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i just purchased a jungson ja-88D integrated, 220v version, and will need a step up transformer for USA/110v. i was looking at 2000 to 5000 watt step up transformer models, as i'm not sure what the power draw will be (it is supposed to do 160 rms class A watts under 4ohms, for powering (self gunned)maggies). i can't find any specs along the lines of what i'd need to know, so i'm hoping someone here can point me to a safe choice re transformer.
thanks,
michael
Follow Ups:
:) it's me again...pulled the fuse on the amp: it's a 'f10al250v', chinese characters = 650 watts, 220v amp. i have that acupwr 1000w 220v to 110v up/down transformer...is this still enough? i still can't find any info to explain the numbers i have. the transformer says it will handle '1000w, 220/240v,4.4amp nom., 110/120v, 8.7amp nom.', or is the 1000w 4.4amp rating re 220v output from transformer safe enough?
thanks,
michael
Go to:
http://www.antekinc.com/
Find then Buy a suitable transformer to Replace the oem one in the goofy Amp you bought. Blow the ~40$
Cheap/easy AND a direct simple solution.
the transformer i had purchased was over $200...my amp is not goofy, but you seem to be. why is it that most here anxiously offering advice appear to have no real world knowledge of the subject at hand...ah: it's an asylum after all. the fuse in question was housed in the ac iec inlet, so i'll just assume the big scary fuse is for protecting too much of that magic fuzzy wave that requires $120000 1' cables to purify it enough to be allowed to enter the most hallowed of .5 watt rms per channel set. but really, i still love that wonderful suggestion to install a dedicated single 220v line from the service...
it (220v jungson ja-88D 09 edition)sounds awesome. transformer works a charm. the amp does run hot indeed. very pleased with my purchase, and to the gentleman who stated a 750v to 1000v quality transformer would be the ticket/no issues using a step up transformer: thank you, you were correct. my maggies have never sounded so sweet.
Wow, you've gotten a lot of responses that have very little to do with what you're asking...
You need to buy a step-up transformer that is adequate, but not overly adequate for the job. You should also check to see if your line voltage is 110V, I bet it's more like 125V.
A 5000W 110V:220V transformer is going to put out a hell of a lot more voltage than 220V if you only have a 160Wx2 class A amplifier.
What you need to do is to determine your line voltage and the expected line voltage of the amplifier; this determines the step-up ratio. Next, if your amp is 160x2 and is class A, then a 600VA step-up should be more than adequate (might be called 600VA). I wouldn't go over 1000VA.
There is absolutely nothing wrong with putting a step-up transformer in front of your gear. There are some people that pay a ton of money for power conditioners that have 1:1 isolation transformers in them, but then those are the same people who will turn around and tell you that a step-up transformer is some kind of insane compromise!
(Oh, something else to consider - you will have an IEC cable with 220-240V AC on it. You DON'T want to plug this into any 110V gear, I tend to paint the ends red on these power cords to reduce the odds of a mixup)
thank you!!! i would be ordering the transformer from amazon, and the advice i see is two to five times the draw from the units available. there was a lone tube amp guy stating that he just got a bunch of hum using a step up, so the internet fear and loathing started to set in...
Yeah, using too large of a step-up will lead to too much voltage at the output. Too much voltage feeding your amplifier will make the power transformer hum. (This is why it's important to know whether the amp is 220, 230, or 240, try to get as close as possible)
i think i had read the amp has a 260watt fuse (not sure the amps). i found a usa made simple step up transformer, much more than the import models, that states it will run at rated output full time, and can handle 120 percent it's capacity without issue, doing 200 percent for short periods. so would even a 500 watt model of one of these do? the big transformer in the amp itself is rated at 675watt, i believe. so if i'm running in 4ohm/160 watts class A, a 500 should do?
A class A amplifier isn't going to show much variation (if any) during playback. You have 135x2, so 270 Watts. Looking a little more specifically at your amplifier, it has regulated power supplies, so efficiency might actually be considerably lower than I had initially imagined.
There isn't a lick of information on the web regarding power consumption, perhaps it might be worth the time to put a clamp meter on the power cord feeding this monster to determine the actual power consumption. In the absence of this information, ask the dealer or the manufacturer for power consumption.
You may actually need a 1000VA step-up.
here is a little bit more info, re (220? at 8ohm) output:
"The amp draws an idle current of 0.75 amperes, making ~173 watts, although my power meter tells 80-90 watts due to the voltage/current phase shift."
does this help? this was from a euro review:
http://www.troelsgravesen.dk/JungSon.htm
Edits: 09/27/15 09/27/15
Either the power ratings are incorrect, the amplifier is not class A, or the power consumption measurement was done improperly.
then we have these numbers, which look 'normal'?
then we have these numbers, which look 'normal'?
then we have these numbers, which look 'normal'?
there was a link on that page i posted where someone had tested the class a wattage...not sure what to make of it:
"I wonder about the class A power from the 30kg beast. Now that we have the schematics with component values, we can easily calculate how much power the amp really outputs in pure class A (and B if we want). Here are my findings.
PclassA = Irms x Irms x Rload.
There are two amps per channel in a bridged configuration, ie in total 4 amps - or amplifier stages if you like. Each of these stages has an idle current of (80mV to 100mV) / 0.25 Ohms x 2, as there are two pairs of output transistors per amp stage. Letīs use 100mV. Idle current aka
Ibias = 0.4x2=0.8A. This is the maximum current that a sine wave can have on the positive side. The negative side of course also can swing this much as we use a push pull design. So, Irms = 2 x Ibias / sqrt(2) = 1.13Arms.
Now we are ready to calculate the class A power that each of these four stages could deliver into a loudspeaker (Rload) :
P classA 8 Ohms = (1.13)^2 x 8 = 10.2 W
P classA 4 Ohms = (1.13)^2 x 4 = 5.1 W
P classA 2 Ohms = (1.13)^2 x 2 = 2.6 W
P classA 1 Ohms = (1.13)^2 x 1 = 1.3 W
Now, we do have two of these amps per channel in a bridged configuration. What does this mean for the class A power? Well, in bridged configuration, we have twice the voltage swing, so we get 4X the power, right? Yes, and no! We do get more class B power but do we really get more class A power? No, we do not.
Also note that in bridged mode, each amp "sees" half the Rload.
The power dissipation without music playing is high and that not only depends on the relatively high Irms but also because we have 4 amps."
Yeah, that would seem to agree strongly with the measured idle consumption, and indicates that the amp should really be called a class AB amplifier (IMO).
The step-up transformer you bought should be totally fine for this. When the amp crosses over into class B, it will draw more power, and the transformer will be OK with that.
darn, didn't see your post last night. the seller just canceled the transformer purchase lol.yeah, from an oz site it is head that some models had a high A bias, so that may explain some. would the 1000v transformer be too much? if so, i'll see if i can reorder the 750...
darn, didn't see your post last night. the seller just canceled the transformer purchase lol.yeah, from an oz site it is head that some models had a high A bias, so that may explain some. would the 1000v transformer be too much? if so, i'll see if i can reorder the 750...
lol, can't find a way to contact jungson, and the seller hasn't a clue...plus, to get my discount before it ended on the transformer, i purchased the 750watt...didn't want that hum you mentioned from getting too powerful step up transformer...so if i don't really need it, would the 1000watt unit be a humming along if all it offers isn't used? seeing as how long this amp has been on the market, you would think there would be at least a bit more info...
Edits: 09/27/15
oh, i have a $20 off ebay coupon that ends today for the transformer. i can go higher to a 750 or the 1000watt, but that gets a bit more pricey.
http://www.ebay.com/itm/ACUPWR-TM-AU-1000-220-110V-1000W-High-End-Step-Up-Transformer-Lifetime-Warranty-/290933093197
lol, i was waiting for the other shoe to drop...we in the usa are dual phase 220. lol wiring to an iec two hots...no really, i'll take the transformer (facepalm). i assumed people answering where from usa or 110-ish v using places...
Ah well he was just trying to help. The north American setup is a little quirky compared to other countries.Technically you are on split phase, the 110v is from one leg to center-tap of a 220v transformer. (Or 240v lol)
I don't think he meant you to wire two "hots" as you call them, I think he was suggesting to run a double breaker with the second breaker connected to the anti-phase bus and run the amp without a neutral in the middle.
(Again, I can't recommend that, as it probably won't pass code.)The real facepalm is knowingly ordering an amplifier designed for use in another country.
I still recommend heading over to DIY Audio or one of the sections here after you get it, and see if there is an aftermarket transformer suitable to replace the 220 50Hz PT in your amp.Best of luck.
△ᴉʇɐuᴉɯnllI oᴉpn∀△
Edits: 09/23/15
what are you smoking? here in the emerald triangle we have nothing that can influence an explanation such as this. an asylum indeed...
You're the one considering buying a 5000 watt step up transformer for a 160 watt amp because for some reason you decided to by a 220v amplifier off of somebody who told you to go shop elsewhere?Maybe you can explain this "2 phase" thing to me? Do you have a lot of Tesla motors kicking around there?
LOL!
△ᴉʇɐuᴉɯnllI oᴉpn∀△
Edits: 09/23/15
I would not go the step up transformer route, I would install a new 240V line for that amp, given its power consumption.
You may, or may not, run into ground loop problems with such a mixed setup, but that would be a problem for later.
Pretty much any additional transformer will affect the sound, most likely in negative way... unless it is a 10kVA or at least 5000VA model. Which will be a HUGE boat anchor.
A new line would be a far more elegant solution... provided you are not too far from the panel.
the amp is 220. i think i'd be safer w/dedicated transformer set to 220. the amp itself is a giant anchor, another smaller one won't be an issue. i was looking at a 5000va unit. so, you're saying i should put two hot 110v legs to the two iec spades, and ground to the ground?
If the amp is actually a 230 volt, then the 240 might not be so bad, but if it is designed at 220V, 240 might not be a good idea.
Connecting it to 240 is probably against building codes, but don't quote me on that.
It is likely is going to have a 50Hz transformer which would probably be OK at 60Hz. (But not vice versa)
If one was going to go to the trouble of buying a huge step up transformer or doing and household changes, it might make more sense just to buy the proper 120V 60Hz transformer for it?
△ᴉʇɐuᴉɯnllI oᴉpn∀△
It all depends on its power consumption, which I don't know, but it could be very close to what the 120V line can deliver. In which case a 120V operation may or may not be advisable.240V lines are OK by the code, and the difference between 220 and 240 might not be important - but this is the question to the amp manufacturer. In some cases people say 220, when they in fact mean 230 - there's plenty of confusion there.
Bottom line - the ideal way about it is by first discussing it with the maker, and then proceed based on the obtained information.
Edits: 09/23/15
"but it could be very close to what the 120V line can deliver."
Gotcha.
"Bottom line - the ideal way about it is by first discussing it with the maker, and then proceed based on the obtained information"
Agreed.
Cheers
△ᴉʇɐuᴉɯnllI oᴉpn∀△
i won't receive the amp for at least a week, but have been looking all morning re the fuse rating with no luck...
i won't receive the amp for at least a week, but have been looking all morning re the fuse rating with no luck...
To contact Jungson and find out what 115V PT they use?
could be, but after several tries buying this amp, and being told i should shop elsewhere (really lol!) and sent invoices for a 'service' rather than an amp...arg, i just want the dang thing home and lit 24/7...
two breakers, duplex outlet each, 10 gauge. i'll ask the seller re the fuse rating. thanks for the replies ;)
i have two 30 amp breakers/dual outlets just for audio, 3.5 ft from the service panel i installed directly off the triplex from the pole in the street. no info re unit consumption, and no experience w/class A only amps.
:(
If you're using 2 breakers (dual) now, that means you have 230V using
both legs, so there's your 230V. Just use the 115V off each leg and
the ground, no neutral.
Edits: 09/22/15
Might try for a ded. circuit off main panel..two 15A breakers
using 14 or 12ga. wire. 15A on each leg is way more than you need.Most outlets are on 20A circuit, lighting circuits use 15A. Your
results may very of course.
Edits: 09/22/15
and size accordingly....
try it! you know you want to!
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