A battery powered mobile guitar rig in a BOSS BCB-30X case

Being most of the time in a caravan and my proper sound gear literally more than a 1000 miles away, I decided it was time for a mobile guitar rig aka pedal board. Not being able to carry my favourite 8×12″ cabinet with me I went looking for a DSP solution that could do it all while being still somehow affordable. But before I dive into the solution, I will quickly list the requirements I put myself under.

The requirements

So, here it is what we are looking for:

1. the whole setup must fit in a single case
2. weight must be under 5kg
3. maximum dimensions: 400mm x 400mm x 150mm
4. no mandatory app or software required to operate it
5. possibility to power it via AC or batteries / power bank
6. runtime while on batteries 4h or more
7. string tuner
8. metronome
9. wireless guitar transmitter / receiver
10. required effects: chorus, compressor, distortion, delay, equaliser, octave, overdrive, reverb
11. optional effects: wah-wah
12. at least 2 footswitches for switching effects
13. dual stereo output
14. audio interface support
15. MIDI support
16. no Thunderbolt
17. possibility to connect to XLR
18. single-track looper support operated by footswitches, with overdub and saving/loading backing tracks
19. optionally drum/rhythm support in looper
20. optional speaker / monitor
21. wireless monitor headphones without noticable latency
22. minimum wireless reach 3m

The setup

As already mentioned before, I started with the search for a DSP or effects processor where hopefully most of the features were already present. And after some looking around, I came across the BOSS GT-1000, the core version in particular. Only the looper and wah-wah with a pedal were not built into that device.

Note1: yes, I know there is a built-into auto wah-wah – but in my opinion this does not come close to a real wah-wah and is not really my thing.

Note2: the integrated looper can only record up to 38s (in mono) and does not let you save or load tracks.

I soon realised that an expression pedal or a full-blown Cry Baby would break the size constraint, so I made a mental note to myself that this was unlikely to make it into the final design. I already knew the RC-505 looper and therefore looked for a single track pedal version of it. With the BOSS RC-5 I also got MIDI support which I would need to sync it up to the GT-1000core. And luckily, both devices use a 3.5mm TRS MIDI connection. With these devices being preliminary selected I went looking for a pedal board box. As it seemed, the BOSS BCB-30X was able to make space for three standard sized pedals, so the double sized GT-1000core and the RC-5 would fit in perfectly. Only the space for the connections seemed a little bit constrained. Connecting the RC-5 via SND1/RTN1 and putting it to the end of the effect chain was easy to do – both physically and configuration-wise. Connecting the power distribution cables showed that the straight connectors that were supplied with the pedal board used up quite some space behind the devices. A cable with 90°-angled connectors would have been better.

As I had good experience with the BOSS WL-50 – a wireless receiver with charger in pedal format that would not fit into the case – I went for the BOSS WL-20L which works perfectly with my Fender Stratocaster or Gibson ES-335. Charging must be done via micro-USB-B (yes, still not extinct – I keep thinking that Roland and BOSS must still have a zillion of these sockets in their warehouses they want to get rid of).

Wireless monitor headphones proved to be more difficult. First, the GT-1000core does not have a dedicated headphones output. It is either MAIN L out or stereo headphones – that’s weird. And the headphones only work in stereo if the MAIN R out is unplugged. Even weirder, the Mono output is R instead of L – normally it is the other way round. But this did not prove to be the main problem. I needed a small and low-latency wireless connection for the headphones. First, I tried a TRS-to-Bluetooth adapter, but that introduced way too much latency – I essentially got an unwanted delay for free in my ear. So, I went for a Rode Wireless GO II (single transmitter with receiver) with a 1/4″ (6.35mm) TRS to 1/8″ (3.5mm) TRS adapter and cable. I could not use the supplied 3.5mm cable as it would not fit into the 1/4″ socket of my 1/4″ adapter. Regarding the headphones, I opted for a pair of used Bang & Olufsen A8 in-ear headphones that had been stuffed away for years. But their sound is still ok. I set the output to -20dB on the Global EQ output settings to prevent the signal from distorting on its way through the microphone socket of the Wireless GO transmitter. Latency is not noticable – at least not for me. And the best part: now I can use any pair of 3.5mm headphones with it – instead of being bound to a specific bluetooth headset.

Note1: the A8 are really comfortable to wear as they are very light and the earphones are not resting on the inside of the ear. They are long time not in production any more. So, I auctioned a couple of spare ones just in case.

Note2: And for some reason my beyerdynamic DT-770 PRO 250Ohms headphones do not seem to distort as quickly as the A8 – mystery …

When I tried to power up the GT-1000core and the RC-5 via the MyVolts cable from a 5V USB socket of the Zendure power bank, I noticed that I could only power one device at a time. With a larger power bank (some no-name, different manufacturer) I was able to power both devices. So, I got myself a 9V USB-rechargeable battery from EBL. And as an alternative, I added a second MyVolts 9V cable and a USB-C to USB-A adapter, so I could power both devices from the power bank. I quickly thought about using a USB-C trigger board and build my own DC-cable. However, the main reason for not doing this was that with a standard 9V battery or the two MyVolts cables I could run it from any USB-A power source. On the other hand, building a custom cable could actually save some space.

And then I found another power bank (Jsaux) with slightly larger dimensions that just fitted in to the box and could power bothe devices at the same time. That simplified things a lot and gave me additional mobile operating time. As I could get hold of only one of these power banks I still keep the Zendure in the case.

I used TS 1/4″ to (unbalanced) XLR cables as the MAIN out connection, as I would be plugging this into active loudspeakers most of the time anyway. And in case I needed to connect to a TS 1/4″ socket, I added two XLR to TS 1/4″ adapters. One never knows …

The application

Just building such a setup does not mean that it is in any way usable or without flaws. After some intensive testing I must admit that I am positively impressed. Regarding the build quality of the case: the setup is extremely compact and the box is sturdy. Even passing security checks at the airport was not a problem.

Note: the case is even that small that I could carry it as an additional hand luaggage with BA next to my bag back.

For putting everything back together and not jamming any cables a little of exercise is needed. And not losing or misplacing any cables not needed when the case is open needs a little bit of discipline, too.

Regarding the musical capabilities: I am very happy with the functions of the GT-1000core. Of course, it does not sound like a real huge amp and it does not have all the vintage tube pedals. But, I am using it as a mobile setup. And the sound keeps more or less the same, nearly regardless of which speaker I am plugging it into. I read about complaints from some people regarding the small display and the need for the PC software to operate the DSP. I must say I can live very well with the small display. For major configuration tasks and backups the software is fine. For fine-tuning I find the display totally acceptable. Wireless range is ok, but turing the back to the guitar receiver can be problematic. And I have never tested it in a very crowded WiFi environment.

Certainly, as always some things could be better. And though the following list seems rather long, for me the positive side weighs way more than just the bigger half:

• the mess with all the different USB cables (A, standard B, micro B, C);
• having a speaker in the box would be nice – but space is really limited;
• recharging all items is time-consuming in more than one sense
  (2 9V batteries, 2 Wireless GO, WL-20L RX/TX and the power bank needing charge sockets);
• the WL-20L cannot be powered off manually but has to be unplugged when not in use
  (otherwise it drains its battery);
• the dual-use of output sockets for SND2/RTN2 and SUB is limiting;
• no rhythm / drum kit section;
• no jazz drum kit on the RC-5;
• no proper looper in the GT-1000core;
• only 99 patches on the RC-5 in contrast to 250 on the GT-1000core;
• no dedicated headphones socket means I have to disconnect and reconnect quite often;
• the metronome of GT-1000core is not synced with the RC-5 (despite of being connected via MIDI).

The parts

The following is a list of all the parts used in this setup with links and some additional information. The numbers (#nn) correspond to the number of the items on the image below.

1. BOSS BCB-30X (#12)
   power distribution and spare 9V connection (#11)
   2* patch cables TS (from a BOSS BCK-12 kit, 90° angled, solderless) (#14)
   USB-C plug to USB-A receptable adapter (#7)
2. BOSS GT-1000core guitar effect processor (#21)
   micro-USB-B to USB-A cable for connection to a PC (#26)
   3.5mm TRS to 3.5mm TRS cable for MIDI connection with RC-5 (#19)
   2* Neutrik NA2FP 3 pole XLR female – 1/4″ TS Mono plug (#30)
   2* 1m 1/4″ TS Mono plug to 3 pole XLR male (#13)
   pointless stomp switch toppers (#20)
   nominal current draw: 670mA @ 9V ^= 6.030W
   operating time with Zendure battery: 37Wh / 6.030W ~ 6.1h
   Owner’s Manual, Parameters Guide, Sound List, MIDI Implementation, limitation of the effects in a single patch
3. BOSS RC-5 looper (#18)
   standard (as in grandma) USB-B to USB-A cable for connection to a PC (#10)
   current draw: 170mA @ 9V ^= 1.530W
   operating time with 1 EBL battery: 5'400mWh / 1.530W ~ 3.5h
   Owner’s Manual, Reference Manual
4. BOSS WL-20L
   consists of transmitter (black, #29) and receiver (grey, #28)
   micro USB-A cable for charging (also used for charging the 9V battery) (#8)
   operating time: ~12h
   Owner’s Manual
5. Rode Wireless GO II Single
   consists of a receiver (#3) and a single transmitter (#4)
   2* 30cm USB-A to USB-C charging cable (#5)
   operating time: ~7h
   User Guide
6. Bang Olufsen A8 earphones (#22)
   1/4″ (6.35mm) TRS to 1/8″ (3.5mm) TRS adapter (#23)
   short 1/8″ (3.5mm) TRS to 1/8″ (3.5mm) TRS cable (#24)
7. BOSS PSB-1U 9V 2A power supply (#16)
   comes with BOSS GT-1000core, but I use it with a 90° angeled Euro plug instead of the 1m cable (#15)
8. 2* MyVolts Ripcord USB-A 9V cable (#9)
   5.5mm / 2.1mm, center negative
9. Jsaux 10’000mAh USB-C PD battery/power bank (#2)
   dimensions: 82mm x 58mm x 26mm; this just fits into the case
   nominal power: 10'000mAh * 3.7V = 37Wh
   Note: this can power both devices at the same time, resulting in an operating time of ~4.9h; however it cannot power both devices while being charged
10. Zendure 10’000mAh USB-C PD backup battery/power bank (#1)
    dimensions: 79mm x 56mm x 26mm
    nominal power: 10'000mAh * 3.7V = 37Wh
    USB-C to USB-C cable for charging (#6)
    Note: this cannot power both devices at the same time, resulting in an operating time of ~6.1h for the GT-1000
11. 2* EBL 9V 5400mWh battery (#27)
    rechargeable via micro-USB-B
    nominal power: 600mA @ 9V = 5.4Wh
12. a set of Ernie Ball regular slinky (#17)
    gauge .010, .013, .017, .026, .036, .046
13. a Dunlop Delrin 500 1.5mm pick (#25)

The details

I wanted to see what the latency of the Rode Wireless GO II would be compared to the normal wired output. So, I connected the SUB R Out / SEND 2 of the GT-1000core (output level 100, and -10dB) to a Sound Devices MixPre-3 II on channel 1 via XLR and PHONES Out of the GT-1000core (-20dB) on channel 5 to AUX1 In. The higher noise floor and the less smoother wave form of the wireless track are apparent (I played a flageolet tone (XII.) on the A string). The time difference is roughly between 8ms and 9ms as we can see from the selected interval on the image below. This equates to a distance of less than 3m of the speed of sound. Playing with a 5m/15ft cable away from a amp/cabinet creates a larger latency. So, this is totally acceptable for me …

The summary

This mobile pedal board runs over 4.5h via the Jsaux power bank or over 10h when combined with the other power bank and both 9V batteries (battery swap required) or somewhere between that with a combination thereof. And all this in an extremely compact and lightweight form factor with tens of effects to choose from. Also, being completely wireless from the case is a real pleasure when playing. I can absolutely recommend it! Now the only thing left is learn how to play …

Corrigendum / Addendum

• Contrary to what I said, the BOSS WL-20L do not completely drain the battery – the transmitter enters standby after one hour and the receiver enters standby one hour after having no connection with the transmitter. This, essentially means, if the devices are not unplugged after use, the receiver will be powered up for at least two hours after use. In my case, I seemed to be just unlucky that the receiver was empty when I wanted to use it next time.
• Depending on the use, I managed to power both devices for up to seven hours instead of just five hours with the Jsaux battery.
• It is possible to power both devices with the Zendure battery, but only when using separate MyVolts 9V adapters for each device. Power up sequence:
  • Disconnect the RC-5 from the 9V distribution (#11)
  • Connect one MyVolts 9V adapter (#9) to the USB-A socket of the battery (#1), connect it to the GT-1000core (#21) power it up
  • Connect the other MyVolts 9V adapter (#9) via the USB-C to USB-A receptable adapter (#7) to the USB-C socket of the battery (#1), connect it to the RC-5 (#12) and power it up
• I added a CME WIDI Jack, so now I can connect via Bluetooth to the GT-1000core. See this article on how to do it.