Hi,

I wanted to post on sound and experiences of the last couple of months since my NOS1 arrived back from Peters as a NOS1a. What a small letter that “a” is but what has transformational effect it has on music played here at home.

Straight out of the box the NOS1a a massive step up on the NOS1 that was sent back to Peter for upgrade. If nothing more came from the NOS1a than that heard on the first day, I would happily go through the upgrade process time and time again for that sound.

Over the last 2 months the target has been to get my NOS1a to approach as much as possible the musical performance I heard at Peters (with a tweaked NOS1) and at Manis with a NOS1a. The common factor listening at Peters and Mani’s has been that they both have / had versions of Peter and Burts loudspeaker system which are IMHO simply in a class of their own. The NOS1a has needed a considerable running in period and I’m still reasonably sure that it continues to improve even after 2+ months of 24 hour a day power.

Although the NOS1a sounds in a completely different class to the NOS1 whilst being driven using just about any XX and PC settings, for me the REAL magic has come with very, very specific PC and XX software settings. I have moved in small steps towards Peters signature settings and those he recommends for the XXPC BOIS. I say slowly because there have been three important system tweaks/mods that have been necessary in my music system to let the NOS1a perform here. I should say however that these tweaks are specific to my system and not related to the NOS1a so I’ll post on these elsewhere.

Today I finally applied the last of Peters under clocking BIOS settings to my AsRrock mobo. What a sound ! The sound is now the most real I have heard save for Peters system and Mani’s (I am still to visit Pauls which I am sure will be added to this list of exceptions). I have stood in awe this afternoon playing track after track. Even the massively rose tinted audio recollection of hearing Blue Monday pounding out at the age of 14 on my first ever night club visit, just could not compare with the way Blue Monday sounded today, WOW !. Milos playing Spanish guitar was simply in the house playing to my family during dinner this evening.  Vestiges of HIFI are absent, music is coherent and cohesive and pushes forwards the performance. It flows with delicacy or power as called for with lifelike dynamic and timbre. My speakers at times appear to have so little to do with the music I think it might be possible to remove them to another room (they do look a little odd when “watching” the musical performance haha).

I want to say an absolutely huge thanks to Peter and Ciska for their dedication and commitment to produce such a remarkable instrument for reproducing music and making it available for people to enjoy.

Nick.

Arjan,

Thanks, I watched the vid and then found 7 out 8 drivers in my speakers had very slightly lose screws when I checked them. The lose screws tended to make a small crack as they moved and tigheded bout a 8th of a turn. I have never checked the screws in 16 years of owning the speakers...

The end result is that bass is tighter music is snappier and siblence and sharpness I the hights has virtually gone.

Great tip.

Nick.

Hi an update on mains company music system upgrades...

The electic company sent another notice asking to do some work on the house meter. Well actually, as seems to be the custom in the UK these days, they threatened to obtain a court order to enter my house to do work on the mains of I did not call them to make an appointment for them to attend..... nice customer service approach !!

This time it was "just" the house electric meter that needed swopping out after 25 years. So Wednesday they turn up and do the work, and I don't even think about possible impact on music until Friday when I put some music on at the end of the week. OMG ! I think they installed a Boogytron 2000 or something , sound is absolutely great ! what an upgrade.

Looked at another way it's disturbing that the old meter was so s**t for sound quality. Glad to see the back of the old meter that's for sure.

Nick.

Sorry, it was not intentional, for sure  . Good to know that i'm in the list.

Best regards,

Nick.

Fascinating Alain,

And I guessed the input might be a pll !

12 phase 480mhz clocks..... no wonder a decent clock and targeted on board bypass capacitance helps so much around the interface board and USB chip !

Also might trow some light on why clock speed and matching are important, will have to think in this.

Nick

Peter hi,

Can I check that I made I to the NOS1a upgrade list ?

http://www.phasure.com/index.php?topic=2965.msg31446#msg31446

Many thanks.

Nick.

Great stuff, I can only imagine how good the sound must be now !

Nick.

Hi,

I though I would also post impressions of listening to Mani’s new speakers and NOS1a on Sunday.
Thank you very much to Mani and his family for such lovely hospitality and putting up with Myself and Paul discussing hi-fi all afternoon 

I have heard Orelo MkI (I think ???) with 12 inch bass drivers at Peters prior to listening to Mani’s new Orelo MkIIs, it was however my first time listening to a NOS1a  and to Peters new Arc prediction filter. So lots of interesting components to listen to.

My comments are based on listening to Manis Orelos and NOS1a with very few hours run in on either, I guess the new Arc prediction software filter was run in fully however (haha). This in mind we all recognised on the day that there will be very significant changes in sound quality to come. What a starting point to the run in process though, right from the first bars with the Orelos and NOS1a you know your listening to something very special. The speed, dynamic weight and continuous spectrum of tone reproduced presents a supremely realistic and “live” level of performance. Detail is absolutely unbelievable however it’s also fully “in the context” of the music so not at all false, overblown or picked out un-naturally in a particular area.

Personally I also felt the bass response was indeed light in weight and as a consequence mids were also a little thinner than you would want and a little down on warmth. Having heard Peters Orelo MK1s I however am very confident that this is down to nothing more than the need to run in Mani’s speakers (possible the long interconnects might play a part as well ?). At Peters there was plenty of bottom end in Peters very large listening room and I understand that the 15 inch drivers and final tweaking of the crossovers in the Orelo MKIIs have if anything made the bottom end even stronger than it was when I heard Peters system. So in this respect I fully expect to hear a perfectly balanced bass response if I am lucky enough to visit Mani when he has the speakers run in.

The NOS1a also left big and positive impression. We were able to compare it with Mani’s NOS1 (with USB interface clock and capacitor tweaks). The NOS1a takes reduction of “harshness” to a whole new level . It is fluid, dynamic and has you immediately relaxing into the performance. With the NOS1 with caps there was a slightly greater tonal solidity that was attractive produced startling real grand piano. The NOS1 with caps had almost intrusive harshness compared with the NOS1a. Just to be clear I would take the NOS1a every time and we all felt that way.

The new arc prediction filter made a very positive contribution too. We played standard and new arc prediction back to back. I would say that the new filter made mids and highs sound less reproduced and more natural.

I’m really looking forwards to getting my NOS upgraded to “a” spec and using new Arc prediction. I think both look as though they do great things for reproduction through high sensitivity speakers where any imperfection in the source can end up writ large across the music.

A great day and a fantastic system Mani , many thanks for having me over to listen.

Kind regards,

Nick.

Peter hi,

I'm loving what you have done, the audio clock right next to the DACs and the USB interface slaved to these clocks, surely it cannot get better  and the output noise plot above WOW !

I think it's time to add me to the waiting list for the upgrade if you would please.

Best regards,

Nick.

Peter hi,

This is an absolutely facinating post 

Partly because its a really pragmatic approach your taking using and analogue scope to determine the spread of jitter and tune it qualitatively.

Also because its great to see such a focused approach being applied to the clock time domain in the NOS1.

Reading your post above and your other resent post on the NOS1 upgrade, if I have understood them correctly you have applied a number of really important changes to the audio clock setup since the upgrades to my NOS1 were applied a couple of months ago. This is moth watering 

Although I don’t have anything line the scope resolution you have with your TS8100, amplitude jitter and audio clock edge smearing and smearing of eye diagrams can be seen hear to some degree even on my modest scope.

The tuned results you are getting get in your last three graphs above look great, is the trace being taken from the directly from the bit clock feed to the DAC chips ?

Again what a fascinating and great post.

Kind regards,

Nick.

Ps I took a look at the spec for the TS8100, what a great bit of kit, I can now add scope envy to the FFT analyser envy I already had haha !

Mani hi,

Your experience using separate balanced transformers sounds similar to what happened here.

A while ago I was getting with slightly confused sound which got markedly worse on complex music with lots of bass energy. When this was happening I had the complete system plugged into a single 3kva balanced mains transformer. I tried plugging my active speaker bass amp modules (rated at 150w class B i think each) into the normal house supply (eg not the balanced transformer) and was supprised that sound got much better. The improvment was so good I bought  a second 3kva balanced transformer just for the active bass amp modules. The original balanced transformer powers PC, NOS1, balanced gainclones (these only typically draw 9 watts from the transformer). The second transformer to power bass really improved sound at lot.

Best Nick.

 Peter. I just want to emphasise that my comment about the weight of the kick drums is such a minor observation when you consider that the comparison is with a live high dynamic range set of instruments :-).

Great that even this small point (considering the achievement of accurately matching live drums) is fixed. What a reply system 

Nick.

Interesting debate.

Personally I love horn presentation. I really value their ability to project sound into the room and generate lifelike dynamics. I'll put up with a lot of "issues" elsewhere to have these qualities. High efficency horns do put the upstream system under a magnifying glass howver and the slightest problem in source or amps is writ large in the sound. sometimes I think these problems are confused with the sound of the horns themselves. Get the front end and amp performing well and IMHO the experience can be magical.

I'm guessing that as the efficency of the horn increases the ability to expose source and amps also increases making it harder to obtain a sound without "problems" being exposed in unglorious fine detail, so a very hard job to get this right with a 118db/w speaker then.

This brings me on to Peter system and Orelo spekers. They are quite exceptional to listen to. The latest NOS1 spec, the active amps and Orelo speakers as a replay chain are spellbinding to listen to. I have to say that Peter makes some bold claims about this system here but having had the chance to listened to it I recognise in the sound all of what he is saying about the Orelos.

Whilst at Peters I listened to his son playing drums live in the house. Afterwards Peter played a recording he had made of the same drum kit back through the NOS1 and Orelos, you really could not tell the difference save for a slightly less pronounced kick in the chest from the kick drum, otherwise cymbals and drums were simply the same as the live drum kit  :-)

Its all about personal preferance I guess. I don't think I could be without horns of some type of horn speaker in my system, but a set of Orelos would be be something else !

Nick.

ps, Mani I have a case of speaker envy even before you have taken delivery of your set of Orelos haha.

Mani hi,

Good question  I'm not sure about how close is close enough. The  sample 24mhz "DIY" clock i used based on a module would should run at 24mhz. I might investigate more but I need to spend more money on measuring equipment to do this.

Regards the dexas drift rate. As mentioned in other posts, there is a cycle of drift between two tuned dexa usb clocks, but this peaks at about 3 or so beats per second so not that large (your clocks were tuned to this tollerance). So far once tuned to each other the frequencies of the clocks appear to be stable over time. I'll keep checking on this but I don't think they are going to need retuning regularly.

Regards,

Nick.

Coen hi,

The posts are none too clear  There are two factors.

1) matching the speeds of the PCIe USB card clock and the DAC USB interface clock.
2) both clocks need to run at close to their nominal frequency of 24mhz.

When I went to Peters I had unknowingly tweeked clock speeds to the point that, the DAC end clock was running > 1000hz above the 24mhz nominal speed for the USB decoder. In addition to this the matching of the two clock speeds also was way out.

Fixing both these points has things very much back on track sound quality wise  .

Regards,

Nick.