Jump to content

ecp audio


dsavitsk
 Share

Recommended Posts

Correct me if I am wrong, but the L2 is not a hybrid if you are meaning hybrid as in an amp that has a tube and SS gain stage.

The L-2 is a hybrid in the sense that it uses both tube and solid state parts in active roles. But, the term is typically used for something that uses a tube for voltage gain and a solid state buffer, which is not the topology used. In the case of the L-2, as Nate noted, the tube is used for both voltage and current. Solid state parts are used for rectifiers, voltage regulators, constant current sources, and biasing shunt regulators. In other words, the tubes do the work, but the solid state parts set the operating points.

Also, the clear up a point, the output transformer has 32 and 300 ohm taps (labeled lo and hi on the front). The transformers have plenty of inductance such that any dynamic headphone should be fine -- you just choose the one that is closest. At the extreme, I found that with 600 ohm Beyers, it was helpful to put a 600 ohm resistor in parallel (to make a 300 ohm load) to make them sound their best (and the T1's did sound pretty good, b/t/w/ -- actually quite a nice combination) through they worked OK without.

Gain into 32 ohm is actually a little less than 5 -- just a bit over 3. Into 300 ohms it is around 8. These can vary slightly with different tubes. Practical power limit is a little under 1/2W, though distortion will be pretty high at that point.

Link to comment
Share on other sites

dsavitsk, thank you for the helpful explanation.

And to all, my bad if I caused a little confusion because I used the term "hybrid" quite loosely back then. I just thought that the L-2 doesn't look like a "traditional" tube amplifier so I went ahead with that term.

Link to comment
Share on other sites

Really nice review. I like the straight forward approach, without unnecessary verbage.

I remember being impressed with the CJ10 prototypes. I also love Doug's "understated elegance" approach to design aesthetic. Who in the world does that remind me of? :)

Funny your mention of the muddy mids of the Adcom. I did not pick up on this myself, until comparison to the Buffalo II. Spot on though.

Link to comment
Share on other sites

  • 3 weeks later...

I received the new updated PSU for my L-2 a week or two ago now. Some pics below for anyone interested.

The L-2 that I have now I initially had as a demo unit, Doug was extremely patient and let me demo it for an extended amount of time. I also want to point out his outstanding customer service, I sent in the "old" PSU for the L-2 and had the new one back in my hands within a week. In my book that's pretty outstanding turnaround time and the workmanship is top notch as well.

As for how the L-2 sounds - I think it's an extraordinary amp. It does an excellent job of getting out of the way - I've been using it with my LCD-2's and they've never sounded better. Btw, nice review Nate I agree with pretty much everything you said.

Link to comment
Share on other sites

  • 4 weeks later...

There are two different power supplies for the DSHA-1. One of them (the "ecp power supply") uses the same case as the L-2's power supply except that there are no venting holes cut in it. It is 8" x 4" x ~2.5". The other is an off the shelf AC wall wart (basically a transformer in a box).

Link to comment
Share on other sites

A reminder that I have a small number of DSHA-1 prototypes available. Circuit wise, these are virtually identical to the production version. The differences being that these run at about 75% the current of the production version, and they use the LL1544a input transformer rather than the LL1674. Both transformers are high quality, amorphous core Lundahls. The difference between them is that the 1544 is a 1:1 or 1:2 step up while the 1674 is a 1:2 or 1:4, and the level handling of the 1544 is a bit lower, so with a very hot source (Meridian), you can clip them in the extreme bass. That all means that the protos won't go quite as loud. Subjectively, they feel like they have a little less bass weight. However, they represent about 95% of the performance for much less money. They do quite well with both Grado and Sennheisers, and are what I use for general listening.

These are $925 shipped in the US. Each comes with the AC wall wart power supply and a balanced to TRS adapter for using unbalanced headphones.

dsha-1p.JPG

Edited by dsavitsk
Link to comment
Share on other sites

  • 1 month later...

The console has a DAC (which is a scaled down version of the Walnut circuit) fed from a built-in Airport Express, a tube phono stage, and an EL84 based fully differential, Class A power amp. (The speakers were designed for us by Dave at Planet 10.) As of now, the components are not really stand-alone products, but the power amp could be at some point.

Link to comment
Share on other sites

What type of potentiometer is being used the in the L-2 and DSHA-1 ? I didn't see them listed in the decription on the website.

I'm hoping to get a chance to see and hear them in person - they look excellent in photos!

Edited by M3NTAL
Link to comment
Share on other sites

  • 2 months later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...