Looking for Better Jitter Reduction in a DAC

I try keeping the temps in the house like Ozzie and harriet enjoyed. They always seemd to be wearing sweaters in every episode. Ricky? Not so much.

Having been deep into industrial electrical affairs including communication equipment for some years, having electronics energized indefinitely never seemed a negative consideration, PROVIDED the temperature surrounding it or them could be kept constantly lower.,

400Hz motor Generator sets, PA systems, etc., amps we used had huge output tubes and the gear necessary for them to operate were kept in a air conditioned space which was always brisk. 60F or less..

Experience proved maintaining lower temps kept these amps trouble free so far as I knew from being there over six years. Never wass one output tube replaced. Nor was there any failures otherwise. This information covered several venuews utilizing the same or similar gear.

At worst, a semi annual opening and thorough removal of dust and dirt accumulation was the only active function required beyond keeping operating temps low and constant..

It’s the main reason I have for keeping electronics apart from the listening area. So they can be kept at a lower steady temp. it amounts to use of an adjacent room and longer spkr cables, and oh, yeah, a dedicated AC unit just for that room.

A very prominent designer of very well regarded power plants once said to me heat kills. The lower you can keep the operating temps the better given the temps enable optimum performance of the amps.

It did not take long to see what temps the amps he made liked as ambient temperature.

Even a tiny little fan can be of great benefit if well placed.

RWV… so perhaps this or that item may take as long as two days under power, though I’d not suspect periods further than that were at all required for ANYTHING.

Those items whose endorsements say “leave on’, appear to be able to do quite well after run in with just a day or so of being re-energized. As was said, engage it all for an hour or so maybe less, and have fun. My SS amps took longer than my Tube amps but only by 30 mins, SS needing more foreplay apparently..

Makers are simply tending to having their caps fully loaded and other areas stabilized in terms of temps and energy.

On another note and not meant at all as disparaging, makers ideas of YOU having on THEIR GEAR at all times read as forever, is not hurting them at all, is it?

IMO, its one of those take with a large grain of salt thingys, as there are alternative means for extending the life of our energized components with simple cleaning and temperature control. Or by simply powering up periodically in advance of listening sessions on the primary system.

With a $900 HT rec I’m not really worried as each one I’ve owned has lasted easily ten years without issue prior to needing once a new IC chip.

With $30 to $$$$$$ worth of electronics , I’d seriously consider finding a way to keep that investment operating safely by maintaining a lower environmental temp. MO.

Here I am again asking for help to troubleshoot the "hard edge" produced by my DAC. Here's an update...

I haven’t tried the iFi spdif ipurifier yet since I’m not convinced the problem is due to poor jitter control. I’m really sold on the HDMI (I2S) interface from PWT to DAC, it presents a realistic holographic image. Music sounds wonderful thru tubes, but there’s the damn harshness in the highs, same as with 75 ohm coax.

I tried an experiment, taking all digital and analogue components and running them thru a power strip on the same dedicated AC line. The result was a very offensive harshness in the top-end. Even though all PC’s are shielded, it’s possible there is backflow from the digital devices into the mains.
Normal setup is a separate line for analogue and digital wired from a subpanel. Low noise-floor, excellent imaging, but music has that digital edge to it. Tried it with and w/o power conditioning, I prefer it without. Also tried different AC receptacles around the house, cheater-plugs and a Jensen Iso-max.

Now I’m wondering if the DAC output of 2.8V (unbalanced) is too high and what I’m hearing is distortion thru the speakers, since it is noticeable on peaks; e.g., massed strings sound fine, but brass and solo violin will sound harsh (can sound like distortion).

My computer is still kaput, so I haven't been able to try CD rips or USB. Anybody know where I can get an inexpensive DAC for a trial or loan? The Cable Company has DAC's in the $2K to 4K range, so the trial would be very costly.

I do indeed think you may well have a gain mismatch between the DAC and the amplifier. What you described is precisely how this would sound like: clipping of louder passages.
Part of the traditional criticism of digital comes from precisely this, as the 2V output for cd players as specified in the Red Book was too high for many amplifiers of the day. Hence Quad after the introduction of CD produced a special input board for their existing amplifiers. These days, there are still many amplifiers that cannot quite handle this signal level. In your case, the situation is aggravated because your DAC has a 2.8V output (what is your amplifier’s input sensitivity?). A telltale sign would be that you do not have to open the volume control very much to get a loud signal. Now you may ask why manufacturers would specify a DAC or CD player with an output level that is too high, or amplifiers with a high input sensitivity. The answer is that the human brain interprets louder as better. So in a demo room, the louder player/DAC or the more sensitive amplifier will always be interpreted as the better.
So how do you find out if this is the case (after all, the problem may be different from what I suggest, mine is only an hypothesis)? The first test is the volume control setting. If this suggests that you may have a gain mismatch issue, there are two options. The technical one is to have a look with a scope. Such clipping is easily visible. The second is to use a clean test tone and raise the volume until you hear trouble. The third one is to insert inline attenuators, and see if that improves the situation. If it does, you also have your (fortunately very cheap) solution.
See here for some demo material and discussion: http://www.harbeth.co.uk/usergroup/forum/the-science-of-audio/amplifier-matching-mismatching-and-cli...

Harshness could also be your power amp or your speakers.

@willemj 

Higher voltages on line level devices has nothing to do with making louder volumes to sound nice. (although loud does sound nice as you hear more low level detail as it lifts the low level sounds above the ambient noise floor)

Generally you only see high voltage levels on Class A+ and pro audio equipment. 

The use of higher voltage more expensive components in a line level device is to achieve better THD+N and better SNR. Better performance.

Consumer RCA = cheap crap that is popular because it is cheap manufacture and can often sound OK to non-discerning listeners

Pro Audio balanced is the gold standard = higher signal level and shielded conne tions with signal wires that arent grounded. Expensive and always equal or better than RCA. 

My Benchmark DAC 3 was recently testsd by Stereophile - it delivers 18 volts on XLR at max volume. This high cost high spec analog output circuitry is how Benchmark achieve market leading specifications.

I am not talking about absolute levels, but relative ones, i.e. a mismatch between output level of the source and input sensitivity of the amp. Pro audio is very good with a properly matching gain structure, but home hifi is often not. I agree about XLR.