[Bob A (SD)]

Well it arrived Saturday morning and I've got some hours on it now.  I'm very pleased   This is everything folks have said it is.      

--Bob

[rmihai0]

What is all this discussion about the Ack Dack output? My integrated is rated: "250mV / 25kohm / Phono". Will I need a High Output option added to my Ack Dack 2.0 that I want to order?

Thank you

[Bob A (SD)]

What is all this discussion about the Ack Dack output? My integrated is rated: "250mV / 25kohm / Phono". Will I need a High Output option added to my Ack Dack 2.0 that I want to order?

The high output is really only needed for those running passive preamps.  Mine is with the standard output and there are absolutely no volume issues.  

The more mine is played the better it is sounding

--Bob

[peakrchau]

What is all this discussion about the Ack Dack output? My integrated is rated: "250mV / 25kohm / Phono". Will I need a High Output option added to my Ack Dack 2.0 that I want to order?...

Rmihai,

Almost all active preamps have the same "input sensitivity" of 250 mV. For the volume control turned full up, it describes what input signal is required to generate 1V out of the preamp and about 28V (100W) out of your power amp.

Most of the time people will listen at about 1 Watt average (-20 dB or about 1/2-way down on your volume pot)  input level. In the majority of active amplifier's, the preamp has a fixed gain stage of about 4 (12 dB) followed by a variable attenutation of anywhere 0dB to -52 dB (1x to 1/10,000) in terms of power or 1x to 1/300) in terms of voltage  before it gets to the amp. It is possible to cause the fixed gain stage to clip if too high a signal in inputted.

The other key specification to look for is someting called "overload margin". It describes the maximum input tolerable in terms of a ratio in dB.  For a 2V RMS signal (like the dAck),  The overaload margin would need to be at least 18 dB.  

Many preamps exceed this number this number.  

Example: If your preamp is powered off +/-15 rails, the overload margin (in volts) will be about 18 dB.  If it is powered of 30 V rails, it will be on the order of 24 dB.

The high output option could potentially give higher signal to noise ratio out of an active preamp providing that it is linear at high swings.  Passive preamps never distort and thus have a infinite overload margin. The limitation becomes the maximum input level that the amp can handle.

In layman's terms, if you find that the orginal dAck has the volume knob turned fully clockwise, the high output option should give you back quarter rotation of your volume knob.


PeAK

[rmihai0]

Any new owner of Dack 2.0 that can let us know his opinion?

Thank you

[rmihai0]

There aren't really any new Dack 2.0 owners that can let us know their opinions?

[JLM]

rmihai0,

O.K. I have a dAck v.2 with high output.  I choose this option because I'm considering getting a Clari-T to drive 89dB/w/m speakers.  This is a pairing that an internet friend has and he finds more than acceptable in terms of spls, but I wanted all the headroom I could muster.

This is my first DAC.  It's about 10 dB louder than the stock Sony S7700 alone and 5 dB louder than my Sony XA20ES CD player.


Peak,

Most audiophiles I know listen at or below 80 dB (as they should because continued exposure to 85 dB will result in permanent hearing loss or worse).  With 90 dB/w/m efficiency speakers that would translate into using just 0.1 watts/channel.  Of course its the peaks that demand "real" power.

[peakrchau]

rmihai0,
...Most audiophiles I know listen at or below 80 dB (as they should because continued exposure to 85 dB will result in permanent hearing loss or worse). With 90 dB/w/m efficiency speakers that would translate into using just 0.1 watts/channel. Of course its the peaks that demand "real" power.

I have 0dB (100W) and 1W(-20 dB)  indicators on my amplifier and usually only see the 1W indicators blink occasionally during normal playback levels. The average power level is probably in line with your estimate of 0.1W average watts/channel.

P.S. How is your dAck 2.0 sounding ...looking forward to your comments.

PeAK

[JLM]

PeAK,

Not having bought new stuff for awhile, this break-in business is getting old.  How do you guys do it?  And why?

The dAck! v.2 has about 60 hours on it.  Chris says that the high resolution option pushes break-in out to maybe 200 hours.  So far the mid/treble has opened up with wonderful detail, but the bass seems to come and go.

I'm handicapped having just gotten over a head cold, using a 7 year old Rotel receiver, and room set-up that is far from ideal.  But we're building a house that will include a nicely designed, dedicated listening room.  And I'll be ordering a new amp to go with my Bob Brines FTA-2000 speakers.  My transport is a stock Sony DVP S7700.

[JohnnyLightOn]

I also have the dAck 2.0 with the high resolution option.  Mine has 70 hours on it, so I have another 2-3 weeks before I can comment.  I'm burning it in 8 hours every night, overnight.  It sounded great after a few hours, then took steps backward as Chris said it would.

[mcgsxr]

Component break in - hee hee, I let my Bolder Teac run in 22/7 (was off for around 2 hours per day from 5-7pm when my wife and daughter are around on the middle floor of our townhouse - system in basement) for over 30 days straight, to come up with the over 700 hours of prescribed break in - the treble would come and go during that time, and so it was a real chore, but now that it is the books... quite pleased.

Hang in there guys, and try to find a way to get long hours on your gear early, so that you can start enjoying it faster!

[peakrchau]

... I let my Bolder Teac run in 22/7...for over 30 days straight, to come up with the over 700 hours of prescribed break in - the treble would come and go during that time, and so it was a real chore, but now that it is the books... quite pleased.

Hang in there guys, and try to find a way to get long hours on your gear early, so that you can start enjoying it faster!

Hey Mark,
Sorry about the delay in getting together to do some equipment auditions.  Did your Boulder Teach have any teflon caps added to it ? How long does it take now to get warmed up from the time you switch power on?  The dAck 2.0 with the hi-rez caps guys are limited to about 8 hours max straight followed by a one to two hour recharge.


PeAK

[ctviggen]

It's very hard to burn in an Ack Dack, without risking injury to the batteries.  You have to be there to physically turn it off.  Heck, there have been quite a few times when I've forgotten to turn my version 1.x off, so I never even attempted to burn it in.

[mcgsxr]

Hey PeAK, how are you?

The Bolder Teac does indeed use teflon coupling caps (Multicaps).

I leave it turned on 24/7 forever, as I do with all my SS gear.  Only my tube preamp gets to turn off.

That way, I am ready to go in about 20mins after turn on, as the pre likes to relax a bit, before serious listening.

[doug s.]

It's very hard to burn in an Ack Dack, without risking injury to the batteries.  You have to be there to physically turn it off.  Heck, there have been quite a few times when I've forgotten to turn my version 1.x off, so I never even attempted to burn it in.

i was tempted to take adwantage of this $100 reduced-price intro offer, to see how this compares against my modded art di/o.  nothing i ever read about the earlier iterations piqued my interest enuff - yust no way i wanna give up what the di/o does so well, & even the folk who prefer non-oversampling dacs like the earlier ack!, scott nixon, etc., say that the di/o has better dynamics, detail & frequency extension.

but, until this dac is offered w/a way to hook up an ac power supply that automatically switches on, to simultaneously recharge the battery and allow use under a/c power, i am not a buyer...  (same goes for the battery powwerd amps, only more so.)

ymmv,

doug s.

[peakrchau]

...jus no way i wanna give up what the di/o does so well, & even the folk who prefer non-oversampling dacs like the earlier ack!, scott nixon, etc., say that the di/o has better dynamics, detail & frequency extension.

but, until this dac is offered w/a way to hook up an ac power supply that automatically swi ...

Hi Doug,
The DI/O certainly gave an idea of what a inexpensive well-designed DAC with good sounding conversions chps and a decent output stage  (and ADC) could do.  It was not without its own issues (high output overloading preamps, phono plug outputs instead of RCA, spuriuos noise sensitivities to AC line quality). Despite this it was able in stock form to present a level of dynamics and detail that many felt welcoming.

For DIY types (like you and I) that previously mentioned issues can be rectified(isolation transformers, in-line attenuation networks, modifed output jacks, etc) but the reality is that most people rather not and do not  want  to deal with these issues.  

The dAck goes one step further in removing the possiblity of AC ground loops by using battery operation. Bottom line is that the "house" sound of the unit is more easily realized in a typical installation. A great advantge.

I guess the last point is that comparisons via half-hour shootouts where by a checklist of aspects of reproduced sound (i.e. detail, extension, dynamics, etc) are compared directly do not necessarily result in long term listening satisfaction

P.S. I still use and tweak my DI/O along with the other 3 DACs that I have in my possession. DIY...the gift that keeps on giving

cheers,
PeAK



PeAK

[peakrchau]

...jus no way i wanna give up what the di/o does so well, & even the folk who prefer non-oversampling dacs like the earlier ack!, scott nixon, etc., say that the di/o has better dynamics, detail & frequency extension.

but, until this dac is offered w/a way to hook up an ac power supply that automatically swi ...

Hi Doug,
The DI/O certainly gave an idea of what a inexpensive well-designed DAC with good sounding conversions chps and a decent output stage  (and ADC) could do.  It was not without its own issues (high output overloading preamps, phono plug outputs instead of RCA, spuriuos noise sensitivities to AC line quality). Despite this it was able in stock form to present a level of dynamics and detail that many felt welcoming.

For DIY types (like you and I) that previously mentioned issues can be rectified(isolation transformers, in-line attenuation networks, modifed output jacks, etc) but the reality is that most people rather not and do not  want  to deal with these issues.  

The dAck goes one step further in removing the possiblity of AC ground loops by using battery operation. Bottom line is that the "house" sound of the unit is more easily realized in a typical installation. A great advantge.

I guess the last point is that comparisons via half-hour shootouts where by a checklist of aspects of reproduced sound (i.e. detail, extension, dynamics, etc) are compared directly do not necessarily result in long term listening satisfaction

P.S. I still use and tweak my DI/O along with the other 3 DACs that I have in my possession. DIY...the gift that keeps on giving

cheers,

[doug s.]

Hi Doug,
The DI/O certainly gave an idea of what a inexpensive well-designed DAC with good sounding conversions chps and a decent output stage  (and ADC) could do.  It was not without its own issues (high output overloading preamps, phono plug outputs instead of RCA, spuriuos noise sensitivities to AC line quality). Despite this it was able in stock form to present a level of dynamics and detail that many felt welcoming.

For DIY types (like you and I) that previously mentioned issues can be rectified(is ...

hi peak,

the di/o can be modded by wayne at bolder cables, for those not into diy.  still cheaper than an ack! 2.0, or at most almost as expensive, depending on what options yure getting w/either one.  the earlier ack!'s yust don't hold an interest for me, based upon what others have said about 'em, even those that like 'em.  the 2.0 is likely a different animal, & i bet it has more dynamics, frequency extension, & detail, like the di/o.  

re: dc power, i never had issues w/ac line noise w/my di/o's - likely cuz i have upgraded p/s, and it's plugged in to an iso tranny.  i know chris is considering a charging system for the ack!, per what i mentioned - if he comes out w/a unit that can be permanently left on, & runs on ac when the batteries get too low & go into charge mode, then i may have to try one...

regards,

doug s.

[Danny Richie]

Doug,

I have a Bolder modded Art DI/O with his power supply that uses his Nitro cable on it.

I also have a first generation Ack dAck that I have made minor mods to. The mods involved chunky the 3.0uF Auricaps for 3.3uF Sonicaps and adding .01uF Teflon film and foil by-pass caps. It's the same by-pass caps Chris offers as an upgrade on the new model. The by-pass cap was a biggy. A minor mod that I left in was adding the Bybee filter on the data input.

The Ack dAck now has good extension to the top end and bottom end, very good!

And comparing the two dac's is really no comparison now at all. The Ack has a higher detail level, is cleaner sounding, has a much lusher mid-range, and is much quieter. The noise floor level drop is a big deal. The DI/O has a digital sound and the Ack sounds like analog.

I will never go back to using a dac that relies on AC power. The battery powered Ack has been trouble free and has run for 10 to 12 hours straight at several shows and here at GR, and I never had one run down. It has been really reliable. I am through comparing dac's for a while. I am sticking with this one.

[doug s.]

Doug,

I have a Bolder modded Art DI/O with his power supply that uses his Nitro cable on it.

I also have a first generation Ack dAck that I have made minor mods to. The mods involved chunky the 3.0uF Auricaps for 3.3uF Sonicaps and adding .01uF Teflon film and foil by-pass caps. It's the same by-pass caps Chris offers as an upgrade on the new model. The by-pass cap was a biggy. A minor mod that I left in was adding the Bybee filter on the data input.

The Ack dAck now has good extension to the top e ...

hi danny,

it's always good to get more feedback from folk who have used the stuff!     from your description, it sounds like yure talking about what folks call the ack! 1.2 wersion.  yure the 1st person i've heard who sez even this iteration is more detailed/dynamic/extended than a modded di/o.  makes me even *more* anxious to hear a 2.0!  

regards,

doug s.