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Ultimate Audio Playback / Chatter and forum related stuff / Re: Gainclone heaven ?
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on: July 01, 2013, 11:27:39 pm
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George hi,
That is a chestnut, long interconnects v speaker cables.
I found that having transformers in the same case as the amp modules really hit sound quality. My current design is two box but to split is amps in one box and transformers in the other. The amp performs much better like this.
If the 4.7uf caps you are looking for are for input decoupling it might be worth hunting out some 22uf or 47uf Black gate nx types (see earlier post). Paul and later Myself have had very nice results with them. I preferred them to mondorf silver gold oil caps, wish I had known earlier !
Cheers,
Nick.
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378
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Ultimate Audio Playback / Chatter and forum related stuff / Hunting for noise
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on: July 01, 2013, 11:16:24 pm
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My plans to hunt down the noise problem in my system got off to a false start with the purchase of an Oscilloscope that turned out to be no better than a toy. ( more here http://www.phasure.com/index.php?topic=2404.msg27276#msg27276) Six months later I'm getting started. A new oscilloscope, a Rigol DS2072, arrived a couple of days ago. I have to say the Rigol is an absolutely excellent bit of kit. I also bought a PC attached USB logic analyser a few weeks ago with 8 digital inputs and 2 analogue traces. The cool thing is that the logic analyser decodes the I2S serial protocol which allows me to view the bit clock, word clock and data values being sent into the DAC section of my NOS1, The bits and bytes look good too after Peter has applied XX magic to them So tools at the ready ! I spent a few hours today measuring round my NOS1, PC and gainclones with the Rigol scope to get a feel for what may be going off that could cause poor sound quality. Some VERY surprising stuff is coming to light. I want to spend more time working up solutions but a couple of things that are interesting so far. 1) there is a LOT of noise in there. 2) I can clearly see activity from the PC (disk drive and PC psu) causing noise on the NOS1 outputs (so the PC does have potential to electrically influence analogue outputs ??) 3) after applying a few ferrites to the system aimed at reducing HF noise my sound quality has taken a leap forwards. The ferrites are treating the symptoms only, dealing with the source of the noise I'm seeing may be a lot harder. 4) I use a "none standard" 22mhz oscillator (clock) in my NOS1. The sound is very good with the clock but the wave form of the clock looks like it could be better. I think I'll need to investigate how to achieve better line matching with the clock input of the USB interface. It's nice to be making some headway and to be using a scope that can be trusted ! Regards, Nick.
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379
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Ultimate Audio Playback / Chatter and forum related stuff / Re: EMI everwhere !
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on: July 01, 2013, 10:16:52 pm
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I have been waiting to post an update, all will become clear. The post above outlines a nasty EMI problem that I thought may be the cause of noise related poor sound quality problems I have been having with my system for a looong time. It was driving me nuts trying to work out how so much EMI was in my domestic environment. Eventually i started to suspect the test equipment and I tried the oscilloscope in a number of places around the UK including Paul's house on a visit to listen to his music system. The noise level was exactly the same at every location. Humm what is the common factor ?... the oscilloscope. The realisation began to dawn, next google for Owon SDS7102 noise and this came up ! http://www.eevblog.com/forum/testgear/review-of-owon-sds7102/1065/Tens of pages describing what people refer to as "SDS7102 ground noise". So it turns out the £400 Owon SDS7102 Oscilloscope is plagued with internally generated SMPS noise. Frankly it seems like Owon set some graduate on the design of the internal power supply boards and the result is a scope that is not even a toy in terms of reliable measurement. Any measured trace below about 1v is swamped in the internally generated noise. Owon as a company have their heads in the sand. There must be hundreds or thousands of customers with SDS7102 scopes that are as useful as a building brick. According to Owon this level of internally generated noise is normal and acceptable in a piece of test equipment. They will not respond to direct warrenty claimes of users (thier products are supposed to have 3 year warrenty...haha) and are basically hanging out all of their users to dry with an expensive and useless product. DO NOT BUY AN OWON SDS7102 OSCILLOSCOPE UNDER ANY CIRCUMSTANCES. Rant over. (Peter if I have broken forum rules above please let me know and I will change the post) So onto the good / more interesting developments, in the end I still have a problem to solve in my music system so I bought a Rigol DS2072 oscilloscope, after a 5 week wait it was delivered a couple of days ago. It is an incredible instrument, I'm very very pleased with it. I will start a new thread on tracking down noise issue in my music system with the new scope. www.phasure.com/index.php?topic=2640.msg27277#msg27277Regards, Nick. Edit - typos and add link to new post on system emi noise
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381
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Ultimate Audio Playback / Chatter and forum related stuff / Re: Gainclone heaven ?
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on: June 30, 2013, 03:46:19 pm
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After trying out a lot of things with 0.9z-9b and Windows 8 the system seems to be very stable and the time has come to ban the input capacitor. For the case of accidents it's easily connected again. Additionally I connected in parallel with the buffering capacitor a styroflex capacitor on the amp board which works beautifully for the heights.
Georg
Georg hi, I tend to agree with Peter. In addition I find the sound tends to get better with input caps. Without is very pure but with seems to improve balance of the sound. I prefer with. Paul and I are using blackgate n types. In my case I use type nx in 47uf size. There is a guy selling them on ebay from japan at the moment. They are expensive but very very good on the input of gainclones. Cheers, Nick.
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384
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Ultimate Audio Playback / Playback Tweaks and Source related subjects / Free Upgrade :-)
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on: June 26, 2013, 12:27:59 pm
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I had to smile yesterday evening. The power distribution company has been doing upgrades to the mains system in my village. Yesterday our house had power cut all day so that the power company could replace the above ground mains distribution wiring to the house across our paddock and up to the house. I think the new wiring has gone back from the house as far as a pole mounted transformer further into the village. I thought it would be fun to try my system and take a listen, had the power company met its most important objective of upgrading my system ? . Well it’s made a real difference to the sound: bass it tightened up and more tuneful, the background is blacker, highs are sweeter and the tone of voices and instruments is much improved. Prior to the EDF (the power company) upgrade I was using W8 and 09-z9 but I was not completely happy with the bass which took a step backwards compared to W7. With the free “mains upgrade” W8 is just where I want it now. Everythnig matters, but it’s especially nice when some things get sorted for free Nick.
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388
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Ultimate Audio Playback / Your thoughts about the Sound Quality / Re: Windows 8 and 09-z9, a match made in heaven?
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on: June 01, 2013, 11:18:18 pm
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Paul hi, It's very interesting that your experience is so different. If I understand what Peter has done with Q5 (from the tool tips) I think that tuning settings might become much more PC specific to motherboards processors and disk types etc. I'm thinking that different PCs may have carateristic periods for operations like memory access, processor scheduling and so on. If Peters Q5 setting is helping to break these characteristic frequencies up and different PC do have specific periods then could be that we will hear very different things on different PCs. To explain more about what I'm hearing its actually very like your system, it just sounds so much more real palpable and dynamic, with a much sweeter to end. There real energy in performance with the whole spectrum contributing in a consistent way to the sound. Might it be that your PC already has a "nice" spread of internal transaction frequencies, so sound is already [extremely ] good ? It would be interesting if Mani and Brian could try the settings I posted above as they have the same mobo and processor and this might give some indication of whether or not we are getting to the point of more PC specific settings now. Perhaps Peter might comment on this ? Of course it may be that these settings just help with my "noise" problem in some way but I don't think it's that. We should get a chance to try stuff at mine soon, it would be great to get your opinion on this and generally how things are improving (I hope). You should bring some ear plugs though just in case, haha. Best Nick.
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389
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Ultimate Audio Playback / Your thoughts about the Sound Quality / Re: Windows 8 and 09-z9, a match made in heaven?
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on: June 01, 2013, 08:54:42 pm
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I’m a little slow to post on 09-z9 because there have been so many change in my system to settle in (new amp, 2nd balanced mains transformer for my woofer modules etc etc). So this afternoon I patched with 09-z9b to take a look at the tool tips for Q5. Just for a starting point I tried Q5=10 and Clock at 1ms (I’m using W7), wow Then moved to SFS of 20 (was 2.5) and again WOW ! The just to see what would happen I put Phase Alignment + on at Phase alignment factor of 2. W T F I am L O V I N G 09-z9b and what Q5 is doing here, I totally agree with Juan and Alan about sound characteristics, there is such a sense of palpability. Now back to listening. Thanks Peter, 09-z9b is spectacular EDIT Double Ooops I thought I was posting in the "09-z9 Impressions" thread. Maybe W7 and 09-z9 are also a match made in heaven haha... And now the version is z9b not the fictional z9a.
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