Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Platefire on June 28, 2015, 10:37:40 am
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Don't know how it is with my other amps but I've been using my DIY Champ lately and everytime I switch it of standby with my new smartphone in its holster, it just makes all kinds of noise. I have to get it at least 20 feet away to stop. Any easy solutions short of turning my phone completely off or moving it away from my amp??? Platefire
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Probably need a grid stopper resistor on the grid input to the first preamp tube. Or, if it's in a cabinet with the tubes oriented upside down, you may need a sheet of sheet metal or screening to cover the open "top" of the inverted chassis.
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Got the grid stoppers. The cab/chassis is classic 5F1 arrangement but no shielding on inside backplate chassis cover. Also playing a non-shielded strat sss. Platefire
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everytime I switch it of standby with my new smartphone in its holster, it just makes all kinds of noise.
That should tell you how much your smartphone is talking to big brother!
Try a 100pF cap across the input jack to see if that will help the amp. Probably can't make the phone shutup without pulling the battery.
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OK! When I back in Lousyanna I'll give that a shot. Thanks, Platefire
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Platefire,
Just more evidence on how awful smart phones are. Anything that would not be compatible and respectful to that sweet Fender amp should be considered suspect at the very least.
I don't trust my smart phone for a minute. I find them to be like unfriendly rabid pitbulls. :cussing: :icon_biggrin:
You should have not gotten one. You have always been such a great guy & I fear that phone will surely be your demise. They are consistently malicious and hostile to anyone born in the 50's.
:embarrassed: :cry: :l2:
With respect, Tubenit
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AMEN!
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Let us ALL rise up and make a noise unto the Tubenit and say amen!
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Amen, Evil Machine! Plus embarising. I walk upon the Church stage to begin Praise & Worship, flip off my standby switch----- not only making a noise but multiple noises simeltaniously. I had to pull off the phone and hand it off to my wife while everbody. Is looking around wondering what's going on. Don't want this to be a continuing episode :help:
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You could just wrap the phone in tin-foil, God usually doesn't call on phones anyway :icon_biggrin:
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You could just wrap the phone in tin-foil, God usually doesn't call on phones anyway :icon_biggrin:
I used to line my hats with foil, but that quit working somewhere in the mid 90's...
New technology I'm assuming, now you have to use an active jammer. :cussing:
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Don't want this to be a continuing episode
Leave your cell phone in the parking lot.
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A conventional hammer should solve that problem, your amp will work perfectly after that.
i wonder what sort of ringtone people use for gods?? :icon_biggrin:
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I'm assuming, now you have to use an active jammer
like, maybe a HF tube, say 50W, put into oscillation and see if the phone still works :dontknow:
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> no shielding on inside backplate chassis cover. Also playing a non-shielded strat sss
You can smash, or tin-wrap, *your* phone, but there are others.
May I suggest that you add shielding to your rig? Come over here I'll give you a 6"x15" hunk of air-duct you can nail over the open side of the chassis. Good hardware/home stores have aluminum tape which might work in the axe. If you are on the road, go in a deli and beg/buy a couple feet of aluminum foil, work it in there so it touches ground but doesn't short anything else.
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you probably have AT&T or T-Mobile or one of their re-sellers. GSM phones: they are the worst. i have verizon: no issues unless i get a text message or call.
whenever richard comes over (he has t-mobile) we get to listen to: chop-chop-chop-padip-padip-padip at random and frequently... :-\
100pF grid to ground or grid to cathode on 1st stage will help A LOT. line the inside of cabinet with copper or aluminum foil. AC duct tape will probably work too.
--pete
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My drummer got a smartphone when they first came out. At about the same time, I had installed a Death Metal mod in my JMP and it developed an intermittent crackle. I took it home, laid it out on the bench, and (as frequently is the case) it worked fine and would not crackle. It probably took me longer than it should have, but I eventually discovered that it only crackled when that guy had his smartphone with him. The other guitar player had a Mesa and the phone had the same effect on it. What was particularly interesting was that it made no difference if the smartphone was on or not - - it broadcasted exactly the same. Sluckey is pretty hip to what is going on here and Toxophilite has a really good solution. Whatever you do, don't put that thing up to your head.
High gain amps pick up those smartphones real good, so guitar shielding makes no difference. In fact, we only notice it when we stop and the volume on the instruments are at zero.
If you are on the road, go in a deli and beg/buy a couple feet of aluminum foil,
I went to the Roswell UFO Museum and the younger people were wrapping their heads in aluminum foil. I didn't know and I didn't bring any and those younger people wouldn't kick down with any.
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I'm assuming, now you have to use an active jammer
like, maybe a HF tube, say 50W, put into oscillation and see if the phone still works :dontknow:
Maybe a smartphone in one pocket, and an old dumb thinline dial job in the other so they cancel out?? :think1:
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I guess the easiest solution is just to leave it in the car.
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I'm assuming, now you have to use an active jammer
like, maybe a HF tube, say 50W, put into oscillation and see if the phone still works :dontknow:
Maybe a smartphone in one pocket, and an old dumb thinline dial job in the other so they cancel out?? :think1:
I like the noise cancelling concept! :l2:
At first I thought you all were pulling my leg. Now I'm wondering if some of the noise issues I've been having are due to the "smart" phone. If it's so smart, why isn't it protected???
Cheers,
Chip
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I heard/read/seen, somewhere that there's now a stray RF phone charger, would that be like "perpetual motion?" :dontknow:
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Well it sounds like just leaving it in the car would be simple enough but when you been wearing your phone in a holster for years everywhere you go, it's not an easy thing just to remember to take it off.
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> just leaving it in the car
If it was just YOUR phone.
But nowadays, everybody and his dog is liable to show up with a phone. (There are cellphone-based dog tracking devices.)
And even if their last-week phone didn't make trouble, it could fall in the toilet and they show up with a new/different model.
And you might play out? If you don't do drunken pubs, maybe someone at church has a phone that dribbles static, or your uncle Fred at the family sing-along.
I think good shielding is important with any high-gain audio amplifier. And even a "tame" older Champ is high-gain in this context. It doesn't have to be headbanger-gain to pick-up a transmitter in the same room or house.
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Well my Champ is DIY with a switchable/Raw tone control to go from 5F1 to 5F2 plus a standby and NFB swith. My first all new build in 2001. I didn't shield the first and second stage preamp grids or the backplate. Never any problem until now. As long as the phone is about 15 feet away-+--no problem.
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Are you back home? Have you tried the cap on the input jack?
I still think the best idea is to leave the phone in the parking lot. Besides transmitting almost continuously, these smart phones make a lot more noises other than just announcing an incoming call.
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No, won't be back until Thursday. One good thing it is helping me get aquantrd with my new phone as I now can do my internet stuff over it.
I
I got in a habit of keeping my phone close when I was chief care giver for my Dad before he passed but now their is no reason to have al phone on 24/7. So I can start laying my phone aside now without major damage. Main thing now is use it go find my wife when we go shopping :l2:
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So I can start laying my phone aside now without major damage.
That's called the freedom phone! Enjoy.
Main thing now is use it go find my wife when we go shopping
I just look for the blue light. :l2:
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Yeah, my wife ALWAYS wonders off as soon as I turn my back when were shopping, like a little kid.
Why do they do that? :dontknow: :laugh:
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Why do they do that?
it's genetic, just make sure you have the keys and agree to meet at the car, I can get a good 30min snoze :icon_biggrin:
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I'm researching smart phone guitar amp apps. Not sure I want to go there but worth looking into. For my Android phone I found "Andrig" guitar amp models and effects. I.m trying to figure out how the interface will work. The last strat copy I bought has an analog/digital coverter to USB connection that might could be used?
BTW---I downloaded the gString app, so I now have a guitar tuner on my phone.
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So did you come up with a solution? My phone puts a whole bunch of hum and hiss into the in-ear monitoring system we use at church. I've tried different receivers. If I put the phone on the opposite side of my hip as the receiver, I can cut it by about 2/3, but the car shielding method is the only thing that's worked for me (shield it with a car in the parking lot).
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Hello Packer
At. Church I usually sit on the front row for easy access to stage. I've tried just leaving it on the front row seat about 20 feet away from my amp, but it still was cutting up from there. The other night we were rehersing and I left in the sound room, then it was coming through the speaker mains/monitors. Like you, the only solution I've found is leave it in the car. Platefire
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I put my phone in an upside down metal mesh trash can (Faraday cage) and that shut it up.
It also screwed up the reception on the phone. You should hear the racket that my router makes if I get an amp too close to that modern marvel.
It's too bad more of the old boys that designed the 50's and 60's tech that we love are not around and working.
They would have fixed the problem by now.
"Airplane mode" is what I use when trying to "mate" a smart phone with amplification.
I don't want to talk to anybody when the guitar is in my hands anyway.
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Hey Platefire. Have you tried 'airplane mode' yet? I think that may be your solution.
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Yeah, I was going to ask if you had the Bluetooth, WiFi, or Hotspot inadvertently turned on? The only thing I noticed with my Major is when recording if I get close to the computer it makes a glorious noise. Not sure if it is the monitor or the wireless mouse and keyboard.
Jim
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Anything that would not be compatible and respectful to that sweet Fender amp should be considered suspect at the very least.
With respect, Tubenit
Oh please......
Jim :m8
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:l2: :l2: PRR you are the best for outside the box! :bravo1:
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Wow! I'll try airplane mode, since I don't think I could handle PRR's metal purse. Let you know how it turns out!