An Edifying Journey ...

[botrytis]

On 8/27/2020 at 8:19 PM, bluesman said:

People where you work have audio systems at their desks that include low latency, high def BT transceivers with good components? Wow - I wanna work there.
 

I’m talking about serious home systems with good sources, DACs, amps & speakers using optical in and out AptX LL / HD BT to connect the source to the DAC instead of wires.  I’m not talking about BT phones and active speakers, very few of which have the latest Qualcomm BT yet.

 

These gents use stuff like that. but then they listen to MP3's  I know.

[fas42]

Finally ... !!! Been wanting to set up a "test bench" for better exploring of mains filtering, conditioning options - this is extremely simple; back to back, ordinary power supply transformers - toroids. 240V in, 240V out - a DIY isolation tranny ... too many life things getting in the way up to now, including fixing up a kitchen drain blockage; this is finally fixed enough to not be fussed on the "last bits", of filling in holes, etc 🙂

 

So, filter unit now assembled, added into the mains cords and filtering chain, right at the beginning - means now 3 stages of filtering going on! Kicked it off to make sure it worked; that no funnies turn up because I missed something; first impressions, seems to have improved the sound - running an Ace Records sampler CD of 60's, etc, pop; solid, immersive presentation, very good detail.

 

Let it bed down for a day or so, then start varying things - and see what that tells me ... 🙂.

[fas42]

Right, first very simple test to confirm that the extra filtering was doing what it appeared to be - by removing, and then re-inserting that 'box' ...  played from this local release,

 

 

this first song, recorded 1928,

 

 

Having the isolation transformer as part of the power supply filtering made a substantial difference; removing it as the first step of the chain turned the string section of the orchestra into a "silly symphonies", cartoon sound - much better integrity when again inserted.

 

 

[fas42]

Okay, some interesting findings ... even though the sound improved at an early point of the warmup, by having the transformer box (iso xfr) in the power chain, the SQ started to develop an edge over longer playing time. Another round of trying this confirmed what was going on - I was getting "more detail", but this built up an unpleasantness, getting worse the longer playback continued ... time to try variations 🙂.

 

The first config was the iso xfr at the dedicated power point, then very long, individual runs to the dedicated filtering for first the DVD then, and then the active speakers. Okay, try iso xfr just before the second level filters, via long run to the wall socket - and split into the two filter chains at that point ... worse!! Major downgrade of quality - this implied that the DVD player and active speakers power supplies were interfering with each other, and this was more a problem than noise from elsewhere, at this stage of experimenting. The Edifiers had already signaled that they needed more filtering than the source unit; so next move was to dedicate the iso xfr to the speaker run; the DVD player now went back to its former dedicated long cable to the socket - this meant that two long runs of cable, and iso xfr now distanced the filtered power feeds.

 

And this immediately confirmed that it was the best setup so far - sensitivity to noise on the dedicated mains spur was still present; but with workarounds in place, SQ was better than ever - very marginal Errol Garner piano tracks were a delight.

[fas42]

Still haven't got further with improving the mains filtering - too much else to do around the place at the moment. But I'm very pleased with the current set of noise reduction workarounds; a very fine standard of replay, from dead cold start - incredibly sensitive now to any of the myriad rough n' ready tweaking of things in place - and very, very easy to disturb one of them; meaning a very definite drop in SQ if not 100% in order.

 

Have to bite the bullet on getting that filtering sorted, as soon as possible. Then, tidy up the crazy mess of workarounds without losing quality - this may be just as difficult as anything else I could work on, 😉.

[fas42]

Long off time for the speakers ... but first up,

 

 

From that,

 

 

Nailed the voice, and the big, big brash brass of the backing band - can too many b's be enough, 😁.

 

Point is that an oldie but goodie set of recordings get the pulse racing - from a dead stop start. Which is what I believe should be a given with a system - it's there to entertain, and if it can't do that without a whole heap of compromises, and waiting, then it hasn't really done its job ...

[fas42]

On 4/15/2020 at 10:25 AM, fas42 said:

First CD to make it obvious where work was needed was that which was tried first thing, from cold start, the next morning,

 

 

Very live, driving sound; modern recording -  this was a "bit much" ... no problems with the energy and punch, but subjectively too much of the "in the face" quality; a good test, from now on, to see how I progress in 'refining' the setup.

 

 

To see how we're faring, tried this again ... much better.

 

Great test CD ... the drums are recorded with all the transient intensity intact, plus plenty of echo! Start the first track with the volume higher than you thought was good for the moment - and the first punch of the drums coming in just about knocks you over!! ... If you're not in the mood for this level of sound intensity, it will be "too much" - but this album rewards you with tremendous musical 'bite' if that's what you feeling like experiencing.

[fas42]

Finally! ... First step in improving the mains filtering, for the Edifiers, in a long time ...  🙂. Very simple addition, the insertion of some ferrite sleeves onto the leads going into the DIY isolation transformer - actually did this some days ago, but didn't concern myself with static matters - meaning that if the ferrites are loose around the cable then that merely creates another problem: after some time an edge builds in the sound. This was determined some years ago - I use some filler semiconducting material as a simple means of tweaking, while experimenting - which I hadn't done yet; and it was clear that I need to do something, this time around as well.

 

Tried TailGators again - turned out I had the volume set for pub pounding volume, and it worked! Very clean, drums nicely presented - no obvious issues.

 

Now trying a disc I have never played before, a gift from N.,

 

 

Still lookin' good ... crossing fingers that this remains a good move, 😉.

[fas42]

As mentioned elsewhere, I had to contend with a static problem, with adding those sleeves - took a bit of fiddling to that part of the electrics to make it physically stable enough to not cause audible issues. But these were only added to the mains feed to the active speakers - what about the DVD player? First play this morning,

 

 

showed that indeed such an addition, or variation that achieved the same thing, was needed - the 'atmospherics' of the tracks were disturbed by having the mains lead to the player's filter "touching the wrong things".

[fas42]

Added the ferrites to the DVD side of things - and this definitely helped. Good signs so far, that the setup is more resistant to the nasties coming through the mains cables - a track like the following could be played at full bore sound levels, and the rippling piano notes came through with full transient bite, and no edginess whatsoever ...

 

 

This was without taking special care that the mains was benign, by doing all the tweaking that normally is needed for best sound to happen ... will see if this holds up, 🙂.

[Rexp]

If I record something at 24/44.1 on my laptop using Audacity and play it back via the headphone out, it sounds like the original. So the speakers are not causing bad sound. 

[fas42]

13 hours ago, Rexp said:

If I record something at 24/44.1 on my laptop using Audacity and play it back via the headphone out, it sounds like the original. So the speakers are not causing bad sound. 

 

Do you mean, recording via a microphone what the Edifiers are producing in the room?

[Rexp]

2 hours ago, fas42 said:

 

Do you mean, recording via a microphone what the Edifiers are producing in the room?

If I record something (a voice for example) at 24/44.1 on my laptop using Audacity and play (the file) back via the headphone out (of the laptop, connected to the analogue in of the speakers) , it sounds like the original (voice). So the speakers are not causing bad sound. 

[fas42]

2 hours ago, Rexp said:

If I record something (a voice for example) at 24/44.1 on my laptop using Audacity and play (the file) back via the headphone out (of the laptop, connected to the analogue in of the speakers) , it sounds like the original (voice). So the speakers are not causing bad sound. 

 

Right, so the record to laptop/playback from laptop via headphone out to analogue in/speakers chain is getting the SQ good enough to do the job ... 👍

[fas42]

On my Edifiers, I'm quite pleased with what the latest, extra, very high frequency filtering is doing ... the SQ was now only very slightly impacted by tweaking/not tweaking the mains noise elsewhere. So, I bit the bullet, and took the mains feed directly from the ordinary consumer quality 4 outlet power board which the TV, etc uses - a good test, because of the very basic SMPS supplies in all those devices; plus, the fridge is on the same circuit ... hmmm, quality is still good, if not a touch better in some ways. Still not perfect, the effect of disconnecting the media gear, etc, and altering the power draw elsewhere in the house, was still discernible - but not dramatic ... quite acceptable, for the moment. Then a touch of reorganising how things were plugged in, adding a surge buster all helped.

 

I was using a CD of 1930's swing orchestra tracks to fine tune this ... the slightest noise issue kills the listenability of this sort of recording quality; when 'aligned', all the depth and space cues come through with ease.

 

This is good news, because I can now get rid of the silly extension cord snakes going everywhere; which were needed up to now to attenuate the noise to some degree.

[fas42]

Hmmm, the extra filtering is still not doing the job well enough to keep out noise from the mains circuit that the TV, etc, is on also, as noted above - I was hopeful that it would be enough to make their presence inaudible, but no cigar, 😉. Switching off either the TV, or the video recorder, and back on showed that there was an impact - a negative one, of course. Interestingly, the standby modes of these devices was not a problem - only powering up the full circuitry caused the issue.

 

Now, these units are adjacent to the DVD player, and active speakers ... was the problem an RFI one, rather than conducted through the mains? I had convinced myself earlier that radiated noise was not the cause, but I thought to double check - to do this, I connected the media units to the ultra long extension cord, and separate mains line, which I had been using earlier to isolate the audio components ... if RFI from the cabinets was the real problem, this isolation technique would not work. And this in fact was ruled out - using conductor distance to isolate the TV and video recorder stopped the degradation of the SQ.

 

This is a good example of using very simple tests to determine what is causing the interaction - however, it doesn't get me closer to a solution ... I want the Edifier setup to be completely resistant to mains interference, and so another round of considering how the filtering is organised will be needed.

[fas42]

A bit more mains cord swapping, and it identified the active speakers as the main concern ... as would be expected. This has been the pattern throughout, the DVD player is less important as regards any interference issue - but is still sensitive, to some degree. This would be good ol' jitter stuff - finally!! 😜 - the optical link would have the character of its optical transmission altered just enough to impact the Edifiers' circuitry.

 

Next step ... I'm not 100% happy with the integrity of how I added the ferrite sleeves to the speaker's mains filtering, so I'm going to try improving that, to see if that helps matters ...

[fas42]

Not so good news on the ferrite sleeve front, as regards dealing with static, triboelectric effects - I was hoping that the noise that mattered was in the region that the sleeves were effective, but it appears not to be the case; a key test chamber music CD that I regularly use for string tone evaluation refused to lift its game - until, finally, I tidied up the mains cables so the normal static issues I worry about couldn't play a part - I had deliberately left them messy to see if I had made progress - tried again ... and, good sound returned, for that disc.

 

The static noise factor is a real nasty one - which isn't helped by the lack of information available to understand this factor. And that means continuing experimentation, to try and evolve an effective counter to this behaviour ... would a different ferrite arrangement do better, or does it need a very different approach? ... Who knows, 😜 ?

[fas42]

Had lost my way a bit with the ferrite thing ... needed to re-establish a "marker point" - so, used a few cable fiddles to restore adequate SQ - and the TailGators CD got into the right zone. Meaning, live in the rehearsal room, with all guns firing, impact ... no downsides. This produces a sense of liveness from the other end of the house, vibe.

 

Incredibly easy to lose this sharp end point of the optimising - a tiny bit of static interference, distortion, intruding kills this quality completely ... if things are changed too much in trying for a movement forward, then what was  achieved before can be broken - and then one has to retrace the steps recently taken, carefully, to determine what has been 'damaged'.

[fas42]

Leaving things in a good space for a bit; before fiddling again, to try and nail precisely how the filtering should be organised ... have a couple of cover discs from the Hi-Fi News, of classical samplers, and these work very nicely. One is https://musicbrainz.org/release/6bcb784c-1ec0-4197-b95e-d4042a718ad3 and what stands out is that this works from a dead cold start - just tried it before. The end track is

 

 

and the grandeur, sheen, heft and scale of this track are all in place, at live listening levels. This is remarkable, considering the cost of the active speakers, and that the system had only the time of playing the earlier tracks, from cold, to stabilise.

 

[fas42]

Not done much lately - a quick experiment ... how does the SQ hold up with doing "some bad things" - in this case, plugging the, normal length, mains leads of the setup into the wall socket adjacent to that feeding the TV and PVR, which have nasty switch mode supplies in them - a good test of how the filtering is now working ...

 

Tried

 

 

from cold - lookin' good ... and sounding better as it warms up ...

 

Big crescendo came ... Bev just yelled out from the other end of the house, in front of the speakers, "Brilliant!!" ... 👍

[fas42]

The not so good news ... still have RF getting through - parts which can act as an antenna, of the mains circuit plugged into, are causing a negative impact. Confirmed by removing or snubbing those sections of conductor - so, more to be done, on that front.

[fas42]

Also, impact of other electrical devices on the same power circuit still not being sufficiently isolated - interestingly, it appears to take some considerable time to become noticeable; say, several CDs being played, from a cold startup ... a budget compilation of Dionne Warwick hits makes this obvious.

[fas42]

Interesting experiment ... just tried out a streaming service, for the first time, Spotify for Free - according to the gossip, this should be abysmal - but it didn't sound too bad on the laptop, to my ears 😉. So, what's it going to sound like on these speakers ... install a streaming capture app, and burn some WAV tracks to CD, and try it on the rig - to make it tougher, how about some old classical recordings? okay, some Toscanini at Carnegie Hall, recorded in 1929 mostly - Verdi Overtures.

 

Hmmm, very noisy of course - but the music came over well; plenty of depth and sense of space ... crescendos were limited, but overall highly listenable - there was very little there that directly agitated one, in the sense that one didn't want to keep listening ...

 

Considering that this was free Spotify, at 160bps compression rate apparently ... I don't have too many complaints, 🙂.

[fas42]

Okay, some feedback from a visitor - likes jazz, so put on an el cheapo, rip off CD of Dave Brubeck, at gutsy volume ... big thumbs up 🙂. Has a boyfriend who's a drummer, she phoned him while it was playing - he thought it was "brilliant", just from hearing it over a smartphone ... that's what I like in a rig; that it can make a strong emotional connection even when the sound passes through rough and ready means of hearing it.