[Tomy2Tone]

Ifi ITube as buffer between pre and your amp. 

That's right, you and Ozarktom! I just looked up DaveC113's old post from page 5 and remembered he's got a tubed pre.

Chris, how do you control the volume? With the DSPeaker 2.0 or Ifi ?

[rodge827]

That's right, you and Ozarktom! I just looked up DaveC113's old post from page 5 and remembered he's got a tubed pre.

Chris, how do you control the volume? With the DSPeaker 2.0 or Ifi ?

Dspeaker Dual Core 2.0 

And that's all yer gettin' till I'm ready to post my review! 

[Tomy2Tone]

Dspeaker Dual Core 2.0 

And that's all yer gettin' till I'm ready to post my review! 

Fair enough. 

I have an itube I use at work for my shop speakers and like what it does. I keep thinking I should bring it home and try on the setup I have here.

[roscoeiii]

Ifi ITube as buffer between pre and your amp. 

Thinking very hard about picking one of these up. But worry that my chain may be getting far too complex...

What I am currently envisioning:

Sources --> preamp (Musical Fidelity kW) --> DSPeaker Dual Core (for DSP and digital EQ room correction) --> Toslink output to a Wyred4Sound Remedy reclocker --> Coax output to Yamamoto YDA-01 DAC --> iTube at +6dB -->XLS 2000 --> SP Tech Revelation speakers

Why? You might ask. Well, let me explain the logic in favor of this complex chain:

1) the Yamamoto DAC sounds great. Killer analog output stage
2) BUT the DAC has a quite high output impedance (2.6 kOhm) which is higher than ideal for the 10 kOhm input impedance of the XLS 2000
3) The iTube as a buffer can provide a lower impedance signal to the XLS, in addition to providing the 3D feature and "Digital Antidote" feature
4) The XLS in my experience seems to sound better with a higher strength signal (pro gear designers probably had the higher levels of XLR signals in mind when designing this amp), so the +6dB option of the buffer could potentially be of assistance.

Of course, all of this flies in the face of the KISS principle. But I can try out the iTube and see, and Music Direct has a great return policy. (This will be once I unbrick my DSPeaker which did not react well to my attempt to upgrade the firmware; great customer support from them in getting that resolved, but no luck yet since I have a very early model).

Feel free to talk me down from that convoluted set-up. It's a lot of gear in the chain for sure.

Or the other alternative would be to run the Dual Core-Yamamoto combo through the tape loop of my preamp and then run the signal from my preamp to the amp.

[Tomy2Tone]

Thinking very hard about picking one of these up. But worry that my chain may be getting far too complex...

What I am currently envisioning:

Sources --> preamp (Musical Fidelity kW) --> DSPeaker Dual Core (for DSP and digital EQ room correction) --> Toslink output to a Wyred4Sound Remedy reclocker --> Coax output to Yamamoto YDA-01 DAC --> iTube at +6dB -->XLS 2000 --> SP Tech Revelation speakers

Why? You might ask. Well, let me explain the logic in favor of this complex chain:

1) the Yamamoto DAC sounds great. Killer analog output stage
2) BUT the DAC has a quite high output impedance (2.6 kOhm) which is higher than ideal for the 10 kOhm input impedance of the XLS 2000
3) The iTube as a buffer can provide a lower impedance signal to the XLS, in addition to providing the 3D feature and "Digital Antidote" feature
4) The XLS in my experience seems to sound better with a higher strength signal (pro gear designers probably had the higher levels of XLR signals in mind when designing this amp), so the +6dB option of the buffer could potentially be of assistance.

Of course, all of this flies in the face of the KISS principle. But I can try out the iTube and see, and Music Direct has a great return policy. (This will be once I unbrick my DSPeaker which did not react well to my attempt to upgrade the firmware; great customer support from them in getting that resolved, but no luck yet since I have a very early model).

Feel free to talk me down from that convoluted set-up. It's a lot of gear in the chain for sure.

Or the other alternative would be to run the Dual Core-Yamamoto combo through the tape loop of my preamp and then run the signal from my preamp to the amp.

Is there a reference webpage anywhere that covers what input impedance and output voltage matches better for each particular component in the chain?

I'm still trying to understand what should work and what should work better vs not a good match at all. When I first got the Perseus I had it between a w4s dac2 and w4s sx 500 amps and it was too much with my Songtowers. I' didn't like it at all and preferred my avr at the time. It wasn't smooth and engaging like it is now with the DSPeaker Dual Core as a dac and Pascal amp with Soundscape 8's.

[ernest787]

I have a 2500 hooked up to my Salk HT3s and a 1500 on my Songtower RTs.  It is a fun little amp and does a very good job for the money... especially on the used market where you can find really good deals. 

That being said, I will likely purchase an AVA amp this year to replace the 2500 on the HT3s.  The 2500 will probably be moved to the other room and hooked up to the STRT. 

[roscoeiii]

Is there a reference webpage anywhere that covers what input impedance and output voltage matches better for each particular component in the chain?

I'm still trying to understand what should work and what should work better vs not a good match at all. When I first got the Perseus I had it between a w4s dac2 and w4s sx 500 amps and it was too much with my Songtowers. I' didn't like it at all and preferred my avr at the time. It wasn't smooth and engaging like it is now with the DSPeaker Dual Core as a dac and Pascal amp with Soundscape 8's.

General rule of thumb is to have the input impedance 10x greater than the output impedance of the device sending the signal. Though some say 5x difference is fine. It also crossed my mind that impedance mismatch could also have been affecting things in Jack's system. Or not. Just more speculation about what wasn't working there...

[steve f]

Just an update on my xls 1500 amps. This was the first time in my experience that break in was quick and dramatic. The second amp went from closed in and perhaps a bit dull to open and pleasant in about twenty hours of play. It got noticeably better rather quickly. The amps now sound identical.

Just some filler until the tour guys post.

Steve

[wisnon]

Dspeaker Dual Core 2.0 

And that's all yer gettin' till I'm ready to post my review! 

Well, Hurry up then! LoL

How you doing Chris?

[jk@home]

Just an update on my xls 1500 amps. This was the first time in my experience that break in was quick and dramatic. The second amp went from closed in and perhaps a bit dull to open and pleasant in about twenty hours of play. It got noticeably better rather quickly. The amps now sound identical.

Just some filler until the tour guys post.

Steve

Speaking of break in. Today I picked up two new XLS1500s from the same Guitar Center that I returned my first one (before it broke in. ) Pretty sure neither one is the one I returned. 

When I bought the first one, had to order it from GC on line, as the local store didn't carry any in stock. Now they have all the models.

This time the plan is to keep them no matter what, if not in the stereo system, then they can replace the old Mackie FR1400s I use in the HT system (driving Paradigm Studios). Nothing else, it will reduce the fan noise coming out of the HT equipment closet.

Now that I have a preamp with high gain and balanced outputs (NuForce MCP-18), hopefully can get the Drivecores right with the KEFs in the stereo system. Also will be adding a MiniDSP NanoDIGI in the digital front end so will have the ability to tweak the tone of the system with EQ. Fun stuff.

[Folsom]

I've modded three amps, and can't wait to hear about results. The 4th is sitting next to me and awaits a few parts then it'll be off for cryo.

[Tomy2Tone]

Ok, I received my two Crown 1500's yesterday from Salis and have been running them since I put them back in my setup.

I'm going to have to refer to Ozarktom for any direct comparisons with the Salis mod vs one of his dozen or so stock Crowns. 

It's been two weeks or so since I last had them and I've changed a few things around. Like different speakers and implementing a tubed pre. But I'll give a comparison between speakers and amps here for a reference.

My setup before consisted of a pair of Salk Songtowers with a DSPeaker Dual Core 2.0 as a dac/pre and Crown 1500's in bridged mode. I also used a Job 225 and a Aluminatti X2 in and out trying to figure what amp I thought worked best. The Songtowers are the standard dome version and really sang with all three amps. The Crowns really opened things up a gave a lot of dynamics in all types of music, I was impressed from the moment I heard them. It was a forward sounding presentation but if I had to nitpick I would say things sounded a little on the thin side but only in comparison to the X2. I probably would be happy if I had just the Crowns with the Songtowers. The X2 was incredibly clear and very neutral sounding and less forward but I would say lacked a little soul and body that the Job provided. The Job I think matched up best with the Songtowrs with offering incredible bass performance and a natural voice to female and male alike. It just seemed right.

Now on to the Soundscape 8's that I just picked up while the Crowns were off to Salis for the mods. The room I'm using is not ideal at the moment and is just temporary until I move later in the new year so bear with me. The Songtowers I thought did really well in this room that is about 12' by 13'. I took them down in an effort to get some time with the Soundscapes before the move. They have the accuton mid with a raal ribbon tweeter and two 8" bass drivers. So just a little different midrange than the Songtowers as well as the bass.

When I first hooked everything up I had the Job in the mix to see if it could drive the 8's. Everything I loved about the Job with the Songtowers was just blah with the 8's. From what I've read the Job is about 180 to 200 watts per channel in 4 ohm speakers so I knew I wasn't getting a whole heck of a lot but it was something. The Job actually sounded lean and kind of lifeless as compared to what it did before. The X2 didn't fair much better but was more enjoyable to listen to than the Job. It's pushing 500 watts per channel in 4 ohm speakers. I decided to pull out a Rogue Perseus tubed pre I've had for a while to see if it could add some spark to the mix. It definitely added some warmth and personality to the situation but I was still not enthused with how everything sounded. I kept saying it's probably the room not letting the SS8's strut their stuff but I was going to wait and see if the Crowns could add anything that was missing.

As soon as I hooked up the Crowns yesterday I had the gain set at 3 o'clock like I did with the Songtowers but in this case I was getting a very high noise floor in combination with the Perseus. Remeber this is in bridged mode giving 1500 watts per channel! I fiddled back and forth for a while on what seemed best and found the Crowns set at 1 o'clock with the DSPeaker maxed out and the Perseus being the main volume control. First thing I noticed was how crystal clear the sound was and being extremely smooth at the same time. Not thin sounding at all! Dynamics and punch with authoritative bass like I expected from these speakers Everything just came to life and I'm amazed I'm getting this good of a sound considering the room isn't the best for these SS8's.

The tubed pre and the Crowns seem to be a great match and I'm looking at sending in the Perseus for a "Magnum" upgrade. The Crowns sound so good I might wait a while before trying another amp and instead look at a Lampizator dac or something.  I'll let these Crowns run for a while before considering getting them the cryo treatment. I know this is long winded but thought it could be useful.

[Tomy2Tone]

I've modded three amps, and can't wait to hear about results. The 4th is sitting next to me and awaits a few parts then it'll be off for cryo.

Hey Salis, would it be possible for you to give a break down on what exactly you did for the mods? In case people are wondering what's involved. I tried looking for what you wrote before but couldn't find it.

[Folsom]

I dampen the filter, remove the line Y caps, replace the PFC diode bridge, and add decoupling to it on the primary side.

[roscoeiii]

Now that I have a preamp with high gain and balanced outputs (NuForce MCP-18), hopefully can get the Drivecores right with the KEFs in the stereo system. Also will be adding a MiniDSP NanoDIGI in the digital front end so will have the ability to tweak the tone of the system with EQ. Fun stuff.

Looking forward to hearing how you like it with a high gain preamp. XLS like a pretty hot signal in my experience.

[Tomy2Tone]

Happy New Year everybody!

Listening some more this morning and I'm still astounded at the level of detail and prowess of the the crowns. I'm trying to understand why and looked up some specs. The Crowns say their input impedance in the balanced connection is 20 kohms. The output impedance of the Perseus is 450 ohms. I can't find the impedance of the DSPeaker but it says it has an output voltage of 7.2 for the RCA connection.

The DSPeaker is basically being used as a dac so it still has volume and I have it maxed out so I don't have to crank up the Perseus's volume because when I do it introduces a lot of noise/ hiss. So with the gains on the Crowns at 1 o'clock and the Perseus at 12 I'm getting a huge soundstage with gobs of detail, even at low volumes it's very impressive.

Any dspeaker dual core 2.0 owners know what the output impedance is of its connections? Their website just gives voltage. Just want to know what's happening and why it's working so well.

Look forward to rodge827 and others take on the Crown. Cheers!

[guest61169]

...I can't find the impedance of the DSPeaker...

I don't own one but I found this thread:

http://www.hifiwigwam.com/showthread.php?100776-Line-level-or-speaker-level-feed

[Folsom]

The Crowns appear to have a front end that would provide details like a buffer would. However, even knowing that, including specs you're not going to be able to understand the reason for detail with these minor bits of information. Distortion, SNR, etc, are clues towards an amplifiers ability for detail but not something that defines it.

The only thing I know abut OzarkTom's perceived difference is that someone in a track he listens to "changed" positions in the soundscape. That tells me that there's increased detail from my modification. The microphone probably places the majority of the person in spot A where many amps place him, but with more detail it orients not the pure SPL of the person, but the characteristics of them in references to the mic so it offsets some of the larger SPL to the ear giving a perceived different location. That's my guess, and it might be really off .

[Tomy2Tone]

The Crowns appear to have a front end that would provide details like a buffer would. However, even knowing that, including specs you're not going to be able to understand the reason for detail with these minor bits of information. Distortion, SNR, etc, are clues towards an amplifiers ability for detail but not something that defines it.

The only thing I know abut OzarkTom's perceived difference is that someone in a track he listens to "changed" positions in the soundscape. That tells me that there's increased detail from my modification. The microphone probably places the majority of the person in spot A where many amps place him, but with more detail it orients not the pure SPL of the person, but the characteristics of them in references to the mic so it offsets some of the larger SPL to the ear giving a perceived different location. That's my guess, and it might be really off .

I'll go with that! 

The Songtowers are 4 ohm nominal and 88db sensitive, the Soundscapes are 4 ohm nominal and 87db sensitive. So not a huge disparity but they are different speakers. All I know is before the mod the crowns, pascal, and Job were fairly close in performance with the Songtowers. Now after the mod with the Soundscapes the crowns are far and away the better performer, not even close.

Curious to hear Ozarktoms take on things. Tommy can you hear me? 

Thanks noway for the link! I appreciate you taking time to share that.

[rodge827]

Gents can speaker wire from the Crown be used on the High Input (speaker input) on a sub plate amp (Bash 300)?

Here's the reason why. I have a 2.2 set up and would like to jumper from the back of my monitors to the speaker input on the sub and eliminate a pair of sub IC's. Some amps are OK with this set up and some aren't due to the stereo amps grounding scheme. Any input would be appreciated.

Tomy don't worry I haven't tried it with your tour amp. 

Posting review tomorrow.