Checkout my DIY Corda HA-1
Jun 9, 2002 at 4:25 AM Post #16 of 29
Kelly,
Photograpy is sort of one of my hobbies. As I've just discovered quality headphones I'm afraid that I will turn that into a hobby as well and spend too much money on it as I have with photography. Actually your prior postings on the corda was one of the reasons I went with it instead of the mg head. I listen to mostly classical and movie soundtrack music. I find your comments on the quickness of the corda quite accurate. I was a little dissapointed with the low end but I just swapped the cheap mini to RCA cable that I was using with some quality IC's and that made a whole lot difference to the low end. I actually bought the Radioshack mini-RCA adapter which allows me to use my regular RCA cables.

No DIY Kit for the META42
frown.gif
. I guess I'll have to learn to read a schematic diagram for this one
cool.gif
 
Jun 9, 2002 at 5:44 AM Post #17 of 29
Nah, get the board and I'm sure someone will have a doc explaining everything before too long if not with the board.

Believe me, this hobby isn't nearly as bad as photography!! At least there aren't expendables like there are with film. I easily blew more cash in the fist 6 months on photography than I had on 14 years of guitar.

I've only put a few grand into this hobby now and it's still going strong. I've put a few grand in film and processing alone nevermind the cameras, tripod, lens (and the good EOS lens aren't cheap as I'm sure you know), filters, flashes, accessories!!
 
Jun 9, 2002 at 1:41 PM Post #18 of 29
sunshine
I'm a little disappointed in the bass response of the Corda, too. It actually is, believe it or not, very good compared to other amps at that price but it doesn't have the bass extension or headroom of the MOH/Max/Blockhead. I'm looking into mods to help correct that and also help smooth it out as I feel the sound is a little on the grainy side. I think the stock Corda is really an awesome value but as always, I just want more.
smily_headphones1.gif


I'm glad you found my posted opinions useful since so many people just find them aggrevating, I think. As much as I like Jan, I'm also sorry to be taking away from Joe's business. Maybe he'll consider trying to get better speed and extension out of an MG Head-priced amp, though. It's a hard one to win. The Head has awesome midrange but at that price you have to give up something.
 
Jun 9, 2002 at 1:50 PM Post #19 of 29
Quote:

Originally posted by kelly
sunshine
I'm a little disappointed in the bass response of the Corda, too. It actually is, believe it or not, very good compared to other amps at that price but it doesn't have the bass extension or headroom of the MOH/Max/Blockhead. I'm looking into mods to help correct that and also help smooth it out as I feel the sound is a little on the grainy side. I think the stock Corda is really an awesome value but as always, I just want more.
smily_headphones1.gif


I'm glad you found my posted opinions useful since so many people just find them aggrevating, I think. As much as I like Jan, I'm also sorry to be taking away from Joe's business. Maybe he'll consider trying to get better speed and extension out of an MG Head-priced amp, though. It's a hard one to win. The Head has awesome midrange but at that price you have to give up something.


His crossfeed filter does thin-out the bottom end. Does this happen with the crossfeed off?

I suppose the op-amps could be oscillating.

Maybe some 'faster' caps on the power supply would help (elna cerafines, blackgates)?

It could also be a characteristic of the LM6171. I've toyed with the idea of changing mine and see if I can find a better opamp.
 
Jun 9, 2002 at 2:00 PM Post #20 of 29
Nezer

There is a *slight*perceived bass dip for me with the crossfeed filters engaged but I feel people have greatly exaggerated this effect and that the response seems overall falt compared to not having it engaged.

My posted impressions are, of course, with the crossfeed disengaged.

The guy modding my unit hasn't gone public yet and it'd be inapproriate for me to post details at this point. He's still reving a few ideas at this point and I'm sure he'll go public when he's done--whether he's offering to do it for other people or just wanting to post what all he did. Hang loose, it won't be long.
 
Jun 9, 2002 at 2:28 PM Post #21 of 29
Kelly I have to say I always look forward to reading your threads. They are entertaining.
biggrin.gif


The most entertaining was the one in Headroom Forum were a guy with just 2 posts had a profile with all sorts of top end gear. Of course you got stuck in to him...

something like this ..............

It always kills me when someone with just 2 posts has so much top end gear ....ect ect.,....

Keep up the good posts
biggrin.gif
 
Jun 9, 2002 at 4:01 PM Post #22 of 29
Quote:

Originally posted by kelly
Nezer

There is a *slight*perceived bass dip for me with the crossfeed filters engaged but I feel people have greatly exaggerated this effect and that the response seems overall falt compared to not having it engaged.

My posted impressions are, of course, with the crossfeed disengaged.

The guy modding my unit hasn't gone public yet and it'd be inapproriate for me to post details at this point. He's still reving a few ideas at this point and I'm sure he'll go public when he's done--whether he's offering to do it for other people or just wanting to post what all he did. Hang loose, it won't be long.


It's not slight to me at all...

So you know of someone actually modding these units?!? I'd be intrested in hearing his ideas when he goes public.

Some things I'm considering is a swap of the op-amps (thinking of OPA627s), maybe trying some faster power caps and possibly hacking-in a buffer across the power rails in the power supply after the regulators but prior to the 1000uf cap. That power buffer mod will probably really difficult on the PCB...

Replacing the op-amps will also likely require swapping some resistors. I'm not sure what Jan uses but I might fancy swapping all the resistors in the signal path with Vishay CMFs.

I'm really interested in putting together a Meta42 and trying a few things. I would bet that the Meta42 with some of these ideas would smoke the Corda.
 
Jun 9, 2002 at 10:16 PM Post #23 of 29
The crossfeed effect is so subtle that I sometimes have to check to see if I've turned it on. I to do notice that it slightly reduces the low end when turned on.

I do wish I have the chance like others here to listen to other amps for comparison but out here in the midwest hifi stores stocking headphone amps are rare.
 
Jun 9, 2002 at 10:35 PM Post #24 of 29
Well, I did it...

I replaced the stock power resivior caps with with 4 Cerafine 1000uf 35V caps. It needs to burn in a while before I can really come to any conclusions but initially the bass response seems to be a LOT clearer. Also, although I don't understand how, the whole thing just seems faster.

But, I will need to burn-in for a few days before I know anything absolute.

I think my next upgrade will be replacing the opamps. If I like how this all goes I may build one on protoboard and tweak it a bit...
 
Jun 10, 2002 at 5:03 AM Post #25 of 29
You might also want to alter the resistors that drive the opamps to class A if you are switching out the opamps, because I believe it is set for 10mA per opamp, which is fine for the 100mA capable 6171, but could possibly be a bit much for something like the OPA627 or others with less current capability. Check to see if they get too hot I guess, and then reduce the current or use heatsinks. I would probably leave the output stage alone because the extra current is nice for some headphones.

I really wish the META42 were a full-size amp board rather than a portable amp board. I have very little use for portable amps. Sure you can add your own monster power supply, but it would be a hundred times easier to have it built in to the stock board. Thus I'm really leaning toward building the Gilmore next if I have to do the power supply board myself anyway. That amp looks like it would be a worthy rival to anything solid state out there, Max included, and not just because Kevin says it sounds better than the blockhead.
 
Jun 10, 2002 at 5:15 AM Post #26 of 29
I was going to go through the spec sheets and adjust accordingly everything.
 
Jun 10, 2002 at 5:32 AM Post #27 of 29
Ken:
Thanks.
smily_headphones1.gif
I actually was making fun of the people (myself included) who are such materialistic bitches that we'll fawn over a newbie if he shows up with expensive toys. Just funny to me. The newb was actually a pretty cool guy and I hope we steered him toward gear that would compliment his Wadia, though I doubt we did since I'm not yet satisfied myself and I don't even have a Wadia.

Nezer:
How's that Analoguer treating you? When you adjust the bass boost on it can you "match" the crossfeed bass drop so that you perceive a "flat response" with crossfeed on? Any side effects of that?

sunshine:
Local stores here don't have much either. My auditions come primarily from:
1) local headphone group meets
2) Headroom loaner program
3) Headroom tour stop
4) (last resport) If I'm absolutely driven to try an amp, I'll buy it used just to hear it if I have to with the expectation of selling it and not taking too bad of a hit on it.

slinderman:
I wish I had that background to build Gilmore's amp. In my experience so far, no headphone amp (high end inclusive) gives me 100% of what I'm looking for. Mostly some hit in some areas, some hit in others--which makes it worse because it makes it more believable that one could hit them all. Maybe Kevin's get's closer than to what I'm looking for than what I've heard so far.
 
Jun 10, 2002 at 2:24 PM Post #29 of 29
Quote:

Originally posted by Ken
Analoguer
can anyone tell me if an Analoguer is a good investment?


It depends on your ears... It was a good investment to me but a high-end source might have been a better investment (which I'm now considering... Things like the Cary 306/200, Wadia 301, etc. I suspect a good source would negate the need for the Analoguer on my home rig in which case it would be moved to the office taking my PJB as a source.


Quote:

Originally posted by kelly
How's that Analoguer treating you? When you adjust the bass boost on it can you "match" the crossfeed bass drop so that you perceive a "flat response" with crossfeed on? Any side effects of that?


Well, it does help but it's different and it depends on the music. It's hard to explain and you would really have to hear it. The bass boost is more subtle than the crossfeed effect and you almost don't hear the new bottom so it's easy to over-do it. You have to really pay attention. I think he only boosts really low frequencies and less so the mid-bass and this really shows.

It does boil down to a matter of taste. The Analoguer helps on both instances but it's just not quite there. As I stated above I'm considering a high-end source and I'm also considering doing some of the DIY crossfeed filters and tweaking until I find one that suites me. I do prefer the headroom x-feed over Meiers but I'm sure others prefer the opposite.
 

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