oicdn Posted November 4, 2007 Report Posted November 4, 2007 Heh...I JUST found this place. I had a uestion about the predator, and there hasn't been an answer. I'm thinking it won't be answered because my suspicions are right. That and any negativity (even if contructive) towards RSA is frowned upon over there. Apparently not so much here, so I'll ask here, lol. Here's the post I made, and it hasn't gotten a response yet: -------------------------------- I have a question about the gain. You say the gain is set at 11 in high. An iPods line out is 1vRMS, which is 2.8vpp full scale(volts peak to peak, according to Vinnie on various threads). Wouldn't you need ATLEAST 32 volts to have a gain of 11 on an iPod so you don't have some serious clipping or distortion when the volume is cranked really high? ESPECIALLY on high load cans like 600 ohm DT880s? Gain was something I was mulling over when I was looking at some DIY designs to power 250ohm Darths, and there was a design that utilized a gain of 11, but it had a powercord/dedicated PSU. When I saw gain of 11, I thought "Predator" and then thought I'de ask if this is the case with the Predator, since I can't see 34+ volts coming out of that LiOn battery. Can you shed some light? This is partly the reason I'm not in bed yet, lol. -------------------------------- Is this the case or am I missing something?
Salt Peanuts Posted November 4, 2007 Report Posted November 4, 2007 Welcome to Head-Case, sorry about your thin skin! And to your question - I have absolutely no fucking idea.
oicdn Posted November 4, 2007 Author Report Posted November 4, 2007 Hah...I have no thin skin...infact, last night I just read the reasoning behind how this place came about...pretty funny, lol. I guess not everybody can let things roll off thier backs, or have an unbiased opinion without getting the "smackdown" from mods who protect certain vendors... Meh, I was curious, it was an amp I was CONSIDERING, but after researching a bit, not so much.
JBLoudG20 Posted November 4, 2007 Report Posted November 4, 2007 Ah crap, you are that super annoying mother. Well, you might want to do a lot of reading around here before you start the shittalk.
Chekhonte Posted November 4, 2007 Report Posted November 4, 2007 jesus christ, you guys have been giving newbs a baptism by fire lately. I'm glad I somehow fall through the cracks wherever I go.
oicdn Posted November 4, 2007 Author Report Posted November 4, 2007 Ah crap, you are that super annoying mother. Well, you might want to do a lot of reading around here before you start the shittalk. WTF?
granodemostasa Posted November 4, 2007 Report Posted November 4, 2007 you're that dude that called trose's rig "serious"... ??? ???
oicdn Posted November 4, 2007 Author Report Posted November 4, 2007 Meaning that's a serious amount of money spent...I guess it's all in context.... I said the same thing about this guys rig: http://www.head-fi.org/forums/showthread.php?t=246541 more specifically, the link in that thread pointing to here: http://66.48.80.139/~idemonor/ws/newrig.html Same saying...different context I guess...meh...
JBLoudG20 Posted November 4, 2007 Report Posted November 4, 2007 Meaning that's a serious amount of money spent...I guess it's all in context.... I said the same thing about this guys rig: http://www.head-fi.org/forums/showthread.php?t=246541 more specifically, the link in that thread pointing to here: http://66.48.80.139/~idemonor/ws/newrig.html Same saying...different context I guess...meh... You DEF are a noob, as many of the guys here have more moeny invested in just their sources.
aerius Posted November 4, 2007 Report Posted November 4, 2007 Is this the case or am I missing something? Yep, you'll need 32V or so to run the amp at full volume with a gain of 11 from the iPod line out. Whether you'll ever crank it up that much is a whole other question...
oicdn Posted November 4, 2007 Author Report Posted November 4, 2007 You DEF are a noob, as many of the guys here have more moeny invested in just their sources. I can head over to Audiokarma and tell you that, I'm just saying as far as having two seperate rooms and TWO high end tables, amps, phono's etc, that's pretty fucking elaborate for TWO rooms...meh...
aerius Posted November 4, 2007 Report Posted November 4, 2007 You DEF are a noob, as many of the guys here have more moeny invested in just their sources. If you're referring to Trose, no doubt. But that Tmij dude has some seriously good stuff.
Filburt Posted November 4, 2007 Report Posted November 4, 2007 2.828vpp is a 1vRMS sine wave. Peak amplitude may differ in actual music but suffice it to say at what is likely 3.7v supply, factoring in headroom, much above unity gain won't be particularly useful. On a smaller amplitude output, such as a PCM2704 (1.8vpp), gain can perhaps be a bit higher but unlikely even 2 when factoring in how close the amp will realistically approach its rails. Probably more than anything, the use of such high gain just raised the noise floor and distortion.
kevin gilmore Posted November 4, 2007 Report Posted November 4, 2007 2.828vpp is a 1vRMS sine wave. Peak amplitude may differ in actual music but suffice it to say at what is likely 3.7v supply, factoring in headroom, much above unity gain won't be particularly useful. On a smaller amplitude output, such as a PCM2704 (1.8vpp), gain can perhaps be a bit higher but unlikely even 2 when factoring in how close the amp will realistically approach its rails. Probably more than anything, the use of such high gain just raised the noise floor and distortion. Filburt and everyone else is absolutely correct. The only reason that the gain of 11 option is available is that it is a copyover from the hornet design. That high gain is designed for sources that have an output voltage of only 100mv or so. This is clearly stupid as the internal dac has an output of way more than that. Given the 4.0 volts (absolutely fully charged and even overcharged a bit) and a rail to rail opamp that looses .4 volts, the absolute maximum output voltage is going to be 3.6 VAC Peak to Peak.
oicdn Posted November 4, 2007 Author Report Posted November 4, 2007 Filburt and everyone else is absolutely correct. The only reason that the gain of 11 option is available is that it is a copyover from the hornet design. That high gain is designed for sources that have an output voltage of only 100mv or so. This is clearly stupid as the internal dac has an output of way more than that. Given the 4.0 volts (absolutely fully charged and even overcharged a bit) and a rail to rail opamp that looses .4 volts, the absolute maximum output voltage is going to be 3.6 VAC Peak to Peak. So why the hell would you put a gain that high? Bragging rights? Nobody is going to brag about a distorted signal. Given the lineararity of his pot, you couldn't turn it over 50% as it's approaching clipping voltages. Is he just hoping nobody uses high resistance cans at high levels or is powering small speakers(some people actually do that, lol)? Also, given the battery life he claims, with it running on high gain, wouldn't the battery life drop CONSIDERABLY when the volume is at anything past 20%? Why would you shoot yourself in the foot like that? The more and more I look at it, the more it seems like a hokey design....
deepak Posted November 4, 2007 Report Posted November 4, 2007 So why the hell would you put a gain that high? Bragging rights? Nobody is going to brag about a distorted signal. Given the lineararity of his pot, you couldn't turn it over 50% as it's approaching clipping voltages. Is he just hoping nobody uses high resistance cans at high levels or is powering small speakers(some people actually do that, lol)? Also, given the battery life he claims, with it running on high gain, wouldn't the battery life drop CONSIDERABLY when the volume is at anything past 20%? Why would you shoot yourself in the foot like that? The more and more I look at it, the more it seems like a hokey design.... Most people planning to buy the Predator are also K1000 owners
PFKMan23 Posted November 4, 2007 Report Posted November 4, 2007 I plan to use my K1k (assuming I don't sell them) with my Pico, so it's not that far off
elnero Posted November 4, 2007 Report Posted November 4, 2007 I plan to use my K1k (assuming I don't sell them) with my Pico, so it's not that far off Paging Boomana....
PFKMan23 Posted November 4, 2007 Report Posted November 4, 2007 I've used my mini cubed with K1ks so.... And yes it was just for kicks.....
ojnihs Posted November 4, 2007 Report Posted November 4, 2007 i love how once everyone comes here, their opinion on RSA changes
PFKMan23 Posted November 4, 2007 Report Posted November 4, 2007 Assumnig you're not just saying that in jest, a lot of it is that on Head Fi, if anything against Ray is said, people are on it like crocodiles, and I for one, don't want to deal with that. On here it's easier to hold a contrarian opinion.
deepak Posted November 4, 2007 Report Posted November 4, 2007 Yup, same here. I don't really read the amp forum unless there is a thread that looks interesting.
postjack Posted November 5, 2007 Report Posted November 5, 2007 DEM PREDATOR HAV THE GAIN FOR THE VERY LOUD IN THE PONES BE LIKE "WHUUT" WIN U ROLLIN
postjack Posted November 5, 2007 Report Posted November 5, 2007 COS COUSIN IT HIT U LIKE LIGHTENIN FROM ABOVE
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