rickcr42
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Post by rickcr42 on Feb 19, 2006 18:41:56 GMT
Um.one post above yours man : Cathode=Kathode,same thing.anode is the opposite congrats ! correct.Improper orientation would mean no "light" unless everytrhing elsewas also wrongly oriented.Really is an all or nothing deal. My pleasure. Mike (pink floyd) also deserves some thanks for sending me the PM at Head-Fi that dragged my butt over to this thread Cool again !Can't wait ! rickmonster
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xerxes
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Post by xerxes on Feb 19, 2006 18:52:23 GMT
Sorry, I meant that the blue end is the anode/positive, so it is the the oposite way round to the Mini-MELF. It seems that zener diodes are rather confusing and that the markings are somewhat manufaturer specific. By contrast LEDs and capaitors, with one short and one long wire, are pretty straight forward.
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xerxes
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Post by xerxes on Feb 20, 2006 13:18:30 GMT
No sign of the missing DC Socket yet, but I've finished putting together the switchable crossfeed: There are some more pictures here. I used the same Rifa Polypropylene Film capacitors and Welwyn RC55Y resistors as found in the WNA headphone amplifier and the wire is some silver plated OFC with PTFE insulation I got from WNA, all cobbled together with some WBT silver loaded solder I had. Being able to switch the crossfeed "in and out" and adjust the level allows me to hear the difference the crossfeed makes far more easily than the original unswitchable one I made. Switching between "Bypass" and the lowest crossfeed setting is very subtle and I'm not sure that you can actually "hear" the difference. The medium and high setting are much more noticeable, the sound becomes more "distant", but for me, doesn't produce an out of the head, speaker like soundstage. In addition, the medium and high setting seem to add a "coolness" to the sound. There seems to be a slight bass cut and the music sounds slightly less rich and involving. All in all, having built it, I think I prefer the bypass and the lowest settings. Still, it kept me off the streets for an afternoon and I enjoyed putting it together. . I should be able to make an ultra simple crossfeed, equivalent to the low setting simply by putting a 4.4K resister between the signal lines of a set of phono leads. [insert lightbulb/idea icon here]. Surely all this crossfeed nonsense makes those channel separation figures for your amp a bit pointless. Lastly, thanks to Mike and everyone that chipped in with suggesions.
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Post by PinkFloyd on Feb 21, 2006 0:33:13 GMT
Lovely job you've made of that! Crossfeed "is" subtle and is only really beneficial with extreme stereo recordings. I personally don't like it in the circuit with normal recordings but there are others who swear by it claiming it lessens "fatigue" Must say I have never experienced this fatigue myself. There's a heck of a load of wire in there and that, coupled with the switches, will suck a bit of life out of the music but really not "that" noticeable and the advantage of crossfeed with heavily panned recordings such as the Beatles Magical Mystery Tour will outweigh the minor loss in bass and slight reduction in volume.... it really is a tool that should only be switched into circuit when necessary and not something that should be used 24/7 with all types of music unless you are experiencing listener fatigue, then it may prove handy with all types of music. You've done a superb job putting it all together and that "is" the Jan Meier bass enhanced crossfeed they all rave about.. you either love it or you loathe it, used when needed and to serve the purpose it's intended for it's a worthwhile and effective addition to your headphone listening rig... don't expect it to perform miracles with normal recordings cause it will underwhelm.... use it as intended and it'll surprise you just how clever and effective it is. What's next on your build list? All the best. Mike.
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xerxes
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Post by xerxes on Feb 21, 2006 9:03:38 GMT
Thanks Mike. I wanted it to match the WNA headphone amp, so I found a similar knob for rotary switch and put it in a sligtly smaller, but matching Hammond case.
I considered that, and I could probably shorten some of the wires by 2 or 3 centimetres. If I really wanted to go to town I could cut the case and halve its length. However, I reckon that reducing the length of the wires by even 5 or 6 cm would have a negligable effect compared to the switches and solder connections, and I can't do anything about those.
I don't actually have any Beatles recordings, but I know the sort of thing you mean. I dug out a 60's compilation I have with a couple of Searchers tracks on it that have all the vocals pretty much on one channel and the instruments on the other. With these tracks the benefit of the crossfeed is evident and it makes them far more "natural" sounding and easier to listen to.
A pair of 2Kw mono power amplifiers - just kidding ;D. I'm not really sure, I'm quite confident in my abilites to "assemble by numbers", but I don't have the understanding necessary to resolve problems if whetever it is doesn't work when I switch it on. To some extent I'm not sure I have the time or dedictaion necessary to really get to grips with electronics and I lack the patience to begin with the useless "flashing light" type starter projects that are probably an essential step to developing the understanding necessary to build more ambitious things that I might actually use when completed.
Having said that, I currently have an integrated amplifier, but if I ever get a pre-power combination I'd like to try a passive preamp, not very ambituous I know, but I'd like to try one just to see how they sound, and I reckon I could put one together without too much trouble. To keep the cost to a minimum, I could use a relatively cheap Alps pot, if I like the results, I could substitute it with a high quality stepped atttenuator. I only have a CD player on my main system, so I could keep it really minamalist, without even having an input selector.
I see that there are also plenty of companies, like WNA, that offer pre-assembled modules, often at little more than the kit price, that would allow you to build, preamplifiers, power amplifiers power supplies etc. I imagine that for the most part these represent good value for money compared to assembled products by the likes of Linn, Naim, Cyrus etc. However, I'm put off to some extend by the fact that you can't hear them before you buy. I was quite happy to spend £250.00 on the WNA headphone amp on the strength of the reviews, but I'm not sure I'd spend much more without being able to hear it first. Have you ever built any pre or power amps, speakers, anything of that nature?
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rickcr42
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Post by rickcr42 on Feb 22, 2006 22:20:02 GMT
Been MIA for a couple so just now catching up; 1-Too damn cool ! Nice job man.Have not checked the other pics yet but will ASAP 2-"I should be able to make an ultra simple crossfeed, equivalent to the low setting simply by putting a 4.4K resister between the signal lines of a set of phono leads. [insert lightbulb/idea icon here]." Turn off the lightbulb dude ! More than just blending going on otherwise a simple 25K pot connected to the left and right channels would be superior (simple blend control). A true crossfeed network actually shifts the image forward and away from the sides while closing ther left/right gap a bit so if to work as a crossfeed must combine the two elements : 1-Allpass filter/image shift 2-interchannel blending ALL old time stereos had a L/R blend because back then every speaker system was pretty large and knowing the woman of the house had a plan that did not include speaker placement sometimes the stereo spread was too wide requiring either use of the "blend" control to narrow the distance or by using another common feature of the 50's and 60's,the "mono" output which allowed using a "center fill" speaker to make the front image seamless. Required another amp and speaker but not only was it common in the early days of stereo but also in ALL movie theaters which was the precursor to full surround (delayed L-R side-rear channels added to the three front channels) Crossfeed tries to make the headphone experience resemble loudspeaker listening where instead of dead full left and dead full right with a void where your head is makes it closer to left with a bit of right and right with a bit of left both shifted to front
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xerxes
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Post by xerxes on Feb 23, 2006 9:02:34 GMT
I've finished putting together the battery power pack: There are some more pictures here. What can I say, it's a black plastic box with a lead sticking out the back. ;D It pretty much does everything it should, with the switch down, a blue LED on the right iluminates to remind me that the amp is running from the batteries. With the switch up, the blue LED is unlit, but the amp can still be used, running from the mains PSU for which there is a passthrough socket on the rear of the battery pack. The one dissapointment is the low voltage indicator, which is impossible to set to reliably come on and go off at a particular voltage, the switching point is just too vague. I reckon it needs a voltage drop of around 4 or 5 volts to iluminate and an increase of a similar amount for the lamp to go out again. I need to measure a change of just 2 volts. As such, I have adjusted it so that the lamp doesn't come on at all for the time being. Later I will diconnect the circuit altogether. The battery charger I have is quite good, when it has finished bulk charging it will switch into a trickle/float charge mode. Later I will move the battery charger socket to the rear of the case and leave the charger permanently connected, so that whenever the amp is not running from the batteries, the batteries are being charged and kept topped up. The amp will run for around 7 hours on a fully charged set of batteries, so I am very unlikely to to over drain and damage the batteries in normal use. Sonically, I'm pleased with the results of battery power. The effect is kind of what I expected, quite subtle, but there is an increase in clarity and the sound is a little richer and less "electronic" when the amp is run from batteries. If I plug the mains PSU into my ISOL-8 Minisub mains filter, the difference is even more subtle, which I guess proves that the Minisub is doing its job. I thoroughly recommend the Minisub, by the way. The effect this had on my system was quite noticeable. Much like the effect of the battery pack on the headphone amp, but more so, there was an increase in clarity, bass seems punchier and some recordings somehow sound more "real". Although, I understand the results of mains filters can vary, presumably the effect will not be as great if your partnering equipment is not particularly sensitive to the mains supply or if you happen to live somewhere where the mains is pretty clean anyway. I was also wondering about the position of the switch/capacitors in the curcuit. Currently I have this arrangement, where the capacitors are bypassed when the amp is running from the 24v output of the mains PSU: I assume that when capacitors are used like this they act as a reservoir, from which the amp can draw extra current when it needs it, and also to "smooth" the supply. Is that correct? In which case, I was wondering if there would be a benefit to having them in the output path whether running from the batteries or the mains PSU, like this: Lastly, many thanks Rick and Mike for all the help and the positive comments.
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rickcr42
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Post by rickcr42 on Feb 23, 2006 18:47:31 GMT
yes but a "black plastic box" you did yourself and a damn fine job of it too. with batteries it is more of an approximation than it is excact anyway.since there is no regulation going on to stabilise the output voltage no matter what the load a battery will sag and reload as the load across it changes so i beleive the indicator can still be useful.For example : Intermittant lighting of the LED you can ignore but steady glow means time to charge since that would indicate a drained battery and totally off after bring "on" a dead battery. there are other merans of indicating battery condition but they involve "fuel guage" chips,mostly SMD parts which can be a real pain to work with. most don't realise just how much crap is on the mains until it is gone.The battery sound in a word is "relaxed" while what you describe as "electronic" is harmonics on the sine wave of the line.some think this is a more detailed sound and the lack of it they call dull but my attitude,and seemingly yours is,if it is not on the disc then it is not natural so this "electronic" sound is no more than artificial detail that may sound exciting on first listen but one of the main reasons for listener fatique over time (along with bright electronics). This sound is a true "trend" and because so many expect to hear this artificiality they find natural and accurate to be dull and lifeless.i can argue with that type until I die and never convince them they have it wrong yet that very same "group" will shun any tone controls in their system saying it is artificial ! Artificial id OK as long as it does not have a "knob' attached to it ? Next up is breaking the digital ground noise when you are ready for your next revelation in natural sound.Can get pricey since it uses audio line level transformers but once you here "digital black" for the first time there is no going back Kind of yes but with one very real exception.A battery is really a big ass capacitor in many ways,very similiar, but far less reactive and has a highish output impedance when compared to other powering methods used for audio circuit powering. The capacitor has a much lower output impedance and series resistance than does a battery so what you are actually doing is lowering the overall power supply output Z AND speeding up the ability of the battery to supply current in short bursts. In an AC supply the caps act as filters and they are needed to get rid of "ripple" from the mains which is a sine wave.DC is a flat line and a sine wave curvy so the attempt is to make the curvy into flat line. The higher the current draw the larger the caps need to be in order to deliver "bursts" of ripple free power to the actual audio circuit.It is about sonics and not just electronics 101 or every power supply would be built to audio/hospital levels. If the ciruit was not for audio use,was not a critical hospital circuit where accurrate readins are essential or for other critical circuits you would actually not even need any capacitors ! The DC rectifier alone can produce whatever current it can pass instantly and without any effort so it is all about CLEAN power delivery with no wavy lines. The reason for a low ESR cap being the type used for audio is the output resistance must be low if it is to drive the next stage efficiently just like in an audio cicuit where you like to have a 10:1 driving/receiving ratio. DC goes in,the cap charges up to full capacity and it releases the voltage in a stream smoothed out by being stored in the capacitor.Draw this current than the cap can discharge and charge or more than the cap can store and you get ripple (not enough time to store the voltage and relase it) or reduced power and THAT is why power suplies are overbuilt for music.Dynamic signals have a way of screwing with the best designs. ,A battery does not "charge/discharge" until it is depleted and if a rechargable you reload it all in one shot but if not,right to the trash.It is done. Because there is no "cycle" of charge/discharge while playing it is not frequncy dependant and is not a filter but is pure DC voltage dispensed as it is called to. so these caps do not "smooth" anything at all since a battery is be design inherently "smooth". But the output impedance and internal resistance is no the best.They are great at pouring out gobs of current/voltage until drained but not so good at instantaneous dynamic responses. If you think of the word "resistance" it is exactly what the word says.A high resistance "resists" the flow of current while a low resistance allows it to "pass" and can be thought of like if you were pushing on a door and if it is stuck would be "high resistance" which also means "high impedance". So your capacitor bank is lowering the "EFFORT" the battery needs to get the power to the next stage and no more ;D Hope I didn't go overboard on the analogy,a habit of mine some find aggravating at the "other" web site
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rickcr42
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Post by rickcr42 on Feb 23, 2006 19:24:47 GMT
"Raises hand" ;D My entire record and playback system is DIY with the excpetion of my recorders,sources (turntable,CDP,etc.) and my main left/right loudspeakers+headphones and all those mostly modified. Every switch,every circuit,most of the audio/video furniture,all my interconnects,all of my room treatments,the AC mains conditioners,passive and active audio devices,and even attempted a Lava Lamp but that is not a recommended project.Mine was a freakin' mess and when you consider what they cost to buy new...............
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xerxes
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Post by xerxes on Feb 23, 2006 21:15:47 GMT
I read somewhere that some manufacturers are planning to reintroduce tone controls due to public demand. Not necessarily a bad thing I say, especially if they're done right and can be completely switched off when not required. It's worth remembering that most pop and rock recordings have been mucked about with a fair bit in the studio, so a purist approach at home is probably a little futile. If you have some reference, audiophile recording, then you probably don't need or want to mess with it. But with some mass produced pop and rock, why shouldn't you alter the sound to your taste if you don't happen to agree with the guy on the mixing desk.
I have a few CDs of music I like, but that sound a little bright or harsh and I wouldn't mind "backing them off a bit". If the whole system was "right" for these recordings, then it would likely sound too dull and uninvolving for everything else. Tone controls would be great for these recordings, I could adjust the sound to suit, then switch off the tone controls completely for recordings that sound good as they are.
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rickcr42
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Rest in peace my good friend.
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Post by rickcr42 on Feb 25, 2006 16:14:13 GMT
Typical for the high end audio industry is to take something away because most are not capable of making that "something" correctly then convince you through articulate arguments and pretty graphs why it is a music butcher so you are better off without it THEN offer it back a 5X the cost it would have been originally because now it is a special feature ! even a simple means to balance the left and right channels has gone away at the high end to maintain a pure signal path yet a damn good portion of humans do not hear eually into of both ears so are told to pound sand up their ass and deal with it. Now here again we see balance controls returning as if some new feature Shameful but is what it is. There is zero valid reason to me personally not to have access to signal processing and signal "tweeking" controls if they can be defeated when not in use and do what they are meant to do without adding noice and i even have a Limiter in my system for listening to DVDs at times when the dynamic range is too much (loud enough to hear dialog means blasted out of my chair in the next scene) Since I build my own gear I get to make my own choices on what I need and how the controls are layed out. That is why I choose the DIY Audio path.Not cost savings since it actually costs me a lot to make my gear but freedom of choice which the "here it is,take it or leave it" crew of the audio High End don't seem to get but the internet and DIY is waking them up since they no longer have 100% control over our gear and must follow consumer demand or continue to try and con the end buyer. Some of the arguments I have had online on this topic prove the ad copy has done a real good job in the brain washing area and instead of intelligent comebacks from a personal perspective 100% of the time it is just repeating what the manufacturer says without ever saying WHY
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xerxes
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Post by xerxes on Feb 25, 2006 18:14:14 GMT
Have you got any pictures? We've gone way off topic, but never mind.
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rickcr42
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Post by rickcr42 on Feb 25, 2006 18:51:38 GMT
Yeah,I DO have pictures (and yeah we are straying off topic but.......................) but am reticent about posting them on the "Bottom feeder Theory" which is the new way to fame and fortune and totally internet based so a new thing. Is where someone does all the work and another person comes along,never gets involved in the actual discussion but copies the ideas then makes a boatload of loot while claiming everything is an original thought. I try to think "outside the box" and am convinced my designs are totally different than what is presently available and since there is a possibility I will be going commercial I am not comfortable with the idea of competeting with my own designs sold by someone else. I have actually helped others who will remain nameless design gear only to see it go commercial and never once get any "thanks for the pointers rick" or toss out ideas in a forum only to see another take credit and it pisses me off on one level while making me gunshy on another. Bottom feeders rarely have any overhead.....or personal code of conduct...................so have to take a pass on doing the"Look What I Done Ain't I The Coolest Human ever born" part even if it IS true . The GOOD NEWS is this site will be the first to "see" any Products if/when offered for sale and if I decide to scrap the idea entirely will do the "blow by blow" step by step details here in the DIY forum.Less exposure than some other audio DIY sites but I am not about glory or ego..........well not TOTALLY anyway........
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xerxes
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Post by xerxes on Feb 25, 2006 19:03:12 GMT
I wasn't expecting detailed plans, just a "here's one I made earlier" type thing.
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rickcr42
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Rest in peace my good friend.
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Post by rickcr42 on Feb 25, 2006 19:21:20 GMT
Just seeing my control layouts will send many to the metal shop because ,at least in my opinion,they are very "intuitive" in the layout and mostly do not even require lettering as "function" identifiers Even though I have over the last year hinted at and suggested to others what direction to go the end product was not close yet folks line up to buy which convinced me : A-I maybe can make some loot too ;D B-since I am not ready for various resons am not willing to be the light bulb over another persons head. Not about THIS site or its members but more about knowing there is a crossover lurker population from another "to remain nameless" high profile site where many have zero compunction about stealing the work of others then selling the products as if their own. Since there is no way to stop the "lurking" or the stealing of ideas combined with the fact that I have already decided to end most of my active participation there I don't even want to toss the morally deficient/nasty bastards a single crumb. sorry man.nothing personal at all but self preservation and a bit of "screw that crew"
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Post by PinkFloyd on Feb 25, 2006 20:48:54 GMT
Quite right too Rick, when it gets to the stage where some people are actually "X-Raying" the opamps that competitors use in their amps (after said competitors sanding the opamp markings off) it's a pretty sad state of affairs and you are damned right to protect your intellectual property.
All the bottom feeders need is a "glimpse" and they'll be ordering up protoboard by the lorry load ready to poach and prototype faster than you can say "scrotum".
You keep this one under wraps Rickster and let the bottom feeders slither around for scraps elsewhere.
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rickcr42
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Rest in peace my good friend.
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Post by rickcr42 on Feb 25, 2006 21:29:11 GMT
Kinda back on topic Here is a thread where they were trying for an improved computer sound card and they at first wanted to go the battery power route but found the "dybanics are a bit lacking" : www.odysseyaudiohk.com/cgi-bin/yabb/YaBB.pl?board=digital_gen;action=display;num=1114920678;start=0#0They went to balanced power which really is an easily heard improvement many times but the battery supply statement seems to back up my previous post in this thread on how many find batteries to be bland while my personal opinion is trhey not only want but need the artificial harmonics produced by AC mains because that is the sound they are used to while those of us a bit older who come to digital from analog first/last/always are happy with a far more relaxed sound and we consider that accurate. Who is right ? Damned if i know...............................
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