|
Post by themystical on Feb 12, 2013 19:59:10 GMT
Mine came today as well. What lovely quality the boards are.......thanks. Avinash
|
|
|
Post by themystical on Feb 3, 2013 20:16:07 GMT
Pet240 See the GB thread in the DIY section for the JLH Ripple Eater Boards. Jon Clancy is running this. Avinash
|
|
|
Post by themystical on Feb 3, 2013 17:35:24 GMT
You feel the bass vibrations with this as you would in a speaker system........
|
|
|
Post by themystical on Feb 3, 2013 17:26:20 GMT
I take it everybody is up and running with the ASIO driver and the latest firmware? It is very stable for me and resolves some of the previous issues I had intermittently playing 96k/192k files on my Linux based Joggler
|
|
|
Post by themystical on Feb 2, 2013 15:01:48 GMT
Tried Orthodynamics? These are one of the best headphones in the world. I have had them for over a year and they have had less than 5 hrs head time so they are practically brand new and probably not run -in. In fact I seem to have gone off headphone listening altogether as none of my other headphones are getting headtime either with me preferring my main set-up. These are the Rev1's I believe although I have not been following all the developments.... They come with the wooden case and all the accessories as I received them. More info on these over at Headfi - but if you are looking at this, you probably know what they can do. I am looking for £625 for these + any Paypal fees (if applicable) + shipping. Shipping will probably be a minimum of £10 in the UK to get the requisite insurance. I am in Wilmslow near Manchester so happy to demo or for collection. Hera are some piccies: Audeze LCD2 by themystical2012, on Flickr Audeze LCD2 by themystical2012, on Flickr Audeze LCD2 by themystical2012, on Flickr Audeze LCD2 by themystical2012, on Flickr
|
|
|
Post by themystical on Feb 1, 2013 17:29:21 GMT
Sneaky ehh Shaun ......you must have got in whilst I was typing. themystical 2 shaun 4 Total 6
|
|
|
Post by themystical on Feb 1, 2013 17:19:54 GMT
I will start the ball rolling. Thanks Jon.
themystical 2
|
|
|
Post by themystical on Jan 28, 2013 15:37:28 GMT
The M77 does sound VERY tube like and pretty much what i was expecting from AN Japan. nice Shaun, You obviously didn't experience the wow factor that I did with this preamp...... It will be interesting to read your thread on the PS for the AN. I will tell you why........I have a theory.... Regulators (both shunt but more so linear) are not very effective in pre/power amps particularly valve amps. Yes, they do hold the voltage rock steady but with anode voltages of 150V or so, a volt here or there isn't particularly going to change the valve characteristics. Yes, they are low noise but again with such a high voltage, extreme low noise is of little consequence and the noise aspects are quite easily dealt with by chokes and bypassing capacitors at the valve pins. The most important thing for these valve circuits is having a very low impedance for audio frequencies to deal with the massive swings demanded. This is where the regulators fall down in comparision with the bog standard choke/capacitor arrangement and I believe stint impact and dynamics. If I were you I would try with and without the regulator to see which you preferred. FYI is a link to another guy's impelementation of the power supply. www.dms-audio.com/audio-note-m77-diy-cloneBest Avinash Sorry for the off-topic post. Will wait for the seperate topic before discussing this further.
|
|
|
Post by themystical on Jan 26, 2013 21:01:28 GMT
Shaun I have never understood this reclocking thing properly. I was under the impression that the Sabre DAC's reclocked anyway so is there something I am missing? Good job on the Kondo M77 preamp...yes the gain is a bit high because he has paralled the tubes. He does have the M7 design which is similar but does not use paralleled tubes if you want to check that out. I also agree that the Aikido was anything but valve like but I stand by my initial comments that the M77 is the most dynamic sounding preamp that I have heard. It would be good to get your impressions of all these and your verdict on the best sound for you. Avinash
|
|
|
Post by themystical on Jan 25, 2013 15:28:29 GMT
|
|
|
Post by themystical on Jan 23, 2013 19:54:16 GMT
Guys; This is Jim from CA. Ended up at 57 ohms trailed by 100 uH choke. No failures. This combination is indistinguishable from the diode, at least to these ears, and with this system. PC>USB>Dacit>Emotiva XPA-5>Snell C/V's Resolving this ground issue (attenuation as opposed to isolation) gives a noticeable smoothness-silkiness. HF is enhanced nicely with no harshness, nor unbalance created with mids and lows. I would say that avinish is correct in his assesment of the effect of the added inductance. I'll get around to playing with a cap in parallel, unless one of you beat me to it. Thanks for your posts. Great info. here. Sincerely, Jim Good to see you here Jim. Keep us posted on your parallel capacitor experiment. Make sure it is directional (electrolytic) and pointing the right way. Avinash
|
|
|
Post by themystical on Jan 23, 2013 15:46:09 GMT
However, it isn't a universal fix, and the difference between 47 ohms in the 0 volts lead and this method is very small indeed , at least in my system, and this method didn't work with Jim's DACiT, as he had already tried similar previously.J Regards Alex Alex Looking at Jim's Blog on CA, he has some issues with earthing on his set-up. For this to work, the earth potentials at both the source and the DAC need to be the same. In the UK, Europe and Australia, this is achieved by the earth pin connection to the power socket of each socket. There are proper earth conductor interconnecting the sockets to make sure that the earths are at the same potential. My belief is that this will work in most instances in most parts of the world. The only exception I can think of is where an item is "double insulated" and doesn't have an earth connection where it might not work. Avinash
|
|
|
Post by themystical on Jan 23, 2013 11:54:28 GMT
Fantastic result Alex. You have now achieved galvanic isolation of the earth conductor, something that even the proffs designing the iFi failed to achieve. You really can't have it better than that......
|
|
|
Post by themystical on Jan 22, 2013 22:59:14 GMT
Jim told me a few minutes ago that he noticed a small improvement at HF, by putting a 100uH choke in series with the 10 ohms. I would be wary when going there though, as even inserting a 5A 100uH choke in series with an internal writer's supply tended to exaggerate HF detail, despite a bypass capacitor after it. Alex Alex From a first principles point of view, a choke in series with say a 10 Ohm resistor sounds like a good idea - provided the USB circuit will function. This is because the impedance of the connection will go up as the frequency increases (z=2(Pi)fL). This means that the higher the frequency, the more effective the isolation. The ideal theoretical solution is the resistor in series with the choke with a directional capacitor in parallel to both - filtering hf from the protected size. Not sure about the sizing but if the USB connection works with it in place thats good. I suspect your caution is coming from a different application of the choke? Avinash
|
|
|
Post by themystical on Jan 22, 2013 21:44:05 GMT
Taking a look at Jim's posts on CA, it looks like he managed to get the USB link working with a diode in line, albeit only for short periods. That is in effect a series resistance of many Megohms. I think it would be worthwhile sticking in a resistance of say 1kohm at some stage and seeing whether the link still works. I see the solution as a user switchable earth isolation switch e.g. Position 1 - No isolation - resistors shortcircuited Position 2 - Earth isolation - 10 Ohm resistor engaged Position 3 - Max isolation - 100 Ohm resistor (or higher value) engaged Thats pretty easy to implement and would cater for the vagaries of different USB devices In a DIY context, there would be no need to do anything special. I mean how hard is it to desolder and solder a different resistance value?
|
|
|
Post by themystical on Jan 22, 2013 20:10:26 GMT
Yo, Well I can confirm that firstly, there is no problem with pen drives being recognised and read (running for several hours now) and there is an improvement with the earth lift rip. Mainly in solidity and nuances such as resonances becoming more evident with more discernible decay. Out of curiosity I popped in the 10ohm earth lift into my jaycar injector, as described above by Alex. I then re-extracted the newest files again and bugger me, not the same amount of improvement but still apparent over the original extraction. Definitely onto something here Hi cj Definitely sounds like we are heading in the right direction with this and the improvement will depend upon "how bad" your laptop/PC is to begin with. If we can get a handle on the maximum size of resistor that the USB link will tolerate, that would be good as the higher the resistance value the better the isolation.
|
|
|
Post by themystical on Jan 22, 2013 16:43:41 GMT
Alex I have not made much progress with this in your absence but one thought that has occured to me is about the sizing of the resistor. In typical power amp situations, 10 ohms would kill hum which is at 50Hz. However, impedance rises in proportion to the frequency so will probably be less effective at higher frequencies. How high can we go before you think the USB link will stop functioning? Obviously the higher you go with this value, the closer it is to galvanic isolation so if for example 1k or 10k is doable (is this a word?) so much the better.
|
|
|
Post by themystical on Jan 22, 2013 12:19:22 GMT
Not at this point. It was quite awkward getting even a DMM across the resistor while the PSU was in use. I was more looking for evidence of some kind of small curent used to tell if the lead was connected or not.It could of course be probing at specified intervals. Jim has already played around with diodes in that area, so he may continue on while I am asleep. Regards Alex I think we are playing around in the microvolt area and transient phenomena so it would be impossible to analyse without a scope. The diodes are a bit of a red herring here as they don't come into play unless there is a real short circuit and ground potential is raised at either end with respect to the other to allow them to conduct. They just fail in the right way and short circuit the added resistor in a real fault situation - no impact on attenuating noise. Does Jim post on this forum?
|
|
|
Post by themystical on Jan 22, 2013 11:26:10 GMT
Hi We will need to try that with and without. You don't normally see earthlift resistors in power amplifiers bypassed, do you ? I can say though that fresh rips in Safe Mode sound even better now ,despite what the check sums say! I have just uploaded freshly ripped versions of a couple of tracks for confirmation by a European RG member and others who have already heard the previous recent rips linked to in Saucerful.(Staff area) Regards Alex P.S. I couldn't measure any steady voltage across the 100 ohms,not even a few mV. Exvellent - Guess it is almost bedtime for you but looking forward to your report on the capacitor addition at some stage. No you don't normally have switches in parallel with the earth lift in power amps but than again, this is less sensitive in a power amp analogue context - in the USB circuit it is catastrophic in the sense that it either works or doesn't? In case it doesn't it would be simple to flick a switch? Are you using a scope for the measurent? I don't think the noise will be steady state and will vary depending upon the quality of the host switched mode supply and what the internal electronics in the host PC/Laptop are doing at that precise moment.
|
|
|
Post by themystical on Jan 22, 2013 10:54:58 GMT
Yes. This USB memory stick still plays "Rhiannon" from Fleetwood Mac in 24/96 without any noticeable problems. Regards Alex UPDATE. I have now done the same to my +5V JLH USB PSU, and a couple of new rips from Jheena Lodwick made in Windows Safe Mode, sound noticeably better than my previous best.They simply sound a little cleaner, with more "blackness" around things. As most of you guys are asleep at present , I have invited a C.A. member from the U.S.A. with a JLH PSU to try this too. Jim's reports are also quite positive, although even with 100 ohms he had a couple of failures after 8 minutes of play with his USB DAC. My USB memory stick continued to play for 90 minutes with 100 ohms, before I ended the test. P.S. Yes, the checksums of the rips remained unchanged. Thats great news Alex. Perhaps an electrolytic at say 0.1uF in parallel connected the right way around might improve it even further? I think a switch to short circuit this arrangement is a good idea as it covers the types of failures that Jim experienced?
|
|
|
Post by themystical on Jan 22, 2013 0:29:08 GMT
I just tried a modified USB Power Injector as a guinea pig, by cutting the small copper land between pin 4 on the incoming USB socket and inserting a 10 ohm resistor. (far left, and centre of PCB)Yes, it does work still, but I can't really evaluate the SQ as although this modified USB Power Injector gives a definite SQ improvement normally, it isn't quite up to the standard of the normal +5V JLH supply when using a USB memory stick.This doesn't necessarily mean that it will still work with other USB devices. Alex Wow that was quick and a very good start. Have you got a 100 Ohm resistor you could pop in and see whether it still works? I guess the acid test is with a high speed USB device but I am beginning to get confident that this is a very workable solution and is indeed the solution used by AMR. I am off to bed now Alex but many thanks for your help and have a good day!
|
|
|
Post by themystical on Jan 22, 2013 0:10:59 GMT
Is your voltage closer to 220V or 240V? Assuming it is around 235V, I would suggest that on the primary side you wire it as 240V which means incoming live on BLK and neutral on WHT (connect ORG to GRY and BRN to BLU) Your secondary at 21V is then YEL and RED. I hope somebody else on this forum will check this and advise you before you get going and energise
|
|
|
Post by themystical on Jan 21, 2013 23:53:18 GMT
Perhaps the capacitor is a directional type - an electrolytic say - which conducts HF noise from the attenuated side to the non attenuated side? Thanks for the JLH Board info Sandy....I certainly would like some. Hopefully Jon will post availability on this forum upon his return.
|
|
|
Post by themystical on Jan 21, 2013 23:33:40 GMT
That is my thinking exactly . In this case, it doesn't sound like a good idea to have a parallel ceramic capacitor. Regards Alex[/quote] Yes I think you are right. The larger you make that resistor, the more it will attenuate any noise in the earth connection. I understand typical values in ground lift applications are between 10 and 100 Ohms. So I guess the million dollar question is will a USB connection operate correctly at high speed with a 10 to 100 ohm resistor in series? Anybody have a chopped USB cable lying around that they can experiment with or is there anything in the USB cable standard that will answer this?
|
|
|
Post by themystical on Jan 21, 2013 22:58:37 GMT
Ahaa....maybe a clue here? A loop breaker circuit? See Fig 4 and explanatory text in this link. sound.westhost.com/earthing.htmOkay it is not exactly the same, back to back diodes - not a bridge but sure looks like the thing. Question is a USB earth connection work if it had a say 10 Ohm resistor it? and surely the parallel capacitor would let HF noise through which is what we are trying to avoid?
|
|