Hello! I ordered the Pass B1 board and am going to power it off of batteries initially. Does anyone have recommendations for batteries they thought were a good choice for sound or cost effectiveness? I am reading various threads but they are either too short without the information or 300 pages! Was thinking about using two of these:
https://www.batteriesplus.com/productdetails/slaa12=2.2f
I may go to a wall powered supply later but for now I am having some trouble with ground loops, so definitely want to do battery to start. Thanks!
https://www.batteriesplus.com/productdetails/slaa12=2.2f
I may go to a wall powered supply later but for now I am having some trouble with ground loops, so definitely want to do battery to start. Thanks!
I like these batteries, and the AA are available in three capacity sizes.
https://www.panasonic.com/global/consumer/battery/eneloop/lineup.html
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They are 1.2V each. The Duracell module also uses series cells, like your car battery.
The individual cell voltage depends on the chemistry.
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Yes, the internal resistance of the batteries will definitely add up as they are used in series. This can lead to a lesser performing power supply than a conventional linear wall powered one. The voltage will sag as the batteries discharge, and will be modulated by the musical signal.
These disadvantages can be overcome, but the resulting circuit might be just as complex as a properly regulated supply. At a minimum you will need a few thousand microfarads of electrolytic caps on the power rails.
I wouldn't recommend leaving the charging circuit hooked up while listening either. Battery chargers can use a variety of PWM techniques to top off the last couple volts. Not good for audio.
Keeping these things in mind, you may still end up with a good sounding preamp, but it may be a rough journey to get there. Best of luck.
These disadvantages can be overcome, but the resulting circuit might be just as complex as a properly regulated supply. At a minimum you will need a few thousand microfarads of electrolytic caps on the power rails.
I wouldn't recommend leaving the charging circuit hooked up while listening either. Battery chargers can use a variety of PWM techniques to top off the last couple volts. Not good for audio.
Keeping these things in mind, you may still end up with a good sounding preamp, but it may be a rough journey to get there. Best of luck.
So basically what we are saying is that using any battery is essentially using cells in series which leads to higher ESR and reduced sound quality? An AC hookup is a much better option.
Hi,
I built the b1, and initially powered it with 2 duracell, 9V batterys connected in series for 18 vdc. as the power supply. A 9v battery is rated at 500 ma. Hrs. Since the b1 only draws about 6ma., if I remember correctly, per channel. The 2 batterys in series would theoretically last about 45 hrs. It sounded just fine that way.
An on/off switch is a must though. Later I upgraded to a nice ,24 vdc switching ,wall wart supply from Jameco for about 12 bucks. It did sound even better. Kept it that way for about 2 years, and enjoyed the heck out of it. Just recently sold it, and built the BA-3 front end as preamp. A killer upgrade in sound.
Build it. You will love it.
Mg16
I built the b1, and initially powered it with 2 duracell, 9V batterys connected in series for 18 vdc. as the power supply. A 9v battery is rated at 500 ma. Hrs. Since the b1 only draws about 6ma., if I remember correctly, per channel. The 2 batterys in series would theoretically last about 45 hrs. It sounded just fine that way.
An on/off switch is a must though. Later I upgraded to a nice ,24 vdc switching ,wall wart supply from Jameco for about 12 bucks. It did sound even better. Kept it that way for about 2 years, and enjoyed the heck out of it. Just recently sold it, and built the BA-3 front end as preamp. A killer upgrade in sound.
Build it. You will love it.
Mg16
Yes, but whether it harms the sound depends on the particular circuit, as well as the ESR.
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My B1 sounded with two 9V blocks lovely.
When I went to my Jazz friends to give the B1 a try, I connected instead a Wall ward supply hoping to get the still better sound for this evening.
It sounded bad and nobody liked it, a few days later I came back with the batteries and they loved the sound.
So the the wall ward supplies seem to be different.
:--))
When I went to my Jazz friends to give the B1 a try, I connected instead a Wall ward supply hoping to get the still better sound for this evening.
It sounded bad and nobody liked it, a few days later I came back with the batteries and they loved the sound.
So the the wall ward supplies seem to be different.
:--))
Wall 'wart' power supplies are indeed quite different from linear supplies, and from each other.
BTW, I use the term wall wart to indicate the blocks that plug directly into the wall outlet. They look like warts growing out of the wall.Pretty much all wall warts these days are SMPS type, designed with cost as the primary consideration. Many are very poor at preventing the switching frequency from leaking onto the output, or even back onto the AC line. On the other hand, brick style SMPS power supplies that plug into the wall with a separate power cord can be quite good. The brick SMPS supplies used with the ACA, both the earlier 19V laptop power adapter and the newer 24V Meanwell bricks supplied with the ACA kits, have been shown to be capable of very good audio performance.
When using SMPS bricks of unknown quality for my guitar pedals, I have taken the precaution of providing some extra filtering between the PSU and the pedals. I made an inductor using 20 ga magnet wire wrapped around a 1/2 inch dowel, with four separate tap points, equally spaced. At each tap point I connected a 220 uF, 25V capacitor. Inductance between taps is approximately 5 uH. Ground returns for each power outlet were separately wired back to the input ground.
Some of my pedals are more sensitive to power supply noise than others, and this little contraption has proven to be effective at quieting the noise. It has the added benefit of providing the correct polarity for typical pedal power connectors. Picture is attached. Something like this could be cleverly hidden inside the B1 chassis to use with an external SMPS brick.
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Wall 'wart' power supplies are indeed quite different from linear supplies, and from each other.
Pretty much all wall warts these days are SMPS type, designed with cost as the primary consideration. Many are very poor at preventing the switching frequency from leaking onto the output, or even back onto the AC line. On the other hand, brick style SMPS power supplies that plug into the wall with a separate power cord can be quite good. The brick SMPS supplies used with the ACA, both the earlier 19V laptop power adapter and the newer 24V Meanwell bricks supplied with the ACA kits, have been shown to be capable of very good audio performance.
When using SMPS bricks of unknown quality for my guitar pedals, I have taken the precaution of providing some extra filtering between the PSU and the pedals. I made an inductor using 20 ga magnet wire wrapped around a 1/2 inch dowel, with four separate tap points, equally spaced. At each tap point I connected a 220 uF, 25V capacitor. Inductance between taps is approximately 5 uH. Ground returns for each power outlet were separately wired back to the input ground.
Some of my pedals are more sensitive to power supply noise than others, and this little contraption has proven to be effective at quieting the noise. It has the added benefit of providing the correct polarity for typical pedal power connectors. Picture is attached. Something like this could be cleverly hidden inside the B1 chassis to use with an external SMPS brick.
I am unfamiliar with ACA but I think I know what you are talking about with the brick style power cords that have the adapter in the middle and two cords going out, one to the wall and the other to something like a laptop. Seems like I had a Dell that had that type of connection. Might have a power cord downstairs to try or I can go searching. Going to start with simple 9V batteries and then try your idea. Thanks!
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I think I will try two 9V batteries to start and then look for some sort of power supply to mess around with. Like I noted above try the 9Vs, then a brick style cord with the "wall wart" in the middle, then maybe try building a real power supply town the road if I feel the need.
And to everyone who has responded, I want to say thanks. A Lot of great ideas that I need to consider once I actually do get this built and have tried the 9V batteries. The board is on the way so I should be able to build it in a few weeks.
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