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Post by dac0964 on May 4, 2013 11:09:25 GMT -5
For those inquiring (or just plain curious) about how long it takes for the 1L to heat up, I've got some delicious data for you. ;D Wow that is super warm (don't want to say hot)! And what if you have two of these?? Thanks for sharing DR. |
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Post by dac0964 on May 4, 2013 11:10:41 GMT -5
There are two things in life that real macho men want to know how hot they get, amplifiers and women. ;D ;D |
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Post by eclypse on May 4, 2013 12:33:44 GMT -5
Heat no biggy.. when i'm listening to music it would be Class A and Heat and for everything else A/B and cooler.
Hope to score 3 of these or 3 XPA-1 for the fronts/center for my Polk Audio LSiM 705s/706 center. Run the 703 surrounds off the Denon 3313CI.
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Post by Dark Ranger on May 4, 2013 12:38:46 GMT -5
Wow...all these data and experiments and so and so but all I want to know is if they sound good...Am I allow to ask that? I am sorry if this question was already answered but I didn't want to read all these pages to find out it wasn't... They sound fantastic! This is my first Class A amp, so I'm very curious when it comes to the technical details. I want to know as much about it as I can, and then I can put the notepad away and just enjoy the music for as long as I own it.  This whole thread (69 pages and counting) is very interesting and informative. If you want the entire scoop on the 1L, grab your favorite beverage, start at page 1, and go for it. If you don't have that much time, I recommend starting at the bottom of page 61 and moving forward. You'll see the latest feedback from the Round 3 shipment of 1L amplifiers. There are two things in life that real macho men want to know how hot they get, amplifiers and women. Yes!! I agree 100%. ;D Dude, you have too much time on your hands <g>! May be time to find a part-time job. And you may need it to pay for the increased electrical/cooling costs from using that beast of an amp... Funny guy!  Thankfully, I've got a great job that allows me to pay for my Emo gear, the electric bill, and many other things. However, it's variable and depends on several things. Sometimes the phone is ringing off the hook, other times it's very quiet. I did not have to put out any fires at work last night, so I was able to run the tests at home. Trust me, it's not always like this. Wow that is super warm (don't want to say hot)! And what if you have two of these?? Yeah, it's definitely super warm! And you know what? I still want two more!  |
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Post by Dark Ranger on May 4, 2013 12:40:24 GMT -5
When I was a kid my dad used the hippopotamus scale. He'd hold his hand over the barbecue and count; 1 hippopotamus, 2 hippopotamus, 3 hippopotamus ... etc, when he had to pull his hand away that was the reading. I think he'd throw the meat on when it reached 5 hippopotamus. We'll need those centigrade numbers converted to hippos before your report is complete. Well, I spent some time trying to convert to Hippo units, but I found that it requires me to divide by zero in the equation. The partial differential equation is solvable, along with calculating the inverse tangent of apple pie. It's just the dividing by zero thing that has me stumped. That said, I did actually hold my hands over the fire (so to speak). I managed to count to 10 hippopotamuses while gritting my teeth. In the spirit of scientific experimentation and repeatability, I had to run the test twice: the first time with both hands on the smooth metal between the heatsink vents, the second time with both hands on the heatsink vents. Imagine my complete surprise and utter disbelief when I removed my hands at the end of counting 20 hippopotamuses, only to find extremely red hands! This concerning problem was remedied by clasping a frozen carton of ice cream for a great many hippopotamuses. The plus side was that the ice cream was easily scooped out with a standard spoon. Mmm, delicious!  |
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Post by ocezam on May 4, 2013 13:13:27 GMT -5
I managed to count to 10 hippopotamuses while gritting my teeth. Jeez! I'm kinda speechless. ... |
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Post by garbulky on May 4, 2013 13:26:15 GMT -5
I got to 14 hippoppopoppo before my brain had to reboot. It has an inbuilt hippopotamus overload control switch.
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Post by AudioHTIT on May 4, 2013 13:30:50 GMT -5
When I was a kid my dad used the hippopotamus scale. He'd hold his hand over the barbecue and count; 1 hippopotamus, 2 hippopotamus, 3 hippopotamus ... etc, when he had to pull his hand away that was the reading. I think he'd throw the meat on when it reached 5 hippopotamus. We'll need those centigrade numbers converted to hippos before your report is complete. Well, I spent some time trying to convert to Hippo units, but I found that it requires me to divide by zero in the equation. The partial differential equation is solvable, along with calculating the inverse tangent of apple pie. It's just the dividing by zero thing that has me stumped. That said, I did actually hold my hands over the fire (so to speak). I managed to count to 10 hippopotamuses while gritting my teeth. In the spirit of scientific experimentation and repeatability, I had to run the test twice: the first time with both hands on the smooth metal between the heatsink vents, the second time with both hands on the heatsink vents. Imagine my complete surprise and utter disbelief when I removed my hands at the end of counting 20 hippopotamuses, only to find extremely red hands! This concerning problem was remedied by clasping a frozen carton of ice cream for a great many hippopotamuses. The plus side was that the ice cream was easily scooped out with a standard spoon. Mmm, delicious! DR the scientific community will be forever grateful for the sacrifices you are making in both testing and documentation. As for the hippo conversion I always suspected my dad knew more math than he was letting on; I'm going to visit him in a couple weeks for his 90th birthday and I'll see if he remembers the technical details of the measurement and conversion process. You have eliminated one variable however by placing your hand on the amp, he had to judge a specific distance above, as actually touching the hot coals of the barbecue was ... problematic. Your ice cream solution however is brilliant, both as a remedy and reward! |
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Post by Dark Ranger on May 4, 2013 13:51:04 GMT -5
All in the name of science and good fun. I got to 14 hippoppopoppo before my brain had to reboot. It has an inbuilt hippopotamus overload control switch. I LOLed! ;D |
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Post by Keith M on May 4, 2013 14:52:54 GMT -5
On most of the other emo amps and other gear i have opened, modded or repaired the amber is the A wire and the blue is the B wire. If you are not electronically inclined the tape option is probably best...sharpie maybe a good option too. Personally i can stand displays and leds that cant be turned off in my ht room...its a distraction...i know when its on as i can hear it playing...amber is fine when its off. I can get my umc-1 and oppo completely blank and thats fine by me. I opened the case and checked for such wires. In fact I found an A and B wire that suggested they were the culprits. But alas, disconnecting them did nothing. In fact when I looked at the board the LED is mounted to it appeared the B wire was not actually connected at all. Odd that. In the XPA-1L there appear to be two multi-color LEDs that are embedded in a translucent piece of plastic. These LEDs have three prongs coming out of them, whereas some of the older gear had separate, clearly labeled two pronged blue and amber LEDs. I attempted to follow the various traces on the board from the LEDs and it appeared that some ran back to a chip on the board. This leads me to believe that there is logic in the chip that controls the color of the LEDs and the A and B wires I found that appear similar to the older models are merely remnants of their older designs. I found a curious issue with this board. It appears that you can't tighten down all four of the screws that hold it to the front of the case without interfering with the function of the power button. You have to leave a little slack in at least the bottom two screws. Initially I was trying some heavy stock paper between the button and LEDs, and I thought that was causing the problem, but after opening the second XPA-1L I found that board was just a hair loose already. I have applied two layers of the standard Light Dims (www.lightdims.com) on mine, and that has brought the level down considerably. I found the Light Dims at Fry's for $2 a pack and have used them on some other electronics in my house that have tended to act as night lights, and they do help. |
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Post by deltadube on May 4, 2013 15:08:23 GMT -5
For those inquiring (or just plain curious) about how long it takes for the 1L to heat up, I've got some delicious data for you. ;D Below are two graphs that show temperature as a function of time T(t):   To ensure accuracy, ambient temperature was kept as close to 74.5 F (23.6 C) as possible. Only the XPA-1L and my computer were running during this test, no other amps, processors, or heat generating devices were allowed to be turned on. Initial temps were recorded in two areas before the test. Measurement of these two areas was repeated and recorded every 5 minutes until 60 minutes had elapsed. The red squares correspond to averaged temperatures along the middle and right-side heatsink venting/perforated rows. The blue diamonds correspond to averaged temperatures along the smooth metal strip between the two heatsink venting rows. The green triangles correspond to the ambient temperature. In Class A/B mode, I couldn't quite hit the max temperature mentioned previously. I believe the difference here is that Friday night's test took place with a lower ambient temperature than Thursday's test. I actually let the Class A/B test continue past the 1 hour mark. At 1h 30m I had a reading of 112 F / 113 F for the two monitoring areas mentioned above. Thursday, I had recorded 116 F / 118 F for these two areas, but had a higher ambient temp of 2.5 F. Anyway, you get the idea. If anyone wants to see the raw data and precise recording, let me know...I've got 5 pages of data. ;D Wow DR great chart... thanks for your hard work.. so would you say for sound quality wise 30 mins is good time for a listen or do you wait the full hr? at the same room temp when do you hit the max temp ceiling? thanks DR |
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Lonnie
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Post by Lonnie on May 4, 2013 16:15:03 GMT -5
On most of the other emo amps and other gear i have opened, modded or repaired the amber is the A wire and the blue is the B wire. If you are not electronically inclined the tape option is probably best...sharpie maybe a good option too. Personally i can stand displays and leds that cant be turned off in my ht room...its a distraction...i know when its on as i can hear it playing...amber is fine when its off. I can get my umc-1 and oppo completely blank and thats fine by me. I opened the case and checked for such wires. In fact I found an A and B wire that suggested they were the culprits. But alas, disconnecting them did nothing. In fact when I looked at the board the LED is mounted to it appeared the B wire was not actually connected at all. Odd that. In the XPA-1L there appear to be two multi-color LEDs that are embedded in a translucent piece of plastic. These LEDs have three prongs coming out of them, whereas some of the older gear had separate, clearly labeled two pronged blue and amber LEDs. I attempted to follow the various traces on the board from the LEDs and it appeared that some ran back to a chip on the board. This leads me to believe that there is logic in the chip that controls the color of the LEDs and the A and B wires I found that appear similar to the older models are merely remnants of their older designs. I found a curious issue with this board. It appears that you can't tighten down all four of the screws that hold it to the front of the case without interfering with the function of the power button. You have to leave a little slack in at least the bottom two screws. Initially I was trying some heavy stock paper between the button and LEDs, and I thought that was causing the problem, but after opening the second XPA-1L I found that board was just a hair loose already. I have applied two layers of the standard Light Dims (www.lightdims.com) on mine, and that has brought the level down considerably. I found the Light Dims at Fry's for $2 a pack and have used them on some other electronics in my house that have tended to act as night lights, and they do help. They are bicolor LEDs that are molded into a laser etched diffuser. The LEDs are controlled by the primary processor that monitors and runs the amplifier. Any modification to this could cause a catastrofic failure in the system. That processor is what controls the auto rail detection, power supplies, does all the protection monitoring, etc. I would like to advise you on what to do, but due to liability reasons I can't. We as a company do not recommend or condone modifying any of the design or circuitry. Having said that though. Instead of modifying the circuit, why not just put a very thin piece of plastic film over the diffuser. |
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Post by Keith M on May 4, 2013 17:38:34 GMT -5
They are bicolor LEDs that are molded into a laser etched diffuser. The LEDs are controlled by the primary processor that monitors and runs the amplifier. Any modification to this could cause a catastrofic failure in the system. That processor is what controls the auto rail detection, power supplies, does all the protection monitoring, etc. I would like to advise you on what to do, but due to liability reasons I can't. We as a company do not recommend or condone modifying any of the design or circuitry. Having said that though. Instead of modifying the circuit, why not just put a very thin piece of plastic film over the diffuser. As I said, that's exactly what I did. Or to be more clear, I applied the light dims directly to the diffuser rather than on the exterior of the case. Thanks for confirming what I thought was going on. I'm not going to attempt to change anything in the processor of course. Clearly they could modify this so that the switch to turn off the front display also turns off the power button LED. But I guess they want their logo to shine brightly. Oh well. I've e-mailed tech support and asked if it's possible to get replacement power buttons. That way I could paint the interior of one set and then if need be swap them out with clear ones if I should ever sell the amps. Perhaps like the black trim this will be something Emotiva will offer to their customers at some point. |
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Post by deltadube on May 4, 2013 17:42:20 GMT -5
Hi Lonnie sounds like great advice...
just wondering is the diffuser like the power button area of the outside of amp?
thanks...
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Post by 12elfthfloor on May 4, 2013 18:00:12 GMT -5
Ive had a quick skim read and search and no luck so apologies if asked before but anyone here compared the XPA 1s with these amps in class A? Just interested in the sound, not power, heat, or dollars.
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stiehl11
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Post by stiehl11 on May 4, 2013 18:53:17 GMT -5
Hi Lonnie sounds like great advice... just wondering is the diffuser like the power button area of the outside of amp? thanks... In my sector of the business we call this a "light pipe". In this application, it is the clear/translucent/opaque ring that encircles the power button sub-assembly. The LEDs are molded into this ring, then the ring is assembled to the button assembly. Its job is to bend and shape the light emitted from the diodes to the desired application. It's the same principle as fiber optics; only for decoration. |
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Lonnie
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Post by Lonnie on May 4, 2013 19:33:46 GMT -5
Hi Lonnie sounds like great advice... just wondering is the diffuser like the power button area of the outside of amp? thanks... The acrylic panel has micro dots laser etched into it to bend the light and turn it at a right angle to it is moving towards the front of the unit. Glued on top of the acrylic panel is a very thin piece of frosted plastic to diffuse the light. The power button sits on top of the diffuser. So the only way to get to the diffuser is to disassemble the front panel assembly because it is on the inside of the unit. |
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Post by Dark Ranger on May 5, 2013 1:47:23 GMT -5
so would you say for sound quality wise 30 mins is good time for a listen or do you wait the full hr? To be honest with you, I cannot detect any SQ improvements yet due to warm-up time. It sounds the same to me after 5 minutes as it does after 30 minutes as it does after 1 hour. If there are improvements, they are very subtle (basically inaudible) or perhaps I cannot detect them for some explainable reason. My recommendation would be to try it yourself, with your own equipment, and in your own room. at the same room temp when do you hit the max temp ceiling? Well, max temps would be sometime after 1 hour. However, the max readings I took at one hour (last night's test) were the same as the previous night when the amp was running for several hours. I doubt the 1L gets much hotter at the ambient temps I had. Honestly, it's not too big of a deal because the controller code monitors the temps and throttles back Class A levels as needed. Yes, these amps run hotter and consume more power in Class A mode than pretty much all of Emotiva's other amps, but that's inherent with all Class A designs. It's very inefficient, but for many reasons, it theoretically sounds the best. Class A offers the best linearity, no crossover distortion, extremely low levels of overall distortion, and basically the most accurate representation of the waveform. If heat is a concern, I recommend you keep it in A/B mode for the majority of your listening. These are still fantastic amplifiers even without Class A. |
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Post by cwt on May 5, 2013 4:41:50 GMT -5
All in the name of science and good fun. I got to 14 hippoppopoppo before my brain had to reboot. It has an inbuilt hippopotamus overload control switch. I LOLed! ;D Hippopotami is more appropriate for such a scholarly effort DR ;D You've gone beyond the call with the xpa1l and it's no coincidence that your insights are valued muchly . |
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Post by Deleted on May 5, 2013 5:39:33 GMT -5
I nominate Dark Ranger for Lounge Lizard of the Month!
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