Buzzing humming sound in new Swart AST Master :(

[Jared Purdy]

Okay, what the F!$%ck! Maybe I forgot to knock on wood when I posted that I have finally got an amp with out issues. Anyways, this is what I have found:

I think that my amp has an issue. I noticed it the other day but it seemed to be intermitent, so I thought that it might be some kind of electrical interferance. Tonite when I picked up my guitar, the amp would not stop buzzing/humming until I put my hands on the strings, but now it makes no difference, the buzz is constant. When I cut the tone, it's still there, though not as much. When the tremelo is on, the buzz pulsates. It won't stop humming/buzzing regardless of the guitar that I use (my Strat Deluxe, my LP Traditional or my daughter's MIM Strat). I took the guitar & amp out to the garage, as it has fairly new wiring, same problem, only when I put my hands on the strings, the buzz was mostly gone, but still there a bit.

I've moved the amp around the house, and it doesn't matter where I plug it in. I have all new wiring in the basement, and it was just as bad there as upstairs. My guitars do not do this on my Fender 75 SFPR, nor any other amp that I have had. It's very loud and cuts through the volume. I just came back from taking it over to my neighbour's, it does it there too.

Suggestions, other than calling Swart in the morning?

[Steve Conner]

Yes, did you try a different guitar lead? Sounds like the lead might have developed a bad ground connection.

[pdf64]

How about if you turn the guitar volume down - does any buzz get through (hands off any strings, metalwork etc).
How about if you use the Swart amp through a different speaker, and a different amp through the Swart speaker (to see if the amp or speaker has any unusual frequency peaks causing this)? Pete.

[Jared Purdy]

Thanks for the replies. I'm/we're not 100% sure what it is. I was on the phone with Michael Swart this moring and through a process of elimination, he doesn't think it's the amp, but it's not 100% definitive (we turned off the volume, MV, reverb trem, turned them on, guitar un-plugged makes no sond, guitar plugged in makes buzz/hummm) . He thinks that it is some kind of interference coming from somewhere in the wiring in our house, or a neighbour's house. He may well be right. All three houses are 100 years old with varying degrees of knob and tube and new re-wiring.

Last night I replaced all of the tubes with spares that I had and that made no difference, so I put the others back in. I tried different cables, and that made no difference. I also took my LP down to the shop, they ran tests, nothng, quiet as a mouse. There is definately a hum, buzz coming from the amp with the three guitars that we have in the house, but not with the key board. It is worse with the LP. There is no hum or buzz coming from my 75 SFPR. I spoke with the shop where I ordered it from and we agreed that when I take my 75 SFPR into have serviced on Thursday (by John Fletcher), that I bring the Swart along and have them look at it too, and they will cover the costs. Customer service is great/amazing, now if we can just solve the mystery.

It may be the sensitivity of the amp combined with some crappy wiring in my 100 year old brick semi that has a mixture of new and knob and tube wiring from the last century. Strangely , when I came back from the guitar shop today and plugged the LP into the Swart, the buzz was not nearly as noticeable. The only thing that was on in the house was the furnace and the stereo on low. And, neither of the neighbours were home. Hmmmm? I called a friend who is a certified electrician to see if he has some magic tools to measure interference, grounding, etc. I love this amp. I want the problem to go away. I have faith in Michael's build. The tone is toi die for, and worth fighting for!

[Steve Conner]

If you have a 100 year old house with knob and tube wiring, it's possible that some (all?) of your outlets could be lacking a ground connection. That would indeed make most guitar amps pick up hum, and match the symptoms you described there. Any electrician should be able to test the grounding for you.

In the meantime why not try some different outlets? Maybe one that you know is on newer wiring. Or maybe not, I guess it is possible that all three houses could have a bad ground. If you take it to the repair shop and it doesn't hum there, I guess that is it.

BTW, does it still hum with the guitar volume turned to zero?

[Jared Purdy]

Hey Steve, et al,

I took the amp downstairs last night, all new wiring into a modern circuit breaker box. Just as bad as in the dinning room where some of the the knob and tube is. My eletrician called tonite. He's coming by Thursday with his box of "magic tools" (as I call them) to check for issues in the wall sockets, the ground, and the guitar (LP) and the amp. I have an arrangement with Swart and the store where I bought it to take it to a third party, a highly respected amp technician, on Thursday. No, it does not hum with the guitar volume turned to zero. And depending on the time of day (so it seems, it may be worse or less!). It's quite quiet tonite (though there is teeny bit of hum when the volume on the guitar is dimed)! Part of me thinks that it is the guitar, though the store where I bought it checked it out today and as far they are concerned, it came up quiet as a mouse.

[Steve Conner]

Oh well, if it didn't hum with the guitar turned down, nor when you tried it with a keyboard, that would excuse the amp itself from any blame as far as I can see. Hum has bothered electric guitarists since Fred Flintstone first plugged in, most electric guitars pick it up to some extent, so I guess the question is why did the hum not bother you with your previous amps? Maybe the Swart has more gain. Or maybe it's just the first amp you've had that has stayed functional long enough to notice.

Does your LP have humbuckers or P90s? Bearing in mind though, that even humbuckers won't necessarily stop the kind of buzz that comes from bad grounding. Only a really good shielding job can help there. Or preferably fixing the grounding.

Lamp dimmers are notorious for making your guitar buzz. If I sit on my living room floor to play, I can tell if my downstairs neighbour has his living room lights on. (I'm pretty sure he can tell that I have my guitar on too. )

[Jared Purdy]

Hey Steve,

The funny thing is none of the other amps buzzed/hummed at all (dispite the other issues that they had), and the Swart didn't buzz/humm when I first got it. That is what is so confusing about this. The LP Traditional has PAF humbuckers, so the noise cancelling shouldn't be an issue. It is much more noticeable with the LP than with my Strat Deluxe, which has the S-1 switching system, effectively making it a "narrow field" humbucker. The Strat is virtually silent. My friend the electrician is coming by tomorrow to run some tests on the amp and the house, and I am taking the amp and the LP into a highly regarded tech (google John Fletcher) tomorrow. I spoke with Michael and the store where I bought the amp and they think it is a good idea and it's not going to cost me anything other than gas, and the tech lives about 5 blocks from my house.

Yes, there are a couple of dimmer switches in the house, though the ones that would affect the amp are turned off most of the time. And, I moved the amp around the main floor and the basement, and it didn't make any difference. I even took it out to the (detached) garage, which has good new wiring, and that didn't make any difference either. And going one step further, I took it too my neighbours (on the joing side of the semi detached) and it was actually worse there!

Tomorrow I'm going to take it to the store where I bought the guitar and plug it in there, with the LP, and see what comes of it, that should show us something. I know from numerous trips there that the amps don't buzz in that store. If the Swart doesn't buzz or humm there, we will know it is either my house or a neioghbours, or both. If it does buzz there, it's either the guitar the amp or both. I'll let you know later.

Another interesting thing to this is that when the switch is in the middle, the buzz is less than when it is in the neck (worse) or the bridge (noticeable, but not as noticeable as the neck). What would be the reaason for that do you suppose?

[Jared Purdy]

After some investigation and technical input by the powers that be, I sent this to Kelly Holsten at Swart. I also spoke to Michael on the phone about it. A couple of stand-up guys man, really great customer service there. Oh, and not to mention the amazing amps they build!

Hey Kelly.

Balance has returned to the universe!! It's the guitar, but it is inherant in the design of the much sought after 57 PAF humbuckers, which are what is in the LP Traditional, my guitar.

I took the Swart and LP over to that tech that I told you and Michael about (John Fletcher). When I plugged it in, it did the same thing in his house: buzz/humm in the neck and bridge position, but not in the middle position. He at first thought that the pickups were out of phase, that they were wired improperly, but he admitted that he did not work on guitars.

So I took the amp and guitar to the store where I got the guitar. It's big, in a really old building with gazzillions of florescent lights. I plugged it in, not a God damn sound! I just about flipped. It seemed like some evil poltergeist was playing a trick on me. The manager of the store came over and picked away (and he loved the amp by the way) and told me that the 57 PAF humbuckers are not balanced pick ups, which unfortunately makes them occassionally hum in the neck and bridge position, but not in the middle. They are wound by hand, and it is precisely the inconsistency that gives them the coveted sound over the PUs that are found on the LP Standard. The inconsistency is what causes them to hum/buzz because they will pick up inadvertent frequencies, but not in the middle position.

After I left the store I went to a cool place called Superfuzz Audio. They repair amps and guitars. They had heard much about Swart amps, and thought that the build quality and the selection was amazing. I was speaking to the guitar tech about this humm issue and he totally corroborated what the manager at Steve's said. His bottom line was it is the compromise you have to pay for the sound.

It's been quite quiet today, possibly because my neighbour, who has a five dimmer switches on his main floor, is not home!

I picked up 3 Tung Sol 12AX7s and the 6V6s, with a rating of IP 26. I don't think they are as "hairy" or raspy as the JJs. Not that the JJs were particularly overly so, but I think the Tung Sols are warmer and smoother. Thanks for pointing that out, re: the 5Y3 and being able to play any Tung Sol with that tube. I'll try that some time.

Time to play. Thanks for all of your time Kelly. You and Michael are great, and you make a great product.

Until next time, Jared.