Positive Grid Spark Cab Thoughts Anyone? Now NCD. Yep I Took the Plunge

[Obrienp]

Has anybody tried the Positive Grid Spark Cab? https://uk.positivegrid.com/products/spark-cab?variant=47614717657321

 

I have a Spark 40, which I use a lot for practising to the recording for songs we are going to cover. I find it very convenient, especially as the Bluetooth connection is very reliable for streaming from phone or tablet. The bass amp voicing is pretty good but the built in tiny speakers do not do it justice. I have on occasions hooked it up to one of my EV active PA speakers (12” woofer) and it sounds great but it is a bit of a faff setting it up and the sloping top of the speaker means you can’t put the Spark on top.
 

The Spark cab looks like a pretty good solution: plenty loud enough for home practice and can also be used with any pre-amp, not just a Spark amp. The Spark 40 sits on top nicely, making it look like a mini stack. It might even be loud enough for a quiet band practice (140 watts, 110+ DB max). Plus it makes an OK acoustic and electric guitar amp (my other interest).
 

There aren’t many reviews about though. Plenty say it has enough power and tends to be a bit bass heavy but there were a lot of complaints about the initial batch being noisy on idle. It’s not clear whether that has been sorted out in later batches but I don’t see any complaints about it in more recent reviews. There are plenty of complaints about Positive Grid’s customer/after sales service though.

 

Anyway, I was wondering if anyone has tried the Spark Cab with a Spark, or preamp for bass duties and what it was like?

Edited October 17 by Obrienp

[Obrienp]

No response from anybody on this but I thought folks might be interested to know how I have got on with one, having taken the plunge. 
 

My NCD was Monday but apart from unboxing, I didn’t have a chance to try it out briefly until Tuesday. The unboxing was a good experience, in that Positive Grid have obviously taken a leaf out of Apple’s book when it comes to packaging. Very well thought out and slick.

 

The cab itself looks well made and matches the Spark 40 with the gold piping and cloth grill. It looks like a mini stack with the Spark on top. Power comes through a standard kettle lead into the back of the cab (no bricks or wall warts). The plus is that there is a 19v out to power a Spark 40 (cable supplied) and USB C port as well (to power other Sparks). The slickness goes a bit when you have to connect the Spark 40 to the cab via the headphone out into a mini jack socket on the cab. There are also 2 combo XLR/1/4” jack sockets which you can use to connect external preamps providing line level input. There is also an XLR DI out socket with level control and ground lift. A drawback is that there is a switch to select the mini jack input, or the XLR/jack combi inputs. You can’t have them all live at the same time. The unit is rated 140 watts RMS into a 10” driver and two 1” tweeters. The cab is ported.

 

All of the above sounds good to me for what I wanted (a louder Spark 40 for practice and preamp platform for quiet gigs) but the reality didn’t prove quite so great. The problem is/was the noise level. Just switching the cab on with the volume rolled off there is 54DB of white noise and an oscillating rumble. Standing back from the cab it sounded like there is a very noisy fan inside but in front it is clear it is just very noisy on idle. This noise disappears when you play through it and it does sound pretty good for bass. The Spark 40 bass voice tends to push the driver to break up at around 85 DB volume (measured at a couple of meters) but I found it coped very well with my Flyrig V2 to nearly full volume (around 95DB). There was plenty of bass response down to low E but I think it might fall off with a low B. Unfortunately, as soon as you stop playing, that idle noise returns and the DI output is noisy too, so no good for using front of house to beef up the output on louder gigs.

 

Now I had heard that this noise issue only affected the first batch of cabs and it had been sorted out on later batches. Consequently, I have asked Andertons for an exchange. I am waiting for the collection at the moment, so hopefully I will get a replacement unit next week. I will keep you posted on whether it has the same noise issue. 

[uk_lefty]

Good to hear! I think it would be a real miss if this is great for guitar but not so great for bass. People who play both and want a flexible, portable rig could be disappointed. I liked it when you said you could use one mains plug for the cab and "head" but then disappointed when the connection is via the headphones mini jack, that just doesn't scream "gig capable" to me.

 

Hope Andertons get you sorted quickly 

[Obrienp]

22 hours ago, uk_lefty said:

Good to hear! I think it would be a real miss if this is great for guitar but not so great for bass. People who play both and want a flexible, portable rig could be disappointed. I liked it when you said you could use one mains plug for the cab and "head" but then disappointed when the connection is via the headphones mini jack, that just doesn't scream "gig capable" to me.

 

Hope Andertons get you sorted quickly 

I agree about the headphone jack, it does look clunky. Shame they couldn’t have made the Aux socket on the back of the Spark 40 two way. At least the cable would be hidden then.

 

Andertons have scheduled a handover for Monday. The courier will bring a replacement unit and I give them the duff one. I like that. I don’t have to wait until they have checked the duff unit, they send me a replacement on trust. Fingers crossed that the replacement is quiet 🤞! I really don’t understand why a Class D power amp would be noisy, if functioning to specification but I have discovered more reviews online that complain about it. Looks like a common issue. I can’t say I am confident that the replacement will be better ☹️. 
 

As an aside, I discovered that Thomann knock out this little HB power amp for under £70 : https://www.thomann.co.uk/harley_benton_gpa_100.htm. 100 watts @8 ohms, 190 @4 ohms. The reviews I have found are all positive, so I have ordered one to work with my Flyrig 2 into my LFSys Monza, as a low volume rehearsal/intimate gig solution. This covers one of the use cases I had for the Spark Cab, so the replacement unit is going to have to be perfect to justify me keeping it.

 

P.S. The other benefit the Spark Cab has is its multi-instrument capability. I did try it out with both acoustic and electric guitar, and it worked well. You do have to play with the EQ a bit, as the cab tends to be a bit bass heavy (good for bass use obvs) and the twin tweeters can accentuate piezo brittleness. I always found the Spark 40’s default acoustic voice very effective and the Clean guitar setting; not so much the more driven settings. The Spark Cab just gives you them louder but being FRFR it also makes their drawbacks more obvious. Again judicious use of EQ might help.

Edited October 18 by Obrienp

[Obrienp]

Further update: Andertons sent a courier with a replacement cab and collected the return at the same time. Great service IMO.

 

Unfortunately the replacement unit is just as noisy as the previous one. I really debated with myself about keeping it, as the bass tone it produces is very pleasing either with the Spark 40, or my preamp pedals (Battalion and Flyrig v2) and the guitar voices are pretty good too. It has a lot of useful features to go with both and is a nice looking piece of kit. It really could be a great universal cab for guitar and bass but the noisy DI out tipped it for me. You don’t hear the noise when you are playing an instrument through it but a noisy DI is going to come through loud and clear in front of house/PA. I really don’t understand how a Class D amp could be so noisy.

 

I have asked Andertons to give me a refund and I am now waiting for their response.

[Obrienp]

Good on Andertons: they are arranging for the cab to be picked up for a return. I guess they will want to check it before coughing up. This time I literally removed the cab from the packaging, switched it on, heard the noise and repacked it. I didn’t put the Spark on top, as it left feet marks on the previous one after only an hour or two on top. I didn’t even open the accessory packaging. Consequently, I am confident that I will get a full refund. They could sell this one as new, no problem.
 

I feel quite disappointed about the Spark Cab. It has the potential to be a really good piece of kit. Unlike some active FRFR cabs, it isn’t a repurposed PA speaker. You can actually stack your Spark “amp” on top without it sliding off. It also makes a good preamp platform. It doesn’t boast massive volume for bass at 140 watts but is more than adequate for guitar. It is compact, light (under 14Kg) and well built. I really liked the bass tone that it produced and I think it would be loud enough for intimate gigs (coffee shops and the like). Just a shame that the power amp they put in it has such a loud noise floor and this gets through to the DI out. Close but no cigar Positive Grid!

Edited October 23 by Obrienp

[Woodinblack]

On 17/10/2024 at 11:43, Obrienp said:

Unfortunately, as soon as you stop playing, that idle noise returns and the DI output is noisy too, so no good for using front of house to beef up the output on louder gigs.

 

Sounds like there is a compressor working there - is this not connected to the spark, or connected to the spark with no effects?

[Obrienp]

59 minutes ago, Woodinblack said:

 

Sounds like there is a compressor working there - is this not connected to the spark, or connected to the spark with no effects?

This happens with nothing connected and the output volume off,  connected to the Spark, or connected to an external preamp. No effects in the chain. The noise disappears for a second when you switch the input between the mini-jack socket input (for the Spark) and the combi inputs.

 

When I said the noise disappears when you play into the cab, I mean you don’t notice it. I don’t know whether it disappears, or is just drowned out be the instrument noise. As soon as you stop, it’s there again, so I guess it is just drowned out.

Edited October 22 by Obrienp

[Woodinblack]

I think it is a shame they didn't make an aux out on the spark when they realised that it was proving popular (and lots of people are hacking them on). If they had the cab would be easier

[Obrienp]

Just to finish the story off, Andertons have issued me the full refund. The last comms I had from them said that their tech department was going to see if they could fix the noise problem (presumably with the last returned cab). I haven’t heard anything further, so I assume they couldn’t fix it. Bit of an indictment of Positive Grid I feel. Anyway good on Andertons and I have to say I was impressed with their after sales support.