[TomS]

Now that there are quite a few pairs of Emerald Physics CS2’s out there in users’ hands, it would be helpful to the community to start sharing your experiences with amplifiers.  The CS2’s require 4 individual channels of amplification, with an upper section that is about 100db efficient and a lower section that is much less efficient and rather conventional in most ways, so this presents some really intriguing options.

While they indeed merit some state of the art amplification options, I’m more inclined to see just what is possible with reasonably priced stuff (depending on your perspective of “reasonable”).  At a price point of only $3k for these gems, that opens up the budget a bit for other gear too, so some will go that way too.

Here are some possibilities:

Approach #1: Four identical amplification channels.  The really nice thing about this approach is you don’t really need to measure, adjust, and match the upper and lower gains.  This can be achieved by four identical monoblocks, two stereo amps either vertical or horizontally biamped, or a multi-channel HT style amp.  Clayton Shaw used Bel Canto stereo amps at RMAF.  Zybar has used 4 channels of an ATI1506.  In my case, I strapped up four channels of an Arcam P1000 7.1 amp with decent results.  Lots of possibilities there at a very low cost. 

Approach #2: Four similar sonic signature amplification channels.  Gain may or may not be the same, depending on topology.  I've considered getting two more Odyssey Stratos channels, but what I'd LOVE to try is Hugh's LF55/LF100.  Other things that come to mind are RWA 70/30's, AVA, etc. (support your local AC vendor!)

Approach #3: Stereo or monoblock bass amps with guts on the LF (typically SS), and something more delicate with finesse for HF (i.e. tubes, even SET options).  I’m using Odyssey Stratos Extreme Mono SE’s for LF and the Bella Extreme 3205 Platinum on HF.  This is a very nice combination, as each amp is playing to its strengths.  The midrange/top end is very open and warm, while I can still apply some tube rolling to taste.  Baseline noise can be an issue at 100db efficiency so you have to choose carefully if that bothers you.  No different than some of the other high efficiency situations with single driver horns, etc.  What works there will probably work here too.  That’s great news because some of those amps are breathtaking in their clarity.

Approach #4: Stereo or monoblock bass amps and lower power SS HF amps (even T-amps or similar).  I’m thinking about trying the Stereomojo shootout winner, Trends TA10.1 ($150), maybe the highly regarded KingRex T20/PSU ($249/$169), or even one of Nelson Pass’s First Watt offerings, either original or DIY clones.  Not sure yet how to apply the various FW options (F1,2,3,4, Aleph J), as this system doesn't use a preamp in the conventional sense.

One issue with #2, #3, #4 is that you must have a way to match the gains, unless you're OK doing it by ear, that is independent of what’s programmed into the DCX.   The current DCX XO program already has +0.3db on the LF and -0.3db on the HF, so the relative amp gain settings must also take that into consideration (in other words, preserving that difference HF to LF).  While I have an o’scope, signal generator, dummy loads, etc. to do this precisely, most just do not have an easy way.  When I get to it, I’ll start another thread for that discussion, with the idea to use collective AC wisdom to come up with a simpler procedure everyone can use.  Maybe some tips and tweaks too

C’mon, don’t be shy, show us what you got 

- What amp combinations have you tried on your CS2’s (#1-#4) and how did it work out?

- What are you planning or would you like to try at some point?

Tom

[sunshinedawg]

Approach #5: Modify your DCX for digital output and use pure digital amps. Candidates for digital amps would be TACT, Lyngdorf, and the Panasonic digital receivers. I don't have oodles and oodles of money so I'm using the pannies. I have a Bolder Cable modified saxr-45 on the the lows and a saxr-25 for the tweets that I got off of ebay for $100. You could pretty much use any amp that has a s/pdif input, like any HT receiver(you would need a pair though).

I think they are fairly easy to drive, the pannies have no problems. There are lots of options here, allowing for personal taste. You don't necessarily need really expensive amps to drive these either. I paid $400 total for my amps(I do have some mods into the pannies, but they will work with out modification). The mods to the DCX cost around $180 in parts, to allow you to use a digital amp.

[GregC]

I already had some Bel Canto Ref 1000 amps that I used prior to getting the CS2 speakers.  They had been tricked out with Level 2 mods from Underwood Hifi and top of the line silver WBT binding posts and RCA connectors.  I considered these to be world class amps that I liked better than anything else I heard close in price, so I did not want to get rid of them.  I figured the amps would have plenty of grip to drive the bass, so I bought a pair of EVS 100M mono amps from Ric Schultz to drive the HF and that has made for a match in Heaven.  The Ref 1000 amps have plenty of headroom and the ability to grip the bass with an iron fist, and the EVS 100M amps have the delicacy, musicality, and air needed for HF duty.  Both sets of amps  have 27 DB gain so there is no problems there with matching.  Both sets of amps are fast and musical.  I have no desire to try anything else.

[sunshinedawg]

Is anybody still interested in an owners circle for the CS2's?

[TomS]

I would definitely be interested in an Emerald Physics owner's circle (not necessarily specific to CS2's).

[doak]

I've had my CS2's for a little over 2 weeks and am finally getting some hours on them.

I chose option #1 for amplification.
I ordered a quad of EVS 100M monoblocks from Ric Schultz to drive the speakers ($1500).
I had the amps a few weeks before the CS2's arrived so I got a chance to hear them on different speakers-REALLY good.
What I can say now is that this combinbation makes music!  The CS2's are VERY resolving and can sound very big when that's appropriate for the recording, or intimate too, but always clean and clear.  I'm using a Sonic Euphoria PLC for a control unit.

One thing that amazes me about this combo is that there's no "need" to turn up the vloume.  The option is always there when I want it though.  Fullness and dynamics are present at low volume like I've never heard on any other system.

I'm still playing around with wires and using adaptors for the balanced in/out of the DCX so the system is far from optimized.  However, I find myself listening to record after record.  For "digitizing" everything that goes through it the DCX does remarkably little damage to the analog signal. 

Loving it now and know it'll get even better.
Doak

[doak]

Is anybody still interested in an owners circle for the CS2's?

Yes!  The EP place over at AA is doing NO business.  It's be great to have one here where WE are.

[TomS]

Is anybody still interested in an owners circle for the CS2's?

Yes!  The EP place over at AA is doing NO business.  It's be great to have one here where WE are.

I didn't know there was one over there   Not that I want to be there anyway.

[TomS]

As I thought about it, one other factor I should have mentioned.  If using different LF and HF topologies, they should also be in phase.  If one inverts relative to the other that's a problem you'd have to deal with.  I think this can be addressed in the DCX if necessary.

[doak]

I had a B&K Reference 200.7 around and put it into the system in place of the EVS 100M's - no contest.  
It's no slouch as far as amps go either.  It was an interesting compare/contrast - 85 lb. of class A/B MOSFET HOT running amp vs. about 24 lb. of COOL class D "ICE Power."  I've definitely changed my opinion that amps NEED to run warm to sound good.

I've had bi-amped systems for at least the last 15 years - mostly using tubes on top and SS on the bottom.  But those systems all crossed over in the 100Hz range.  The main reason I chose four identical channels to drive the CS2 is the fact that the crossover is at 1KHz. For this reason I wanted  the voicing of the amps the to be exactly the same.  100 watts on the compression driver is certainly WAY more than enough, but this makes for a truly seamless integration of the upper and lower frequencies/drivers.  

I'm sure there are other ways to get there but I wanted to take that possibility/complication out of the mix.

[TomS]

I had a B&K Reference 200.7 around and put it into the system in place of the EVS 100M's - no contest. 
It's no slouch as far as amps go either.  It was an interesting compare/contrast - 85 lb. of class A/B MOSFET of HOT running amp vs. about 20 lb. of COOL class D "ICE Power."  I've definitely changed my opinion that amps NEED to run warm to sound good.

I've had bi-amped sytems for at least the last 15 years - mostly using tubes on top and SS on the bottom.  But those systems all crossed over in the 100Hz range.  The main reason I chose four identical channels to drive the CS2 is the fact that the crossover is at 1KHz. For this reason I wanted  the voicing of the amps the to be exactly the same.  100 watts on the compression driver is certainly WAY more than enough, but this makes for a truly seamless integration of the upper and lower frequencies/drivers. 

I'm sure there are other was to get there but I wanted to take that possibility/complication out of the mix.

Yes, my instinct says having 4 identical or very similarly voiced amps makes a lot of sense.  Not so much because of where the XO point is, but because the CS2's are so unusually fast and revealing in that region around a few hundred hertz, smack where those upper bass foundations are for a lot of stuff.  Despite my two amps of different character/lineage, I can't sense any obvious discontinuity though.  Also, I'm starting to think not only the HF, but the LF doesn't take big power either, so that makes it more interesting. 

Like I said, I'd love to try a couple Aspen LF's or even two First Watt F4's if there is enough voltage gain left in the Didden mod DCX to swing them at unity gain  aa

[nicksgem10s]

I just recently joined the Emerald Physics CS2 family.  I have very few hours (less than 50) so far.  I am using the CS2s with a stock DCX 2496 at this point but already have the Jan Didden kit and other improved parts set aside for the modifications.  I am glad I have had a brief chance to hear the speakers with the stock DCX unit so I have a basic idea of what the stock sound consists of. 

I am currently using an upgraded Charlize amp on the HF & a AVA Ultra 550 on the LF section.  I have sold off most of my expensive equipment and am actually using a Sony Playstation 3 as a source for the moment.  Having modest electronics (AVA Ultra excluded) I did not really have very high expectations for these speakers initially because of my associated equipment.

Once I hooked them up and played them for a couple hours I could tell there was a lot more potential waiting for me.  I am anxiously awaiting more reports from other users for amp combinations and levels of success.

One thing that is really clear to me even this early in owning the CS2s is that the tweeter is ultra sensitive.  The upgraded Charlize amp I am using on the HF was quiet on the other two pairs of speakers I used the Charlize on.  The other speakers were not near as efficient or revealing as the CS2.

I am kind of worried to try tubes because of the noise issue that could occur.  I am pretty sensitive to noise and hope to find an excellent match for the CS2.  I really can't even believe the quality of sound I am hearing now with the Charlize on the HF and the AVA Ultra 550 on the LF.  I am thinking Tom is on the right track with the First Watt suggestions.  I am kind of leaning towards a First Watt F3 or DIY clone possibly.  A Red Wine Signature 30 on HF would probably be really sweet and no worries about the noise issue.

I can't wait to hear them with the modified DCX unit and Didden active pre kit.

Does the Didden kit have any remote volume control options?  This is the one thing I am hoping to get figured out because I am getting lazy in my old age (30).

Great thread and I look forward to following it and contributing when I can.

Dynamics are nothing short of incredible and I know that they will improve with some break in and some modifications.

On a side note I am pleased with their appearance especially compared to what the online photos look like.

-Nick

 

[TomS]

Nick,

Great to hear you took the plunge and are enjoying them so far.  I didn't think there would be a huge break-in effect, but mine have really started to change over the past week or so.  George experienced the same thing a few weeks ahead of me too.  Yes, with the high sensitivity noise is going to be an issue, but as with most high sensitivity (horns, single driver) speakers, it can be overcome with the right choice of amps.  Quite  often people use SET's with those.  Just curious if you tried the AVA amp on the tweeters, to see what it does in terms of noise?  I would think it would be dead quiet based on the 2 or 3 AVA amps I've heard briefly.

You are in luck.  The Didden mod can be used with any $5 generic remote control.  All of the output gain functions can be changed - level, balance, hf level, lf level, along with 3 presets to use with different amps, which is really nice.

Tom

[cloudbaseracer]

Hello Guys,

I am trying to locate a phone number for Ric with EVS but have not had any luck.  The contact phone and email information on the tweakaudio.com site do not work.  Can anyone help me out with this?


Thanks,

James

[TomS]

Hello Guys,

I am trying to locate a phone number for Ric with EVS but have not had any luck.  The contact phone and email information on the tweakaudio.com site do not work.  Can anyone help me out with this?


Thanks,

James

You might try sending him a PM here

[cloudbaseracer]

I don't have any information on him.  I was just reading this thread and then did a search for his company and his name.  Do you have his contact details on here?

Thanks,

James

[TomS]

Look up "Ric Schultz" under Members and click on the Private Message link.  It should send him an email if he has it selected in his profile.

[hjsouth]

I suspect I will be the lone true budget guy that posts an answer to your question, at least compared to the gang residing here on Audio Circle, but I couldn't resist putting in my 2 cents.  I have a true CS2 budget system.  I chose option one, utilizing four IRD MB100 mono blocks (which are still inexpensive), a Tube Audio Design TAD150 Signature preamp (tube hybrid), with my source component a modded JD100 CD player.  The stock Beheringer is being used, at least until the dust settles with all the mods and options that will become available.  Interconnects are all DH Labs BL1 which I sent back and had factory terminated XLR to RCA.  Cables are four runs of BestDealCables.

I am quite happy with the results from the amps, which at least to me, are quiet, smooth, have enough headroom for anything I listen to and were pocketbook friendly.  I have considered other amps but will likely wait until I am sold on the switching amps or ice based amps and can get them in a single box, four channel set to save on space.  Won't bite on this though unless I can demo it first.  Wish I had a dedicated room like most of you guys have, to move the speakers out about 5 feet into the room.    

hjsouth

[TomS]

Sounds like a great setup and thanks for sharing!  And don't sell yourself short.  That's a sizable investment and a very carefully chosen system.  I am still waiting for someone to tell us they're using a pair of Trends 10.1's or Sonic Impact T amps though 

Tom

[hjsouth]

I believe Clayton has tested the pro audio ART SLA1 and SLA2.  Would love to see a post from someone that used those.  My dealer had an SLA2, which he let me borrow to compare to my IRD but couldn't get it fired up without horrible screeching from the tweeter.  Had to use the XLR adapters so maybe that was the problem.  Anyway couldn't get it to work so just stuck with the IRD's since I suspect they were quieter and had a little more finesse.