Emerald Physics CS2 with modified DCX crossover

brj · « **Reply #20 on:** 11 Dec 2007, 12:40 am »

Nice work, Mike, on both the mods and the review - sounds like you, Wayne and Mike had a fun afternoon! Keep us posted on future iterations...

mgalusha · « **Reply #21 on:** 11 Dec 2007, 03:17 am »

Quote from: Ric Schultz on 10 Dec 2007, 11:59 pm

However, using an op amp based output stage is not going to give the best results possible.

Actually the output is taken directly off the CS3318 chip through a build out resistor. There is 1 op amp per channel, to convert the balanced signal from the DAC to single ended to feed the volume chip. There are likely op amps inside the 3318 chip but whatever it uses internally works very well.

Using something else for level control introduces other compromises that may or may not work better and of course everything is a compromise in some regard. I originally was going to use a passive output feeding a 6 gang stepped attenuator and 6 channels of discrete gain/buffer stages. However, I decided that for my use Jan's was a better and less expensive solution. I am unwilling to accept dropping bits and am also unwilling to feed it an analog signal that's already undergone a D/A conversion and then through a preamp. IMO the volume control needs to occur in the analog domain and for me that means after the DAC's.

Jan's kit also address the analog input section for those who do want to use this. I have done an A/B of the digital vs analog input from my hot rod Squeezebox and while the digital is better, the analog is much much better than stock. I have connected up my TT to the analog inputs and while not a pure analog setup it sounded better than I expected it to. This was one of the compromises I was wiling to accept to use a digital XO versus an analog XO such as the Marchand XM44 I was using. The greatly enhanced flexibility and much simplified signal path were worth digitizing my TT for the limited amount I use it. I am fairly sure once I replace the PS with a liner supply my TT will be just fine as the only issue I have with the current sound is a slightly tizzy sound at the very highest frequencies sometimes. Fortunately all of the A/D - D/A conversion takes place at 24/96 so it doesn't seem to crap up my analog much. It also makes it trivial to add a rumble filter to stomp out woofer movement from bad pressings.

brj · « **Reply #22 on:** 11 Dec 2007, 05:55 am »

Doak, welcome to AC!

I would suggest starting a new thread with your question, both to avoid taking this thread off its focus of reviewing a personally modded DCX, and to expose your question to a wider audience more specific to your question. The "Audio Central" circle might be an appropriate selection, although others may be suitable as well. I would also recommend checking out the Critic's Circle Guidelines for more background on this circle.

Thanks, and have fun!

janneman · « **Reply #23 on:** 11 Dec 2007, 12:23 pm »

Ric,

What you say are all valid issues and I'm sure most of us face those at one time or other. I did look for ways to make the signal path even shorter. At one time I contemplated using two CS3318 chips and two channels per output so I could go balanced straight through. But then you run into issues with the DC on the DAC output signals, they have a common mode of 2.5VDC. My choice for the LM4562 was not arbitrary, I'm convinced that this chip is at least as transparent as a good coupling cap if not more.

Then there is the issue of board layout, of course. How do you do the signal routing, in which order do you run your grounds, to what point, where do you connect the digital and signal grounds and the output reference grounds etc. Mess that up, and even a straight wire will add distortion and noise!

There's a few more but I don't want to give out everything

Jan Didden

zybar · « **Reply #24 on:** 11 Dec 2007, 12:51 pm »

Quote from: janneman on 11 Dec 2007, 12:23 pm

Ric,

What you say are all valid issues and I'm sure most of us face those at one time or other. I did look for ways to make the signal path even shorter. At one time I contemplated using two CS3318 chips and two channels per output so I could go balanced straight through. But then you run into issues with the DC on the DAC output signals, they have a common mode of 2.5VDC. My choice for the LM4562 was not arbitrary, I'm convinced that this chip is at least as transparent as a good coupling cap if not more.

Then there is the issue of board layout, of course. How do you do the signal routing, in which order do you run your grounds, to what point, where do you connect the digital and signal grounds and the output reference grounds etc. Mess that up, and even a straight wire will add distortion and noise!

There's a few more but I don't want to give out everything

Jan Didden

Jan,

Based on the limited time I have spent with your product, I can say you have nothing to apologize for. Your kit is producing some very transparent and dynamic sound that definitely takes the already good CS2's to a whole new level!! Great job.

George

zybar · « **Reply #25 on:** 11 Dec 2007, 05:58 pm »

Quote from: Ric Schultz on 11 Dec 2007, 05:20 pm

One can talk design or the like all day long (I know, I have...he he), but the only way to know if something is superior or not is to listen to it. Certainly, Jan's circuit is better than stock. However, there will be other modded DCXs, including ones from RAM and myself. Because this is the first modded DCX out there, does not mean it will be the best, or the best in your system. However, it is a very clever and elegant design and I am sure most Emerald Physics lovers would welcome it gladly over the stock unit. Well done!

Ric,

If you can get me your modified DCX between Christmas and New Year's when I will be home, I would definitely have time to compare it to the mods in my current DCX (Jan's mods + a few other tweaks).

George

zybar · « **Reply #26 on:** 11 Dec 2007, 07:28 pm »

Quote from: Ric Schultz on 11 Dec 2007, 06:50 pm

George,
Just starting on this. I am sure Jan spent weeks/months? on his circuit, sourcing parts, making boards, literature, etc. Just sourcing the parts I want will take weeks. What you want will be the "somewhat" all out discrete version with shunt output volume control, superclock, super regs, separate linear supply, etc. This will take some time. And the all out super versions (battery power, or external monster power supplies, Ultraclocks, wooden boxes?, exotic connectors, etc.) will take even longer. The first cheaper output volume controlled versions and versions without volume control on the output (for those using only analog in) will be done first (in a few weeks). These less expensive units will have one op amp or less in series with the signal. I would say late Jan. for a version that you would appreciate. I will probably first send it to Clayton and then to you. It won't be cheap (probably $2000 or more depending on jack options (WBT, etc.), etc. Mods will start at around $3-400. A unit similar to Jan's using one op amp and volume control and more would be around $700? These are pure guestimates.......I will have more actual pricing as I develop the mods.....which could change as I do listening tests.

Guess that was a little silly thinking you could have something in 2-3 weeks.

Whenever you have something let me know. Depending on my schedule I will be happy to compare and contrast.

George

cryotweaks · « **Reply #27 on:** 12 Dec 2007, 03:20 pm »

aaaaanyway. Back to what the original discussion was about. We did try to run the Transport wide open through the stock Behringer, but after being spoiled by the modded Behringer, we couldn't do it for too long. It was simply too fatiguing and unengaging. The tweeter sounded metallic, the bass was shallower, the soundstage narrower and less rich, and the dynamics were not nearly as real as with the modded Behringer.

I thought the stock setup was very good to begin with, and it still is. But it was shocking just how much better it could get. Ignorance may indeed be bliss.

The absolute best sound was attained with the modded Behringer and Mike's Modded Squeezebox. The sound reached another level of speed and dynamics. So much so that I actually jumped at the start of the John Lee Hooker track (I can't recall which one). Even at low volume, the dynamics were simply amazing.

I could listen all day to this setup. For the money invested in it, I think it is a screaming bargain. I would love to hear it up against a $50k + system.

Needless to say I have placed my order for the Linear Audio Active analog I/O kit. I like the fact that it will fit inside the stock chassis, and I won't need a preamp. Oh, and it sounds phenomenal too.

I think this is the beginning of something really exciting in high end audio. I look forward to Ric and everyone elses developments. Very exciting...

zybar · « **Reply #28 on:** 12 Dec 2007, 03:27 pm »

Quote from: cryotweaks on 12 Dec 2007, 03:20 pm

aaaaanyway. Back to what the original discussion was about. We did try to run the Transport wide open through the stock Behringer, but after being spoiled by the modded Behringer, we couldn't do it for too long. It was simply too fatiguing and unengaging. The tweeter sounded metallic, the bass was shallower, the soundstage narrower and less rich, and the dynamics were not nearly as real as with the modded Behringer.

I thought the stock setup was very good to begin with, and it still is. But it was shocking just how much better it could get. Ignorance may indeed be bliss.

The absolute best sound was attained with the modded Behringer and Mike's Modded Squeezebox. The sound reached another level of speed and dynamics. So much so that I actually jumped at the start of the John Lee Hooker track (I can't recall which one). Even at low volume, the dynamics were simply amazing.

I could listen all day to this setup. For the money invested in it, I think it is a screaming bargain. I would love to hear it up against a $50k + system.

Needless to say I have placed my order for the Linear Audio Active analog I/O kit. I like the fact that it will fit inside the stock chassis, and I won't need a preamp. Oh, and it sounds phenomenal too.

I think this is the beginning of something really exciting in high end audio. I look forward to Ric and everyone elses developments. Very exciting...

Eventually I will be comparing the stock CS2's + modified DCX to my Vandy 5A's.

I say eventually because I am still struggling to find time to play with my toys and because I still need to figure out what the best combination of amps is on the CS2's.

I do agree that one can put together an absolutely killer system for a very reasonable price with CS2's at the heart of it.

George

Ric Schultz · « **Reply #29 on:** 12 Dec 2007, 06:28 pm »

George, Mike and all CS-2 users,
How are you guys connecting your analog output cables on the back of the Behringer? Are you using adapters or putting XLRs on one end of a cable.....or are you going out fully balanced? Seems to me that RCA jacks are a must on a modded unit, so many of us use RCA cables and some have spent a lot of money on them. Adapters are very compromised.

zybar · « **Reply #30 on:** 12 Dec 2007, 07:01 pm »

Quote from: Ric Schultz on 12 Dec 2007, 06:28 pm

George, Mike and all CS-2 users,
How are you guys connecting your analog output cables on the back of the Behringer? Are you using adapters or putting XLRs on one end of a cable.....or are you going out fully balanced? Seems to me that RCA jacks are a must on a modded unit, so many of us use RCA cables and some have spent a lot of money on them. Adapters are very compromised.

For my initial listening I have been using adapters.

The two tube amps I want to try (Atma-Sphere M-60's on the top and Bella Extreme 100's on the bottom) will be used balanced.

George

doak · « **Reply #31 on:** 12 Dec 2007, 07:06 pm »

Quote from: Ric Schultz on 12 Dec 2007, 06:28 pm

George, Mike and all CS-2 users,
How are you guys connecting your analog output cables on the back of the Behringer? Are you using adapters or putting XLRs on one end of a cable.....or are you going out fully balanced? Seems to me that RCA jacks are a must on a modded unit, so many of us use RCA cables and some have spent a lot of money on them. Adapters are very compromised.

Damn, I didn't know that the DCX that comes with the CS2 has only balanced analog outs!!!!

No wonder so many people are using "Pro" type equipment with these things. This is a PROBLEM for me and mine are due to ship today.

TomS · « **Reply #32 on:** 12 Dec 2007, 07:46 pm »

Quote from: doak on 12 Dec 2007, 07:06 pm

Quote from: Ric Schultz on 12 Dec 2007, 06:28 pm
George, Mike and all CS-2 users,
How are you guys connecting your analog output cables on the back of the Behringer? Are you using adapters or putting XLRs on one end of a cable.....or are you going out fully balanced? Seems to me that RCA jacks are a must on a modded unit, so many of us use RCA cables and some have spent a lot of money on them. Adapters are very compromised.

Damn, I didn't know that the DCX that comes with the CS2 has only balanced analog outs!!!!

No wonder so many people are using "Pro" type equipment with these things. This is a PROBLEM for me and mine are due to ship today.

I bought some relatively inexpensive adapters from this guy. Reasonable price and quick shipping http://cls.audiogon.com/cgi-bin/cls.pl?accstwek&1200779601

They are definitely a compromise. I didn't really care as mine will be modded relatively soon anyway, likely to RCA's. If you're going digital in you also likely need a transformer type adapter or something to go SPDIF to AES input.

Tom

zybar · « **Reply #33 on:** 12 Dec 2007, 07:46 pm »

Quote from: doak on 12 Dec 2007, 07:06 pm

Quote from: Ric Schultz on 12 Dec 2007, 06:28 pm
George, Mike and all CS-2 users,
How are you guys connecting your analog output cables on the back of the Behringer? Are you using adapters or putting XLRs on one end of a cable.....or are you going out fully balanced? Seems to me that RCA jacks are a must on a modded unit, so many of us use RCA cables and some have spent a lot of money on them. Adapters are very compromised.

Damn, I didn't know that the DCX that comes with the CS2 has only balanced analog outs!!!!

No wonder so many people are using "Pro" type equipment with these things. This is a PROBLEM for me and mine are due to ship today.

Doak,

Simply use some XLR to RCA adapters. Ric should be able to help you with this.

George

doak · « **Reply #34 on:** 12 Dec 2007, 08:09 pm »

Damn, I didn't know that the DCX that comes with the CS2 has only balanced analog outs!!!!

No wonder so many people are using "Pro" type equipment with these things. This is a PROBLEM for me and mine are due to ship today.

[/quote]

Doak,

Simply use some XLR to RCA adapters. Ric should be able to help you with this.

George
[/quote]

Well I do intend to have the unit modded so it'll be "right" eventually. However, I really dislike putting extra thingies like adapters into the sigmnal path.

Doak

hjsouth · « **Reply #35 on:** 13 Dec 2007, 01:04 am »

I am not generally a poster in Audiocircle but I have also purchased the CS2's and they will hopefully will be here before year end. Because of that I have been following the chat here on these speakers and Beheringer mods. I felt possessed to put up a post for those of us that are not electrical engineers, modding experts or wealthy tweakers. I would love it if one of you guys came up with a workingman's mod that does not cost more than $500 i.e. best bang for the buck. Isn't that what these speakers were supposed to be about? Many of us out here can only work in that price range without the wife going ballistic about how we spend our money. aa

My modest system will be mating the CS2's, stock Beheringer, four IRD monoblocks, and TAD150 Signature preamp. I am having my DH Labs interconnects re- terminated with the appropriate XLR connectors. I am praying this beats the Vandersteen 2Ce Sig setup I had previously. Thanks for listening/reading.

shell_05@bellsouth.net

TomS · « **Reply #36 on:** 13 Dec 2007, 01:36 am »

Quote from: hjsouth on 13 Dec 2007, 01:04 am

I am not generally a poster in Audiocircle but I have also purchased the CS2's and they will hopefully will be here before year end. Because of that I have been following the chat here on these speakers and Beheringer mods. I felt possessed to put up a post for those of us that are not electrical engineers, modding experts or wealthy tweakers. I would love it if one of you guys came up with a workingman's mod that does not cost more than $500 i.e. best bang for the buck. Isn't that what these speakers were supposed to be about? Many of us out here can only work in that price range without the wife going ballistic about how we spend our money. aa

My modest system will be mating the CS2's, stock Beheringer, four IRD monoblocks, and TAD150 Signature preamp. I am having my DH Labs interconnects re- terminated with the appropriate XLR connectors. I am praying this beats the Vandersteen 2Ce Sig setup I had previously. Thanks for listening/reading.

shell_05@bellsouth.net

I think you'll be very pleased with the setup you have on the CS2's (stock DCX). I have been listening to mine that way for about a week or so and find it very satisfying. For the obsessive compulsive types (like me) it's just knowing that with some effort and incremental investment it can be made oh so much better. At the least, it's nice to know it's there if you choose to pursue it. If not, enjoy just them as is. They sounded terrific to a LOT of people at RMAF, who thought enough of them to buy a pair on the spot.

Best of luck!

Tom

zybar · « **Reply #37 on:** 13 Dec 2007, 01:36 am »

Quote from: hjsouth on 13 Dec 2007, 01:04 am

I am not generally a poster in Audiocircle but I have also purchased the CS2's and they will hopefully will be here before year end. Because of that I have been following the chat here on these speakers and Beheringer mods. I felt possessed to put up a post for those of us that are not electrical engineers, modding experts or wealthy tweakers. I would love it if one of you guys came up with a workingman's mod that does not cost more than $500 i.e. best bang for the buck. Isn't that what these speakers were supposed to be about? Many of us out here can only work in that price range without the wife going ballistic about how we spend our money. aa

My modest system will be mating the CS2's, stock Beheringer, four IRD monoblocks, and TAD150 Signature preamp. I am having my DH Labs interconnects re- terminated with the appropriate XLR connectors. I am praying this beats the Vandersteen 2Ce Sig setup I had previously. Thanks for listening/reading.

shell_05@bellsouth.net

hjsouth,

While upgrading the crossover definitely improves things, the stock setup is no slouch!

I am extremely confident that the CS2's will be viewed as an improvement over the Vandy 2CE's.

As for lower cost mods...that remains to be seen. Having "anything" modified for under $500 is a real challenge unless one is technically capable of doing things themselves. The reality is that the skills required to perform the mods cost a certain amount (I would guess at least $50/hour...I am probably way on the low side with this guess) and when you add this to parts, it easily and quickly surpasses the $500 boundary.

Enjoy your CS2's and worry about mods and upgrades later.

George

richidoo · « **Reply #38 on:** 13 Dec 2007, 02:09 am »

Quote from: hjsouth on 13 Dec 2007, 01:04 am

I would love it if one of you guys came up with a workingman's mod that does not cost more than $500 i.e. best bang for the buck.

Jan Didden's passive upgrade kit for DCX: http://www.pilghamaudio.com/index.asp?pgid=52
It was the focus of this article in AudioXpress. It has no active gain stage though, so you gotta be careful with impedances, cables and such following the DCX. Probably better to save for the active buffered version with analog volume trim.

Good advice from George and Tom to just enjoy first, worry later. You will want to be fully accustomed to the speakers and their nuances so you can properly judge the mods you make. It takes time to get used to a change in the system, speakers are the biggest change of all. You might find it is plenty good enough as is.

Rich

Russell Dawkins · « **Reply #39 on:** 13 Dec 2007, 02:16 am »

I understand they were demo'd at RMAF with a stock Behringer, and apparently were good enough to attract a lot of attention and even sell a relatively large number.

Does anyone know which Bel Cantos were used? I understand Clayton used 6 1000W (500 into 8 ohms) unhoused ICE modules in his first showing of the CS1.