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Post by The Mad Norseman on May 5, 2012 14:34:41 GMT -5
I received an interesting response from a Parasound dealer when I asked him (via email) if they thought I'd have any problems driving the new Parasound A31 3 channel amplifier from my Yamaha's pre-out jacks rated to output 1.0V/1.2K Ohms. Here's the response I received (copy/pasted in here):
"Yamaha has been problematic with external amps for years, because they have unusually low output voltage. At full volume you will get less than half of the rated power from the Parasound, This is not an unusual for any external power amp, and the Parasound fully complies with THX recommendations for sensitivity. You should consider a different receiver/preamp brand than Yamaha. Yamaha has kind of painted themselves into a corner".
I've asked Emotiva engineers the same question about driving the XPA-2, 3, or 5 with this same receiver's pre-outs, but received nothing but positive responses. So now I'm confused. Will my Yamaha RX-V1900 put out the necessary voltage to get FULL power out of (any) of these external power amps, or not?
(I'd like to get a 3-channel amp to drive my fronts & center channel, and am now confused...trying to make a decision on which way to go...).
Mad Norseman
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Post by roadrunner on May 5, 2012 17:19:27 GMT -5
Emotiva purposely designed their power amps to handle the relatively low voltage output from receivers and on top of that the Emo amps have a gain factor of 32 -- which is significantly higher than the gain of the Parasound power amps. The Emotiva XPA-3 may be just the amp you are look for.
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Post by Topend on May 5, 2012 19:50:30 GMT -5
I had an XPA-2 and XPA-5 connected to a Yamaha RX-V3800 with no issues at all.
Dave.
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Post by firemanast on May 5, 2012 22:42:07 GMT -5
I am running a XPA-5 with a Yamaha RX-A3010 with no issues.
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Post by Deleted on May 6, 2012 1:24:26 GMT -5
Mad Norseman, here are some possibly relevant thoughts.
The Parasound Halo A31 lists for $3000. It is spec'd at:
250 watts RMS x 3, 20 Hz - 20 kHz, 0.2% 8 ohms, all channels driven
400 watts RMS x 3, 20 Hz - 20 kHz, 0.2% 4 ohms, all channels driven
A new review in HT magazine on the Halo A51, which is spec'd at the same exact power per channel, all 5 channels, actually tested out at 198.7 watts into 8 ohms at 0.1%. With two channels it was 301.1 into 8 ohms and only 357.2 watts into 4 ohms (about an increase of 18.5% over the 8 ohm output). A 50% increase from 8 ohms to 4 ohms seems to be more common in this class of amp. I'm not too impressed with these figures.
The Emotiva XPA-3 lists for $699. It is spec'd at:
200 watts RMS @ 8 ohm (0.1% THD) (all channels)
300 watts RMS @ 4 ohm (0.1% THD) (all channels)
The XPA-3 tested on the Audio Precision machine measured 209.2 watts into 8 ohms, 0.03%, 1kHz, all channels. At 4 ohms it measured 303.2, all channels, almost a 50% increase over the 8 ohm power.
I post these figures only to show that it appears that the Emo XPA-3 might produce even more power than the A51 (and supposedly the A31) although it seems to me that the published Parasound specs are somewhat overstated at least with all channels. Just some food for thought.
Also, depending upon available discounts the A31 costs about $2300 more than the XPA-3. With the 30 day no questions asked return and the 5 year transferable warranty, this choice seems to be a no-brainer to me.
You might put in the back of your mind (or maybe even the front), that Emotiva will soon have out their new state-of-the-art XMC-1 pre-pro at $1499 which would be a huge upgrade from the RX-V1900. More food for thought. You still would be ahead $800 plus what the RX-V1900 would sell for.
;D ;D ;D
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Post by The Mad Norseman on May 6, 2012 15:48:42 GMT -5
Thanks to everyone here who took the time to read and respond to my question - much appreciated! One member pointed out the higher gain of Emotiva amps being the difference, but the Parasound Halo A31 utilizes an adjustable gain control for each channel +/- 6db, so (theoretically) it should be able to match the Emotiva's gain, etc., but they still say it can't be driven to more than 1/2 output by the Yamaha, so I'm still confused... Perhaps an Emotiva engineer could weigh in on this for us to clear the air? And thanks for pointing out the big difference in cost (which is not lost on me - believe me!). I'll probably end up going with the Emotiva amp(s), but I just want to get my facts straight and understand this better than I do now. Attachments:
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Post by roadrunner on May 6, 2012 16:33:09 GMT -5
Thanks to everyone here who took the time to read and respond to my question - much appreciated! One member pointed out the higher gain of Emotiva amps being the difference, but the Parasound Halo A31 utilizes an adjustable gain control for each channel +/- 6db, so (theoretically) it should be able to match the Emotiva's gain, etc., but they still say it can't be driven to more than 1/2 output by the Yamaha, so I'm still confused... Perhaps an Emotiva engineer could weigh in on this for us to clear the air? And thanks for pointing out the big difference in cost (which is not lost on me - believe me!). I'll probably end up going with the Emotiva amp(s), but I just want to get my facts straight and understand this better than I do now. I guess I should have spent more time emphasizing the Emotiva power amps are designed to better match the low voltage output from some receivers, like the Yamaha 1900. The gain structure is just part of the reason the Emotiva perform well with receivers. The input circuitry of the Emotiva power amps were designed to handle lower voltage inputs than most other amps, like the Parasounds. This input circuit on the Emotiva power amps permits driving them to full output with a relatively low voltage from the input device. Other amps require a higher input voltage to drive them to their full rated output. Hopefully, this makes it clearer why the Emotiva amps are able to perform at their full rated output when competing power amps may not. You need to examine both the input circuitry and the output circuits, not just one or the other.  |
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Post by The Mad Norseman on May 7, 2012 21:37:21 GMT -5
I had an XPA-2 and XPA-5 connected to a Yamaha RX-V3800 with no issues at all. Dave. Hi TopEnd - Did you EVER feel like your Yamaha RX-V3800 wasn't delivering enough voltage to your amps while running that set up? How about after you got your new pre-pro? Did you notice more headroom, or any difference then that would make you think the previous setup just wasn't delivering full portential from those amps? I'm just trying to get a 'warm-fuzzy' that my '1900 will get the most from an XPA-2 and/or XPA-3...thanks! |
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Post by The Mad Norseman on May 7, 2012 21:43:45 GMT -5
Mad Norseman, here are some possibly relevant thoughts. The Parasound Halo A31 lists for $3000. It is spec'd at: 250 watts RMS x 3, 20 Hz - 20 kHz, 0.2% 8 ohms, all channels driven 400 watts RMS x 3, 20 Hz - 20 kHz, 0.2% 4 ohms, all channels driven A new review in HT magazine on the Halo A51, which is spec'd at the same exact power per channel, all 5 channels, actually tested out at 198.7 watts into 8 ohms at 0.1%. With two channels it was 301.1 into 8 ohms and only 357.2 watts into 4 ohms (about an increase of 18.5% over the 8 ohm output). A 50% increase from 8 ohms to 4 ohms seems to be more common in this class of amp. I'm not too impressed with these figures. chuckienut - I subscribe to HT mag too (LOVE that magazine!), and also just read the review on the A51 five channel amp. I wondered HOW they could still give it their 'Top Pick' designation when it couldn't generate the 250w with all 5 channels driven at once - as advertised, pretty poor when it costs $4,500!). Though I understand that everyone who's heard it loves its sound, so... Anyway, the A31 has adjustable gain, and I expected the response to be "no problem with the Yamaha", like with Emotiva. I've been toying with the idea of a Yamaha RX-A3010 (150w/channel) plus the Emotiva XPA-3, but am not so sure now... |
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Post by The Mad Norseman on May 11, 2012 19:51:41 GMT -5
Here's an update on this situation: I contacted Yamaha's online support who claim they've heard of no such issues with their AVR's pre-out's voltage being inadequate (but were also non-commital when pressed...). And now a Parasound rep. (not an online sales guy as before), tells me that: "Your suggestion will work fine. Some of the Yamaha AVRs' line out jacks do not have muting when the digital sources are switched or you channel surf on a cable box. With a direct coupled amp like the A 31 you could experience a small thumping noise. Yamaha knows the artifact is there because they mute the digital transitions for the speaker outputs". So now I don't know what to do, or who to believe!  (sigh...). |
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Post by paintedklown on May 11, 2012 20:30:21 GMT -5
Just to toss out another plug for Yahama... I am running a Yamaha RX-V667 as a pre/pro for Emotiva XPA-1 monos and an Emotiva XPA-5 with zero issues. This setup gets plenty loud and with no audible distortion, hiss, hum, buzz, etc. that you may expect from a "non-audiophile" grade re-amp. Get the Yamaha you want and never look back!   Good luck with whatever you choose. |
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Post by The Mad Norseman on May 12, 2012 10:38:08 GMT -5
Just to toss out another plug for Yahama... I am running a Yamaha RX-V667 as a pre/pro for Emotiva XPA-1 monos and an Emotiva XPA-5 with zero issues. This setup gets plenty loud and with no audible distortion, hiss, hum, buzz, etc. that you may expect from a "non-audiophile" grade re-amp. Get the Yamaha you want and never look back! Good luck with whatever you choose. Thanks for the encouragement Paintedklown! The new Parasound A31 3 channel amp, and their 5250v.2, (250w x 5) amps now feature adjustable gain (+/- 6db from the THX standard of 29db - which is what those amps are set at 'in the middle' of that adjustable range) which is a really great idea! I understand that Emotiva power amps are rated at a gain of 32db. So theoretically, I should be able to adjust the Parasound up 3db, and thus get the same result. The Parasound's sound SO sweet!, but I may go Emotiva anyway, as its hard to justify the cost difference for what is probably a small performance difference. Thanks again! |
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Post by casey01 on May 13, 2012 18:07:36 GMT -5
I received an interesting response from a Parasound dealer when I asked him (via email) if they thought I'd have any problems driving the new Parasound A31 3 channel amplifier from my Yamaha's pre-out jacks rated to output 1.0V/1.2K Ohms. Here's the response I received (copy/pasted in here): "Yamaha has been problematic with external amps for years, because they have unusually low output voltage. At full volume you will get less than half of the rated power from the Parasound, This is not an unusual for any external power amp, and the Parasound fully complies with THX recommendations for sensitivity. You should consider a different receiver/preamp brand than Yamaha. Yamaha has kind of painted themselves into a corner". I've asked Emotiva engineers the same question about driving the XPA-2, 3, or 5 with this same receiver's pre-outs, but received nothing but positive responses. So now I'm confused. Will my Yamaha RX-V1900 put out the necessary voltage to get FULL power out of (any) of these external power amps, or not? (I'd like to get a 3-channel amp to drive my fronts & center channel, and am now confused...trying to make a decision on which way to go...). Mad Norseman Time and again, I see this response from manufacturers who are suppose to be experts but in reality, don't have a clue how their equipment interacts with others. Over the years, I have used three different Yamaha AVRs as Pre-Pros with three different type of outboard amps and the output level is fine. It is easy to tell since if the AVRs(of any brand) per channel output is rated similar to the outboard amp then volume levels should be similar to each other in each case whether the speakers are connected to the AVRs speaker outputs directly or through the outboard amp. In all my examples volume levels at a given setting were very similar. |
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Post by The Mad Norseman on May 13, 2012 21:55:34 GMT -5
[/quote] Time and again, I see this response from manufacturers who are suppose to be experts but in reality, don't have a clue how their equipment interacts with others. Over the years, I have used three different Yamaha AVRs as Pre-Pros with three different type of outboard amps and the output level is fine. It is easy to tell since if the AVRs(of any brand) per channel output is rated similar to the outboard amp then volume levels should be similar to each other in each case whether the speakers are connected to the AVRs speaker outputs directly or through the outboard amp. In all my examples volume levels at a given setting were very similar. [/quote]
Thanks casey01,
Its been my experience when asking company's online tech support that I really can't trust any of the answers I get back!
Doesn't give me a 'warm-fuzzy' that they know what they're doing, and I should take any answer given with a grain of salt. So why do I keep asking when I can't tell the competent answers from the others? Good question. I'm sure some know the right answers, but how can I tell?
A real conundrum...
I've decided to keep my Yamaha RX-V1900 for now (which is a superb HT performer!), and get what ever external amp I want and just try it.
If it doesn't work (which I don't expect), I'll move up my timetable to get a new pre-pro, but if it does work, then I'm 'good-to-go' for awhile.
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Post by The Mad Norseman on Jul 9, 2012 12:58:32 GMT -5
I had an XPA-2 and XPA-5 connected to a Yamaha RX-V3800 with no issues at all. Dave. Dave, When you had the XPAs hooked up to your Yamaha RX-V3800 did you find that the volume control on the Yammy then needed to be turned up more, or less than when you were only using the Yammy's internal amps??? (I'm trying to get a feel for what the practical differences would be with the XPA's 32db gain, vs. the Yamaha's internal amp gain. And your old '3800, and my present '1900 both have the same pre-out voltage specs. Right now I watch TV at about -40db, and Blu-rays at -20db). Thanks. |
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Post by sharkman on Jul 13, 2012 9:19:34 GMT -5
In theory the room correction software should just bump up the levels so your amp gets a hotter signal, but that would still not exceed the 1 volt max output. Onkyos are the same with the pre out levels.
BTW, bumping up the Parasound's gain knob would not be effective as when the gain is at full volume it would be 29 db. Gain is a tricky thing, this is why some Emotiva owners have complained about hiss at zero volume with some higher sensitive speakers. With my XPA-3 I can get hiss with my speakers, but I can't hear it at my seating position. But that's the risk of a high gain of 32db, and partly why almost all amp companies stay away from it.
Speaking of which, most pre pros have the output voltage of around 2 volts which is what the Parasound amps, and most others are designed for. But as others have said, you can't really notice it unless you run your system at full or max volume. At your usual listening levels you might have to turn up the volume a few db, if that.
On the Parasound vs Emotiva amp, I just replaced my XPA-3 with a Parasound A-21 for my 2 channel system. What improvements are you looking for and what do you listen/watch mostly?
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Post by The Mad Norseman on Jul 13, 2012 12:50:40 GMT -5
In theory the room correction software should just bump up the levels so your amp gets a hotter signal, but that would still not exceed the 1 volt max output. Onkyos are the same with the pre out levels. BTW, bumping up the Parasound's gain knob would not be effective as when the gain is at full volume it would be 29 db. Gain is a tricky thing, this is why some Emotiva owners have complained about hiss at zero volume with some higher sensitive speakers. With my XPA-3 I can get hiss with my speakers, but I can't hear it at my seating position. But that's the risk of a high gain of 32db, and partly why almost all amp companies stay away from it. Speaking of which, most pre pros have the output voltage of around 2 volts which is what the Parasound amps, and most others are designed for. But as others have said, you can't really notice it unless you run your system at full or max volume. At your usual listening levels you might have to turn up the volume a few db, if that. On the Parasound vs Emotiva amp, I just replaced my XPA-3 with a Parasound A-21 for my 2 channel system. What improvements are you looking for and what do you listen/watch mostly? You typed: "BTW, bumping up the Parasound's gain knob would not be effective as when the gain is at full volume it would be 29 db". But the Parasound A31's gain is already at 29db in its 'middle position'. The adjustable gain is +/- 6db from that point. So it should be able to go to, and even PAST, the set gain of 32db that Emotiva's XPAs are set at. The question I've never seen satisfactorily answered is when a spec says (say) "1.0V / 1.2k Ohms" (for pre-out output in this case) - what EXACTLY does the 1.2k Ohms mean as to output, and how does it factor in to voltage output capability? I see a lot of other specs at 460 Ohms, or 2k Ohms, etc. There must be an influence... (Onkyo AVRs have the weakest pre-out output voltage I've heard many times now, but I'm not sure which AVR brand has the strongest though?). I'm primarily looking for improved dynamics, and headroom, (which is really the same thing I suppose!). Seriously considering the new XPR-5 now, or maybe an XPA-2 & 3 combo...decisions, decisions,... Love the sound of my Yamaha, (which is FAR better than Yamaha's lower tier AVR line's sound, like the RX-V863 I ditched before getting this one!). So trying to figure out a way to 'have it all'!  |
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Post by sharkman on Jul 13, 2012 13:52:26 GMT -5
Yes, some of the specs are hard to figure out! On the gain question, I cracked my A21 manual:
I'm not sure that the A31 is the same, but they probably have the same approach to gain on all their amps with this option. Another neat option is signal sensing turn on/turn off. You don't need a 12 volt trigger if your system doesn't have one. Pretty cool if you ask me!
Anyway, I don't think you can increase the gain above 29db with the knobs, only reduce it if needed for gain staging. But it shouldn't be an issue unless you want 120 db levels at your listening postion. Ouch.
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Post by The Mad Norseman on Jul 13, 2012 22:02:21 GMT -5
Yes, some of the specs are hard to figure out! On the gain question, I cracked my A21 manual: I'm not sure that the A31 is the same, but they probably have the same approach to gain on all their amps with this option. Another neat option is signal sensing turn on/turn off. You don't need a 12 volt trigger if your system doesn't have one. Pretty cool if you ask me! Anyway, I don't think you can increase the gain above 29db with the knobs, only reduce it if needed for gain staging. But it shouldn't be an issue unless you want 120 db levels at your listening postion. Ouch. The adjustable gain controls on the A21 are different from those on the A31. On the A21, 29db is the set maximum gain at the full clockwise setting. Whereas on the A31 amp, 29db is the middle (12 O'clock) setting, and can be adjusted +/- 6db from there. The following was lifted from the A31's manual: "The Gain control knobs should be left at the 12 o’clock Normal/THX setting for most applications. When a Gain control knob is set to Normal the gain for that channel is 29. This is the THX Ultra2 Reference Level where 1V input = 28.28V output. (28.28V driving an 8Ù speaker equals 100 watts.) If you are unsure where to set the Gain control knobs it is best to start with them in the Normal position and only change them if needed, as described below. When to Set the Gain Control Knobs Above or Below Normal You can increase loudness by turning the Gain control knobs clockwise if your system will not play loud enough with the Gain control knobs set at Normal. This could be the case if your A 31 is driven from the pre-out jacks of an AV receiver (as opposed to an AV processor). We recommend advancing the gain as little as possible past Normal. As you increase gain settings you increase the chance of hearing a “hiss” sound from your speakers. You also run the risk of damaging your speakers (not to mention your hearing) if the volume level is too high". Still wondering about that input impedance figure I mentioned in my previous entry, and what effect that has on pre-out voltage output... |
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Post by Entity on Jul 13, 2012 22:06:19 GMT -5
I must be weird for not worrying about the gain on the amp, or preout voltage...if I can turn the volume knob up and it makes sound, then it works for me.
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