[PostMDMA]

I have a friend who is a salescritter at the store where I bought my Rotel RX-1052. After I got my iMod and burned it in for about 30 hours, I took it down to his shop and we battle-tested it against the RCD-1072 with a well-recorded and -produced/-mastered acoustic jazz CD. (We used a high-end Pioneer int amp, but unfortunately all I remember about the speakers were that they were $4K a pair.) The results were interesting.

* The iMod sounded quieter than the RCD at the same volume level
* The iMod sounded less sparkly than the RCD
* The iMod bass wasn't as crisp as was the RCD

I'm going to leave it playing all week to burn it in some more, but I expected more out of the iMod. I can't yet say I'm sorry I bought it, but if it doesn't improve significantly over the RCD after 170 more hours of burn-in, I may sell it and my 5G iPod and get an RCD.

[PostMDMA]

One more thing . . . the iMod is an input source for my Rotel RX-1052 (140w @ 4 ohms) and a set of Magneplanar MMGs. The iMod is a great improvement over the 5G iPod I was using for sure . . . my MMGs are sounding off bass notes that I didn't think they could make.

But what I noticed when I plugged in the unmodified iPod into the USB jack and played some Apple Lossless tracks was what was promised to me in the iMod--sparkle, greater bass def, treble and midrange clarity, etc. I get somewhat more of that now, but after that Rotel CD player audition, I want more out of the iMod, enough to justify its cost and to keep up with or exceed the quality of entry-level audiophile CD players.

I have plugged my iMod into a power source and have it set on "shuffle" with 8.8 days worth of music, so by next Sunday night I should have enough burn-in time to find out what this thing can do.

Straight up: is the burn-in going to make that much of a difference? Thanks!

[Vinnie R.]

Hi PostMDMA,

Welcome to audiocircle and the RWA forum!

A few things to note:

Straight up: is the burn-in going to make that much of a difference? Thanks!

Yes, and please make sure that your iPod is connected to your amplifier during this burn-in process.  Letting it play for 200 hours but not connecting the line-out to your amplifier is not going to burn it in.  You really need to put on 200+ hours of burn in on those Black Gate capacitors before you can critically judge the iMod.

* The iMod sounded quieter than the RCD at the same volume level
* The iMod sounded less sparkly than the RCD
* The iMod bass wasn't as crisp as was the RCD

The output voltage of the iMod is 1.0Vrms.  I'm sure the Rotel is at least 2Vrms, so when comparing units you need to turn up the volume more with the iMod.  Precise level-matching is difficult to achieve for an A/B test between the two sources. 

Often, the source with the higher output voltage will sound like it has stronger bass, more top-end, etc.... when it is just a matter of turning up the volume more when using the source with the lower output voltage.  Just something to be aware of...

Even though the iMod does not use a NOS-dac, the sound of the iModded iPod sounds quite similar to a NOS-dac.  The top end is not exaggerated and the over-all tonal balance is a little on the warm, analog-ish sounding side.  It doesn't sound like a typcial digital source.  In many systems, this is a big welcome, but if your system is on the warm side to begin with, I can see how one might prefer a brighter source.

As always, it is really is all about system synergy.

But what I noticed when I plugged in the unmodified iPod into the USB jack and played some Apple Lossless tracks was what was promised to me in the iMod--sparkle, greater bass def, treble and midrange clarity, etc. I get somewhat more of that now, but after that Rotel CD player audition, I want more out of the iMod

Just let it burn in (connected to your amp) for 200+ hours and then please report back.  At around 30 hours, it is not even there yet. 

Thanks for posting,

Vinnie

[gary]

A few comments:

1. If you're going to make a comparison like this, the level matching is critical. Did you use a given track and an SPL meter to make sure the volume was the same for both sources before comparing? If not this alone could explain everything, the iMod will output a lower volume to the amp than the Rotel and as a result it will appear to sound worse if the preamp is set to the same level for both.

2. The iMod sounds more like a NOS dac than a regular cd player, and as a result it will sound less "sparkly". What it offers in return is a sound that I would call liquid and analog-like, making it more engaging and enjoyable in my opinion. Not everyone likes this, and you may well prefer a upsampled or oversampled or digital filtered cd source.

3. I've come to believe that the bass problem is with the Apple firmware, it's as if there's a software EQ that you can't disable. Switching to Rockbox gives you much tighter, louder bass, but unfortunately Rockbox is not very stable. In my opinion it also makes the iMod sound more "digital", and takes away the NOS character that I really enjoy.

4. 30 hours is nowhere near enough time for the caps to burn in. Give it 200 hours, and repeat the above comparison but use an SPL meter to match volumes before you begin. It'll be interesting to see if your opinion changes any.

Gary

[PostMDMA]

A few comments:

1. If you're going to make a comparison like this, the level matching is critical. Did you use a given track and an SPL meter to make sure the volume was the same for both sources before comparing? If not this alone could explain everything, the iMod will output a lower volume to the amp than the Rotel and as a result it will appear to sound worse if the preamp is set to the same level for both.

2. The iMod sounds more like a NOS dac than a regular cd player, and as a result it will sound less "sparkly". What it offers in return is a sound that I would call liquid and analog-like, making it more engaging and enjoyable in my opinion. Not everyone likes this, and you may well prefer a upsampled or oversampled or digital filtered cd source.

3. I've come to believe that the bass problem is with the Apple firmware, it's as if there's a software EQ that you can't disable. Switching to Rockbox gives you much tighter, louder bass, but unfortunately Rockbox is not very stable. In my opinion it also makes the iMod sound more "digital", and takes away the NOS character that I really enjoy.

4. 30 hours is nowhere near enough time for the caps to burn in. Give it 200 hours, and repeat the above comparison but use an SPL meter to match volumes before you begin. It'll be interesting to see if your opinion changes any.

Gary

We didn't use an SPL meter. This was strictly a seat-of-the-pants test. I doubt I can talk the salescritter into doing a full-blown test, as they kind of pooh-pooh digital audio because it can't be controlled from more than one room (except they sell the Sonos, which can).

Please indulge a newbie to DACs. What is a NOS dac and why would it sound different than a regular CD player? I gather the difference is a more analog sound, so I know what it does, but a tech explanation would be great if anyone has time to let me know.

Thanks again!

-= PostMDMA =-

[mfsoa]

FWIW, my 1072, to me on my system, sounds rather foreward in the treble with the images out in front of the speakers. This in comparison to a modded older Rotel 971, which sounds lusher with images receeding nicely in depth back through the soundstage.

So the 1072 has more "WOW" to it, but I feel less pleasant and musical than my 971.

Perhaps the iMod might also be better in long-term listening but might seem to fall short in A-B testing?

Never heard an iMod and not trying to diminish your experience, MDMA, just offering my experience in comparing the 1072 to other digital sources.

[gary]

We didn't use an SPL meter. This was strictly a seat-of-the-pants test. I doubt I can talk the salescritter into doing a full-blown test, as they kind of pooh-pooh digital audio because it can't be controlled from more than one room (except they sell the Sonos, which can).

Please indulge a newbie to DACs. What is a NOS dac and why would it sound different than a regular CD player? I gather the difference is a more analog sound, so I know what it does, but a tech explanation would be great if anyone has time to let me know.

NOS stands for Non-OverSampling, meaning that there is no digital filtering applied. Supposedly without the filtering or over sampling you reduce jitter, and the compromise is that you roll-off the higher frequencies (I'm not an ee, and I can't explain it better than that, but if you look around the web you can find a lot of technical papers & discussions on the matter). So many people tend to think NOS dacs sound more analog or organic, although they give up microdetail and resolution. I like the iMod because to me it has the same character as a good NOS dac without the loss in detail. Take that for what it is though, a subjective opinion. I haven't tried to measure frequency response and compare them objectively.

Gary

[PostMDMA]

We didn't use an SPL meter. This was strictly a seat-of-the-pants test. I doubt I can talk the salescritter into doing a full-blown test, as they kind of pooh-pooh digital audio because it can't be controlled from more than one room (except they sell the Sonos, which can).

Please indulge a newbie to DACs. What is a NOS dac and why would it sound different than a regular CD player? I gather the difference is a more analog sound, so I know what it does, but a tech explanation would be great if anyone has time to let me know.

NOS stands for Non-OverSampling, meaning that there is no digital filtering applied. Supposedly without the filtering or over sampling you reduce jitter, and the compromise is that you roll-off the higher frequencies (I'm not an ee, and I can't explain it better than that, but if you look around the web you can find a lot of technical papers & discussions on the matter). So many people tend to think NOS dacs sound more analog or organic, although they give up microdetail and resolution. I like the iMod because to me it has the same character as a good NOS dac without the loss in detail. Take that for what it is though, a subjective opinion. I haven't tried to measure frequency response and compare them objectively.

Gary

This is very interesting. My iMod has been running continuously for three days now, and it had been played for at least 30 hours before that, and I'm starting to notice a change along the lines you suggest. I am listening to an electronic track right now and I hear plenty of detail. But the overall sound is "warmer" and less crisp like the RCD. I am still getting plenty of clear bass note resolution. Now the track has switched to a Queen song and I hear warmer-sounding guitars. This is right in line with what you guys have been saying, but was totally unexpected.

I guess the bottom line is what you say, analog-ish sound with digital clarity. Quite nice. I guess it just needed to open up a little more.

If I were Vinnie I would make sure potential buyers know about this aspect of the iMod. I was ready to go off and sell my iMod and buy an RCD. But now that I know what the iMod is about, that it's not a direct competitor to a typical CD player in sound quality, I will hang onto it for dear life because of its analog sound with digital detail.

Cool! Thanks!

-= PostMDMA =-

[miklorsmith]

It would have been even better had you noticed those things before being told what to expect, i.e. the placebo effect would have been reduced.

I have no doubt the placebo effect is real in audio.  Trying to balance the googoo eyes with healthy skepticism is one of the most challenging aspects of this hobby.

Oh right, back to the thread, the changes described sound like what would be expected.  Beware the brief store demo.

[elcaptain88]

The only thing that 'breaks-in' is the space between your ears; you get used to the new sound after listening to it over 200+ hours. Whether you prefer it or not is up to you - sounds like you came into this prefering the Rotel sound. Mechanical components (i.e. drivers/headphones, etc.) may benefit from some initial working in - but well designed electronic circuits don't.

[miklorsmith]

This may or not be true.  There are countless adherents to each side.  The manufacturer of this particular piece believes the capacitors especially need time to break in.

[PostMDMA]

This may or not be true.  There are countless adherents to each side.  The manufacturer of this particular piece believes the capacitors especially need time to break in.

I'm on the side of the "break-in-is-true" and "placebo-effect-may-or-may-not-be-true."

--The iMod definitely sounds different after about 100 hours of use. My Rotel sounded different after many days of use, too.

--I was told how it would sound, but hey, it genuinely sounds different now than it did when I first plugged it in and played it. I detect greater warmth, now with a little loss of detail on the high end after another hour of listening this morning. I have to say, I do prefer greater crispness and sparkle that the Rotel RCD would deliver, but the iMod is still a decent input source for my purposes.

I'm not going to play the "appeal to authority" card, but I personally feel very confident in my ability to listen and discriminate. And I feel that people are definitely susceptible to the placebo effect, including myself, so you can assess my susceptibility however you want.

This has been a fun thread!

-= PostMDMA =-

[jrebman]

This may or not be true.  There are countless adherents to each side.  The manufacturer of this particular piece believes the capacitors especially need time to break in.

There are changes which happen in nearly all components, however minor, at both the physical and quantum levels, and whether or not they effect signals in the audio range and at audio levels is only partly predictable.  Because of the high number of variables involved, it is generally difficult to predict exactly which parts, and to which degree, and the ultimate effect on the sound, but things absolutely do "break-in".

When I worked in high-energy physics research 25 years ago, nobody in their right mind would think of energizing a power system designed to run at 120,000 volts at it's full operating potential without "conditioning" the circuit components (i.e. - break-in).  We'd start out at 10kv, and gradually work our way up -- generally over the course of days, and only then would full power be applied.  These procedures were also performed whenever a system was taken down for maintainance -- whether or not any components were replaced.

Capacitors definitely break in, inductors to some degree, vacuum tubes for sure, and different solid state devices to different degrees.

As to the question of whether it is my ears breaking in or the component, it is probably some of both, but I have most definitely run amplifiers into dummy loads for 200 hours or more without listening, only to then hook them up to speakers or headphones and discover a completely different sound.

I'm sure any of you who bought a new Clari-T and kept it for 100+ hours or more can absolutely say that the amp with time on it was a totally different beast from the factory-fresh one.  No?

-- Jim

[gary]

I find the people who call themselves "skeptics" and dismiss observed phenomena out of hand because they know of no scientific explanation for it to be almost as annoying as creationists. Case in point, here we have someone who is certain that electrical circuits can't change in time and feels the need to tell other people what they must or must not be hearing.

Essentially every manufacturer who uses BG caps notes that they change in sound throughout the first several hundred hours of use, and the way that each manufacturer describes these changes is markedly similar. Add to that the numerous end users who observe the same thing and you have pretty solid evidence that something is indeed changing inside the capacitors in time. The "skeptics" who insist these observations cannot be real need to go back to high school and learn a little more about the scientific method. If they did, they'd understand that science begins with observation, follows with description, and leads to a prediction that can be falsified. Regarding this thread, am I doing science when I decide my iMod sounds better after 200 hours than it did out of the box? No, and I don't claim to be. I'm making an observation. When someone else insists that what I've observed is imaginary because they know of no plausible scientific explanation for it they're doing the opposite of good science. They're simply making an argument from ignorance, and making themselves look bad in the process.

Instead of telling me what I do or do not hear, the one valid complaint a "skeptic" could make is that I'm not following through with the scientific method and doing the work that I would need to do to convince them that my observation was indeed of a real event that can be predicted, repeated and understood. If that's what they said (and it's funny how they never seem to), I would respect them but still remind them that my intention was not to convince them of anything, only to describe what I heard. I don't have the time to investigate the kind of changes that may be happening inside the capacitor on the atomic level that would explain what I've heard, but that doesn't mean I should discount my own experience and refuse to believe such phenomena could be occurring. Of course if I did that I'd be a Luddite who ignorantly insists stuff like this can't possibly be real, and I try hard not to be like that.

Gary

[elcaptain88]

The problem with spirited 'differences in professional opinion' like these is they become based more on 'religion' as opposed to fact. Perhaps the designer of the Imod can explain in more detail how and why capacitor "break-in" has any effect on a lowly audio signal and the related performance of their product. I've yet to see any reasonable explanation as to how this might occur - I'm sure these are talented and knowledgeable folks designing this equipment. I studied engineering in college (U. of Illinois) and took several EE classes so I'm definitely not 'ignorant' and I'm sure I could contribute some enlightening theory to the discussion. 

[gooberdude]

Hi,

i'm new to this forum but wanted people's thoughts on my situation.  I am not too big on digital or cdp's...i like vinyl.  Been working like mad to get some of my vinyl into my Ipod, this endeavor has taught me lots about what works & doesn't work.    

My current cdp is the Sony SCD-595.  the sound ain't bad, but i must forward to each new track in order to avoid HF shrilliness that occurs after about 5 minutes of play.  Once i go to the next track, or start a track over, the sound really sweetens up & is acceptable BUT only for 5 minutes.  I've searched the 'net and people have reported similar issues...no placebo effect here.   somehow hitting next or pause renews something in the circuitry that gets 'backed up' after 5 minutes.

TRL mods this cdp for $800 - I do not want to spend the $ though on a $140 cdp.  An Imod would fit the bill and i'm very interested especially after getting a brand new 40gb 4th Gen from Apple a few weeks back - Applecare protection finally paid off!

My real question is:

Has the modded Ipod hindered your ipod use, since reg earphones won't work anymore w/o a headphone amp?  I'll probably get a nano or new video for this purpose - I have to ask though.    I'd only use the Imod in my car & in my main system so its not much of an issue, just something i haven't read about in the archives here.

Also, I now have the TVC preamp from Promitheus and i'm not sure if 1v will work...i'll try soon on my ipod though.  Any TVC users with ipods/imods??    So far i've had no issues with source compatibility except having to increase the phono preamp from 40db to 50db.

GD

[gary]

The problem with spirited 'differences in professional opinion' like these is they become based more on 'religion' as opposed to fact. Perhaps the designer of the Imod can explain in more detail how and why capacitor "break-in" has any effect on a lowly audio signal and the related performance of their product. I've yet to see any reasonable explanation as to how this might occur - I'm sure these are talented and knowledgeable folks designing this equipment. I studied engineering in college (U. of Illinois) and took several EE classes so I'm definitely not 'ignorant' and I'm sure I could contribute some enlightening theory to the discussion. 

That's a fair question, and I'd certainly like to hear what Vinnie (or BG really) has to say about it.

gooberdude -

The biggest problem I have now is that I could get a cable for my New Jetta that would let me plug my iPod in to the stereo and charge it. Unfortunately this won't work with my iMod because the audio out through the dock connector is disabled, but I'm not too concerned because the price was more than I was willing to spend ($175 + $100 for installation or something).

The mod definitely makes the iPod less convenient because you have to use an amp with it, but I bought a Xin Super Micro IV and as you can see in this picture the combo is still pretty portable. The super micro is a terrific little amp, it's pricey but worth the $185 it costs to me because I travel so much.

Gary

[gooberdude]

Thanks Gary,

I checked out the Xin website some time ago...that guy has really cool designs
and i dig that the amps are tiny and have upgrades/mods avail.  Did you compare before you bought?
My only experience w/a portable is one of the Altoid box homebrew amps sold on ebay for $40...the grain & hash were so bad i sold it a few weeks later & never looked into another.

Now, the Imod still charges in the same manner as the ipod right, through the dock connection?

For your car, couldn't you get an ipod cable with RCA's and the 1/8" plug (std cable) for the signal and then add the dock connector charger that plugs into the cig outlet? I'd call Crutchfiled before gettin bullied by a dealer.  I see the chargers on ebay for $25.  My Alpine cd head unit required a $10 adapter from Crutchfield that lets RCA's plug into the CD Changer input.

My honda has a trick ipod dock connector IC run from the back of the head unit, through the center console & into my cup holder...totally invisible.   I searched everywhere for a dock connector cable with RCA's...only 1 firm made them at the time & its OEM $20...damn Apple & their proprietary ways.    i knew way back when that the 1/8" output stunk and that the extra gain from the ipod vol knob was muddying the sound.   So, i've been using my ipod in the car with the dock connector cable for years w/o being able to charge it...not an issue for me since the longest i drive is about 4 hrs to go see the folks.   I'll have to get a new cable with the Imod, no big deal though.

Does the Imod drain the batteries any faster?


GD

[gary]

GD-

My first amp was an XMoy2 from PracticalDevices.com, which was sort of a cmoy amp but with a number of design improvements. It sounded great, especially for the $90 or so that it cost, but the supermicro was a big step up from it. Plus one AAA battery seems to last forever, at least 40 hours or so if not more. I wasn't able to compare any other amps bofore buying the Xin, so I had to rely on reviews and the general consensus at head-fi is that while Xin's amps sound phenomenal his customer service leaves an awful lot to be desired. So be prepared to wait a couple of months if you order one.

Thanks for the advice on Crutchfield and the RCA adapter, I'll have to check into that. I'm afraid that my head unit doesn't have changer controls or an RCA in because it's got an in-dash 6 disc changer but it's worth a look.

Also the iPod still does charge and sync through the regular cable after Vinnie performs the mod, and from what I can tell it doesn't affect battery life.

Gary

[Jampot]

I'm as enthusiastic as Gary when it comes to using the iMod in my systems. I have phono to minijack ics left in them and just move the ipod around.

But (and for me it's quite a big but) I never (before I had it) did any critical or extended earphone listening so I was starting from scratch with the modded article. I don't doubt that it sounds better with an amp but to say it 'won't work' without is just not true. Sure, you need to introduce a volume control (because with ordinary phones the output is still too loud) but your music is available when travelling. I bought a Koss in line volume control (about $10) which has way too much wire, but gets the job done.

I followed Vinnie's link to Headfi and was amused that some people have more than one....

GD, did you see the post about the show (montreal '05 I think) when Vinnie and Louis had vinyl in the room, let the cartridge track a record but played music off the iMod - Visitors are reported to have commented about how good the vinyl sounded

May be an 'apocryphal' story but I like it

Jim