Crown CDi1000 Power Amp Review and Measurements - Stream of Consciousness

Some context here: https://www.superbestaudiofriends.o...solid-state-power-amp-adventures.3789/page-29



I picked one of these up for cheap, thinking it would be be Class D based on its light weight. (I'm still looking for a class D amp that I find satisfying). Looks like I could have gotten fooled (explains why I actually thought this thing sounded too damn good for class D?). I realized that only the Crown DriveCore stuff or DSi series are officially stated to be class D. Crown's lineup is extremely confusing. I'm not sure that even their reps can explain. I don't know if the CDi (non DriveCore) is class AB? Crown is very coy about a lot of shit these days.

The light weight of the CDi1000 is actually from the switching power supply. The CDi1000 puts out 275W into 8-ohms and 500W into 4-ohms. There would a giant transformer and more heatsinking if an LPS were used. Well, even though it's not class D, at least I'm now beginning to be a believe that SMPS can sound good. Maybe by 2030, I will like class D amplification. (And yes, I've heard the Hypex ncore stuff, including a $10k one - I still think they sounds like ass, insipid - or maybe it's just bad synergy with the speakers I happen like, which tend to have simple xovers and be highly efficient).

What I'm trying to figure out are the differences between the CDi1000 and XTi1002. The specs and functionality seem to be same, but the CDi series is twice the price. The CDi does supposedly have better digital goodies (this is 2020 now, so these amps have DSP capabilities such as xover, EQ, delay, protection, etc.), but I have not tried them out yet. The most evident differences are on the back of the chassis where the CDi series, being meant for fixed installation, uses Phoenix and screw terminals for input and speaker outputs. The XTi series, being for portable sound reinforcement, offers XLR inputs and Speakon and binding posts. I do wonder if the XTi from a pure sonics (not DSP functionality) point of view sounds any worse than the CDi.



For those who are concerned about the Phoenix 3 terminals, adapters can be found for cheap. We will need the female XLR. https://www.amazon.com/gp/offer-listing/B003D83OWC/ref=dp_olp_0?ie=UTF8&condition=all


For my evaluation of the amp thus far, I've switched the DSP off. I'm curious as to how much of a sonic penalty there is with its functions switched on. What makes the Crown CDi series super appealing is that I might be able to build active systems with ease, i.e., without the use of say a MiniDSP and 8-gang pots if I wanted to do something like a crazy four way.

By the way, the one fan in the back is actually quiet. Nothing at all like the old school power amps. The fan does appear to speed up when more power is demanded.

 

So how does the CDi1000 sound?

Surprisingly fantastic! I put this to war against the Schiit Aegir (Stereophile Class A or whatever) and it holds its own! It's actually more a matter of different than better. I've struggled with a lot of high power amps because of the kinds of speakers I run (e.g, Lowthers in a Oris horn + OB woofers in the other room, Fostex BLHs, Altec, etc.). The commonality between these types of designs is simple or no crossover and high-efficiency. I was thinking I simply just wasn't getting "synergy" because I was typically asking for well under one watt of power. The JBL 4698b are pictured below. JBL fudged on the efficiency spec, mainly because the woofers are 4-ohms, but realistically, we are probably talking about 98db per W at 1m.



I'll just get to the point. If the Schiit Aegir is a Toyota GT86, then the Crown CDi1000 is a Camaro SS 1LE.

The Schiit Aegir is refined, responsive, midcentric, nuanced, plenty poised in the mids, and resolves a lot of information. Its transients are more rounded. I won't delve deep into the Aegir, but I suggest that readers start here: https://www.superbestaudiofriends.org/index.php?threads/schiit-aegir-power-amp-impressions.6953/

The CDi1000 is a beast. While it's not quite there in terms of microdynamic nuance, microdetail, and refinement of the Aegir, it carries these qualities more than sufficiently well, but with an incredible dose of raw power. It's not a boat like a Dodge Challenger which is just pure horsepower. The thing that came to mind is that this amp will "slay Slayer" per @Psalmanazar desires. The Aegir not quite so, because 20W, despite the efficiency of the JBL 4698s, will just not do. I had Aegir monoblocks which were cleaner sounding, but I eventually decided on just a single Aegir because of its warmer and sweeter sound, despite being softer. I guess we have to wait until a 200W monoblock version of the Aegir comes out.

Comparatively, the CDi1000 has more heft in the lows and more air up top (hence my saying that Aegir is more mid-centric, which it is to many other amps). The tactility and palpability of sound waves is much more so. If there is a downside, and if we can even call it a downside. The CDi1000 won't take the bite out of trumpets, the sibilants out of vocals, or the crunch out of guitars when the recording calls for them. This is not to say that the CDi1000 has the bad kind solid-state of quality. It's just saying that if you want an amp that will slay Slayer without reservation, than this is it. There is no pervasive solid-state glare or nasties at all. The amp's not going to hiding sibilants in recordings were a lot of this exists (Alanis Unplugged for instance). Also, I think speakers that might already have issues in the upper mids might not be a good match.

BTW, I cranked up Rage Against The Machine last night to 110db (at the couch location). I needed earplugs to get that close. It was glorious! My wife was screaming at me, and the kids and I were being stupid doing the dumb dance moves like the floss in the adjoined kitchen.. The sound was damn clean. The JBLs will take 400W pink noise and 500W Program (live music) continuous. Maybe I should look into the CDi2000.

Anyway, check out used priced on the CDi series. This isn't audiophile gear, it's pro gear that will last forever and take a beating. Scratches on pro audio gear is a sign of honor. Definitely super highly recommended for entry level audiophiles or advanced audiophiles who aren't wimps.

P.S.

The gain is super high at 30db. Super high efficiency speakers like the JBLs here will have just barely noticeable hiss at about 7 feet away. Depending upon your preamp or passive pot, you may find yourself not turning up the volume knob past 10 o'clock. As I said, namby-pamby audiophiles need not apply. (I don't think these issues should present themselves for speakers up to 94db W m, and we can always turn down the sensitivity knobs at the front of the amp.)

 

No idea how the CDi1000 compares against that stuff. It is an improvement over the Crest CA2 (which I have had sitting around) for sure. The Adcom 5800 is old-school, LPS, big power transformer, and I'm not sure would it be any worse than the old pro audio stuff. You go used pro gear to be cheap and not pay the audiophile tax while getting great class AB performance.

The CDi1000 does have a 70V / high Z mode.

 

What's the point of a Lotus Elise with an Celica motor compared to a Camaro SS 1LE with a OHV V8? Ultimately they are different. Now of course would be best to combine the best of both. That would be a McLaren 600.

The Aegir most definitely is a specialist amp. The CDi1000 is doing especially well in the lows in my particular system discussed here because the E155-4 woofers are nominal 4-ohm, but dip down to 2.5-ohms in spots if I remember correctly. Probably too much to ask from Aegir to get such explosive and tight bass.

I would have a hard time believing of major changes, but given that I think the CDi could be class D (and not AB), I can see significant changes to sound because of tweaks. What components did you use with your XTi1000s? The CDi1000 I can see being a bad match with brighter speakers or speakers with weirdo exotic drivers which are badly integrated. Top it off with sigma-delta DACs of the early 2000s, and I'm pretty sure we can get an nightmare sound. The big JBLs I have are kind of on the laid-back sounding side of things (confirmed via measurements here on SBAF).

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Yup, looks like class D. It's funny how Crown is being super opaque about this. I first thought it may have been class AB because of its power and current spec at the wall, at least compared to the DriveCore stuff. I think the DriveCore is simply their newer class D with more integrated parts which is more efficient.



If it is class D, it's the first one that didn't sound insipid to me... is it snowing outside in SoCal today?

 

Please read this before delving into measurements: https://www.superbestaudiofriends.o...ically-incorrect-audio-blog.7261/#post-249242

Do not be a measurement extremist!

51.5Vrms or 331W into 8-ohms


At very high levels of output, we start to see the even harmonics come into play.

5Vrms or 3.13W into 8-ohms


At lower levels, we just see odd harmonics, with a tiny bit of second order, but nothing in terms of the rest of even order, i.e.g 4th, 6th, etc.

In theory, this amp shouldn't sound good with all its odd order distortions, particularly the higher order odd order. But the CDi1000 doesn't like the stereotypical bad etchy glarely solid state amp at all.

 

Quick note: That little rise between 5k and 7k appears to be an artifact from this cheap Micsig differential probe that I am using. I need to use the probe on x50 to avoid high voltage accidents on my AverLAB, which isn't cheap. I may need to evaluate other probes for future measurements.

 

The CDi1000 actually hits a bit past 500W before clipping into 8-ohms. Keep in that Crown's 275W spec is for continuous sustained loads. I double checked voltages with DMM, so I am fairly sure I did the calculations right. I got scared because the parts inside the amp actually start to sing the signal once I started to hit the higher power levels. I was also afraid that the wirewound resistor would start smoking or explode.



There's the big resistor and diff probe. A maybe 10 seconds at 500W got that thing freaking hot. It's only rated to 250W.

 

Here is the last one I will post. Distortion across frequencies for three levels, 1, 5 and 10Vrms into 8-ohms. Bandwidth was set to 48kHz. THD+N is fairly consistent; however, there is a slight rise toward the mid treble when then subsides.