Power Station PS-2A hum

Stage & Studio Power Station PS-2
1

I have a problem with my Power Station PS-2A.

When I engage the standby switch (to “Operate”) I get a hum.

The hum disappears if I remove the top panel on the Power Station, but re-appears when I re-install the top panel. The hum actually appears even if I just hold the top panel close to the top of the Power Station. The top panel does not have to physically touch the Power Station for the hum to appear, it only has to be close to the top of the unit. The hum starts to appear when the top panel is about 3-4 cm away from the Power Station and gradually increases when it gets closer.

The ground lift switch does not affect the hum at all.

I’ve tried several different electrical outlets in my studio with exactly the same result.

None of my other studio gear have any problems with hum.

The hum is the same whether an amp is connected to the Power Station or not.

The hum is the same no matter what speaker (or speaker impedance) I’m using.

Replacing the tubes do not make any difference whatsoever to the hum.

The hum increases very slightly if I crank the “Depth” knob.

There is no hum whatsoever in “Bypass” mode.

This is a 230V/240V unit.

Do you have any idea what’s causing this?

Thanks!

1 Like
2

It seems to me that the hum might be originating from a transformer inside the Power Station. I can literally feel the top panel starting to vibrate in my fingers, at seemingly the same frequency as the hum, when I bring the top panel close to the Power Station without actually touching it.

As it is, the Power Station is useless to me. I purchased it for recording, and although the hum isn’t extremely loud it’s bad enough that I can’t have this amount of hum adding up over several tracks of guitar.

1 Like
3

I forgot to mention that the hum is ONE rather wide spike centered around approx. 156 Hz, which means it’s not the kind of hum I would expect from ground related issues. Like I said, the hum seems to originate from inside the Power Station itself, but the hum disappears when the top panel is removed.

Using the unit without the top panel is obviously not an option.

1 Like
4

3 days and not a single reply? I thought this was the place to get in touch with Fryette support? Is there another way to contact them?

1 Like
5

The top panel part is perplexing.

Is this related ?

1 Like
6

Maybe it is this ?

7

Thank you for your fast reply!

Yes, the thing with the top panel is very strange indeed. If anything I would have expected the panel to provide shielding from hum/noise. I can actually feel the top panel starting to vibrate when it comes close to the unit, without actually touching it (even holding the panel upside down 3-4 cm above the unit will make the hum appear). My guess would be some kind of magnetic interference from a transformer, but I’m not an electronics engineer, so I really have no idea what’s going on.

I actually saw that video when I started troubleshooting, but no, that doesn’t seem to be related at all. The hum is present with no amp connected to the Power Station. Connecting an amp doesn’t have any effect on the hum whatsoever.

That single 156 Hz spike means I’ve got a noise floor of approx. -70 dB at normal recording levels. This may not seem THAT bad, but when the majority of that noise is from a hum centered around 156 Hz it gets audible on recordings. Especially when it builds up over several tracks of guitars.

I have to say I’m a bit disappointed with Fryette support. They seem to be deliberately ignoring my posts at their support forum, while answering others.

Kind regards,

Truls Eriksen

lør. 5. okt. 2024 kl. 13:47 skrev stephen sawall via Fryette Support <notifications@fryette.discoursemail.com>:

8

Hi @Trerik and @stephensawall

Thanks for making the suggestions I was going to make @stephensawall this is exactly why we started the forum - the community is knowledgeable!

I can assure you it’s nothing personal @Trerik its a fine question and you are in the correct place. We are just busy and some times questions get lost.

I want to see the frequency and my power station, it’s also a PS-2. What’s your mains frequency? 156Hz could be a third harmonic of 52Hz?

You could send the unit in for a service? It’s very hard to offer advice on this type of issue because nothing associated with this problem is user serviceable.

Regards

Dan

9

Thank you for your reply!

Power Station hum
Power Station hum1230×821 119 KB

Yes, it looks like it might need a service. I’ve already been in contact with the dealer.

To answer your questions and correct some inaccurate information I gave above:

The mains frequency in my country is 50 Hz (230V).

To be honest I don’t know for certain if the hum is centered at exactly 156 Hz. Looking at it again it may just as well be 150 Hz. I don’t have the equipment to measure this precisely, I’m just zooming in on it when monitoring through my DAW, see attached screenshot.

However, I don’t think the peak looks like what I would have expected from mains hum. It’s a pretty wide peak. I would have expected a 3rd harmonic to be a much narrower peak??? Or maybe not? I really have no idea…

I checked the behavior of the hum at different settings again, and my previous description wasn’t entirely correct.

The Flat/Bright/Edge switch does not seem ti affect the hum at all.

The Flat/Warm/Deep switch DOES affect the hum, but in a rather surprising way. The hum is actually at it’s lowest at the “Warm” setting. It actually gets slightly louder at the “Flat” setting and loudest at the “Deep” setting. It’s not a huge difference, around 2 dB.

The Volume knob also affects the level of the hum, there’s a difference of around 12 dB between the lowest and the highest setting.

The HI/LO switch also affects the level of the hum by around 20 dB

The Presence knob also affects the hum, but only very marginally when cranked.

The Depth knob boosts the hum a bit more when cranked, around 5 dB.

Does this make any sense at all? Is this likely to be a faulty unit, or is this to be expected?

Would there be any concerns about permanently removing the top panel and building a new cover out of wood? With adequate ventilation of course. I’m a luthier so I can easily make something that would fit nicely, but if the unit is likely to be faulty I would of course want it repaired, to avoid any future problems related to this,

10

The screenshot was made at typical recording levels btw.

11

If this is “normal” I would call it a rather significant design flaw… Surely this can’t be normal behavior? The Power Station seems to get excellent user reviews everywhere, and I can’t see that happening if they’re all like mine???

12

That’s for the debugging info.

Could you give measurement details, the signal path that gives that peak in the DAW? I guess that is taken from the line out or your speaker cab being mic’ed?

13

I’m mic’ing a cab. I have never used the line out. When I took that screenshot I didn’t actually have an amp connected, but the hum is exactly the same with an amp connected, and regardless of whether the amp is switched on or not.

The settings on the Power Station when I took the screenshot were:

-Top switch: Brite

-Bottom switch: Flat

-Input Level: HI

-Volume: 11 o’clock

-Presence and Depth: 12 o’clock

-Line output level at full (adjusting it does not affect the hum)

-FX return level at LO. Changing this setting between LO/HI seems to temporary increase the hum for a fraction of a second, just a very short spike, before the hum settles at the same level regardless of the LO/HI setting.

-Input and output impedance set to 8 ohms (going into a single 8 ohm speaker, from the Speaker Out “One” jack socket).

-Ground lift not activated. Activating it seems to increase the hum VERY slightly. It’s not enough to make an audible difference, but I can see it on the meters in my DAW.

The cab I’m using is a Grossman ISO-box, which combined with the Power Station enables me to make (more or less) completely silent recordings at home.

When I took the screenshot the cab was mic’ed with an SM57, going straight into the mic input on an RME Fireface UC, with the mic preamp gain set at 30 dB. This is representative of the micpre gain (and Power Station settings) that I typically use for an optimal recording level with this setup.

This simple signal chain was just for testing purposes though. Normally I would run the signal through various outboard gear and go into the line inputs on the Fireface. I scaled down my actual recording studio and moved it to a smaller location last year, because I didn’t have the time to run the studio full time anymore. I brought a lot of hi-end recording gear home. My home recording setup is now in many ways cooler than my actual recording studio. :slight_smile:

I typically use micpres like Neve, API, a TG-2 an LA-610, various eq’s like Pultec and compressors such as LA-2A, an 1176 (or rather a Purple Audio MC77) some older Joe Meek stuff and others. Basically the “classics”. I use lots of different mics. The hum is always there though, no matter what the rest of the signal chain is. And without the Power Station in the signal chain there is no hum.

The amps I use are various tube amps, both vintage and newer models, between 5-30 watts, Fender, Marshall, Matamp, Vox, etc. But the hum is always there, and always the same.

The Grossman Iso-cab enables me to change the speaker element very fast, so I use different speakers from Fane, Jensen, Celestion and Eminence. I made the choice to only use amps that can be set to 8 ohms in my home studio, and to only use 8 ohm speakers, to make sure I avoid any costly mistakes. This of course means that both the input and output on the Power Station is permanently set to 8 ohms. When troubleshooting the Power Station I also tested it briefly with 4 and 16 ohm speakers. The amps and the Power Station were then obviously set for 4/16 ohms but the hum was still the same.

And of course, if I plug an amp straight into the cab, without the Power Station, there is no hum whatsoever (well, except for my old Dynacord BassKing which is probably overdue for a cap job, but even then the hum isn’t nearly as bad as with the Power Station).

The building I live in was built only 5 years ago, so the electrical wiring is very new and modern. I even had en electrician come to check everything when I moved in, because I had some problems with dimmers that made the recessed spots in my roofs “shimmer” slightly. The problem was with the “smarthome” dimmers (wrong type for the spots apparently) not with the wiring, so there shouldn’t be any dogdy grounding or anything like that.

One more thing I just noticed is that the Depth knob on the Power Station seems to make quite a bit of noise when turned. I didn’t actually listen to it as my studio monitors weren’t switched on at the time, but based on the on-screen frequency spectrum I would say it seemed to be more of a “rumble” rather than crackling/hiss. Is this normal? This isn’t really a problem for me, I would never turn this knob during recording. I’m just mentioning it in case there’s a chance it’s somehow related to the hum.

14

I totally understand that this problem will most likely not be solved here, but if you get ANY ideas about what may be causing this after reading my last post above, please let me know. Unfortunately there are no Fryette dealers in my country so I had to buy the Power Station from abroad, Which means that shipping it out of the country for a warranty repair will mean lots of customs paperwork to avoid paying 25% VAT upon it’s return. Not to mention the shipping costs and the potentially long wait. If there is even the slightest chance that I can somehow avoid this, please let me know.

15

Hi @Trerik

Let’s get some advice from the shop to see if they have seen this before. Please standby. They might have a solution or they might need to see it. Yes shipping is a PITA but do you pay VAT on second hand goods?

This will take a day or two, I hope to reply by the end of the week as worst case.

Regards

Dan

16

That sounds great, thanks!

Yes I have to pay 25% VAT as well as additional customs handling fees (and for some products even import taxes on top of all that) for pretty much everything except books, UNLESS it’s an item that has been only temporarily exported for a warranty repair. I will need to make sure I have all the necessary documentation to prove this, and that means a bit of paperwork. If I have to do this, it’s fine, no problem. But if there’s any chance I can avoid this… that would be great.

17

One last thing:

I have probably given the impression that the hum appeared recently. That’s because I actually thought this was the case. However, I just checked some recordings I did shortly after buying the Power Station, and yeah… the hum is definitely there from day1.

I was working with a hi-gain/metal oriented project at the time, which is probably the reason I didn’t notice the hum. I generally work with musical genres that require cleaner/quieter guitar recordings, and with cleaner guitar tones as well as more “open/airy” arrangements the hum definitely becomes a problem.

1 Like
18

Any updates on this?

19

I spoke to Dave today, he mention he will take a look at the todo list. Sorry , please stand by.

1 Like
20

Still nothing? :worried: I will soon have to return the Power Station to the dealer if there’s no solution to this.