[HumanMedia]

Quote:

Originally Posted by auditude /img/forum/go_quote.gif I'm really interested in your thoughts on this DAC. Not very well known outside of the head-fi community (at least from what I've found). Would really appreciate any opinions vs. the benchmark dac1, the MSB link III, PT P3a with modwrigth level II mods??? Please let me know...just would like more input vs. all the tweak stuff that I've found. TIA

Cant compare to any of those. However it does trounce the Zhaoulu (with opamps). I plugged my Zhaolu back in last night and it really is a step down, and I could never find any opamps which sounded neutral and unconstrained. My gut feel is that a Zhaoulu with a transistor output stage, whilst costing more, is likely to sound a little better than a 7.2x. I never liked the Benchmark in the brief times I auditioned it - too forward and hifi sounding - excusable in a $200 DAC, but not for the Benchmarks price. I never compared it back to back to the 7.2x though.

I did compare to a Rega Apollo that wasnt burnt in, and the Apollo had a smoother more delicate midrange but it wasnt enough for me to upgrade from the 7.2x (and I would in an instant if I felt it better in all areas). In this comparison I felt the 7.2x had better bass and more detailed treble, although the 7.2x has a slight metallic taste in highly percussive treble. The Apollo was more neutral in the treble but coarser in these high frequencies. However neither the Apollo or the 7.2 were fully burned in at this stage so the comparison was a little unfair.

Note that for me, getting these DACs in the first place, was to avoid spending money on yet another disc spinner. However the upgrade bug is always biting and I will be auditioning the Cambridge 840c (with digital in!) and the Rega Saturn, and if these are dramatically better, I will upgrade. But so far no CDP under USD$1000 has swayed me.

 

[rumatt]

Quote:

Originally Posted by HumanMedia /img/forum/go_quote.gif *After the 4 front screws *pull the volume knob straight out without twisting *Undo the hex nut inside the volume knob *Front panel should pull off a little, so you can: *Undo the 2 cables into the rear of front panel *Undo the bottom two screws on underneath right *Undo the 4 screws on the back (2 center and 2 right rear) *Right side should pull forward and off

Ahhhhhh. Thanks.

I did it a different way. I took all the hex nuts out of the back, and the back comes right off. Then slide half of the case back.

 

[auditude]

that with it's dynamics and somewhat strident presentation this would mate well with a full tube rig?

Again, this is my first venture into ext. dacs but it seems to be a steal for the money in stock form and great with the upgraded clock. I'm not sure which camp I'm in yet for NOS, oversampling, single bit or 24 bit etc. however I'm very excited for this lil' guy to come into my dig front end and shake things up.

The seller stated that he went to an Aero Audio dac to replace the 7.2 @ close to 20x's the price...I don't know if that's overboard but you found the same results with it?

My transports are going to be a Pio DV59 elite, a Sony 999es and a Marantz 63se. I'm trying to cut down on the spinners in the system as rack space is limited. Ideally, I'd be honing everything down to just one digital source. I could never find the right mix of audio performance with great video performance either one or the other or with both just ok.

Right now, I am very very impressed with the video performance of the pio and feel that the sony is 80% of it and could live with it if the audio were up to par. I thought about the hi $ universals but found it hard to separate with my $. I felt I would be leveling the playing field by adding a decent DAC into the picture and having my cake and eating it too.

I hope I'm on the right track with this ext DAC theory - esp with the citypulse at it's playing price.

Thanks again for your insight; though I'm fearful of entering the head can arena with the previous experiences with all audio - I've slipped enough down the previous slippery slopes enough to know when to say when...I'm just wary now of the DAC slope and soon, with the citypulse and it's head can out, the can arena as well.

All the best and Happy Holidays and turkey day to all!

Angelo

BTW, if there's anyone out there in the S.F. bay area willing to part with their DAC for a day or five in order for my audition purposes I'd be more than indebted to you. Just thought I'd throw it out there since it seems that some of the members have multiple DACS.

 

[HumanMedia]

Ive noticed that the Citypulse sounded better later into the night. There are a few things that contribute to this - lower audible background noise, more focus because you are relaxed. Ive been used to this effect but it seemed way more pronounced with the 7.2x. Another contributing factor to this effect is the reduction in RFI from other households shutting down for the night (im in an apartment block) This RFI affects digital circuitry. The RFI is usually transmitted through the powerlines and picked up by the power cord which acts as an antennae, and into the equipments power supply. Digital equipment particularly DACs are the most susceptible.

Ive had 10awg unshielded cord (DIY VHAudio Flavor 4) into the DAC, which worked perfectly for the Zhaolu and a shielded DIY Flavor 2 into the transport, which along with other digital stuff was isolated from the DAC with twin Auricaps in a switchless power board (Eichmann).

I really havent played much with powercords on the 7.2x leaving my previous wiring in place. However with the 'nighttime' effect so pronounced I thought that I would try a shielded cord on the DAC and isolate it on the Auricap tweaked power board with the transport into the wall.

I tried the good old Volex 17604 on the 7.2x with immediate improvement in clarity in the midrange and lots of detail. Too much detail for me with the SWO-XXX in the wall. Went back to the unshielded large gauge cord - too bassy and murky and restricted in midrange(!). Normally this cord is fine with everything, but not this DAC. Next I tried a DIY Flavour 1 (shielded with ground) and it seemed a great match, adding finer detail tightening bass and giving improved clarity in the midrange.

Not getting too excited I left it for a day and rotated the cords again with my girlfriend listening the next evening, and the pattern repeated itself. Each cable was very different, in fact the differences seemed larger on this DAC that any other component Ive tried cords on. My partner asked what I was changing around at the back and when I told her just the powercords she shook her head in disbelief that something so simple was making such a change.

Anyways for my particular setup, isolating the DAC with the Auricap tweak and using a DIY Flavour 1 (12 awg copper, shielded with ground) is a considerable improvement. But it is one that compliments my setup and may not work for others. However I believe the isolating the DAC with the Auricap tweak and using a shielded cord of not too high-a-gauge is the key.

I highly recommend trying a few cords out with this DAC and if the current sound is a tad bright go with something like the DIY Flavor 1 (12awg and foil shielded), and if your current sound is a little flat in the top end, go for the tried and true Volex (14awg and foil shielded) at around USD$10.

For some reason it also seemed that moving the higher gauge cord to my transport also contributed to its sound (!) and with all of these minor changes it seemed like some clearly audible barrier to performance had been removed from the system.

Skeptics can move on, nothing to see here. Others should try a shielded Volex immediately and based on the results of that try some other cords to steer the sound in a direction appropriate to your systems.

 

[auditude]

power cords to try out on the citypulse. I've got a Signal Cables pc and the tried and true volex in 2m length.

I'm really excited about the dac. I'm also thinking about picking up a sonic frontiers sfd 1 MKII and a pac valves modded diyeden gm from a local for
sh!ts and giggles.

The SF is a bit more of an investment financially but I can gain a whole lot of knowledge from these 3 dacs.

Thanks again for your help folks. One more DAC to throw into the mix, the MF x-can v3...is the citypulse still the giant killer in this picture?

TIA

 

[anddre]

Hi All,

I just ordered my TXCO so I can't add thoughts on that area so far.

On the other habd I did a couple of tests with some power chords with very good results.

The ones I tested are:
- Signal Cable;
- Aural Thrills Silver Power Chord
- PS Audio

Unfortunatelly I don't have two of them to test the combo with the CDP.

The best combination in my setup is:
Aural Thrills on the CDP with the PS Audio on the DAC.

Since I live in a small farm, background noise isn't an issue. I also have a dedicated power supply for the stereo setup. In other words, this means that you should really consider to have a very good power supply to be able to get the most of your system.

Another very important issue, for the ones like me that are using this DAC for a speaker system, is the room accoustic.

Regards to all,
André

 

[HumanMedia]

Quote:

Originally Posted by anddre /img/forum/go_quote.gif Hi All, Since I live in a small farm, background noise isn't an issue. I also have a dedicated power supply for the stereo setup. In other words, this means that you should really consider to have a very good power supply to be able to get

Also consider that ones own household is also a major source of RFI, especially computers, wireless LANs, your transport, video and DVD players, air conditioners, subwoofers, TVs, microwave ovens, mobile phones...


The 7.2x must be quite susceptible as the difference the Auricap tweak and VH Flavor 2 cord made on the on the 7.2x was quite marked.

 

[anddre]

Hi HumanMedia,

I will try some other power chords from very good and talent brazilian manufacters.

Thanks for you insight on the RFI.

I should be back home tomorrow so I will try to post some pictures of a DIY vibration isolator that worked very well with this DAC.

Regards,
André

 

[anddre]

Hi all,

As promised here are my 3 cents on this matter:

1 cent: increase the mass of your DAC

There are two basic ways, among others, that I would like to comment:

a) Hi-end and very expensive damping:
Put some of your stereo magazines on the top of the unit

:

b) use a kind of asfaltic membrane. Here in Brazil we have a product called VEDACIT.

I am planning on doing that as soon as I install my TXCO.

2 cents: There is a non expensive way, but still very clever, of doing this:

- Drink 6 or 8 cans of beer and collect 3 or 4 mouse balls;
- Take a nap;
- compress the cans to achieve the following format:
- place a glass on the top of them to support the DAC or CDP.

They are called here in Brazil as LCBM that stands for, translated of course, as soda can and mouse's ball. The beer idea is just to add a big voodoo into this experience

.

http://web.295.ca/~peak/audio/transport.html

3 cents:
Silicon taps from Doctor Feet. You place you DAC on top of 3 of those and voilà!!

Project Design:

Those are the contributions from the Brazilian Audoophile Group

, many thanks to Leonardo and Eduardo.

I am using the second possibility but I have a 4 can sandwich instead of the current example. It works very well.

Best Regards,
André

 

[anddre]

Hi all,

I opened this morning my Copland Hybrid Amplifier and found that the previous owner glued some rubber bands on the unit cover. This could be another interesting and simple way of increasing the DAC weight. You just need to get a high density rubber without causing any heat increase.

Here is the picture to illustrate it:

For the Vedacit option I posted previously, I am going to interlacate it with an asphaltic cover to avoid the heat reflex the aluminium side will cause.

Regards,
André

 

[anddre]

Hi all,

Did anyone test the LP analogue output through the audio in of this DAC?

Thanks,
André

 

[HumanMedia]

On Eddie's suggestion I am testing out the replacement of some of the capacitors in the 7.2x.

A couple of others recommended changing the 6 power supply caps, or alternatively two caps in the output stage (the 25V 100uf ones underneath the square red plastic units).

I went with the easy and cheaper option of the two in the output stage.

For many days the sound was awful and muddy. I must have made a big mistake, as the closest value caps I could find were 50V 100uf. Maybe the higher voltage rating made it all too slow hence the horrible audio mud.

I know that caps have a long break in time and after 10 days of listening and two 60 hour straight weekend burnins, it was still bad. Many times I thought I should put the stock caps back in so I could listen to music properly again. But I kept reminding myself that caps need lots of break in and I set my DVD player on repeat (I want to save wearing my cd transport). Its a couple of days later now, and Ive come home to a new audio butterfly unfolding. Treble is refined again, bass is back and midrange is fantastic. Still a little forward in the midrange but a very nice change overall. Smoother across the range and more dynamic. Still settling though, so it may take another swing to the worse, but at this stage (maybe 200 hours in) the results are very promising.

I will report back soon on further progress.

 

[lesserpanda]

any update

 

[HumanMedia]

Hehe. Yeah.

The capacitor replacement is highly recommended.
The end result is more refined with smoother highs more coherent mids with a very warm bass. In my particular capacitor choice, a little too much bass.

The only thing I had at hand were 50V 100uf caps (Blackgates) and Im thinking that using a nice high quality cap closer to 25V may be perfect to tame and tighten the bass. You will need 2 x 25V 100uf non-polarised capacitor to use in place of the ones under the Red boxes (literally under, you have to lift out the red boxes to access them).

The reason why Im not rushing out and trying lots more caps is the burn in time. It took as long as the DAC initially to settle - about 400 hours, and went through the same sorts of changes.

Im living with the fattened bass for a while because its not too bad and the rest sounds so good, and I dont feel like another long burn-in right now. So if anyone else wants to carry the batton, this is the direction to do it in.

Eddie says that someone else sourced a great replacement cap from Europe or England which worked well.


BTW I am still trying to audition a burned in Rega Saturn and Cambridge 840 but the local dealer keep selling them and is always out of stock before I get a chance to go in. However the Citypulse with the internal cap tweak (and the shielded power cord with auricaps filter) is keeping me quite hapy in the meantime.

 

[GaryBr]

Quote:

Originally Posted by HumanMedia /img/forum/go_quote.gif The capacitor replacement is highly recommended. The end result is more refined with smoother highs more coherent mids with a very warm bass. In my particular capacitor choice, a little too much bass.

HM,
Do you know what these caps are doing? Are they power supply caps for the output stage or are they DC blocking caps?
Thanks,
---Gary