Double Bass Good battery powered amp/pa for busking

[SuperFunkyPete]

An update.

The Warwick Gnome was seriously underwhelming into a custom 8” + compression driver bass cab rated at 200W @8 ohm. It theoretically should deliver 130W into that, but would distort out at volume or on boosting bass EQ or slapping. The cab was fine; the amp just couldn’t give any more. I determined this by swapping to a more powerful head, more on which in a second. (This was all on mains power as well.)

My first portable power supply was a disappointment also. It was an Allpower S200 (Amazon.co.uk), which is meant to be 200W. The Gnome would only start sometimes using this. It didn’t seem reliable though it should have had enough juice to power my 130W peak demand. I chatted to the manufacturer support team and they talked me through some potential troubleshooting steps, but I’m spooked. It’s getting returned.

I did check with Warwick support about whether there was a surge power demand when turned on, but it doesn’t seem so. They said they found it hard to advise me of much as they didn’t intend for their amp to be used portably.

However... I had some other wins.

I tried a second, more powerful power station. The Allpower SS-005 (Amazon.co.uk), which is 300W average with 600W peak. This was a roaring success at powering both the Gnome and my main head, a Bergantino B-Amp v1. Both started fine and sounded flawless, no noise, just my bass signal. Same as on AC.

The B-Amp (AC powered) into the custom 8” cab was an absolute ripper. Tons of volume and plenty of bass. I was shocked. The Berg gives 350W into 8 ohms, so plenty of juice.

The Allpower SS-005 powering the Berg seems to work well. The Berg was pulling 17W at low volume playing with moderate bass boost. I need to take this setup for a proper spin with my band though and see how long it lasts. The Allpower is rated 288Wh, but I’m sure I will be putting a lot more demand on it when playing with a loud guitarist and portable drum kit. Still, I only need it to last 2 hours or so…

I like the Everse 8 for its lovely sound and portability. It’s not the same as having a bass specific rig, though.

But stepping up to a proper ‘bass’ rig from a ‘PA’ type solution clearly comes at a price and weight premium. I’ll need to carry or cart around 34 lbs worth of bass cab, bass amp, and battery. On the other hand, it’s a cheaper if I use existing equipment I already own and pay for enough battery to power it…

Another option I considered was to step up from the Everse 8 to the Everse 12. However the Everse 12 is about 31.2 lbs, fairly large, and I’m not sure how it sounds with bass. Probably still not as good as an actual bass rig. And I think I’d still need a cart.

I looked at the Traynor BM12Mobile amp too. (BM12MOBILE Battery Powered Bass Amp | Traynor) Genuinely think this looks great. I’d buy one if I didn’t own amp equipment already. But at 36.9 lbs, it’s no real difference to what I’ve already evolved from my own equipment. Plus it’s expensive and I’d have to import it.

@Wasnex found in his own threads that powering his own amp with a solid portable power station was his best solution. I’m inclined to agree, after trying out what I think is the next best thing (the Everse 8).

As ever, the Pareto principle applies - getting some of the right bass sound with the Everse 8 is generally easier and lighter. But getting the last bit of bass extension that I want and using a genuine bass rig takes more weight/schlep.

 

[SuperFunkyPete]

Further update.

I have hit a major snag with the Allpower SS-005, which is that as I turn up, I get a high pitched buzz noise coming through the system. It doesn't seem to be from picking up noise from nearby devices (I tested far away from electrical sources.) Touching my strings etc makes no odds, so it's not a grounding issue. (I understand portable power stations like this one not to have a ground.)

I think that it's the sine wave form generated by the AC from the unit itself. The literature says its a pure sine wave, but I don't think it is. Or at least not pure enough for my Berg B-Amp.

So, it looks like I need to return this one and look for an alternate power source with a truly clean sine wave. I'll try a proper Jackery next, probably.

I've also contacted Bergantino to find out if what I want out of the B-Amp is indeed possible - running off a portable ungrounded power station with a pure sine wave AC at 230V.

 

[Wasnex]

Further update.

I have hit a major snag with the Allpower SS-005, which is that as I turn up, I get a high pitched buzz noise coming through the system. It doesn't seem to be from picking up noise from nearby devices (I tested far away from electrical sources.) Touching my strings etc makes no odds, so it's not a grounding issue. (I understand portable power stations like this one not to have a ground.)

I think that it's the sine wave form generated by the AC from the unit itself. The literature says its a pure sine wave, but I don't think it is. Or at least not pure enough for my Berg B-Amp.

So, it looks like I need to return this one and look for an alternate power source with a truly clean sine wave. I'll try a proper Jackery next, probably.

I've also contacted Bergantino to find out if what I want out of the B-Amp is indeed possible - running off a portable ungrounded power station with a pure sine wave AC at 230V.

Yes, others have experience some level of noise when running amps off power stations. I believe some mitigated the problem by connecting a wire between the chassis of the amp and the power station. I do not know if this is always safe. Also some power stations don't have any sort of exposed metal point for the connection.

I have a Jackery 300 I got to experiment with my GK 700RB. The amp does produce a low frequency hum while running on the Jackery. It does not produce a whine. The level of the hum is pretty low, but it would be audible in a quiet environment. I have not tried connecting the chassis of my amp to the 300.

Since a power inverter is floating, by nature it is not grounded. My Jackery 300 does not have a ground lug in the outlets. Not certain, but the Jackery 300 Plus may have a ground lug. If I remember there was some discussion. The older 300 uses an inline power supply to convert the AC to 24V DC. Since it's not connected directly to AC for charging, AFAIK a safety ground is not required. The Plus version connects the AC directly to the power station for charging. If I remember correctly, because of the direct AC connection, a pass through ground is required for certification.

I believe one person here on TB compared the 300 to the previous gen 240 and the 240 was a bit quieter.

 

[SuperFunkyPete]

That’s a really helpful @Wasnex , thanks!

I have no intention of messing with homebrewed grounds and whatnot, I have no idea what I’m doing.

I emailed Bluetti, Jackery, and Ecoflow about some of their models to ask about THD spec for AC sine wave power, after looking for suggestions from Claude AI.

Claude suggests the B-Amp may want very clean power of no more than 2-3% THD. We’ll see what Jim Bergantino says when he comes back to me, for a more definitive answer.

The AI also suggested a power conditioner outlet like the Furman SS-6B might clean up the existing power I already get. I might try that too. But on the whole I’d prefer to just get a portable power supply that has low THD sine wave AC in the first place.

 

[SuperFunkyPete]

I also found one of the threads talking about portable power sine wave AC noise.

Thread '(advice) Busking pure sine wave power bank noise'

Oct 19, 2020

Hello! Here I am once again begging for advice.

After being annoying in this thread (got a rumble studio 40 in the end, loving it!) I got this thing:

Hurakan 200W / 41.600mAh – Litionite

Pure sine wave, 200w, all good.

I plug my amp. Noise. The rest is in the video:



What do you guys think? Is this normal? Should I just try to work around it with come weird cabling from the power bank to the bass and some manual shielding (I have some conductive tape).

I need a light power bank that can power my amp for at least 3 hours and this is the best I could find...

• Snowbro
• busking inverter noise problem
• Replies: 29
• Forum: Live Sound [BG]

 

[Wasnex]

That’s a really helpful @Wasnex , thanks!

I have no intention of messing with homebrewed grounds and whatnot, I have no idea what I’m doing.

I emailed Bluetti, Jackery, and Ecoflow about some of their models to ask about THD spec for AC sine wave power, after looking for suggestions from Claude AI.

Claude suggests the B-Amp may want very clean power of no more than 2-3% THD. We’ll see what Jim Bergantino says when he comes back to me, for a more definitive answer.

The AI also suggested a power conditioner outlet like the Furman SS-6B might clean up the existing power I already get. I might try that too. But on the whole I’d prefer to just get a portable power supply that has low THD sine wave AC in the first place.

I doubt the Furman will do any good.

 

[SuperFunkyPete]

I think you’re right. I googled it further and it doesn’t do any active power conditioning. Mostly surge protection and EMI/RFI attenuation.

 

[SuperFunkyPete]

Some further feedback.

(TLDR version - try buying a shielded power cable to connect an amp to the mobile power station.)

I ended up ordering a Jackery Explorer 300+ to try out against the Allpower SS-005 (appears to also be known as S300). Jackery responded to me that the THD for the AC sine wave power is <3%, so that seemed worth a punt. EcoFlow responded that their RIver 2 unit has <8% THD for AC sine wave power, so I gave that a pass. I didn't get any emails about THD for AC sine wave power from Allpower or Bluetti yet. It's with their technical teams.

Results with the Jackery were not good. I still had a huge amount of buzz, plus the Jackery has a fan that also creates rhythmical electrical buzz as it cycles.

Through a series of experiments using different basses, I actually found one bass through which I had no buzz at all - a Squier Jazz bass. Everything else - particularly basses with humbuckers - seemed to act as ?aerials for huge amounts of buzz. The buzz got worse as I turned up volume, turned up treble, or put my basses nearer to the given power supply. It got better if I turned down passive tone knobs or turned down treble, or moved away from the power supply. But Even 20 feet away from either power supply, I still got noise....so my first theory about radiated EMI causing issues was wrong.

I also noticed that I did have some separate noise that got better when I touched the metal bridge of basses. So having a floating ground in the Jackery/Allpower was working against me as well. Either me or the bass was acting as an aerial for EMI and when I touched the metal bridge I was acting as the ground shunt for that.

Both the Jackery and the Allpower therefore seem to output large amounts of ?conducted EMI, as a separate issue to the pure THD sine wave quality of their AC power. Or so I speculated.

I tried a few solutions.

- A ferrite core clamped to the power cable from the B-Amp did not do much.
- I double checked that my instrument cables were shielded - they are.
- I tried putting the power supplies further away from the B-Amp by using an extension cable. This seemed to make the main buzz a little better, although bringing the bass nearer to the connection with the extension cable made the buzz worse again. So maybe I had a little radiated EMI as well.

However, I then had a major win.

I obtained a well shielded 240V IEC mains power cable. Using that to plug the B-Amp into either power supply, massive amounts of noise disappeared. I think this means that a significant amount of the EMI that I have been fighting has been conducted, not radiated.

Interestingly, I now find that the element I thought was grounding noise is mostly gone too. I think the larger mass of metal in my humbucker-equipped basses was acting as an antenna for the conducted EMI. Oddly enough my Jazz bass was more proof against this. Now all my basses sound equally great and don't seem to act as antennae for noise.

When using the new shielded power cable, I can hear that the Jackery has a much less noise than the Allpower. It's not totally silent, but it's still much better. I assume they have better quality sine wave power + must pay a bit more attention to EMI, though without the new power cable, neither unit would have been usable for me.

I was just about ready to throw in the towel, but there you go. Significant conducted EMI along an unshielded power cable was my biggest issue here. I have never seen a shielded mains IEC power cable until now - I had to buy one marked 'audiophile use' as they seem uncommon otherwise. (Barf..)

I'm going to return both of these power units and experiment a little with others. Maybe I can find one that deals with EMI better from the get-go. I'm particularly interested in the Jackery 240 v2, as there seem to be good reports about that model for busking musicians. I'll feed back what I find out.

 

[SuperFunkyPete]

....or maybe I won't try out another unit...Jackery just offered me 8% of the cost of the unit back and a free carry bag if I'll keep it. Hmm...

 

[Wasnex]

I obtained a well shielded 240V IEC mains power cable. Using that to plug the B-Amp into either power supply, massive amounts of noise disappeared. I think this means that a significant amount of the EMI that I have been fighting has been conducted, not radiated

Not sure your assessment is correct. Here's an alternate theory. Perhaps the unshielded power cable is the source of radiation...and somehow despite the missing ground, the shielded cable radiates less EMI.

Mine is the 300, so there is no metal lug in the ground socket of the AC outlet. Does the 300 Plus have a ground lug? If yes, it's only grounded when plugged into AC mains. However, the connection should bond the chassis of the amp and Jackery, which I believe helps. AFAIK, it basically makes the Jackery, amp, and bass share a ground plane. Not sure it will reduce radiation, but perhaps the shared ground plane helps with noise rejection.

It's been a while since I experimented. I successfully played the Jackery with my GK 700RB and an Ashdown LB30. I only used my main bass, a Yamaha TRB6P. Perhaps other basses would be more receptive to noise. My recollection is the amp had a bit of LF hum, even with no instrument plugged in. There was also some additional noise with the bass plugged in, but it was pretty minimal. Moving the Jackery in relation to the amp and possibly bass seemed to reduce the noise a bit. Placing the Jackery behind the amp and messing with the angle of the Jackery and lead dress for the power cord definitely helped.

I did not try bonding the amp to the chassis of the Jackery or to an actual ground.

 

[SuperFunkyPete]

Hmm. That’s an interesting thought.

I just checked. Both the Allpower and Jackery units have ground lugs at the AC socket. And both behaved better when I used the shielded cable.

I don’t have a convenient way to ground either unit, so I haven’t tried that either.

I’m just glad I managed to find a solution. I’ve never seen anyone else try this, and I’ve been scouring a lot of sources. When Claude AI suggested it, I figured I had little to lose. It’s a lot cheaper than trying to clean up the AC signal in other ways.

 

[SuperFunkyPete]

Another thought. I wonder if these sorts of power stations are primarily designed for 120V/USA market, and then adapted to work in UK/Europe/230-240V.

@Wasnex your reports of the noise from your Jackery are quite different to mine. Perhaps the voltage differences mean designs that act differently over here. Higher frequency switching noises for higher step-up voltages? Different EMI certification requirements?? Etc.

 

[Wasnex]

Another thought. I wonder if these sorts of power stations are primarily designed for 120V/USA market, and then adapted to work in UK/Europe/230-240V.

@Wasnex your reports of the noise from your Jackery are quite different to mine. Perhaps the voltage differences mean designs that act differently over here. Higher frequency switching noises for higher step-up voltages? Different EMI certification requirements?? Etc.

The level of noise I get is much lower than in the thread you referenced above in post #25. But there is some noise.

The requirement to supply double the AC voltage could definitely be a factor.

 

[SuperFunkyPete]

Simply FYI. Bluetti came back to me about their AC2A power station, and this has 3% THD for the sine wave AC power.

So it looks like Jackery, then Bluetti, have the best THD figures for their AC power.

 

[loukash]

EV Everse 8

Just yesterday I bought one, after testing (albeit with a Fender-J BG, not with a DB) the whole bunch: Bose S1 Pro+, Mackie ShowBox, JBL Eon One Compact, HK Move 8 – nah, those just don't cut it, for various reasons, either soundwise or lacking a specific feature.

The Everse 8 is just amazing.
Not only does it sound good, but it also has practically all features that I actually need.

This afternoon, a rehearsal with a blues/rock/soul trio: vocals/e-guitar/keys, drums (not amplified), me on upright bass.
A totally clear sound with lots of punch, the Everse basically linear with only some trebles rolled off (using a simple Gewa DB-1 piezo pickup).

In the evening yet another rehearsal, this time me on acoustic bass guitar with a pop-rock band (vocals, a-guitar/keyboard, drums).
Great and punchy sound again.

 

[SuperFunkyPete]

EV Everse 8

Just yesterday I bought one, after testing (albeit with a Fender-J BG, not with a DB) the whole bunch: Bose S1 Pro+, Mackie ShowBox, JBL Eon One Compact, HK Move 8 – nah, those just don't cut it, for various reasons, either soundwise or lacking a specific feature.

The Everse 8 is just amazing.
Not only does it sound good, but it also has practically all features that I actually need.

This afternoon, a rehearsal with a blues/rock/soul trio: vocals/e-guitar/keys, drums (not amplified), me on upright bass.
A totally clear sound with lots of punch, the Everse basically linear with only some trebles rolled off (using a simple Gewa DB-1 piezo pickup).

In the evening yet another rehearsal, this time me on acoustic bass guitar with a pop-rock band (vocals, a-guitar/keyboard, drums).
Great and punchy sound again.

That’s great! It sounds perfect for you.

I just sold my Everse 8. I just couldn’t get out of it what I needed at high volumes. It was really too much of an ask for a little cabinet. Plus at high volumes I heard a lot of resonances. I’m awaiting an LFSys Goodwood 10” cab now.

 

[loukash]

I like the Everse 8 for its lovely sound and portability. It’s not the same as having a bass specific rig, though.

For a DB, however, it actually provides the required bandwidth, without even having to use a hi-pass filter.
Also, it has multiple stages of EQs: 3-band channel EQ, 3-band master EQ, plus a 7-band graphical EQ, switchable to parametric (!) for absolutely surgical fine tuning.
Plus multiple "shaping modes" per channel, including a "Bass Guitar" mode, plus multiple general use shaping modes, like "Music", "Live", "Speech", "Club" (very bass heavy!), and "FRFR".

I just sold my Everse 8. I just couldn’t get out of it what I needed at high volumes. It was really too much of an ask for a little cabinet. Plus at high volumes I heard a lot of resonances.

Sure, there is a physical limit. Although… compared directly to the other similar boxes I mentioned above, it seemed to me that the Everse somehow defies the laws of physics…

Another good thing about the Everse is that it has an XLR Out, and it also has an crossover split mode, meaning I can hook it up to a subwoofer (e.g. using my SWR Workingman's 12 power amp input) to get more low end when needed.

I’m awaiting an LFSys Goodwood 10” cab now.

Looks interesting. Surely more powerful than the Everse. And the price seems right, too.

For me, however, the size was a very important factor.
And flexibility with multiple inputs, so that we can also run a vocal mic (or more) through it.
And the monitor mode is a nice extra as well.
And battery!
Does the Goodwood run on battery? It doesn't seem so. Also, it has a couple of cm too many on all dimensions for my space and transport requirements, as a square box being a bit too bulky.

 

[SuperFunkyPete]

For a DB, however, it actually provides the required bandwidth, without even having to use a hi-pass filter.
Also, it has multiple stages of EQs: 3-band channel EQ, 3-band master EQ, plus a 7-band graphical EQ, switchable to parametric (!) for absolutely surgical fine tuning.
Plus multiple "shaping modes" per channel, including a "Bass Guitar" mode, plus multiple general use shaping modes, like "Music", "Live", "Speech", "Club" (very bass heavy!), and "FRFR".

Sure, there is a physical limit. Although… compared directly to the other similar boxes I mentioned above, it seemed to me that the Everse somehow defies the laws of physics…

Another good thing about the Everse is that it has an XLR Out, and it also has an crossover split mode, meaning I can hook it up to a subwoofer (e.g. using my SWR Workingman's 12 power amp input) to get more low end when needed.


Looks interesting. Surely more powerful than the Everse. And the price seems right, too.

For me, however, the size was a very important factor.
And flexibility with multiple inputs, so that we can also run a vocal mic (or more) through it.
And the monitor mode is a nice extra as well.
And battery!
Does the Goodwood run on battery? It doesn't seem so. Also, it has a couple of cm too many on all dimensions for my space and transport requirements, as a square box being a bit too bulky.

The Everse 8 I can see being ideal for DB. It’s a great unit and the mixing capabilities are incredible. I thought the EQ and the presets were incredibly helpful. And there’s no beating the carry.

The Goodwood definitely doesn’t run on battery, and it’s a very bass-specific rig. It needs a separate amp, and I’ve chosen to buy a battery to power it all. My busking rig will now weigh 34 lbs and I’ll be better to move it around on a little luggage cart thing.

But. I don’t need the mixing capabilities of the Everse, and I need more volume and low end. I also found it sounds less good at high volume with electric bass. So, I’ve had to move on. I’ll have to pay the price for that…

 

[Povl Carstensen]

Now, if the Everse had 48V phantom power, I could not not buy it. But I guess its 12V output could run my Rolls 48V supply...

 

[loukash]

if the Everse had 48V phantom power

It has, albeit only on channel 1.
That was one of the major factors why I've chosen it over the others, because it lets me plug the Tech21 QStrip as an analog "quick EQ" on that channel if needed, without having to use a 9V battery.

However, now that I've tested bas(s)ically all of my basses with the Everse, this little thingie just makes every bass that I own sound good literally right "out of the box". Even my trusty old fretless Eko ABG which has a very crappy piezo in it as installed by the previous owner and which was always a p.i.t.a. to dial in a good sound on any other amplification I've used so far. I only added some compression, rolled off the treble and enabled "Bass Guitar" mode on the channel, "Live" mode on the master, and voilà.