[pigmode]

Quote:

Originally posted by Vertigo-1 And it might've been above the stock Corda, but below the modded one. Of course nobody wants 1st 2nd 3rd impressions, but rather how the thing actually sounded.

Still, that's a mighty impressive testimony for a DIY amp.

 

[andrzejpw]

Just wondering. . . why are you calling it an "eta42?"

 

[eric343]

The ETA42 is the previous board revision of the META42; since META42 stands for Morsel Eric343 Tangent Apheared 42, ETA42 stands for Eric343 Tangent Apheared 42 because we named it before Morsel really sunk her teeth into the project.

 

[andrzejpw]

So is the meta > eta?

 

[fiddler]

Regarding the addition of a cascode current source... How much of the improvement can be attributed to connecting the opamp's output to V- as opposed to V+ as in the original design, and how much to using a cascode as opposed to a resistor? I was hoping maybe Kurt or Jan could comment...

 

[JohnActon]

And again, another excellent, excellent review!

I especially liked the comparisons to the MID, as I have one. I found it interesting that the Corda Blue was more detailed (and I'm inferring from this, consequently faster) than the MID, which I think is a very fast, detailed amp in its own right. It's amazing that the Corda can surpass this without becoming edgy. I'd like to hear one.

And then, you say that the Headmaster goes even a level beyond this? Well now, you've got me dying to hear one of these. Aside from a couple dissenting opinions that it's a bit "bright" (and these are definitely in the minority) I've never seen a disparaging review of the Headmaster. If you get a chance, I'd love to see how it does as a preamp.

Thanks again, Kelly!

 

[KurtW]

fiddler, I can't give you a definitive answer to your question, as I did both changes at the same time. There are many who say that the resistor approach isn't nearly as good, and certainly in terms of having a constant bias, it's not.

JohnActon, the Sugden is a very good preamp for it's price range, but is not the proverbial "wire with gain". The sound wasn't quite as transparent when inserted between my DAC and amp as going direct was (I didn't need the gain). Nothing else is either, but I've heard better in this test, although they were much more expensive preamps. For a Headphone amp with a preamp built it, for the price the Sugden is fantastic.

 

[fiddler]

Kurt, any ideas on how to remove that annoying nut on the Corda behind the crossfeed switch knob without buying a special tool?

 

[KurtW]

Yes it is annoying; mine never had it. I wouldn't mind buying that special tool if I knew where to find it. The only solution I know of is using a dremel tool to cut it off. Any scars left next to where the nut was will be covered by the knob. Just be careful not to scratch the front panel while doing the work.

 

[Nezer]

Quote:

Originally posted by fiddler Kurt, any ideas on how to remove that annoying nut on the Corda behind the crossfeed switch knob without buying a special tool?

I wedged a small flathead screwdriver and hit the end until the nut came loose. Now I just use my figers and tighten/loosen. I tighten it just enough to stay on so I can get it off next time.

 

[fiddler]

Brilliant, Nezer! It came off just as you said it would. I just did the only mod I could do due to lack of parts: connect the resistor to V-. Did it make a difference? To my ears, yes. What immediately hit me was an increase in impact, particularly in the bass. In fact, the bass in general is fuller and better defined. The midrange also benefited; it seems to have a little more body than before. Remember, these are just initial impressions and my opinion may change dramatically after a little more extensive listening, but there is a clear difference to my ears. I'll post more detailed comments later.

Oh and by the way, I didn't put that wretched nut back on, as I didn't really see the point of it being there... Does it serve some sort of purpose? The only thing I could think of that the switch could get damaged when the knob is pushed in suddenly, and it could break off the PCB?? Kurt, does your Corda just not have ANY nut there, or does it have a more conventional one?

 

[eric343]

I assume you're supposed to remove the knob, first...

 

[fiddler]

Quote:

I assume you're supposed to remove the knob, first...

Oh really? Was I supposed to do that first? Darn, that's why the faceplate broke in half. I'll be sure to take the knob first before doing that again.

<--- sarcastic, by the way

(What was the point of that post, Eric?)

 

[eric343]

I was just suggesting that there might be a way to remove the knob in order to get at the screw, instead of mucking about with screwdrivers and arcane tools.

No offense meant

 

[KurtW]

My unit was a kit, and there was no nut. The switch is held to the pcb by two screws. I suppose the nut makes it even more rigid, but I don't see the need for it.

I'm glad to hear that this worked on two units now. Good job, Nezer! Seems like I tried doing this but gave up because I was afraid of the screwdriver slipping out and scratching the faceplate.

fiddler, if you're interested in some "used" OPA627 at a good price to try in there, let me know. I tried the 627 and then ended up using 637 after increasing the gain closer to the recommend value for the 637, so I have some 627s left over. This is an easy mod, just lift some pins.