) which effectively minimizes the audible effects of cross-over distortion and of noise.

Other parts included:

* A total of 2800 uF storage capacity.

* Wima caps for the crossfeed filter.

* Custom-made 9.5 mm Alps potentiometer with build-in switch.

* metal-film resistances.

* Custom-made Pactec enclosure.

Cheers,

Jan
 
Jul 9, 2001 at 12:51 PM Post #10 of 60
* will allow it to change between high and low impedance headphones?

No, it won't. I didn't have enough space on the front panel for an extra switch or headphone jacket.

However, I'm considering adding an adapter plug. No promises, however.

* And what'll be the estimated price?

Rough estimations:

DIY-kit $100,-
Assembled unit $125,-

However, don't kill me if prices are somewhat higher. I still don't have price-offers for all the parts like enclosure / potentiometer / opamps / front-plate etc.

Be patient ;-P

Jan
 
Jul 9, 2001 at 2:53 PM Post #13 of 60
I know what I want for christmas!

....well, provided I haven't made my own amp by that time and I don't still need to buy about 300 CD's.
wink.gif


I've noticed that you're also carrying AKG finally, Jan. When did that happen?
 
Jul 9, 2001 at 8:22 PM Post #15 of 60
Sorry Tyll and Todd - I WANT A PORTA CORDA!
 

Users who are viewing this thread

Back
Top