[jacko2x]

Just received the EVA 2 Preamp last night for my SDS-254 Super Class D Amp. I'm in the process of burning it in, so as of now I can't really comment on it until it has been burned in properly. But this ends my search on a preamp and also completes my separates setup (for now). At the beginning of my search, I was looking at 3 other passive preamps (vol control):

1. Pass Labs B1 Buffer
2. Django TVC http://www.diyhifisupply.com/catalog/74
3. Ultimate Volume Control (with option to add a tube buffer stage in the future) http://www.diyhifisupply.com/node/599

Pro's with building the B1 was price and the enormous community support and reviews on it. To build it would cost approx $100-150 and up. The Django TVC on the other hand was well regarded in a lot of very well respected review sites, but the price of entry was too much for me. The ultimate volume control, looks really good on paper to me, plus it's ability to add a tube buffer stage in the future and remote control capability was another plus.

But after looking at several passive technologies for months, I remembered about LDR passives and saw some good reviews on it as well on the DIY community. Which brought me to the EVA 2 LDR preamp.  There was a time when the stock on these units ran out pretty fast, but my chance came up last week so I took the plunge for less than $400 shipped. Not sure if this is considered cheap and cheerful, but my other requirement was the need to have a remote control, and adding remote capability to the earlier 3 mentioned passives would add up to the cost so the EVA 2 fit the bill for me.

http://diyparadise.com/shop/index.php?main_page=product_info&cPath=18&products_id=113



The remote allows both volume control and input selection. To read more about LDR's diyaudio has a lot of info there but for the EVA 2 you can find what others are saying here:

http://www.rdhworld.myzen.co.uk/mybb/showthread.php?tid=11028&page=1
http://diyparadise.com/forum/index.php?topic=1088.15
http://www.hifiwigwam.com/view_topic.php?id=49222&forum_id=7

Also, the EVA (not the EVA 2) is available at a much cheaper price in a wood chassis and still maintains remote control, but only allows 1 input option. But it's out of stock.

So with all the available passives out there, I guess it's a matter of picking one's tastes.  Btw, this is my first passive and my first preamp so please go easy on me .  I may or may not get a tube buffer to see how well a tube stage will improve my setup. But the real reason for getting the tube buffer will be to make my solid state guitar amp/effects sound less solid state.

Cheers everyone...

EDIT: Forgot to mention that my setup is as follows:
Transport: Airport Express (Toslink) & Bravo D1 DVD/CD Player (Coax)
DAC: Audio-gd DAC19DSP
Preamp: EVA 2
Power Amp: SDS-254 Kit

* Added picture

[jacko2x]

Wasn't able to post any updates to the EVA 2 due to work and the completion of my Class D amp chassis.



Now that the chassis is done and my amp build complete, and after 2 weeks of burning in the EVA 2, I'll be able to give my feedback after the long weekend.

Cheers and Happy Holidays Everyone!
Ed

[jtsnead]

Hey Jacko,
Where did you get the "Super Class D" Logo?
Nice case, also like the power switch.
Love my SDS254!!

[Mariusz]

Hey Jacko,
Where did you get the "Super Class D" Logo?
Nice case, also like the power switch.
Love my SDS254!!

+1

[jacko2x]

jtsnead, Logo is etched and painted over.

Hey Jacko,
Where did you get the "Super Class D" Logo?
Nice case, also like the power switch.
Love my SDS254!!

[jacko2x]

Update:

So far as listening is concerned, the lows have more headroom than the lows on my 18wpc tube amp. Keb Mo tracks, Eric Clapton's Unplugged album,  Eagle's Hell Freezes Over, Diana Krall's The Girl In The Other Room and Yo Yo Ma's Cello never sounded better.  When listening to August Rush's acoustic guitar tracks, I can feel how real the guitar tapping is and how the guitar sounds decay very well. The soundstage is superb. The highs sounded sweet to my ears. On Lars Danilesson's Salzau Music on the Water album, when playing Part 2 & Part 3 you can hear how well the instruments separate. This recording was made in Salzau Pond during a Jazz festival in 2005, so you should be able to perceive being outside hearing wind, percussion and string instruments playing all around you. The percussion instruments (scaffolding, sound rods, cutleries and steel wires) in the track's recording of Part 3 are placed in such a way that you hear them clinking from left to right. There are instances when these percussive instruments disappear into the background so ever slightly until they just disappear, and the amp rendered it effortlessly and to my ears never sounded harsh, musshied (if it's the right word) and cramped. http://www.amazon.co.uk/Salzau-Music-Water-Lars-Danielsson/dp/B000FQJO56

And so goes my subjective review of the amp compared to my 18wpc  Qinpu Hybrid Amp.

Old Setup:
1. Integrated Amp: Qinpu A-6000 mkII
2. Source: Airport Express (AE)

Current Setup:
1. Power Amp: SDS-254
2. Preamp: EVA2 LDR preamp
3. Source: Audio-GD DAC 19 mk IV - Connected to my Mac (USB / Optical / streamed via AE) and CDP (Coax).

Speakers: Infinity Primus 360's
4. Source Material: 16/44 to 24/192 recordings from Keb Mo, Lars Danielsson, Yo Yo Ma, Eric Clapton, Diana Krall, Eagles, Peter Cetera Live, August Rush, Tuck Andress.

[RCduck7]

Since i received my EVA 2 that i ordered from DIY paradise i was impressed by the music the moment the unit was switched on apart from the hum i can hear through the speakers when the music is not played loud or at silent passages.
I have this the moment a source is connected to the EVA, i tried a few.
I'm not sure if i will still have this hum when i connect the EVA to other power amps, i didn't try yet but i didn't have "hum" with an active pre amp to my amp.
A friend told me that a passive pre or volume control has to be very good build to not have hum.
Do i have a faulty or not good tweaked EVA? Anyone have those problems? Or is the EVA2 made for low Watt class D amps and not so for power monster class A/B amps with lots of power and big transformers inside?
Anyway, i have to test some more or think of different options becausse i can't live with the hum.
The amp i use is a Dussun V8i integrated but the pre stage can be disconnected from the power stage is open to the user for other pre's to be connected.

[roymail]

A friend told me that a passive pre or volume control has to be very good build to not have hum.

I've never heard that, nor does it match my experience using both cheap diy and expensive passive controls.  First, I'd try it with another amp and/or gear.  Second, change out your interconnects.

After doing that you should have a better idea of what's going on with your setup.  Not saying it couldn't be the Eva, but I recommend you eliminate the obvious first.

[RCduck7]

I haven't had the oppertunity to try it with an other power amp yet but...

Well, this friend told me it was the EVA while my first thaught that it was the power amp.
Guess what, it is the power amp!
When i use the Dussun V8i integrated as a power amp, if i'm right it is the same as the volume is way up to the max of the V8i, then i can hear hum without the EVA connected.
I also tried an other active preamp, again hum, so i'm sure it is the power stage of the V8i, propably becausse the amp has big transformers inside, capable to 1200 Watt for each channel and i guess while this is a good thing it can generate a bit of hum i think.
I did have reduced hum when i connected my sources to the V8i and went from the "line out" of the V8i to the EVA and then to the power amp section.
I also tried to connect the EVA between pre an power stage of the V8i and there was almost no hum, but i don't intend to use the pre of the V8i together with the EVA, i like the sound of the EVA as it is as a stand alone to a power amp.
I also want to try out a tube buffer stage soon between the EVA and the Power stage of the Dussun it might kill a bit more hum to in the process.
But for now i'm happy connecting the line out of the V8i to the EVA, i can live with that.
My confidence is restored in DIY products.

[jacko2x]

Update:

EVA 2 has been performing flawlessly for the past 3 months. Like Roy, I hear no hum, but I discovered that the remote it comes with cannot be replaced with Apple's new (unibody-esc) remote. Too bad, but the good news is the remote now controls my unibody Mac Mini (music server). So many new toys this year

Based on the good reviews on the Dodd Buffer and now that I'm heavily invested in DIY separates, I just recently bought a 6922/ECC88 tube buffer from ebay called the Indeed Valve Buffer. If anyone plans to try out this product, my advice would be to get the cheapest one and go out to find some better tubes that'll suite your liking.  Seller says it runs in Class A operation, which I don't know how to verify (anyone care to help me identify this? there are circuit diagrams on the ebay posting) and the input impedance on it is 1MOhm. If both the LDR and the buffer synergize well, I'll be stripping off the EVA 2 and the buffer from their chassis' and merging them into one chassis and power them from a single clean power source (instead of two external power supplies). Soon I need to think up some plans to be able to have the signal pass thru the tube buffer or not. That way I can listen to music colored/uncolored by the tube just by switching it on/off. So it's off to looking for tubes and waiting for the delivery from HK to get here next week.

Cheers,
Ed

[RCduck7]

Update:

EVA 2 has been performing flawlessly for the past 3 months. Like Roy, I hear no hum, but I discovered that the remote it comes with cannot be replaced with Apple's new (unibody-esc) remote.

It seemed the hum was coming from a ground loop from my power amps, all bad things were gone when i disconnected grounding from the power amps.
I'm also intrested in a tube buffer, the reviews of the Eastern Electric tube buffer are promising but it is defenitly not the cheapest you can get.
If the Easter Electric buffer would be better then your average tube buffer that would be questionable.

[RCduck7]

I know this topic is old, so is this EVA 2. i connected this one again after a long time and there is a problem with it. When i power it, it goes on and off constantly and screen is blinking. I think i took the pre out for an pre in instead. Is it dead now or just a fuse. Can it be fixed again?