Mani, no contest    with bridged parallel you should have power and current delivery,  just the thing for quads. I'm actually excited to hear the results, could be very very good indeed. Fingers crossed.

Paul your very welcome to drop in, and thanks for offering to bring you cables over. If you get some idea on dates drop me a pm and we can get set up.

Cheers,

Nick.

+1 on the enclosures 


Mani,

They look fantastic, a great build by Bert and I bet the post cannot come fast enough   

Not just 8 Blackgates but 8 BG N types, that should really help the sound.

I think I can count 4 amps per channel, are we looking at bridged parallel for each channel with differential inputs ?

Very, very nice I understand why you want to hear them.

Best Nick.

Hi Paul,

Thanks, I am really pleased to have found the solution. The interconnects I use are XLO Type 4. I have had them for years (out of production now I think)  they are an unshielded design woven around a tubular hollow core. I really like there transparency but VERY unforgiving if all is not well.

Speaker cables are Van den hull 102 hybrid. I have to say that they are ok but I have tried better. Problem is I also have 4 x 6m runs to wire up so good stuff tends to get very expensive. Now your copper cables are on the cards as soon as I have carpet down in the room where I listen. At the moment we have tiles and I am not convinced enamel on wires will last long on this surface 

Thanks for doing the test for "tape hiss", knowing it was not a normal situation really helped in getting the problem solved.

Cheers,

N

Hi,

A small update that might be usefull to NOS users.

I have been experiencing a rather annoying "tape hiss" type sound in the background on very quiet passages. This has been coupled with slighly confused sounding mid/highs that are at their worst when the passage being listened to has some low frequency content. The strange thing was that the symptoms were only present when playing CDs at 8 and 16 times over sampling. After 3 or 4 weeks of methodically trying everything I could think of and hours spent with test disks and frequency sweeps the sound is fixed, yippee !!!

In the end it was quite a simple problem, the fix was two things; move the NOS off the top of my amp and connect NOS to amp with a 1.0m set of interconnects instead of exactly the same type in 0.5m length. The result is much, much better music. If you have audible "tape hiss" you may want to experiment with the above.

Generally, I am just loving the NOS there is no going back once you hear this DAC

Regards,

N

I couldn't resist buying the Densen Demagic disk to give it a try. It popped through the post this morning and was duly played. To my relief no UFOs mistook it for a landing signal. Music followed and wow what just happened ? Sound after demagic is more musical with noticeably less grain and tighter and more extended bass. A great tweak for the outlay, thanks for mentioning it Peter.

I am just doing the peak extend / no peak extend test now. There is defiantly a difference am trying to make sense of it before posting more detailes thoughts. Right now I would say that peak extend turned off gives a more natural presentation with good ambiance. Peak extend on has more attack but seems ever so slightly harsh in passages with high dynamic swings.

Rs

N.

Paul hi,

Do keep the bybee posts coming, fascinating stuff. I think I understand what you are trying to convey when you talk about neutrality and convincing bass. Also the dislocation of sound from your speakers, this has to be one of my favorite tricks of a really good system.

I would still not be considering investing in Bybees were it not that you have also gone down the bi amp Gainclone route. The link being that we have a common reference point for trying to describe improvements.

I am very interested  to hear what Peter's tweak does and what it is about.


Waiting for further updates,

Best regards,

Nick.

Ps I agree with your comments about the "head room" of gainclones. I have the feeling that at some point they will stifle improvements but so far it just has not happened. Long live cheapfi !

Paul hi,

A great finding and very interesting to hear about the tests and the effect of the bybees. I have been interested in the theory bybees but given the costs had not really concidered trying them. Our systems are so similar however that if I can stump up the cash they would proberbly be a good upgrade here as well.

Its funny you should mention tape hiss being more prominant, I am having a bit of a problem with tape hiss when I play at 8 or 16 x up sampling. I wonder if I could ask you to do a small test. Could you try the recording that has the tape hiss but play it with up sample rate set to 176k (4x) and 88k (2x). With these settings is there and change to the amount of hiss you hear ?

Best regards,

Nick.

Peter hi,

Thanks for the information about the input and output noise values. A great amp performance even with mains 

I was thinking that given the low smoothing PSU capacitance used by gainclones, as the power consumption goes up that mains noise may start to rise. I know power supply noise rejection is very good but there must be a limit to what 1000uf or so of psu smoothing can do. There is also quite a lot out there about transformer size improving / regulated supplies improving aspects of the sound.

One question about the noise measurement, did you look at input / output noise with the amps at a reasonable working load ?

Best Nick,

Ps still searching for a practical charging solution and not that easy....

I have been considering changing my Gainclone amps and thought that I would post the idea.


To recap first, the amp is a bi amp Gainclone setup with options of direct input or volume control via TVCs. A further point is that the bass channel of my speaker system is active so  the system is tri-amped, the main point is that there is no bass power load on the gainclones.


The aim would be to take the gainclones off the mains and improve the power supply to the amp by using battery power. The hope would be to benefit from the air, transparency and natural tone of battery power, but to ensure that nothing is lost in terms of speed substance and dynamic slam.


I am still researching the exact approach (surprisingly I cannot find many posts talking about this) but the idea looks like this:


Batteries to give +- 19.2v rails, currently the amps mains supply's are running at 28v but with 103db sensitivity speaker I think 19.2v could give enough headroom. Not sure if the voltage drop could impact sound elsewhere though ?


Batteries will defiantly be LiFePo4 and most likely A123 brand, these things are fantastic things. Massive current delivery, superb transient current delivery and very, very quiet form a noise point of view.


I would like about 100 hours turned on with no music playing and about 20 hours playing at normal listening levels (quite loud :-) ). Also important is the ability to swop between battery and mains playback.


The main issue right now is finding a battery management system that will help me mange the batteries. LiFePo4's need clever and careful charging. I am prepared to have four separate BMSs in the case one for each battery /PSU rail. They will need to be capable of managing  a 19.2v (6 cell) 5.2Ah battery. The charge cycle on the BMS has to start automatically (eg I want to throw a play/charge switch and have charging start automatically.


No parts have has been bought yet, if it goes ahead it will be a winter project, it's still just an interesting option but I just have a feeling it might give some very good results.


If anyone has any thoughts and in particularly how to set up the BMS and where to get one that would be great.


Cheers,

Nick.

Gerard hi,

That's great congratulations ! That is now three of us with 300b SETs who have moved over now. Not that I have anything at all against 300b sets, but its amazing when you think of the relative cost of the gainclone amps and how they can sound driving suitable speakers.

KR,

Nick.

Paul hi,

On my setup before I turned Windows Audio off I got all the usual pings and tunes played by Windows, so I would think other software would work.

Of course sound quality could be another question all together 

Rs

N

Mani, Paul hi,

LoL, that's exactly the sort of question I ask before travelling 
 Plenty of safe parking here.

I need a couple of weeks to sort out a couple of points before the system is ready for listening. My Duos are old models but still 103db sensitivity and a fun listen. I will pm you and Paul when I know went all will be ready and we can set up a date.

Best,

Nick.

Paul, Mani,

Its good to hear that your visit and listening went so well, what posertive comments, congratulations Paul.  It sounds like the NOS1, gain clone, AN Es are quite a combination. I have only heard AN Es once but the dynamic presentation is one of the main impressions At the time.

Let's get a trip to mine arranged if you would like to hear some Duos. My listening environment is less than optimal let's say (you will see) but it's fun to hear different set ups.

Regards,

Nick.




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Flecko hi,

Could you run to £25k ?

http://www.gtaudio.com/forsale.html

I would love them too.