Bottlehead Forum
Bottlehead Kits => BeePre => Topic started by: aroide on November 12, 2014, 07:30:31 AM
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I have a BeePre and really crappy power. I have a filter/distribution unit, and I see that voltage sags from 120V with nothing on to 114V and lower with everything on. Of course, the same 15A circuit is used for both the listening room and family room A/V setup. My BeePre does have a bit of 60z hum at a low level (stronger in the left channel) and transformer hum. Sometimes when the voltage dips, I get a sharper square waviesh hum that varies volume based on the brightness of the plasma TV in the A/V setup.
I've ordered a PS Audio P3 regenerator to clean up the listening room power. My question: would turning on the multi wave option affect the BeePre operation in any negative way? Multi-wave adds a 120Hz sine overlaying the 60Hz and improves ripple. So I've read, tube amps benefit greatly.
I want to be sure that the design of the BeePre won't change (rectified voltage increase, etc) if I turn this on. Any experiences with PS Audio regeneration and multi-wave are appreciated.
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IIRC you should never use multi-wave on tubed equipment. I might have to look that up.
But regeneration has been good for my system. I not only have a constant voltage but can correct my VPI HW-19 speed with 61 Hz. See the link:
http://bottlehead.com/smf/index.php?topic=1372.msg9575#msg9575
BTW, the BeePre should not have hum. That probably is another problem.
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114V is likely low enough to cause some regulator dropout. Can you measure a different outlet on a different circuit under these conditions to see if it's an overtaxed circuit or an issue from the street in?
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Unless I'm missing something that multiwave thing is adding in exactly the stuff we are trying to get rid of with the power supply filter of the amp.
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I've been using a P500 for years for my sources and preamps [I remember reading somewhere that you shouldn't use them for tube power amps for a reason I can't remember but...] and use a Twave setting and 117v.
The manual states that
[TWAVE] TubeWave-TubeWave is specifically designed to optimize the performance of tube based audio products
[MWAV2] MultiWave2...MultiWave2 is a 60Hz SineWave that incorporates a pseudorandom collection of
frequencies which are dithered from 55-65Hz. Using this slightly random frequency deviation is similar to adding dither on a digital audio source.
Power supply dithering can lower the perceived noise floor and help remove apparent glare on the audio signal.
Is using the TWave a no-no? Should I be using the straight sine function instead? I also don't remember why I chose 117v instead of 120v, probably to extend the life of my tubes but would 120v be a better choice?
thanks
Bryon
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I have my HW-19, Eros, Foreplay 2, Paramours and Dungeness subs all powered by my P300. I use sine wave and there have been no ill effects.
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Couldn't resist having a nosy at the manual http://www.psaudio.com/wp-content/uploads/2011/11/P500-reformat1.pdf (http://www.psaudio.com/wp-content/uploads/2011/11/P500-reformat1.pdf)
[SINE] SineWave
In the SineWave mode the Power Plant will generate a perfect SineWave (50-120Hz).
[TWAVE] TubeWave
TubeWave is specifically designed to optimize the performance of tube based audio products. TubeWave uses the same pseudorandom generation of frequencies as MultiWave2 wave -
form, however it generates more tube-friendly frequencies.
[MWAV1] MultiWave1
MultiWave1 is a single 60Hz SineWave with a minute amount of 3rd Harmonic SineWaves mixed together to form a single partial square MultiWave. This is an improved version of PS2 from the original MultiWave™ series. The partial square wave setting improves the power supply’s ability to charge the capacitors in equipment by extending the length of time available to "top off" the capacitors' voltage. Use this setting to enhance the performance of both source and power equipment.
[MWAV2] MultiWave2
MultiWave2 is a 60Hz SineWave that incorporates a pseudorandom collection of frequencies which are dithered from 55-65Hz. Using this slightly random frequency deviation is similar to adding dither on a digital audio source. Power supply dithering can lower the perceived noise floor and help remove apparent glare on the audio signal.
[MWAV3] MultiWave3 MultiWave3 is a combination of Multiwave1 with a slight degree of 3rd harmonic addition (MultiWave1). Try this setting and see how the audio sounds and the video looks. All systems can respond differently to each MultiWave pattern.
[MWAV4] MultiWave4 MultiWave4 is full combination of MultiWave1 and MultiWave2. It generates a pseudorandom collection of frequencies, however instead of generating SineWaves it generates the same waveform as MultiWave1. Again, try these setting on your system to see which one has the highest perceived benefit in terms of performance.
Interesting ideas, though they do seem counter intuitive to me. I thought the whole point of the Perfectwave was to correct the sine wave into as close as possible a perfect sine, i.e. [SINE] mode.
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I have my HW-19, Eros, Foreplay 2, Paramours and Dungeness subs all powered by my P300. I use sine wave and there have been no ill effects.
Grainger
The P500 only has four outlets which provide regenerated power - the other two provide filtered ac which the manual suggests for power and tube amps. I have an Eros, Extended FPIII, cd player and active crossover plugged into regenerated power supplies and Paramounts in the AC filtered outlets. My turntable motor is battery operated so not plugged into the P500.
I'll switch to sine from twave and see if I can hear any difference. Using sine has one advantage in that you can adjust frequency as well. Something else to play with. Although I can imagine the Eros or cd player prefering a different frequency than does the FPIII.
What voltage are other people using?
Bryon
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I've been inside a P500 as well. Poster Paully used his Paramounts on the P500 regenerated outlets.
To get everything on regenerated power I added a few Power Port outlets. Using another outlet and running the amps on regenerated power is better than using the filtered power for the amps.
Give it a try. Just don't exceed the power rating of the P500.
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however it generates more tube-friendly frequencies
Well that pretty much explains it, huh.
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Its my experience that features like this, that sound like snake oil, really do come from some place where someone somewhere found this change sounds different (better to them at least). I think the theory is that you spend less time in the off mode with rectifier diodes and reduce dI/dt in the transformer, and other subtle changes. In effect I imagine this is intended to make the AC->DC power supply more efficient, lower impedance, something of that sort. I'll definitely set and get used to good 'ole 60Hz mode and then try multi wave later and report out.
As to the voltage drop, yes it is only on that one circuit. That 15A circuit drives a plasma tv, pio receiver (thankfully class D), misc source components, 2 ceiling fans, a few floodlights (all LED now), and then my listening room setup with a Rogue Atlas amp, BeePre, and various source components. I will try and improve the IR drop throughout that circuit by 1) replacing the 21 yr old circuit breaker that has been baking in the Arizona sun, and 2) coat the breaker contacts and all outlet and wire nut connections I can find with a thin layer of silver conduction paste.
And then of course I'll add the Bottlehead DAC to the mix when mine arrives... can't wait :-).
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If the voltage on one circuit is drooping and it is not on others there is a loose connection in that circuit.
The circuit breaker or outlets might be the problems. The service panel is not enough isolation to allow branch circuits to droop, all would droop.
But back to the hum problem you have with your BeePre, I think regeneration will not make any difference except to keep the voltage where you set it. A CVT will do that, and small ones are cheaper than regenerators.
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I'm not really suggesting the box doesn't do anything. I'm simply suggesting that the manufacturer is not really making me want to try it. A little more detailed explanation than "tube friendly frequencies" could help. The cartoon image of sine waves shaking hands with a 6L6 comes to mind, and it does not inspire confidence.
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In my system a power plant premier DOES make a positive difference. I don't use the modified sinewaves or anything like that and I output 120v. My ppp powers all the system (ten power amps when I run the horns). When I take the ppp out, the sound is less relaxed (more stressed?).
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Ps audio p3 arrived. I replaced the breaker on that circuit with a new cafci breaker. Voltage droop was marginally better. Silver paste still in the ups truck, due to be delivered today.
With p3 in the system and burning in, initial impression is sound improvement. The best way to describe dynamics is 'effortless'. Funky noises that I had when the plasma tv was on are gone. Even with input voltage at 114.7, output is steady at 120. Incoming THD is 3.4% output is 0.2%.
Will wait a bit for more critical listening and application of silver paste to all my outlet boxes on this circuit.
And yes, I'll have to take a close look at the BeePre hum. It's mostly left channel, low level, but annoying when added to the very low level 60hz the rogue atlas produces. I'll recheck all voltages and inspect all power supply related solder joints.
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I'm curious, did it cure the hum in the BeePre?
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Let's understand a difference between some of these PS Audio regenerators. The P500 produces balanced power, whereas the PPP and the P3 units do not. In my experience, balanced power has made a positive difference on the performance of my gear. I won't go into detail here, but that is my experience. I have owned the PPP and for me, it didn't have the same effect. Of the three different PS Audio units that I have owned the P500 is my favorite. One thing that all of the units should have in common is the ability to deal with voltage spikes, sags, and line distortion on the power line itself. One last thing that I might add is if someone is using an older unit, the power supply caps should probably be changed. As to the hum that you are experiencing with your Bee Pre, it does sound as though there may be a problem with the unit itself, not that your current power situation didn't cause it in the first place. Lousy power makes things ugly, and can be hard to deal with.
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I have a PPP and have for years, longer than about any piece of audio gear. It's the one constant in my system and the one I wouldn't want to do without. My plasma and most of the audio gear are hooked into it. Regenerated constant 120v power is nice especially if you have noisy mains, move often or have way out of spec wall voltages.
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Update on my hum research:
No change to the hum with the P3 in. It is low level and accompanied with a low level 'thermal noise' type hiss. The hum is in the left channel only. The EE in me thinks this is 120/60 coupling due to the power switch and cabling running down that side of the BeePre. When I opened my preamp up to inspect solder connections and grounds on that channel, I did notice that I wired my power switch in a way that ran it much closer to the preamp circuits than the manual photo showed (pic attached). I had just enough wire left to redo this and keep the wire as far away from filtered preamp circuits as possible. This DID make a reduction, just not to essentially zero.
But I did fix my issue. I put my magic home-brew -12dB L-ped attenuators back in the system (thread here on how I made them). I made these as the gain of the Bryston 3BST amp was far too high for the BeePre and I had lots of thermal noise hiss and some hum. When I switched over to the Rogue Atlas Magnum amp, I thought i didn't need them as the gain is lower. But putting them in, reduced the hum and hiss to inaudible, and also had a side benefit of making the system sound much better. Before I was running the BeeQuiet in the -27dB range. Now its in the -9dB area. The BeePre sounds much better operated with a stronger signal. It likes it here. And I still have headroom to get as loud as I ever will before hitting 0dB.
I still haven't spent the time to apply the silver paste to the outlets and breaker, but with the P3 in, and the attenuators back in, the system really has come up a notch in musicality. I can't tell which change did what at this point. I did turn on multi wave, and nothing bad happened. But I didn't hear anything very obvious change. If I had to guess, it made vocals appear a bit further back (which I don't like). I'l have to see how it affects vinyl and my turntable.
Was the PS audio regenerator worth the price? For me it was. It fixed some nasty voltage droop issues that, I believe, caused my BeePre regulators to go offline. And it has improved dynamics and musicality in a noticeable way. Before I had this, I thought my system sounded best late at night. Which I later realized was because other stuff (heat pumps, washers, dryers, plasma TVs) was off and voltage drop was minimal. Now any time sounds really nice ;D
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Nicely done, a coherent and logical description of how you went about fine tuning thngs.
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Glad to hear that you have solved the hum problem. It can be maddening! You surely were down at the noise floor of the BeePre.
IIRC, when Paully and I did the final assembly of his BeePre we used hot glue to tack down a number of wires/cables to the top plate. Those things can move over time flipping and tweaking on a circuit.
Unless you have aftermarket outlets just buy some Hubbell hospital outlets, don't worry about the silver paste. If the prongs within the outlet is fatigued it still won't grip. And if it were me, retired EE, I would just replace the breaker. The same thing goes for the breaker's prongs.
Don't get me wrong, the silver paste will help (hey! send me some!). But the devices are suspect.
I know you know this but I have to say... don't use mulitwave on the turntable. (if it was you who said that your TT is DC powered, ignore me)