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adrianhouse
New member
Correction - it does say "12V DC in" on it (as I posted above)
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terryt
New member
Wrong adapter TEMPORARILY killed my Porta 07
I had to write,
Just last week . . .
Although I had the CORRECT adaptor to my Porta 07, I accidently plugged in the WRONG adaptor (same barrel size). Also, same 12 volts, but WRONG polarity. Although the Porta 07's transport still worked, the neg voltage blew out the circuit board. I thought it couldn't be fixed. Or could it? After a little research on the web about inverted polarity destroying circuits, I decided to spend a few dollars ($10) on suspicious parts on the power supply section of the board. Some of the larger capacitors were fried/leaking so those were replaced. Since they were cheap, I replaced most of the smaller ones too. I could only replace two of the four transistors in the power supply section. (One transistor's number couldn't be cross-referenced, the other was not in stock.) Lastly the main IC chip (14 pin voltage inverter) was replaced with EXACT duplicate (about $2). Because the IC is static unstable, first solder a 14 pin socket, then just plug the IC into it (use a static stable area. Does anyone still use those cheap wrist static guards when inserting more ram into computers?). Because I had to use higher value capacitors it took a nervous few seconds to finally power up. But what about the rest of the board and the sound quality? I put in a recorded cassette and it works like before. Amazing, I am usually not so lucky.
Tip of the year? Put labeled tape on each end of ALL adaptors with the name of the correct appliance so this doesn't accidentally happen again.
cheers!
I had to write,
Just last week . . .
Although I had the CORRECT adaptor to my Porta 07, I accidently plugged in the WRONG adaptor (same barrel size). Also, same 12 volts, but WRONG polarity. Although the Porta 07's transport still worked, the neg voltage blew out the circuit board. I thought it couldn't be fixed. Or could it? After a little research on the web about inverted polarity destroying circuits, I decided to spend a few dollars ($10) on suspicious parts on the power supply section of the board. Some of the larger capacitors were fried/leaking so those were replaced. Since they were cheap, I replaced most of the smaller ones too. I could only replace two of the four transistors in the power supply section. (One transistor's number couldn't be cross-referenced, the other was not in stock.) Lastly the main IC chip (14 pin voltage inverter) was replaced with EXACT duplicate (about $2). Because the IC is static unstable, first solder a 14 pin socket, then just plug the IC into it (use a static stable area. Does anyone still use those cheap wrist static guards when inserting more ram into computers?). Because I had to use higher value capacitors it took a nervous few seconds to finally power up. But what about the rest of the board and the sound quality? I put in a recorded cassette and it works like before. Amazing, I am usually not so lucky.
Tip of the year? Put labeled tape on each end of ALL adaptors with the name of the correct appliance so this doesn't accidentally happen again.
cheers!
D
doulos24
New member
correct the circuit will not draw more amps then it needs its not posible by the facotrs of the components used
there are regulated ac to dc adapters and regulated and filtered ones so that is not true. Radio Shack sells regulated ones. If it's unregulated and has higher current you can damage equipment even if polarity is right. The voltage swing not current on say a 9 to 12 volt unregulated adapter could be as high as 20 volts at power up do to not having a current load till the circuit is turned on which can fry chips rated at say a max of 15 volts. Where A regulated supply will stay a consistant voltage and be perfectly safe and a regulated and filtered supply will be best cause there will be no ac on the dc lines thus less noise in the supply and in your audio path
now you know
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dementedchord
Psychotic State alumni ch
what i now know is you haven't a clue....
regulation is about sustaining the voltage at a speific value... NOT about current.... specified current in an adapter is an indication of it's max sustained capacity... as long as it's rated somewhere abouve what the unit draws you'll be fine... the regulation and filtering are typicly inside the unit NOT the adapter... in it's most basic configuration this is simply a zener diaode and an electrolytic cap... and i do have a clue... i spent years as a pro technician...
so now YOU know... and stay away for the know nuthin bastards at RAT SHACK...
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doulos24
New member
how about you read my freakin post you moron there are regulators in the adapter in regulated supplies which give off constant voltage unregulated ones varry supply voltage based on current draw a adapter without a current load that is unregulated will have a higher voltage then a regulated power supply on power up. To high of voltage fries chips and does not blow the protective reverse polarity diodes in the unit thus causing more problems.
now since I'm the moron acording to you lets let some EE of notority tell you the same freakin thing
how about you read up on the subject
Why is my 9v adapter putting out 12v+?
This is usually detected when one is measuring the voltage of the adapter without a load on it. An unregulated AC to DC adapter will have a voltage and a current rating. When the circuit being powered is drawing the rated current from the adapter, the voltage will sag from the 12v or 13v unloaded down to the rated 9v. If the current requirements are less than the full rating of the adapter, the voltage will be proportionally higher since the load is lighter and there is less sag. The solution to this potential problem is to use a voltage regulated adapter which will supply a steady voltage at any current draw from nothing up to its maximum rating. They are more complex than the unregulated versions and more expensive. - Jack Orman
there are regulated ac to dc adapters and regulated and filtered ones so that is not true. Radio Shack sells regulated ones. If the supply is unregulated and has higher current then the device your using you can damage equipment even if polarity is right. The voltage swing not current on say a 9 to 12 volt unregulated adapter could be as high as 20 volts at power up do to not having a current load till the circuit is turned on which can fry chips rated at say a max of 15 volts. Where A regulated supply will stay a consistant voltage and be perfectly safe and a regulated and filtered supply will be best cause there will be no ac on the dc lines thus less noise in the supply and in your audio path - ME
IN LAYMAN terms If you have an unregulated supply for 12 volts at 1000ma and your device is rated for 300ma the voltage will go up on an unregulated supply based on the current draw which when the supply voltage gets bigger then the max voltage of an IC or Op Amp it frys the chips understand?
I agree with JACK ORMAN
now you know
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doulos24
New member
here is some more
There is one more layer of subtlety here.
If you are speaking of 9V regulated output wall warts, the advice is correct - they supply 9Vdc nominally, and will do that from 0 current up to at least their specified maximum. The pedal will eat only as much current as it wants out of the maximum.
However:
If the wall warts in question are not regulated, a sneaky characteristic can be a problem. It is common for the makers of transformers and wall warts to specify their minimum voltage at the maximum current. That is, they will guarantee for example that you get at least 9V at 300ma, or at least 9V at 1A.
Since they are not regulated, if the load is less than the maximum, the voltage goes up. At very light load, the voltage may be 10% to 40% higher than at the specified maximum. Many pedals are OK with this. Some pedals are not. It depends on the insides of the pedal whether it can take the higher voltage with no problems.
Also, regulated pedals will be much quieter than unregulated. The unregulated ones may have a lot of hum. Always prefer regulated power supplies when you can get them. -R.G
whos R.G. Keen?
After 30 years as a senior engineer and project manager for IBM, R. G. Keen, widely recognized as one of the founding fathers of the boutique effects and amplifier industry, has joined Visual Sound LLC as ‘Chief Engineer’ through his company, Keen Design.
In the earliest days of the Internet, R.G. began publishing his vast knowledge of musical electronics on the Web, first on newsgroups, then on his own site www.geofex.com. From his copious contributions on newsgroup and on GeoFex, countless do-it-yourselfers gained the knowledge needed to start making their own amps and effects.
There is one more layer of subtlety here.
If you are speaking of 9V regulated output wall warts, the advice is correct - they supply 9Vdc nominally, and will do that from 0 current up to at least their specified maximum. The pedal will eat only as much current as it wants out of the maximum.
However:
If the wall warts in question are not regulated, a sneaky characteristic can be a problem. It is common for the makers of transformers and wall warts to specify their minimum voltage at the maximum current. That is, they will guarantee for example that you get at least 9V at 300ma, or at least 9V at 1A.
Since they are not regulated, if the load is less than the maximum, the voltage goes up. At very light load, the voltage may be 10% to 40% higher than at the specified maximum. Many pedals are OK with this. Some pedals are not. It depends on the insides of the pedal whether it can take the higher voltage with no problems.
Also, regulated pedals will be much quieter than unregulated. The unregulated ones may have a lot of hum. Always prefer regulated power supplies when you can get them. -R.G
whos R.G. Keen?
After 30 years as a senior engineer and project manager for IBM, R. G. Keen, widely recognized as one of the founding fathers of the boutique effects and amplifier industry, has joined Visual Sound LLC as ‘Chief Engineer’ through his company, Keen Design.
In the earliest days of the Internet, R.G. began publishing his vast knowledge of musical electronics on the Web, first on newsgroups, then on his own site www.geofex.com. From his copious contributions on newsgroup and on GeoFex, countless do-it-yourselfers gained the knowledge needed to start making their own amps and effects.
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dementedchord
Psychotic State alumni ch
my but you have gotten yourself in a tizzy... my comments were based on the original question which was about the manufacturers recommended WALLWART... i said nothing about tabletop boxes often used for experimentation or customized personal use... you're so quick to try to win an argument that didnt exist that you missed the whole point of the thread... typicly the units that use wall warts have the regulation and smooting built into the unit... and that's whether it's done by a simple zener or transistors... show me a regulated wall wart that the manufacturer specified and i'll kiss your ass and give ya a half hour to draw a crowd...
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doulos24
New member
wtf man you still dont get it that is not what they are refering to
One size just might fit all.
Save your batteries. Use this 3-12V 1000mA adapter for your electronic devices. Adjustable voltage: 3, 4.5, 6, 7.5, 9 and 12V coupled with the 1000mA current draw make this the right adapter for a myriad of devices:
Universal input voltage: 3, 4.5, 6, 7.5, 9 and 12V, 1000mA (1A), includes 1 adaptaplug
Energy Star approved
Regulated output, noise filter included
UL/cUL certified
Morley 9V 300mA regulated adapter for use with all Morley pedals. Center polarity is negative. Equipped with handy LED to show that power is
on.
i can tell you first hand the power supplies I've had for my presonus bluetube my headphone amp every guitar pedal I own my drum machines my drum trigger brians my line six pods all my multi effects etc all have regulated supplies why wouldn't this tascam?
why do you think many companies say use there recomended adapter? its to avoid repairs from the shop from wrong polarity and unregulated supplies
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dementedchord
Psychotic State alumni ch
look dip-shit... on the one hand i couldn't care less... but maybe you ought to do your homework... just taking the first thing from your personal list....
http://presonus.com/products/Detail.aspx?ProductId=11
towards the bottom of the specifacations page you'll see that the adapter is 16V AC!!!!
am i an EE no... i just spent @15 yrs doing factory warranty work on all kindsa equipment from the big touring consoles all the way down to shitty little guitar pedals
http://presonus.com/products/Detail.aspx?ProductId=11
towards the bottom of the specifacations page you'll see that the adapter is 16V AC!!!!
am i an EE no... i just spent @15 yrs doing factory warranty work on all kindsa equipment from the big touring consoles all the way down to shitty little guitar pedals
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doulos24
New member
my bluetube is the old one so it's actully 18 volts ac at 900ma, but with no load on the adapter it measures 19.8volts. since no current load is on the adapter the voltage swings to 19.8 or 10 percent unloaded which is fine
Here is proof in action for you. I have an unregulated 12 volt 700 ma supply when I measure the voltage across the pins it reads 17.41 volts. Most opamps have a max voltage of 15 volts. In a low current circuit say 100ma this would fry the opamps in a heart beat. Your wrong just face it your not a E.E. It depends on the circuit and what's inside it if you can use an unregulated supply vs a regulated one. You have to know the current draw of the device and then I'd still recomend using a regulated adapter something you said didn't exsist to begin with. Since words are to hard for you understand I thought I'd send you some pretty pictures to look at instead. If you still can't understand then there is no help for you. If i needed 12 volts of power I would want 12.06v comming from the wall rather then 17.41v or 45% more voltage then what I need this seems obvious at least to me. Now lets do some rough math we know that if we are using 700 ma the adapter will be 12 volts and we know at zero ma it's at 17.41 subtract the two you get 5.41v now lets use a base ma of 100ma there are 7 100 ma in 700ma so divide 5.41 by 7 which is about .77volts more for every 100 ma your circuit doesnt use. At 600 ma the voltage will be 12.77v at 500 ma 13.54v at 400ma 14.41v at 300ma 15.08v at 200ma 15.85v at 100ma 16.62v 0 ma 17.39v so maybe this will explain to you why the ma rating on an unregulated supply is important? now imagine at 1000ma what the numbers look like so yes it is important thats my final calculated tested an proven answer!
homework? I JUST TOOK YOU TO SCHOOL
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dementedchord
Psychotic State alumni ch
boy you are persistant... and once again you missed my point... this time i pointed the adapter for the presonus out because it is AC and therefore NOT regulated.... i've waisted enough time on you so BYE !!!