Duke Spinner Posted September 7, 2006 Share Posted September 7, 2006 ....... know that a tube amplifier can deliver about 5 times more current (voltage?) than a solid-state amplifier, making low powered tube amplifiers sound better than their low wattage would indicate. where in the world didja get that info , Colin ...???.......[:$] Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted September 7, 2006 Share Posted September 7, 2006 As the load (impedence) decreases, more current (amperage) is needed to deliver a given amount power (watts). So basically, high-current amps are amps that can deliver high amounts of power into low-impedence loads. For example, typical receivers are rated only into 8 ohms, and indeed most cannot deliver enough current into lower impedences to make their rated 8 ohm power. But a true high-current amp design (Krell comes to mind) will be able to double it's power output, with each halving of impedence; 100W into 8 ohms, 200W into 4 ohms, and 400W into 2 ohms. In the real world, few high-current amps can do this clear down to the 2 ohm range, because this usually involves huge power supplies, heat sinks and price tags. As for your RF7's, their high efficiency somewhat mitigates any current demand. They are an 8 ohm speaker anyway, and as such would not be a difficult load for any decent receiver/amplifier. this is a correct explanation ... The RF-7 do go down to an impedience of 2.8 near 32 hertz I believe hence if a quality amp is not given with enough current, the rf-7 will not exhibit alot of bass. Hence alot of forum members expressed surprise and says their rf-7 sounds soo much different when they get a stronger amp or reciever. The new rf-83 I believe they have remedied the low dip. The RF-7 are not 8 ohms but 8 ohms capatible. Quote Link to comment Share on other sites More sharing options...
DrWho Posted September 7, 2006 Share Posted September 7, 2006 Petrol, for $1k you can start looking into seperates...which will demolish even $4k and $5k recievers while also making future upgrades much more affordable. Might I suggest you check out some of these combo options from Outlaw Audio: http://www.outlawaudio.com/mofcart/combos.html Or if you already have a decent reciever you can just purchase a multichannel amp - or maybe even just a 3 channel amp (for the LCR). This would be connected to your current reciever's pre-outs. If you end up going with a reciever, then I would argue that you should just purchase one based on the feature set that you need. The sonic differences really aren't going to be that big compared to the difference the source material / speakers / the room can make. Quote Link to comment Share on other sites More sharing options...
Petrol Posted September 8, 2006 Share Posted September 8, 2006 Thanks for the info Dr. I have been leaning in the reciever direction... mostly because I had thought quality separates to expensive and, well, requiring of a bit to much space for the tv/equipment stand that I have. Dr Who, Jay, et. al, the main reason I'm even considering it is because my current sony, a couple year old strde-995. I bought it new as a replacement after lightning took out a bunch of gear at our house back in '04. It is in very nice shape, no scratches, dings or dents. I still have the original box, paperwork and remote control. It functions perfectly and I have never had any trouble with it.... UNTIL my wife and duagther are out of the house and I find myself wanting to do some serious listing that includes a bit more volume then their presence allows (system is in living room of small house) Then I'm struck with the fact that it is pretty weak on anything other then straight two channel listening, and even then I'm having to crank it up to far to get much out of it... when I toogle between 2 ch and multi channel, the volume is reduced significantly, maybe as much as half (kind of pittiful, I know) While sony rates it at 110wpc x 7 from 20Hz-20k Hz, I guessing that it MIGHT deliver about 70wpc x 2 and drop to about 30wpc or so when driving all seven anyway, it really takes the fun out of watching a concert dvd when I have no ablity to approach live levels even briefly and I was recently offered a sweet deal on what was Pioneer's non 'Elite' top shelf reciever, a VSX-1015 for $300, but I just don't want to drop a single dime if the performance isn't going to be noticably better, along with the ability to really crank it up when needed, lol What do y'all think ? Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted September 8, 2006 Share Posted September 8, 2006 I heard the 1015 is a pioneer elite and that it gets pretty loud on non klipsch speakers (meaning it must get really loud on klipsch speakers due to the efficency!) Also if that doesn't suite you, you can get 3 more db by biamping with that reciever. You just go from 7.1 to 5.1 but use the left and right plus the two back ones to gain bi amp capability or doubling the wattage to 240 watts. Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted September 8, 2006 Share Posted September 8, 2006 Jay .... Bi-Amp ...?? where's the electronic x-over gonna come from ...??? Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted September 8, 2006 Share Posted September 8, 2006 well when you remove the binding posts jumpers, you still have internal crossovers. Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted September 8, 2006 Share Posted September 8, 2006 Ahhhh.... you mean ...... Bi-Wire Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted September 8, 2006 Share Posted September 8, 2006 well .... I gotcher drift, Jay .. it's not what I first think of ...full range signal to both Bi-Amp ..not exactly, either, huh .... better see SpeakerFritz's take on Reflected Power ....doing That ...... Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted September 8, 2006 Share Posted September 8, 2006 its not bi wire because it is sending double the wattage..... I cannot goto the pioneer website at the moment, I dunno I think my campus is buggy at the moment. But it is biampable the pioneer 1015 Quote Link to comment Share on other sites More sharing options...
keepinitcool Posted September 8, 2006 Share Posted September 8, 2006 There are some receivers, and probably some amps that limit current during operation. This is to protect the devices used in the amp, or meet some safety criteria, so for example a 100W per channel 8 ohm receiver may only output 100W at 4 ohm also, even though it's supposed to provide more power. In reference to these type of products, non-limiting amps are "high current." Quote Link to comment Share on other sites More sharing options...
jerohm Posted September 9, 2006 Share Posted September 9, 2006 My first 'real' amp was an SAE 2200. The engineers over there always joked that you should be able to arc weld with the shorted output, without damage to the amp - that was their design goal anyway. They were also very big on slew rate ... at the time 40V/uSec was considered very good (that is from memory - so I could be wrong). I believe most decent amps now-a-days are pushing 100V/uSec Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted September 9, 2006 Share Posted September 9, 2006 still got my 2200 .....[] Quote Link to comment Share on other sites More sharing options...
Arky Posted September 9, 2006 Share Posted September 9, 2006 Petrol, for $1k you can start looking into seperates...which will demolish even $4k and $5k recievers while also making future upgrades much more affordable. Might I suggest you check out some of these combo options from Outlaw Audio: http://www.outlawaudio.com/mofcart/combos.html Or if you already have a decent reciever you can just purchase a multichannel amp - or maybe even just a 3 channel amp (for the LCR). This would be connected to your current reciever's pre-outs. I have been using Outlaws 990/7500 for 4 months with great satisfaction. You can test for 30 days & only risk is return shipping. At least it was when I ordered. Quote Link to comment Share on other sites More sharing options...
esl_57 Posted September 9, 2006 Share Posted September 9, 2006 ... nuf said. :-) Quote Link to comment Share on other sites More sharing options...
Spkrdctr Posted September 11, 2006 Share Posted September 11, 2006 Sorry I've been gone for so long guys! I have been busy with a personal move from Orlando to Port Richey Fl. Also, the terrorist activities have had me running. But, to answer the question of wanting more than a Sony 100wX7 reciever, you really must go to seperates. But remember, you will need to at least DOUBLE the power rating for a 3 db increase in volume. If you need more than a hundred watts, be sure to get at least 200 or more. As you can see, cost goes up radically when you want real high powered amps. I know some of the guys have the Sunfire equipment which is very robust. I would recommend buying one used if you can. Good Luck! Quote Link to comment Share on other sites More sharing options...
Petrol Posted September 12, 2006 Share Posted September 12, 2006 I don't really have 'room' for separates in my current equipment stand, which I built I'm just begining a mild kitchen remodel that involves new counter tops, sink, flooring and demolishing one wall to 'open-up' into the existing dinning room... I'm not excited about the idea of taking on the construction of a new stand right now And, I really don't think the sony is putting out anything near an honest 100 wpc.... more like 60-70 wpc in two channel mode and maybe 30-40 wpc in 7.1 surround... I'm hoping that one of these spiffy 'High-Current' recievers rated at 120 wpc x 7, that I can pick-up for a reasonble amount and drop in my current stand, will provide what I want. If not, I'll have to tolorate the sony for quite a while longer... Quote Link to comment Share on other sites More sharing options...
Petrol Posted September 13, 2006 Share Posted September 13, 2006 anyway, with all this talk about amp ratings, does anyone have any links to some 'Bench-Tests' showing what these things 'really' deliver? Quote Link to comment Share on other sites More sharing options...
DrWho Posted September 13, 2006 Share Posted September 13, 2006 The only bench tests I've seen are going to be way outdated by now. Will you be making your purchase at the local Best Buy or brick and mortar dedicated home audio store? If Best Buy, you could just take advantage of their 30 day return policy until you find one that satisfies your cravings. If your local audio store I would talk to the sales dude and see if you can't get him to let you bring home gear to demo. From another viewpoint, all these amplifiers are going to be very similar in topology, which means similar design tradeoffs. One of the limiting factors for an amplifier's output (especially at low impedances) is the dissipation of all the extra heat. Generally speaking, heavier amplifiers will play louder because the extra weight is usually the result of larger power supplies and/or larger heatsinks. Efficiency has gone way up since the 70's so you don't need a monoblock weighing 80 pounds, but you might want to consider going with a reciever that is significantly heavier than others in your price range. One thing is for certain: the ratings they put on the recievers are always true. But knowing how they arrived at those ratings is a completely different issue. If you're planning on cranking multichannel music then you might even try emailing the tech support of the various companies to see if they won't share how the recievers behave in those applications. Usually they only advertise the maximum output for only one channel being driven at a time. Quote Link to comment Share on other sites More sharing options...
Petrol Posted September 13, 2006 Share Posted September 13, 2006 Thanks for your reply Dr., I guess I should maybe go with first things first... I'm wanting to send my current sony str de995 from my small 17' x 14' living room to my tiny 14' x 10' men's club and replace it with something that will be able to really kick out some multi channel volume when I toss in music dvds. It does "ok" for movie, but that's only because my wife seems to think that movie sound tracks and dioluge are meant for 'background-entertainment', lol I would most likely be going with a mass market AVR, my 'short' dream list includes Denon 3806, Yamaha RX-V2600 & HK635... being a little more realistic, I may back down to maybe a lesser Yamaha, denon, Pioneer or ???? I most likely would make the purchase, if there will be one, at the local Best Buy / Curcuit City... the only dedicated home audio stores around here that I found only have the stuff that is out of my range in stock and I wouldn't expect them to order something in unless I'm committed to buying it. I guess I'm ignorant to Best Buy's 30 day return policy... Don't they charge a 15% 're-stocking' fee on returned electronics? If not, Yahoo!, lol until you find one that satisfies your cravings. If your local audio store I would talk to the sales dude and see if you can't get him to let you bring home gear to demo.and yes, I think the numbers that sony is putting up, at least in the case of my current str-de995, is to advertise the maximum output for only one channel being driven at a time [] Quote Link to comment Share on other sites More sharing options...
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