eddie current ec-ss - Page 9

Just how much longer do we wait for EC/SS???

Placed my order with Todd today after speaking with Craig. If you bought the ECSS from Todd recently, you're likely one of the 20 units being shipped to Todd at the end of March, shipping thereafter.

It's going to be one hell of a painful wait, but anticipation is always a very good thing. Can't wait to hear this little brick sing!

I got an "accidental" email from Craig today (meant for TTVJ, but since my name is also Todd and I've emailed before, he sent it to me by accident). He OK'd my posting the info.

Yes, end of March is the latest ETA. A little more info, quoted verbatim from Craig's email with his permission:

- I pulled the trigger on the AD811 video amplifier. After A/B'ing it with the AD847 there was no contest

- I had been running the AD847 which is also fantastic, but the amp just came to life with the AD811

- EC/SS is shipping with 2 AD811's. and 1 AD708. It has a 50K input impedance, and is now a firm favorite with my RS-1's. Needless to say it is quiet enough for ear buds, but powerful enough to easily drive 32 ohm cans to several watts

- The AD708 is only used for the DC servo, and the integrator time constants are so long it is invisible to the audio signal. This keeps the DC offset error at the headphones below a good cap coupled amp, because even the best caps having some leakage resistance. My Grado RS1's don't even sound like Grado's anymore, and they have become a firm favorite

(End Quoting)

I had actually pre-ordered from TTVJ a while ago, and I can't wait for this to come in! I know a comparison was done between EC/SS and the Heed (which I now also own), but I believe the opamps used then were the AD847 or something else. Sounds like Craig's pretty high on these new video amps.

Yes, in particular Craig seems very excited with how the RS-1's bass gets controlled with the newest iteration. He mentioned the bloom was eliminated, which bodes very well, since the boominess can be distracting at times.

Do you need any mod to use the AD811's ?

I'm GUESSING no, but I'm no authority; it'd probably cost too much to add these opamps (they are pricier than the others) AND mod the circuit to accept them.

A look at the specs on the opamps may tell as well.....

AD847Spec

AD811 Spec

Did Todd receive the EC/SS's yet?

I believe its a slightly different circuit. The original EC/SS while being DC coupled doesn't have a DC server, so you needed to make sure that your source was free from serious DC offset, as well as choosing an opamp to roll in that either had great DC offset characteristics, or a DC null offset on one of the pins. The AD811, being a video opamp and not necessarily created for audio, would be an example of a "cranky" opamp that takes a bit more implementation to have it work. Hence the inclusion of a DC servo that would require the AD708 to make it work.

Please correct me if I'm incorrect. The new EC/SS have new circuitry including AD708 to accommodate the AD811's.

Can we use the older EC/SS version with AD811 without any mod ?

Please read and refer to skull guise's post #123 which is referenced to an Email from Craig. It specifically outlines a different circuit. That email corresponds to my discussions with Craig as well. If you tried to use an older EC/SS with the AD811, it would probably oscillate like crazy and dump tons of DC offset into your cans. The DC servo that utilizes the AD708 takes care of that issue

Confirming and adding to what recstar just said. Craig and I had email discussions about the opamps in the original EC/SS (mine is one of the originals). It was fitted with AD797's stock, and Craig told me it could use OPA627's just by swapping them in. I tried that but preferred the 797's - more air and detail while the 627's sounded distant. He also mentioned that AD825's could be used, but that they were surface mount chips and required soldering to an adapter. He said he preferred the 825's over the others, but with zero soldering skills I have not tried them.

At no time were the AD811's mentioned, and I'm sure if they could have been used in the first EC/SS's, Craig would have mentioned it. I really want to hear the new amp, as I'm curious about it's sound compared to the original.

A_Sr.

noticed I'm reaching 400 posts now, so I thought I'd take the oppurtunity to provide some information for a change

Interested in the all-discrete red hat amplifier discussed sometime last year, I recently shot Craig an email about it before the NorCal meet. He replied quite quickly, saying that the red hat had evolved into the EC/SS pro, which is his new solid-state balanced offering.
However, what interested me more was his mention of a discrete upgrade module to the existing EC/SS. It will be a single board which will drop into the existing op-amp sockets and effectively make this amp all-discrete. I think for his current run of amps he plans to fashion these modules and in later runs the plan is to integrate these modules onto the board, phasing out the sockets completely. To offer something like this in what I consider to be a tiny amplifier package is nothing short of amazing, but the real showstopper (for me at least) is that it's still going to be the same price as before.

Anyways hope this stirs up some interest, he's a great guy to talk to. I for one can't wait to try it out.

If I've said too much, please let me know and I'll edit/take out this post. Thanks!

i too was really interested in the Red Hat amp when the impressions started coming out a few months ago. i emailed Craig then, and was told that casing problems (among other things) prevented the first run from happening, but that it might be revisited in the future.

pricing was also a concern for Craig, indicating that the Red Hat might hurt the sales of the EC/SS. it sounds like he came up with a great solution. upgrade the EC/SS to fully discrete, and then add a balanced version in another price bracket.

great news, especially if the upgrade comes gratis.

at the EC/SS's current price point, it wouldn't be absurd to buy two to use as left and right monoblocks...

I'm bumping this thread to ask what the current opamp configuration of the ecss is. anyone know?