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Audio-Technica AT-HA5000 vs. Higher Fidelity HA-01 (photos) - Page 7

post #91 of 126
Sorry, no pics for now Im in contact with the HK service centre for higher fidelity. I hope we can work something out about the gain... I'd prefer to know which 2 resistors to change for a diy lower gain setting than sending it all the way back to HK.

EDIT:

What a great service! We exchanged 3 mails in less than 12 hours, arrangment is made that i get a new amp board shipped (free!) and send my old one back after i got the new one. They believe its a faulty component on the board, the amp is designed to be used with both low and high impedance headphones.
post #92 of 126
hehe, i have also been in contact with the service center the last couple of days. They will send a new amp board to me as well. Great service for sure!

This amp will be killer with the noise issue resolved.
post #93 of 126
Thread Starter 
It's good that the Higher Fidelity service center is responsive and working to resolve the noise issue.

Hope it works out, you guys have our thanks for being the first to make the plunge.
post #94 of 126
Bobs, you better get your soldering skills together, see below..

Some more pics from the Inside:



main pcb removed...



Line In signal arrives here.. ALPS pot in the background



The final output stage for both headphone outs.



The other 2 amp stages..



What is under those things?....



Nice! No cheap connectors used for internal wiring,
all soldered to the PCB. These go to...



The headphone output (below).

Overall this looks like a very serious and clean design
with alot of quality parts. Even the power switch
feels great to switch on and off!

I am really curious how it would drive higher impedance
phones like the HD650, K701 and the others..
post #95 of 126
Still I wonder if the new board will fix this problem. Is it even possible to detect the headphones impedance and change the circuits gain setting accordingly? Any EE around? I somehow doubt this but im sure the people at higherfidelity know what they're doing. Or maybe they'll just send us a board configured for low impedance phones.
post #96 of 126
Bobs do you think your HA01 improves with burn in? I listened to "Fiona Apple - Extraordinary Machine" on the first day i got the HA01 and just again today, after leaving it on for about 100h. The drums on that recording sound sooo punchy, its just amazing. I was listening to that album with the AD2000 (which i got a few days ago) and thought "wow thats a f***** punchy headphone. Then i double checked it with the W5000 and wohoo it was the amp bringing the impact and punch. The amp has a very powerful sound. Also the pianos sound great and accurate, mellow when played quietly, aggressive when being hit alot harder. Even a hard played piano sounds kinda mellow out of the CD5300, but its not "warmer" at all, just as neutral as the HA01. Missing attack probably?

The AD2000 btw improves less with amping compared to the W5000, but it does improve enough to make it worth having a nice amp
post #97 of 126
Quote:
Originally Posted by bizkid
Sorry, no pics for now Im in contact with the HK service centre for higher fidelity. I hope we can work something out about the gain... I'd prefer to know which 2 resistors to change for a diy lower gain setting than sending it all the way back to HK.

EDIT:

What a great service! We exchanged 3 mails in less than 12 hours, arrangment is made that i get a new amp board shipped (free!) and send my old one back after i got the new one. They believe its a faulty component on the board, the amp is designed to be used with both low and high impedance headphones.
Good to know that their customer service QC is available and helpful....hope the new board will eliminate the nasty humming.

Please keep us posted with the results as I'm STILL up in the air with this amp.
post #98 of 126
Quote:
Originally Posted by bizkid
Bobs do you think your HA01 improves with burn in?
I honestly cant say that i`ve noticed any changes with burn in. It might have, but its hard to notice because i listen to it everyday. The punch/impact you are talking about is the first thing i noticed about the amp though, it really makes the W5000 a better headphone IMO.

I miss some of the warmth from a tube amp, but i`m gonna try to fix that with a new source, maybe a DAC-AH or something.

BTW, have you heard anything more from the service center? I have not heard from them since they told me about the new board.
post #99 of 126
Would it be safe to say that solely for use with the W5000, and without regard to budget, the HA5000 would be the one to get between these two? I don't suppose anyone has both these amps to compare head to head?
post #100 of 126
Bobs, after sending them my address i havent heard back yet

Nobody has compared both of them yet. I may probably get a HA5000 after my tax return and decide which to keep of the 2. If i just werent to lazy finishing it already
post #101 of 126
OH! now i got it! I should have read the manual earlier The whole point of the amp and its (patented) 3stage amping design is to allow the gain to be adjusted

from the manual:

"The Stage 1 Amplifier, which acts as the refernce amplifier, has the gain adjusted to amplify signal from the original input driving the Stage 3 amplifier"

"The Stage 2 Amp, which acts as the comparative amp receives a feedback signal from the output of stage 3 amp is then adjusted to obtain a null output signal except distortions these distortions from the stage 2 amp are simultaneously combined with the output signal of the stage 1 ref. amp for driving stage 3 amp"

"The Stage 3 amp which acts as the power amp receives the differentiated voltage signals ad simply transform into power signals dynamically with rise and fall at the speed of the original input signals without distortion"

So if im not mistaken it indeed looks like something isnt working correctly with this amp.

EDIT: Huh, the manual doesnt recommend using both terminals at the same time :?
post #102 of 126
Quote:
Originally Posted by bizkid
If i just werent to lazy finishing it already
Me too.
The socialistic suckers do owe me $6000.
Should be enough for a few toys.
How do you plan to power the HA5000?
Step down transformer?
post #103 of 126
Yes i plan to get a step down transformer but it's still somewhat in the future, i got no concrete plans yet. Maybe for xmas

Bobs, my board is on the way now, shipped via EMS
Amazing service. Alot better than what you get from most german companies.
post #104 of 126
Quote:
Originally Posted by bizkid
Huh, the manual doesnt recommend using both terminals at the same time :?
Yeah, i saw that too. However i cant hear any degradation of sound quality when i have both AD2000 and W5000 plugged in.

Just received an email with shipping information as well, looks like they are basically handling our case as one. My guess is they started to react when they received two complaints in one week from europe. After all, they are very interested in the western market, manual being in english and all.
post #105 of 126
Got my exchange PCB today. They told me to wait for further instructions before installing it but i went for it anyway ofcourse
Unless they will give some gain-tuning instructions later, they new PCB didnt help at all but actually there is a little more gain now, music is louder at the same volume setting than before.
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