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Post by MaN227 on Jan 11, 2007 0:13:51 GMT
Dr. Frankenstien, the monster is ALIVE! I fear there is no turning back now ;D I've gone and compounded my searching woes, I just snagged a pair of HKG K701's lol , its like I've come down with a sickness of some sort how does this change what I should get , if it does at all. It appears that both cans need a fair amount of power to drive them proberly. sound signature , I don't even know where to begin on that one. look forward to more thoughts on choices. ;D
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Post by MaN227 on Jan 11, 2007 6:26:44 GMT
I tried to edit my error of HKG to AKG and when I try to modify it keep saying i hadn't entered a msg. very strange. just thought I'd let ya know
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rickcr42
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Post by rickcr42 on Jan 11, 2007 18:29:29 GMT
..the joint is still a bit wonky since sone idiot hacked the site yesterday though how I avoided any problems is still baffling unless pure dumb luck
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Post by MaN227 on Jan 12, 2007 0:45:09 GMT
hey ricker, I hope your situation has improved and not TOO hung over I just tested the page and it loads up fine on my end using firefox ... humm
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rickcr42
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Post by rickcr42 on Jan 12, 2007 0:52:29 GMT
Actually felt great this morning and especially so since I woke up in my own bed As to the site,I tried firefox also yesterday and I drew a totally blank page.Just one of those things man and likely it will work for me today but to be honest am a bit pressed for time having a funeral to go to in the morning and everyone acting a bit nutso so likely will giver her another shot tommorow unless i get the time this evening
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Post by MaN227 on Jan 12, 2007 1:00:35 GMT
funerals ... well SUCK, I feel for you mate and sorry for the loss. nuff said.
it could be one of many things as to why the page wont come up for you.
Pink Floyd, any thoughts on that amp you'd like to share?
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rickcr42
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Post by rickcr42 on Jan 12, 2007 3:55:00 GMT
OK,looking at the pdf file right now and from that looks to be a very tidy design and I can honestly say even without hearing it that the amp likely will sound just fine with Senns in the opamp/chip driver configuration since the OP2134/TPA chipset are already established as good preformers with those cans. The AB stage is an unknown without details on the biasing so could be fine,could have a large amount of crossover distortion may be smooth may be bright,total unknown that I would try to round up independant reviews on so you can get a measure of the "flavor" but beware most like their own amps so will mostly review with that prejudice. build quality and construction look to me top notch plus the features like the blinking LED for a low battery state a nice touch.If I was one to pick it would be the lack of an external power supply option for home use,something to me essential in a dual use amp because you get better dynamics with more voltage feeding the opamps plus having an external supply would also allow bumping up the Class AB output stage bias further up into Class-A operation which would make the low level detail and to be honest most of the music up to the loudest peaks sound a lot better. On the road that would be a battery killer,in the home would transcend the portable amp limitations and make it a true domestic amp and i have always wondered why none of the self proclaimed "geniouses" never thought to add a simple "low bias/high bias" switch when the output stage is one that can accept it. I know,picky picky Bottom line I like the idea of the amp it being well thought out and seemingly well put together but the REAL test is for someone to actually grab one then report back on the SQ rickster
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Post by MaN227 on Jan 12, 2007 4:25:45 GMT
I read this to mean for home use you flip a switch on the rear of the unit and you use the power supply as you would any other. what you are saying sounds quite encouraging as I know you "know the ropes" when you speak of a low and high bias switch. is what they are calling a "gain" switch the same thing?
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rickcr42
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Post by rickcr42 on Jan 12, 2007 19:43:58 GMT
No.
Gain is the amount the circuit will increase the input voltage so if an amp has a gain of X10 a one volt input signal will give you a 10 volt output signal
Bias is the amount of current the active devices use during the "idle" stage.that is amp is on but no music is playing.
With full Class-A bias the transistors will be on full all the time with nothing changine from a no-signal present to full signal present condition
Class-B bias is where the amp is in the off state (draws no current) until there is an input signal which it then responds to
Class AB is "A" to a certain point where the amp is always in the "on" state then goes to "B" in response to a signal over the preset bias point where it uses the additional power for the louder portions of music.
LOW Bias means the amp idles at a very low point so will drain the batteries very little until actually playing music,then very early switch over to the B state
HIGH Bias means it will idle higher before the handoff to the "B" operation so a good portion of the music will be in the better sounding class "A" portion of the drive.
Why class a sounds betterthan Class B (and why the higher you bias AB the better it sounds) is because in class a the amp is "ON" ready to pass the music along where in the "B" mode it is "OFF" and must respond to the signal instead of just passing it along at an increaed level
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rickcr42
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Post by rickcr42 on Jan 12, 2007 19:46:55 GMT
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Post by MaN227 on Jan 13, 2007 8:14:16 GMT
actually I suprised myself lol , I understood all of that pretty much. thanks so much for sharing that I know this will be Oversimplified but here goes. so this particular AB amp is going to sound pretty much as good as a class A amp? and have longer battery life? so did I read that right about the power supply for in home use? that it does indeed have the ability of using power from an outlet instead of just using the rechargeable battery?
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rickcr42
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Post by rickcr42 on Jan 13, 2007 14:54:33 GMT
Actually the opposite,guess I wasn't really clear.Looking at the panel I see no inlet for an external power source nor do I see an additional switch position label to accomodate int/off/ext switching something that I feel should be a standard feature in ANY portable amp that has aspirations as a dual use "Home" and "portable" amplifier since adding it is no more difficult than adding a power inlet and a DPDT switch in place of the SPST switch.Not a knock on the Xenos as much a knock on just about ALL portable amps that limit use for no reason than to save $5. The battery only operation also suggests the AB section is a low bias design or the batteries would drain rapidly.Low Bias= Less Class-A operation since it is class A that eats current by "pre-warming" the transistors (keeping them always in the "on" state) to a certain point in the overall current delivery curve so was also commenting it would be nice to see a "control" in combination with the above ability to use a line based power supply to adjust the bias UP making a good portable into a good home amp taking advantage of the discrete transistor output potential to be better than the TPA chip. See,the main problem with integrated circuits is that they are a closed design where all the parameters are pre-adjusted then the entire circuit closed up in a little black box (the chip).This leaves the designer with limited options other than how to feed it 1-feed the input terminal to the circuit 2-feed the power supply pins 3-feed the fedback loop if one is present 4-Eliminate RFI/EMI from feeding IN so you drop the chip in then design what goes on around it.The actual operational parts are locked up tight inside the chip with usually zero access to any.Sounds limiting and it is but what you gain is efficient operation with batteries,low internal heat generation (usually) allowing tightly packed casing and mostly an idiot proof "anyone can get it to work" layout.All things that are a plus for a portable device where size and battery life are the main features of importance with sonic quality secondary even though it can be good. Discrete Circuits have every single operational point open to whatever the designer is trying to accomplish so can range from operation as in the above IC example to a battery killing current eating heat generating big ugly monster.This monster can sound GREAT but use it with batteries and you would go broke in a day plus it would have to be large to get the extra transistor cooling inside the cabinet and likely it would still run hot-not the best for pocket placement but would kick ass on the audio rack. So the trick is to have something that is easy on batteries but that is good enough to use at home without being crippled by the portable use ability and since the two are total opposites in requirements a tall order without accepting certain limitations : 1-reduced SQ for a portable when used in the home when compared to a true home amp 2-reduced battery life when used on the road if designed for home use SQ So let's take the two versions of the same amp : Version #1 uses the TPA6120,a very good sounding chip and one that to me sounds better than all the usual suspects used as the current stage after an opamp stage inportable amps-the DIP IC buffer chips and the reduced current diamond buffers (retardation at work.take a good design then cripple it for no good reason than just because ;D ).Strictly for portable use I would choose this guy.Maybe even as my headphone amp at the computer and definately good enough for all laptop home/away duty. Versions #2 uses a Class AB discrete stage.This is where is gets to conjecture because there is not enough information available on the operating points to know if this is just an attemp to get more ULTIMATE output power at the expense of low level detail (pure AB with very little "A") or an actual improvement in sonics by selecting the point where the class of operation hands over being one that keeps all the low level detail,the majority of the music in the better sounding class A region with only the loud stuff banging over to AB. Using the example of an AB home power amp for loudspeakers,the better ones are big even when they are low powered because they are mostly a Class-a amp for all signals ecept for the very loud peaks so from the input jack right up to the driver section ARE pure class-A (in fact a "mini-amp" that if you stopped right there would make a dandy headphone amp in many cases ).Usually this will be a single pc board,the front end "module".Next is the "muscle",the speaker driving output power resistors that moves the cones. In a low cost amp,one where a certain price point has to be met which means less parallel devices and a small heat sink area (heat sinking is expensive) the entire output stage will be pure AB,will run cool and will also likely sound like shit because BOTH sides of the A/B will be mostly in the "off" state until responding to signal hence there will be a lag between the "+" signal and the "-" signal where the two will not quite meet in the zero crossing area.This is called crossover distortion and is a sonic butcher. So what designers do is trade sonics for cost with each incremental step up the "retail price" ladder allowing more and more class-a operation on both sides of the output stage with the more you have the less that has to "turn on' hence reducing crossover distortion with each increase in classs A operation all the way up to what would be a very expensive push-pull class-a amplifier because as you turn on the transistors and they run hotter you need more and more heat sink surface area to disperse the additional heat generated or the amp will burn itself up ! There is a goofy formula somewhere that goes anount of ponds per dollar of amp cost and which goes to how it should sound because of how much into class-a it operates hence heavier. The ones that give the best dollar/perfomance ratio get 80-90% of the music into the better sounding class-A region saving the final 10-20% for peaks,the loud parts of the music where the sheer volume alone will mask and small amounts of distortion by being LOUD then when the signal drops back to normal levels,back to class-A..... In the Xenos I have zero clue where this point is in the discrete output model.It could be a better amp than the one using the TPA chip or it could just be a more powerful amp overall but not better and that is the question needing an answer that i don't have. and that led to my "would be nice to see a bias switch for portable/home use " along with an external power port for optimising the amp 9or any amp having a discrete output stage) for intended use be it home or away. Not much help to you man but thought I should explain my earlier statements in more detail to avoid confusion ;D
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rickcr42
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Post by rickcr42 on Jan 13, 2007 17:26:48 GMT
finally got into the Xenos home page and it ONLY took me four attempts today.....
All their amps are battery duty only with a port for the charger with a "coming soon" strictly home based amp.Too bad they didn't combine the two because strictly as a portable amp the Xenos has a lot to like but i would think no match for a TRUE home based amp or they would not be introducing one themselves
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Post by MaN227 on Jan 14, 2007 9:17:08 GMT
great point rick and thanks alot for explaining in the post above last appreciate it mate. so strictly as a portable amp the 219$ or the 179$ one you think is better one? personally i don't like the thought of buying to seperate amps but I am beginning to wonder after all you great info you have shared already if that will indeed to be a necessity as I would like to get VERY good products not just , "it'll get the job done"
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rickcr42
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Post by rickcr42 on Jan 14, 2007 15:59:08 GMT
well I'll be honest and say anyone that puts this much bullshit in the initial ad copy should be looked at with suspician : "This headphone amplifier using a super FET Operational amplifier, ALPS Hi-end potentiometer, Super High Grade Capacitors, large high capacity batteries with specialized customization quality, through excellent design and precisely selected Components(Red WIMA capacitance, Sanyo1000uF, the Japanese professional ALPS potentiometer, AD822BR pre-amp OP*2+the AD8532 low-voltage level operational amplifier*4, LM317L Regulator. TL431*2 precision voltage reference)" Still can't find a single "super" FET Operational amplifier in any of my data sheets and that is maybe one of the most extensive on the planet earth being all CDROM based cross-referenced files,the TL431 is anything but a "precision" reference even though a nice shunt-reg if used correctly and I'll be damned if i can tell what a large capacity battery with specialised customization quality" is. If that is not hype and deceptive ad copy then I don't know the meaning of the words no matter what the amp sounds like. more : Using LMXXX V-regs and all thos buffers is pure overkill on the battery side and especially so when a single TO-220 package buffer will get you just as much current delivery as a boatload of DIP pack opamp devices in parallel not that I can personally think of a single instance where "250 mA" is even needed (plus i highly doubt it gets there anyway except on peaks).Seems like a damn lot of active circuitry just to do it it may sound good but i would not buy one it being way bloated in design and way over hyped which goes to attitude of the seller/builder which is "I will dazzle with catch phrases no one knows the meaning of to bait the hook" because anyone that DOES know would laugh out loud. worse,for home use a switching suply ? Fkn kidding right ? If there is one thing in combination that is a no-no it is high speed op-amps and a DC switcher with the ONLY reason for going there to get higher voltage from a battery to gain enough voltage headroom to drive medium impedance headphones but in the home ? What is the limiting factor there on available voltage ? seems linear V-regs on the road and a DC Converter in the home is exactly backwards from what it should be Um...why not just say it has a tone control and cut the words down to two ? More hype is why. more hype over substance THIS is also an "authentic Alps Potentiometer" and it goes for $3.99 at radio shack so ? more hype first thing I have yet read that makes any sense or could be true deceptive again.............. I wouldn't buy shit from anyone that went so far out of their way to hype,make shit up and tell half truths no matter what the amp actually sounded like but that is me and my opinion only.It is getting a bit ridiculous out there though when any knucklhead can slap a couple of opamps in a case with a power supply then tout it as something revolutionary when in many cases a single opamp with dual nines Ala a CMOY will usually whip the shit out of many of the bloated designs with the right chip inside Things being what they are you either get "serviceable" for both home and away or shoot right to "best tool for the job" because the requirements for each are TOTALLY different unless you build in flexability as in the original Headroom Cosmic,more roadworthy home amp than it is portable that works in the home once hooked up to the "dock/power supply" unit. There is only so much voltage you can get from a battery until or unless you either stack batteries (makes the device bigger and we all know tiny is in) or go to a DC Converter which while a sonic killer in a high end system may be fine for the road.That is the "medium impedance" amplifier because they are voltage whoes and if there is not enough voltage available the amp will clip trying to make it happen (and why the above automatch crap laughable) For lower impedances you don't need any voltage drive in many cases and when you do very little but you DO need current drive if you expect any kind of bass response.There is "peak" current and "continuous" current and then there is "idle" current with the last being how much battery power is used in a no music state but with the amp on.as the volume is turned up and the music plays the current used will increase as the output current delivery is also increased so a direct relatinship between battery LIFE and ultimate power. batteries in Series connection where battery A has its minus terminal connected to battery B plus terminal "X" the amount of batteries will increase voltage for medium to high impedance headphones but does shit for current.In fact a 9V battery is 6 1.5 volt batteries in series internally. Batteries in Parallel connection effectively double the current delivery so would give a longer life when used with a current hungry headphone but the VOLTAGE would remain the same so depending on use the requirments change enough to make designing for universal portable use a real bitch and so you MUST make comprimises if you want to satisfy the requirement for long life and small size.Electronics 101 and you can't change the rules just because you would ike to only apply the rules with what you beleive to be the BEST comprimise Home use places zero restrictions on either parameter because now you have what can be considered unlimited voltage and unlimited current available so can concentrate on the audio circuitry being the best you can make it rather than the best you can do and still have it run off a low voltage current depressed power supply. so yeah,two amps if you want the best
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rickcr42
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Post by rickcr42 on Jan 14, 2007 23:32:51 GMT
damn bro,I was expectiong to get beat up pretty good over my comments Like I said,the amp may well sound good but being so overhyped and with such cryptic not quite truths does not instill a whole lot of confidence PLUS i still am 100% baffled on the DC Converter for the home/Linear regulator for the road thing which is exactly opposite to how you normally do it DC Coverter : Used to take a battery voltage and either increase it or increase it AND generate a dual polarity from a single battery Linear Regulator : Used to convert the mains AC to a voltage usable with low voltage electronics while reducing ripple and providing a stable voltage from the varying/crap filled AC mains voltage.Because the wall outlet will usually give at least 5 amps there is plenty of current headroom.the drop from the mains to the device voltage headroom is evident. so why would someone use a DC-DC supply in the home ? Efficiency and to save cost in the electrical bill which at these currents is a non issue so why I am totally baffled as to the intent here
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Post by MaN227 on Jan 15, 2007 15:56:13 GMT
mrarroyo, I chk that out, and it appears to me to be 99.50 usd, the 49 $ it said something about write a good review or some such and get half off. 100$ price is appealing for sure. I would like to find more opinions from those that have heard it. better then the tomahawk? hummm. thats VERY good as the Tom gets much good talk about it. I was just telling someone that I'm about getting the best sound I can for the least amount of $$$$ I could care less about names and bragging rites having expensive stuff. I reference my OPPO DVD player, that baby only cost me 190 us and it compares well with units costing much much more. thats the kind of thing I'd rather brag about. the better deal , thanks for the info. rick, at 100$ price point I'm guessing the target "audience" for this amp is not the very knowledgeable, but rather noobs like me , that and those that are easily wooed by 50 cent word spewage . the wording part don't sway me, what sways me is someone like mrarroyo in plain words telling us that its worth a look. All the over use of technical terms and crap they used don't impress me none either btw hehe. I like plain english, so techy talk is good , but at a certain point it all just blurs together when there is TOO much of it. this has turned into the anything goes thread LMAO anyone have anything they would like to share about any of the products I listed as considerations at the start of this thread?
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rickcr42
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Post by rickcr42 on Jan 15, 2007 22:00:46 GMT
And why the overblown hype is even more of a point with me.
Why can't someone just say "makes a great entry amp that you would be hard pressed to better at near the same cost" which would be honest instead of the techno-babble meant to confues,mysterious operation qualities that have zero information other than big words and "new words" such as "Super JEFET Op Amp".I have had about my fill of audio hype when it comes to high ticket audio but when it hits the bottom feeder amps too there is something seriously wrong in audio.
I also beleive the circuitry itself is far too "busy",another "trend" that is no more than most trying to be set apart rather than go with tried and true (kinda hard to hype up a set ofbatteries and a single op-amp with a buffer even if it IS better) with everyone looking for an angle so they too can have a slice of the headphone amp buyer pie.
Would be nice to see "here is my amp,sounds good,good price,I back it 100%,thanks for looking" and let the product stand or fall on the merits rather than base sales on how many new words someone can come up with or how many new ways they can think of to re-invent the wheel even if the present wheel is just fine..............
no axe to grind guys,just hate to see Ramblers calling themsleves Corvettes in disguise
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rickcr42
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Post by rickcr42 on Jan 16, 2007 0:21:29 GMT
SWEET !
Both though i think i would take the Beetle they being more scarce than they once were and the only vehicle I ever flipped in then tumbled in three or four times that everyone walked away from without a scratch !
The car ? Ended up on its passenger side,we flipped back over then changed the flat tire and trucked on down the road laughing about it
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Post by MaN227 on Jan 16, 2007 5:28:43 GMT
the only vehicle I ever flipped in then tumbled in three or four times that everyone walked away from without a scratch ! The car ? Ended up on its passenger side,we flipped back over then changed the flat tire and trucked on down the road laughing about it someone or something was watching over you and your friends that day for sure. any new thoughts on any of the amps we have brought up in this thread?
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rickcr42
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Post by rickcr42 on Jan 17, 2007 0:05:47 GMT
Story of my life.How those other knucklheads have fared over the years is a total unknown but I personally should have been put down permanantly yet walked away untouched so many times I must have a protector somewhere.Of the "old crew" that I know about most are either dead,have been married multiple times,are strung out or are doing doing prison time. I managed to escape all the above even though at one time was pack leader being the most hard core of the bunch plus a natural Alpha so where I led others followed even if they should not they not being me thus not up to the task.
The VW experience is one that sticks in my minds because all i remeber is starting to go sideways then all kinds of shit flying around including nasty ass cigarette butts and ashes.I also remeber climbing out the top "hatch" that was formerly a side door,landing badly and spraining my ankle like an asshole plus the bunch of us telling the story to each other as if we weren't there over drinks.Taught me young that you can do a thing and have a totally different expereince than the person that was right there sharing in the reality of it-perspective is all
The amps ?
My first instinct says the Xenos with the TPA chip but the discrete output stage intrigues me because it MAY better and if not may have the potential to be better there being more to play with/dial in.If done right no doubt it will be the more powerful of the two in pure dynamics.Not much help i know but the best i can do without hearing one or seeing more details on the output stage
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rickcr42
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Post by rickcr42 on Jan 17, 2007 0:56:00 GMT
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