Joyo MA-10B

[JSbass]

I'm waiting for one of these to arrive from Thomann, but can't find much info online regarding the technical specs beyond a stated output of 10 watts, that the speaker is a single 5" and that there are two channels, normal and drive.

 

I'll be using this unassuming  little thing mainly as a practice amp, through the built-in speaker and through headphones, but also as a low volume, battery powered rig for when I'm on my boat or away from mains power and fancy bringing my 4 string passive bass along to an acoustic jam.

 

Having read Happy Jack's thread on battery powered rigs, I'm beginning to wonder whether this tiny unit could be modified to become something more than just a micro practice amp. I was thinking along the lines of adding a connection for an external speaker that could bypass the built-in 5" driver, when required, allowing the use of a proper, lightweight cab equipped with a decent driver (1x10, 1x8 or even Phil Starr's little 1x6 House Jam Micro Cab). Hopefully this would make better use of the 10w output, but still with the option of running on six rechargeable AA batteries, a small sealed 12v lead acid battery with a 12v to 9v step-down adapter, or a USB power bank with a 5v to 9v step-up adapter.

 

Before I start dismantling the Joyo when it arrives to find out what's inside, I thought I'd ask if anyone here knows:

 

A). Is the amp output mono, ie, with the whole 10 watts going entirely to the single 5" driver? The spec mentions two channels (normal and drive) but I'm unclear whether this means the output is split between them, and hence reduced to 5w. I'll only ever be using the normal clean channel and can't really see the point of a dedicated overdriven channel when the same effect could be had by simply cranking up the gain control.

B). Is the 10w output at 4 ohms or 8 ohms? I guess the built-in driver would most likely be 4 ohms to maximise the volume.

C). One of the customer reviews on Thomann suggests that the amp is high pass filtered at 60hz, which would make sense with such a small driver, but I can't find any detailed spec to confirm this.

 

I know there are several ready made battery powered combos such as the Roland Bass Micro Cube or Boss Dual Cube, along with amp heads like the GR Pocket 50, Quilter Interbass 45, Hotone Thunder Bass, and various low cost, home brew solutions using Chinese D-Class boards of indeterminate quality, but all are quite costly, involve DIY projects with no guarantee of success, or need much bigger, higher voltage battery power sources than I'm prepared to cart around. The Joyo seems to get pretty good reviews tone wise, but falls down in the loudness department, hence my interest in improving on the latter.

 

 

[Dan Dare]

You'd need to look for the most efficient driver you can find and use an efficient cab design with only 10W to play with. That would most likely mean a larger cab, which would defeat the object of having something very small and portable. A direct radiating cab - even a reflex design - is unlikely to cut it for anything other than home practice at low volume when driven by 10W. At the extreme end of the scale, some of the hi-fi horn designs produce tremendous output from 5 or 10 watt amps, but they are massive. They also do not produce a lot of low frequencies, which you would need in a bass cab.

[Hellzero]

This was recorded with my phone just after I received the bass you see in the short video with this Joyo MA-10B, which is my "bedroom" amp.

 

It handles the low B very easily at low to mid level.

 

It's not a twin channel amp, but it has a switch for the drive, nothing else.

 

If you don't push it beyond its limits, it sounds very good. 

 

I use it all the time with this powerbank: https://www.thomann.de/gb/harley_benton_powerplant_powerbank.htm

 

Sorry for the out of tune slides, I was just noodling.

Edited April 22, 2023 by Hellzero

[itu]

On 16/04/2023 at 22:42, JSbass said:

A). Is the amp output mono, ie, with the whole 10 watts going entirely to the single 5" driver? The spec mentions two channels (normal and drive) but I'm unclear whether this means the output is split between them, and hence reduced to 5w. I'll only ever be using the normal clean channel and can't really see the point of a dedicated overdriven channel when the same effect could be had by simply cranking up the gain control.

 

B). Is the 10w output at 4 ohms or 8 ohms? I guess the built-in driver would most likely be 4 ohms to maximise the volume.

 

C). One of the customer reviews on Thomann suggests that the amp is high pass filtered at 60hz, which would make sense with such a small driver, but I can't find any detailed spec to confirm this.

A) Most of the amps that have two channels, mean that the preamp has two sets of adjustments to a single power amp. A stereo power amp is really rare, as is a bi-amp.

 

B) I do not get your point. If impedance is low or very low, your amp needs to be able to push lots of current through the power amp. Sometimes higher impedance is easier to the power amp, and the speaker may be actually (but usually only slightly) louder than its lower impedance sibling. Do not mix loudness (dB) and power (W)!

 

C) Speaker size and the lowest reproducible frequency? They are only faintly related, otherwise a hifi speaker couldn't go to 20 Hz. But power handling is another story. Still, a 4 x 10" may be able to go down to 60 Hz only, and everyone's happy: 31.5 Hz B sounds great!

[JSbass]

Well, the Joyo finally arrived from Thomann, and I have to say it's not at all bad for the tiny amount it cost. It will do fine for practice especially as the aux in allows me to play backing tracks and songs via my phone and music player. The headphone output is fine and the speaker doesn't fart out unless you overdo it on the gain control.

 

I had suspected that the 'two channel' description was just fancy sales speak for an optional overdrive, so I guess the full 10w is reaching the Joyo's built-in 5" driver. I asked because combos with multiple speakers, eg Roland Bass Micro Cube, seem to be described as stereo, implying two or more separate amps driving the speakers rather than a single amp section.

 

I had assumed, wrongly, that a 4 ohm load, drawing the full power available from the amp would always be louder than an 8 ohm load only able to make use of a reduced power output. Thanks for clearing that up.

 

My main reason for wanting to adapt the little 10w Joyo to drive a larger, more efficient cab is the ability to use frugal amounts of DC power when off grid, but still giving me enough volume and tone to keep up with acoustic instruments (maybe even drums with brushes at a pinch?), but just a bit better than the Joyo can on its own. Clearly there are simple solutions using AC such as an Elf, Gnome or Bam 200 into something like a 1 x 8 cab to get impressive volume yet still be super portable, and I could of course run it off a 12v lead acid battery and inverter when off grid. But for my modest needs, using the Joyo has its attractions.

 

Happy Jack's video series on battery powered rigs shows how his 5w Hotone Thunder Bass, when it chose to cooperate with his powerbank, was able to deliver sufficient volume to keep up with his acoustic mates, albeit driving an efficient Embee cab. Presumably 10w should be able to do the same.

 

Thanks for the Thomann powerbank recommendation. Nice to know that's an option that works.

 

 

[Mottlefeeder]

There are a number of integrated circuit chips that provide stereo, so having 2 x 4ohm speakers maximises the power output from the amp chip. That may be why the likes of Roland/Boss went that way with the cube range.

David