Hum Problem and Power Supply Specs



  • Hi... I know loads of people have posted about the "hum" issue and the fact the power supply isn't grounded (which causes the hum).

    I have contacted PG now several times... With mixed/recycled spiel and advice. But I just wanted it sorted... Don't want to have to wait months on a replacement power supply. Will buy alternative as long as it works and doesn't harm amp.

    Can anyone give me either the exact spec needed or point me in the direction of a good grounded supply that works and is safe? I have tried a friend's laptop power supply @19v and it solves the issue (so too does connecting it via USB to laptop btw).

    In the meantime, I am avoiding the issue by using the original power supply, with a wireless sender/receiver instead of cable to the guitar, but am wary this is a temp solution.

    Please help... It's a great piece of kit. I just want to minimise issues, and as a beginner/improver, would live to continue my guitar journey without any issues.

    Fingers crossed

    S.



  • @spikethelizard The power supply has to be 19volts, have at least 2.5amps, the connector that plugs into the amp must be 5.5mm outside dimension, and 2.5mm inside dimension and the center must be positive. It can have more than 2.5 amps, that won't be a problem since the power supply will only put out the power that the device asks for, but it does have to have at least that. If you're using the original power supply with a wireless guitar hookup then you're all set until you need to use a cable. If the power supply that came with your amp causes hum that is resolved when you use your friend's computer power supply then purchase a replacement that has the same specs. Here is a link to one that people have reported works well with the Spark amp:
    https://smile.amazon.com/dp/B074QLP7WF/?coliid=I2R3831TV5072W&colid=2D0SWD0ZGAB7D&psc=1&ref_=lv_ov_lig_dp_it



  • thanks for the specs..the connector dimensions were the troubling factor for replacement



  • @dhbailey Awesome!!! Thank you!!! I am so excited, as when it works... It rocks!

    Just wish a lil bit more time had been spent on quality control, power supply and global electronics (I get that it's a "pre-order", didn't say "beta", but feels like it is an unfinished/unsafe product).

    Hum/power supply issue aside...Spark seems awesome. Wish I was one of the lucky ones not experiencing hum!!! Why are some and not others... Sure ground every PS all will be fine???

    Just watched a YouTube video of a guy having issues after firmware update (not beta) and wasn't before... Sounds familiar as thought FW update would be better given it came out of beta.

    It seems like testing and quality control has been a total after thought! Not mentioning economics... ahem ahem.😀

    S.



  • to be honest, I've never seen a grounded power supply on a music product other than mixers, hdd recorders and big stuff.(which have internal switch modes anyways)
    I've bought heaps of stuff over the years, and all have 2 pin plugs.
    This is the first product that I've seen uses 19v though.



  • @thomasid58 There are a lot of 19V laptop adaptors available with 5.5mm x 2.5mm DC plug and they will fit the Spark Amp.
    I think you will find the correct DC plug size is 5.5mm x 2.1mm for a robust fit.
    Electronics stores will be able to supply a 2.5mm to 2.1mm DC plug Adaptor.



  • @crystalpit said in Hum Problem and Power Supply Specs:

    to be honest, I've never seen a grounded power supply on a music product other than mixers

    Makes sense if you think about it- If there is one thing a mixer needs to be, it's to be noise-free.



  • now its a 2.5 mm or a 2.1 mm inside dimension???



  • Yes can we have exact confirmed specs... Anyone from PG advise/confirm???



  • @thomasid58 Its 2.1 for sure. However if you have a 2.5mm with the 2 spring loaded claws inside your plug, it will fit... Best to find a 2.1mm with those little claws inside.



  • thanks Alex



  • @dhbailey The acer laptop ac adaptor is 90V / 4.74A and has the 5.5 2.1 mm connection.

    Acer 91 Series Compatible 19V 4.74A Laptop Charger with 5.5mm x 2.1mm Tip



  • Like many others it seems, I turned on my Spark 40 and was immediately turned off by the HUM. I could get around this by plugging in USB to a grounded device. Hardly ideal but it worked. I also got intouch with customer services about it and received a reply saying that they would, " source, test and supply a new power supply". Yes thinks I and how long is that going to take? Imagine my surprize when out of the blue, less that a wek later a new, grounded power supply arrives and hey presto, NO HUM. Well done Positive Grid. BUT, why were they sent out like this in the first place.



  • @crystalpit a lot of digital/modeler type products need the ground. My Helix and Yamaha THR both have grounded plugs. the yamaha is a 15V or else I would just use that power supply. the pin is almost the same...



  • Just submitted my second request for a new power supply. Apparently I made the mistake of combining the registration issue and the power supply problem on the same ticket, and thus the second issue was ignored by PG completely. I really wanted to like this and it has lots of potential, but the company isn't selling me on the quality of it's products at present and a refund is beginning to sound tempting.



  • I just got my Spark. They shipped it very FAST! I got it in a few days from order date.. Now the hum issue. I did get hum when i took my fingers off the guitar on some configurations of amps. However, in other cases there is NO hum. In one case i was getting a bit of hum and used the noise gate which took care of it. Since i just got my Spark, I am thinking that maybe they are using a new power supply. Can anyone indicate what it says on their old power supplies so that i can see if it is different?



  • @r_koby said in Hum Problem and Power Supply Specs:

    I just got my Spark. They shipped it very FAST! I got it in a few days from order date.. Now the hum issue. I did get hum when i took my fingers off the guitar on some configurations of amps. However, in other cases there is NO hum. In one case i was getting a bit of hum and used the noise gate which took care of it. Since i just got my Spark, I am thinking that maybe they are using a new power supply. Can anyone indicate what it says on their old power supplies so that i can see if it is different?

    can you take a picture of your power adapter and the socket and send them here please?
    thanks



  • Just received my Spark really pleased with it but it did have the hum problem. I am in the uk and have a backgrounders in electronics. The noise goes away when you touch the strings contacted support they asked me to shoot a video. I found an alternative grounded supply from Batt Dept £13.99 it is the same power supply as used by Asus laptop U32U-RX019V 19V 3.4A 65W (be careful as there are more powerful adaptors with similar connectors)0_1596719307357_image.jpg 0_1596719269757_0C82B2B3-736C-4BAE-A1B6-0229698ECC04.png



  • T-Power Grounded Power Supply -- search for "ASIN B00F5EZBKU" -- works great with the Spark amp. Available on Amazon for $17. Correct electrical spec and connector size.
    Any grounded power supply for the JBL Xtreme or Xtreme 2 boom box/bluetooth speakers will work with the Spark.



  • @johnchuter hey John, my amp turned up today, and the buzz and hum is hideous. Luckily I have WiFi connections to be able to use. Did you get this supply and it works? I wasn't sure from your post whether you had only just ordered, or had received the new power supply and was now happy?