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Post by namikis on Dec 4, 2016 11:30:40 GMT -5
A friend has an esoteric high end phono pre with a battery-based power supply (the battery charges while on stand-by mode, you flip a switch to get it into battery power mode when ready to listen), and it does sound impressive. So last night it occurred to me to try the XPS-1 on battery power, using an A23 12V battery, and the results were very good, but lasted only one song before I had to put another battery in. The improvement is most noticeable in the clarity of the upper octaves and soundstage. So: has anyone in the forum experimented with better power supplies for the XPS-1? I am considering designing something than the A23-based hack, perhaps using a 12V lead acid battery that will last longer before requiring a charge. It would be cool to learn of any good results from others obtained by adding a better linear power supply to this already good phono pre. Thanks, Nam Audio by Jose Sifontes, on Flickr
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Post by mgbpuff on Dec 4, 2016 11:40:17 GMT -5
The Sutherland PH3D runs on 16 d cell batteries.
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Post by Dan Laufman on Dec 4, 2016 11:41:07 GMT -5
Hi Nam, Interesting approach... Please remember that the XPS-1 has an internal megahertz range DC to DC inverter power supply that should theoretically isolate if from external power supply influences. Its taking whatever DC voltage is presented to it and creating it's own highly regulated and isolated DC rail voltages for the phono stage to operate on. It certainly won't hurt it to run it on a battery power supply, but I'd be surprised if any real audible improvements are made. Have fun! Big Dan
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Post by mgbpuff on Dec 4, 2016 11:54:54 GMT -5
SLA batteries come in many sizes and chargers are sold specifically for them.
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Post by namikis on Jan 4, 2017 9:17:19 GMT -5
The Sutherland PH3D runs on 16 d cell batteries. Ok, I took another stab at this after looking at the Sutherland, this time using 8 D batteries. I am now able to test for extended periods of time. I am running the battery-fed XPS1 into a CIAudio PLC1 passive controller, connected to a pair of VTL Compact 80 monoblocks, which in turn feed a pair of Nautilus 803s. The sound is undeniably better - much quieter and dynamic. Yes - you may think I am suffering from some sort of self fulfilling prophesy effect (I did look at the output of the standard Emo power supply on the oscilloscope after reading Big Dan's comments and it looks very very clean - pure 12V - so I assume the inverters are in the wall wart and doing their thing) But then the batteries seem to sound better. Next: I will add a DPDT switch so I can quickly compare wall wart power with batteries. If the results are confirmed I will need to build something prettier and more permanent to house the batteries (using a cheap plastic battery pack I ordered from Hong Kong). Also - I need to confirm how long the batteries will last (aiming for 8 months with 2 hours of use every other day - need to measure voltage drain to confirm). Regards, Namikis Audio by Jose Sifontes, on Flickr
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Post by routlaw on Jan 4, 2017 10:19:05 GMT -5
I don't recall what other forum this came up on, might have been Steve Hoffman but do some checking around. The long and short of it is, there have been others who have implemented a battery powered source for the XPS-1 and realized noticeable improvements. One fellow changed some of the capacitors on the unit as well, which cost more than the entire phono stage new which took it up another level.
Given the design of the wall wart PS, as Dan points out, its difficult to understand why there should be improvements, but FWIW in the conversation when I owned the XSP-1 pre-amp with built in XPS-1 phono stage and also had the stand alone phono stage to compare it with, at least to these ears and at the time I preferred the built in version on the XSP-1 to the stand alone. I assumed at the time this was due to using a linear PS in the pre amp vs the wall wart for the stand alone unit. While I was careful to use identical interconnects on input and output those differences might possibly have been from the extra connections and wire, impossible to determine that however.
I keep thinking about buying another one of XPS-1's to compare to the DIY Tubes 4 Hifi PH16 phono stage I built last winter.
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Post by namikis on Jan 4, 2017 10:38:14 GMT -5
I don't recall what other forum this came up on, might have been Steve Hoffman but do some checking around. The long and short of it is, there have been others who have implemented a battery powered source for the XPS-1 and realized noticeable improvements. One fellow changed some of the capacitors on the unit as well, which cost more than the entire phono stage new which took it up another level. Given the design of the wall wart PS, as Dan points out, its difficult to understand why there should be improvements, but FWIW in the conversation when I owned the XSP-1 pre-amp with built in XPS-1 phono stage and also had the stand alone phono stage to compare it with, at least to these ears and at the time I preferred the built in version on the XSP-1 to the stand alone. I assumed at the time this was due to using a linear PS in the pre amp vs the wall wart for the stand alone unit. While I was careful to use identical interconnects on input and output those differences might possibly have been from the extra connections and wire, impossible to determine that however. I keep thinking about buying another one of XPS-1's to compare to the DIY Tubes 4 Hifi PH16 phono stage I built last winter. Well now you have piqued my interest in other upgrades to XPS-1 - like upgrading caps. And yes - hard to understand what the engineering reason for the improvement might be, but the slight improvement sure is there (hey - I am still trying to understand how the heck the Audioquest Jitterbug helps my DAC - as an electrical engineer I was against it for the longest time - until I tried it. Now I am a believer. Could be a mental thing, but as long as I hear it that is ok by me. I can see your dilemma testing the XPS-1 against other stages - I ended up with the XPS-1 after doing back to back testing against my Jolida jd9 tube/hybrid phono stage. I found the XPS-1 sounded better or at least as good - so sold the Jolida and saved the difference. Namikis
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Post by routlaw on Jan 4, 2017 11:50:12 GMT -5
Well now you have piqued my interest in other upgrades to XPS-1 - like upgrading caps. And yes - hard to understand what the engineering reason for the improvement might be, but the slight improvement sure is there (hey - I am still trying to understand how the heck the Audioquest Jitterbug helps my DAC - as an electrical engineer I was against it for the longest time - until I tried it. Now I am a believer. Could be a mental thing, but as long as I hear it that is ok by me. I can see your dilemma testing the XPS-1 against other stages - I ended up with the XPS-1 after doing back to back testing against my Jolida jd9 tube/hybrid phono stage. I found the XPS-1 sounded better or at least as good - so sold the Jolida and saved the difference. Namikis Thats quite an endorsement, given the existing appreciation for the Jolida in the industry. Regarding cap upgrades, while I haven't tried it with my PH16 yet, it is on my list of things to do. Roy Mottram of Tubes4Hifi recommends it and says it can make a significant difference. I have rolled the tubes to much better ones than the stock issue, which did make a significant difference and might have done the same for you Jolida, assuming you did not go that route before selling.
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Post by namikis on Jan 4, 2017 12:59:05 GMT -5
Well now you have piqued my interest in other upgrades to XPS-1 - like upgrading caps. And yes - hard to understand what the engineering reason for the improvement might be, but the slight improvement sure is there (hey - I am still trying to understand how the heck the Audioquest Jitterbug helps my DAC - as an electrical engineer I was against it for the longest time - until I tried it. Now I am a believer. Could be a mental thing, but as long as I hear it that is ok by me. I can see your dilemma testing the XPS-1 against other stages - I ended up with the XPS-1 after doing back to back testing against my Jolida jd9 tube/hybrid phono stage. I found the XPS-1 sounded better or at least as good - so sold the Jolida and saved the difference. Namikis Thats quite an endorsement, given the existing appreciation for the Jolida in the industry. Regarding cap upgrades, while I haven't tried it with my PH16 yet, it is on my list of things to do. Roy Mottram of Tubes4Hifi recommends it and says it can make a significant difference. I have rolled the tubes to much better ones than the stock issue, which did make a significant difference and might have done the same for you Jolida, assuming you did not go that route before selling. I did several upgrades to the Jolida JD9 (note: this was not the Mark II model) while I had it, including rolling several op amps (the Jolida is not pure tube, really hybrid, ended up with six OPA627s) and rolling a ridiculous number of tubes (ended up with old Mullards - the Tung Sols it comes with are best described as "passable" IMO) and adding high end caps (ended with Auricaps). All the mods helped, but it irritated me (in sort of a good way) how close the Emo XPS-1 came to matching it, so I sold it and cleared a shelf in my rack for something else. I did have a blast modding the Jolida, and almost made my money back on the sale. Also - note that this is a game of synergy, so it may have been that with other components in the chain the Jolida may have kicked the XPS' butt (especially in my case, since I use a CIAudio PLC1 passive line stage that does nothing to help the impedance match). One other planned upgrade for me and the XPS-1 is to turn off the gain and use custom made SUTs (10:1 turns) to match my cart (a Van de Hul Frog std edition, best described as a high-output MC). I think that will help things further. I am criticized by (some) local audio geeks for using the XPS-1 as my phono stage ("you have a Ferrari cart connected to a Hyundai phono stage" is the typical refrain). I ignore them - all I care about is the sound. Namikis
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Post by leonski on Jan 6, 2017 19:25:19 GMT -5
I'd think about a LITHIUM ION solution. The high capacity versions have very low internal resistance which may benefit your system. Bad news? 3 cells are 11.1 volts while 4 cells end up as 14.8 volts.
Maybe a chat with EMO Technical about max input voltage the internal regulators will handle would be in order?
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Post by namikis on Jan 7, 2017 9:29:12 GMT -5
Yes - Lithium batteries could be a next step. For now I am testing to see how long the 8 D cells last. Have gone through 12 LPs no issue, and left it on overnight by mistake once. To prevent that from happening again I crafted a switch with a secondary LED and a normally open relay that is powered by a trigger from the preamp. So even if I forget to power the switch off (the XPS-1 is somewhere behind the rack, hidden) the relay will go open when the pre is shut down. If the batteries lasts a couple of months, that is manageable (I can buy an Amazon Basics 12-pack of D cels to last me for 6 months for $11). If they last less, that can be a pain that could send me looking for rechargeable Lithium-ion or a second bank of D cells in parallel. So far I am really happy with the sound - a cheap upgrade with great impact on sound. Audio by Jose Sifontes, on Flickr
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Post by leonski on Jan 7, 2017 14:28:15 GMT -5
The very high discharge rate Lithium stuff has very low INTERNAL resistance which might help your pre. It's gonna draw very high peak current for very short time periods. I think the output of a lithium battery would better track.
You ARE, however, on a very good track with the D-Cells. Lots of power and very inexpensive for your experiment. Good Job.
Theoretically, when dealing with a LiPo batters, the higher 'C' Rating indictes it'll discharge more quickly.
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Post by namikis on Jan 7, 2017 20:49:44 GMT -5
Yes - Lithium batteries could be a next step. For now I am testing to see how long the 8 D cells last. Have gone through 12 LPs no issue, and left it on overnight by mistake once. To prevent that from happening again I crafted a switch with a secondary LED and a normally open relay that is powered by a trigger from the preamp. So even if I forget to power the switch off (the XPS-1 is somewhere behind the rack, hidden) the relay will go open when the pre is shut down. If the batteries lasts a couple of months, that is manageable (I can buy an Amazon Basics 12-pack of D cels to last me for 6 months for $11). If they last less, that can be a pain that could send me looking for rechargeable Lithium-ion or a second bank of D cells in parallel. So far I am really happy with the sound - a cheap upgrade with great impact on sound. Audio by Jose Sifontes, on Flickr *****IMPORTANT***** If per chance any of you were considering trying this mod out - PLEASE HOLD. I am trying to isolate the specific cause, but the XPS-1 is no longer working - the LED light goes on (with either battery of wall wart power) but there is no output. It was great while it lasted! If I figure out the cause (could be unrelated to the mod, but it feels likely it was) I will let you know via another post here. Thanks! Namikis (he who may soon be ordering a replacement XPS-1 )
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Post by leonski on Jan 7, 2017 22:45:57 GMT -5
find out from EMO tech support what the INTERNAL regulated voltage is.
Please keep everyone informedas to what the problem turns out to be. Now I'm REALLY curious.
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Post by namikis on Jan 8, 2017 12:07:30 GMT -5
I disassembled the XPS1 and injected a 1 khz sig from the sig gen into the inputs. For a several minutes I would get a signal on one of the outputs (I was listening through headphones) for only 4 secs or so after power up (like a capacitor loading then dying, best way I can describe), but not on the other. After power cycling several times, the signal came on steady on both channels.
I have to go out and run some errands so will let is seat off for a while until I get back. Will trace the signal with help from the oscilloscope to see if anything is amiss. Strange.
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Post by leonski on Jan 8, 2017 12:55:49 GMT -5
What is the vovltage from the Wall-Wart? Could 8xD-Cells put out enough higher voltage (When FRESH) to pop or damage a capacitor which was perfectly spec'd at the Wall-Wart Voltage? Maybe the space for the cap was too small for a higher voltage version?
I want to borrow your scope for a month or so.
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Post by namikis on Jan 8, 2017 16:21:28 GMT -5
The 8 D cells put out 12.97V new. they were down to 11.9 yesterday. The Emo wall wart measured a very flat 12.0V on the meter and on the scope. On the plus side - if the issue is a bad cap (I see a couple of big Elnas in there) that would be an easy fix. Will keep you posted.
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Post by routlaw on Jan 8, 2017 16:58:33 GMT -5
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Post by namikis on Jan 8, 2017 17:22:53 GMT -5
The 8 D cells put out 12.97V new. they were down to 11.9 yesterday. The Emo wall wart measured a very flat 12.0V on the meter and on the scope. On the plus side - if the issue is a bad cap (I see a couple of big Elnas in there) that would be an easy fix. Will keep you posted. I checked the caps - they are Elna2200 uf 6.3V bipolar and measured fine: Audio by Jose Sifontes, on Flickr Audio by Jose Sifontes, on Flickr (I thought of changing them out for higher-voltage ones, but did not have any BP of that spec on hand) I need to slowly check the other components on the board: Audio by Jose Sifontes, on Flickr If the LT1115 op amps (the big chips in the pic) somehow got fried, I am SOL (those op amps are at the heart of why this stage is so good, IMO, very low-noise). I ordered another phono stage that arrives Tuesday - in the meantime I have Tidal to keep my tunes going. Namikis
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Post by Axis on Jan 8, 2017 17:25:55 GMT -5
Watch out for FOD, Namikis. The 8 D cells put out 12.97V new. they were down to 11.9 yesterday. The Emo wall wart measured a very flat 12.0V on the meter and on the scope. On the plus side - if the issue is a bad cap (I see a couple of big Elnas in there) that would be an easy fix. Will keep you posted. I checked the caps - they are Elna2200 uf 6.3V bipolar and measured fine: Audio by Jose Sifontes, on Flickr Audio by Jose Sifontes, on Flickr (I thought of changing them out for higher-voltage ones, but did not have any BP of that spec on hand) I need to slowly check the other components on the board: Audio by Jose Sifontes, on Flickr If the LT1115 op amps (the big chips in the pic) somehow got fried, I am SOL (those op amps are at the heart of why this stage is so good, IMO, very low-noise). I ordered another phono stage that arrives Tuesday - in the meantime I have Tidal to keep my tunes going. Namikis
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