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Post by fyrn on Oct 11, 2014 13:47:59 GMT -5
I was thinking about adding an amp strictly for two channel music. I'm currently using a UPA-2 but have a UPA-1 laying around, I would like to go the mono block route for music. Which would be better. 1. Get/add another UPA-1 2. Get/add another UPA-2 (use them biamp as monos) Price is basically the same.
Or would it not be much difference from just a UPA-2 as stereo amp?
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Post by knucklehead on Oct 11, 2014 14:46:51 GMT -5
I've owned both but not at the same time. I didn't notice any real differences other than having mono-blocks in the audio rack. The UPA-2 is a fine amplifier. So are the UPA-1's.
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Post by danny01 on Oct 11, 2014 15:02:21 GMT -5
I used to have upa-1's and now run a single upa-2. To echo what knuclkehead said, I didnt notice a difference between the two amps. I wouldnt advise running two different amps for a stereo.. youd probably be better off selling the upa2 and buying an xpa200 with its larger transformer and more cap storage.
Sent from my SM-P600 using proboards
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Post by broncsrule21 on Oct 11, 2014 15:26:16 GMT -5
My experience was different. When I moved from the UPA-2 to the UPA-1s, I noticed better imaging and soundstage. I had them at the same time. Actually still have them. YMMV...
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Post by knucklehead on Oct 11, 2014 15:49:32 GMT -5
In the over 45 years I've been playing around with audio gear I've found that speakers and room interactions have more affect on imaging than the electronics. YMMV.
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Post by fyrn on Oct 11, 2014 16:22:51 GMT -5
I wouldnt advise running two different amps for a stereo.. youd probably be better off selling the upa2 and buying an xpa200 with its larger transformer and more cap storage. Sent from my SM-P600 using proboards Even mono blocks? Any particular reason? Or are monoblocks preferred for HT and stereo amps for 2ch music?
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Post by danny01 on Oct 12, 2014 0:13:53 GMT -5
I wouldnt advise running two different amps for a stereo.. youd probably be better off selling the upa2 and buying an xpa200 with its larger transformer and more cap storage. Sent from my SM-P600 using proboards Even mono blocks? Any particular reason? Or are monoblocks preferred for HT and stereo amps for 2ch music? Value is the reason. I said that because I assumed the OP is value conscious given that he is looking for a UPA-1 and not a pair of XPA-100's instead. I can't say that I would pay any more for a pair of used UPA-1's than a single XPA-200.
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Post by broncsrule21 on Oct 12, 2014 1:26:25 GMT -5
In the over 45 years I've been playing around with audio gear I've found that speakers and room interactions have more affect on imaging than the electronics. YMMV. I agree, but at the same time, I compared them head to head. Both are great amps still performing for many hours everyday.
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Post by repeetavx on Oct 12, 2014 10:42:07 GMT -5
I'm vertical biamping with XPA-2s. Short speaker cables help with controlling bass frequencies. Lowering the number of voice coils that an amp channel has to control increases detail and reduces distortion, though it's subtle.
When I went with moving my XPA-2 out of my rack and putting next to my speaker, I reduced the speaker cable length from eight feet to two and a half feet. Then put the new XPA-2 next to the other speaker and wired it up identically.
What I got was a lot more control of bass frequencies. A doubling of power, and power reserve, and reduced treble glare.
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Post by fyrn on Oct 18, 2014 14:13:39 GMT -5
Is there a place where cap storage and transformer size is explained when it comes to amps, I get wattage, but not fully understand the others. When do they matter?
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Post by garbulky on Oct 19, 2014 13:17:38 GMT -5
Is there a place where cap storage and transformer size is explained when it comes to amps, I get wattage, but not fully understand the others. When do they matter? When it's not enough! Sorry that's as much as I know!
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Post by Gary Cook on Oct 19, 2014 15:03:06 GMT -5
Is there a place where cap storage and transformer size is explained when it comes to amps, I get wattage, but not fully understand the others. When do they matter? Keeping it simple, 'cause I'm a simple guy, the power supply does what it's name implies, it takes the supply voltage 110 or 230 volts AC and converts it to the voltage/s that the amplifiers requires, generally also converting to DC. The transformer can be considered to be the steady state supplier of enough power to amplify the input sound. The problem is transformers are relatively slow at changing their power output. Whereas capacitors can supply instantaneous power for those nanosecond increases in volume, drum strike, guitar chord etc. But capacitors get exhausted very quickly, so the transformer has to recharge them. Lots of big capacitors can satisfy temporary loud sounds but in a good amp you need the right sized transformer. Good quality transformers are expensive and heavy, so lower cost amps tend to have smaller transformers. That's where the old rule of thumb "good amps weigh more" comes from. That still applies to Class A and Class AB amps, but Class D amps use a different power supply process, so the "heavier is better" rule doesn't always apply. Cheers Gary.
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Post by danny01 on Oct 19, 2014 16:42:02 GMT -5
Another thing to keep in mind is that Class AB amps are roughly around 60% efficient. So if you have an amp with a 300VA transformer, you can expect 180 watts of output. But Emotiva rated the UPA-1 for 200 and 350 watts into 8 and 4 ohms respectively while using a 300VA transformer. How do they manage to do this? It's because the UPA-1 has tons of cap storage, so it can temporarily put out a lot more power for dynamic peaks than what the transformer can supply. The UPA-2 has the same 300VA transformer, but it is shared between 2 channels, and it also has 1/4 the cap storage per channel of a UPA-1. So in the case of the UPA-2 we're talking about 90 watts max per channel when caps are drained. It might not sound like much, but I have a UPA-2, and I've never went past 1.2 amps from the wall on 120V.
Sent from my HTC6500LVW using proboards
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Post by fyrn on Oct 19, 2014 19:26:03 GMT -5
so here comes the stupid question. Where does the "headroom" of the amp reside? in the cap size or the wattage?
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Post by garbulky on Oct 19, 2014 20:12:23 GMT -5
so here comes the stupid question. Where does the "headroom" of the amp reside? in the cap size or the wattage? In the watts
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Post by fyrn on Oct 21, 2014 12:55:11 GMT -5
The UPA-2 has the same 300VA transformer, but it is shared between 2 channels, and it also has 1/4 the cap storage per channel of a UPA-1. So in the case of the UPA-2 we're talking about 90 watts max per channel when caps are drained. It might not sound like much, but I have a UPA-2, and I've never went past 1.2 amps from the wall on 120V. Sent from my HTC6500LVW using proboards So let me make sure I have this clear so I can compare apples to apples. The XPA-5 for example is 200watts (per channel), 1200va power supply (shared or per/ch), 60,000uf cap (shared or per/ch). If shared would this be the equivalent of a monoblock 200w, 240va, 12,000uf. I know it would depend on how much each channel is pulling, but basically speaking?
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Post by garbulky on Oct 21, 2014 13:44:23 GMT -5
The UPA-2 has the same 300VA transformer, but it is shared between 2 channels, and it also has 1/4 the cap storage per channel of a UPA-1. So in the case of the UPA-2 we're talking about 90 watts max per channel when caps are drained. It might not sound like much, but I have a UPA-2, and I've never went past 1.2 amps from the wall on 120V. Sent from my HTC6500LVW using proboards So let me make sure I have this clear so I can compare apples to apples. The XPA-5 for example is 200watts (per channel), 1200va power supply (shared or per/ch), 60,000uf cap (shared or per/ch). If shared would this be the equivalent of a monoblock 200w, 240va, 12,000uf. I know it would depend on how much each channel is pulling, but basically speaking? Basically speaking.... not essentially yes, but in a way yes. I imagine things don't always cut out that neat when taken in real life. For instance I'm not sure a power supply will divide exactly equally or a capacitor will divide exactly equally. If you look at the AP tests on multichannel amp with all channels driven each successive channel gets a slightly different wattage - usually slightly lower than the preceeding one. And in real life the surrounds take up very little and usually it's either the center speaker or the front stereo speakers hogging all of the power of the XPA-5.
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Post by fyrn on Oct 21, 2014 14:13:13 GMT -5
I understand it's a tug of war between the channels depending on each one's demand. I was just not sure if each ch had its own cap/power or if it was shared. Just one more benefit of monoblocks.
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Post by danny01 on Oct 21, 2014 20:54:41 GMT -5
I understand it's a tug of war between the channels depending on each one's demand. I was just not sure if each ch had its own cap/power or if it was shared. Just one more benefit of monoblocks. I'm not sure if it is a benefit to have each channel its own set of caps. As garbulky said, some channels will require more juice, in which case more of the stored power can go to that channel. In a monoblock, you can't draw power from the other channel's amp when it's caps are drained. Sent from my HTC6500LVW using proboards
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novisnick
EmoPhile
CEO Secret Monoblock Society
Posts: 27,230
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Post by novisnick on Oct 21, 2014 21:03:21 GMT -5
I understand it's a tug of war between the channels depending on each one's demand. I was just not sure if each ch had its own cap/power or if it was shared. Just one more benefit of monoblocks. I'm not sure if it is a benefit to have each channel its own set of caps. As garbulky said, some channels will require more juice, in which case more of the stored power can go to that channel. In a monoblock, you can't draw power from the other channel's amp when it's caps are drained. Sent from my HTC6500LVW using proboards Here! Drain this!!,,,,,he,,,,,he,,,,,,, Edit: I'm sorry, sometimes I just can't help myself.
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