I experienced similar interference years ago before I built the listening room bunker. In my previous rooms, cell phone signal, errant noises from other things would occasionally be heard when the phono stage source was selected. Now, with the bunker….nada. I purposely moved my phone around in the room and the Io did not pick up stray noise. No more of that irritating buzz from Electonics. Now, the room is a virtual dead zone for wi-fi devices.Audioquest4life - proverbial whistle in the first stage
Can you describe? Some sort of hum, or interference?
When I do the tube noise testing, with the volume unrealistically high (two thirds of max maybe) in order to get clear readings from the db meter, I can hear whatever goes on, electrically speaking...even with a dedicated line. Like maybe there is a radio station trying to say something. A couple of years ago we had to move the alarm box away from the listening/living room since it was sending data bursts to the central every 8 minute, sounding like a noise storm through the Io. I still hear a tiny bit of interference, now, maybe it can be improved with some cable dressing but as long as it is so low I can live with it. In my system, now, the noise level from the Io is quite similar (a tiny bit louder) to the noise on the digital input. Quite a change.
Any tube that is getting gassy - or starting to hiss/pop/rumble audibly gets thrown out. The noise will only increase over time. No point in moving them to another position or the power supply, they will impart their noise no matter where they are used.Fozgometer testing, well worth it, still going on.
Anyone with advice, what do you do with your very good NOS tubes in the first gain stage, sounding musical as ever but gradually developing more background tube noise? Are these actually "low hanging fruit" later in the chain - in positions where the noise level is less critical? Should I try them in a later gain stage, or in a power supply - or are they best forgotten?
OGH - yes, I have replaced the stock AC cables with Nordost Odin cables. The stock power supply umbilicals were also replaced with a set of custom cables made for me by Audience. The power supply cables really lowered the noise floor. The replacement AC cables helped with dynamics of the system.audioquest4life - Todays AC cables perform way better
Have you experienced this, changing cables to the Io power supplies?
(I have sort of grown tired of cable changes, those I have a fairly good...I think)
I should caveat that statement by saying today's cable have a better to price performance ratio due to trickledown technology from some manufactures high end and exotic cables. Of course, some tried and true cable geometries with appropriate shielding are stunning for what they offer. Case in point, Neotech OCC copper or silver cables are great and have a niche following in some of the audio circles I follow. Neotech cables are reasonably priced and if you order DIY you can add whatever connector you want. I used lots of Neotech power cables for years because they did not do anything to change the sound...the sound just comes through.audioquest4life - Todays AC cables perform way better
Have you experienced this, changing cables to the Io power supplies?
(I have sort of grown tired of cable changes, those I have a fairly good...I think)
I always start with the Cardas formula and then tweak from there. Cardas formulas The idea is to put the speakers in a bass null in the room, then adjust to get the flattest response. I also use a sound level meter and a frequency sweep. To finish it off, I use a recording with a good vocal that is centered to adjust width and toe in.Dear friends
With better sound, I have rearranged my speakers. Earlier, I may have compensated for non-optimal azimuth by speaker position tweaks, and I want to correct this. But what would be the best way to do it? Start with just one speaker, get the best bass in the room? Place the speakers exactly symmetrical in the room? Or just use my ears?
I started with just my ears. The rearrangements yesterday were done just by listening, no measurements. Just small shifts of speaker positioning and toe-in. Listening to music.
Today I measured and found that I had positioned the left speaker was 182 cm from my listening chair while the right was 181.9 cm.
I was quite impressed. 1 millimeter difference. Not bad for old ears.
Yet the measures show that even if the listening triangle was perfect, the speakers are not quite symmetrically placed in the room. So maybe things could be improved even more. Advice welcome. I will adjust the levelling so the speakers fire exactly the same towards the listener since I know this matters. My speakers are heavy floorstanders, positioning them is not good for my back, but thankfully they are on gliders not spikes.
All supplies are twisted pairs for V+ and V- and each pair is shielded. There is also a shield placed over the entire wire bundle. They also used an updated copper wire (higher purity).Any idea, how they did it? Is it costly?
The umbilicals are long wires that can act as antennas to pick up any noise. Even the rectifiers impart some noise. The twisted pair helps prevent incursion of any environmental noise. This also improves the grounding (or V- return path) and helps lower noise.So I am curious, what kind of noise was lowered with the Audience version. My impression is that most of the tube noise comes from the first gain stage. Not the ps. Unless there is something wrong with the tubes there.
I sent in my existing umbilicals, they ordered the connectors and used a DVM to wring out the wiring. They simply replicated my existing cables and connectors with their wire and added shielding.Any idea, how they did it?
OGH - as I may have said before, depending on whether you use balanced or single-ended output and the input sensitivity of the amplifier, it may be that a 15:00 setting on the Io requires the external preamp to lower (reduce) the signal.Oldvinyl - thanks. I run Io at ca 15 o’clock – 62 db gain, into my preamp. Fairly low, thanks to the quite strong 0.56 mV Atlas output. Now, with very low noise tubes in Io first gain stage, I don’t have a problem with background noise. My analog chain sounds as good as my digital chain, in this respect. Green light – noise is not a big problem. Yet it is interesting that the noise can be lowered even further, upgrading the umbilicals. This is probably more relevant with a lower output cartridge, like 0.30 – 0.20 mV.
OGH - for signal cables, I agree that shielding can have various effects. The umbilicals from the power supply only carry the V+, V- and a ground -- no signal. Reducing noise on the power to the signal tubes will lower the noise of the system.Oldvinyl - my experience is, shielding is better some times, other times maybe not. In theory a cable can resemble an antennna - but is it in fact a problem? Shielding can also mean that the sound becomes less fresh and immediate...I think...just my subjective experience. I do prefer balanced cable to single ended, where possible. But my best single ended interconnect, which I also use as tonearm cable, is unshielded. Go figure.