[TempleOfEar]

I'm about to buy Bada 12 or G & W 2.6 in china (my dad is down there) And I figure getting a power transformer is no big deal next to saving hundreds of dollars for the amps. But I wonder, is it safe? how do power transformers work? will they be as reliable and as pure as feeding actually 220v to the amps? thanks and sorry if I seem like trolling with these 'my dad's buying me a chinese amp!' threads but this is the only day he can do that cuz of his schedule and the window of time is closing...

 

[jmmtn4aj]

Transformers step down your power supply from several thousand volts in the powerlines outside to the 220-240V or 110-120V in your household. Transformers also step down the wall current to a lower voltage before it gets converted to a DC current, when you plug appliances like a handphone charger into the wall outlet.

As for how it works, electromagnetic induction and magnetic flux.

 

[TempleOfEar]

right... actually, your post was way too technical for me . They do have step-up transformers like these http://www.goldenshop.com.hk/AI-trad...m/m_stepup.htm I'd need 60w+ one if I'm to get G & W 2.6.


I really can't decide between it and BADA 12! 12 has that cool futuristic look but G & W seem to have more positive reviews going for it. which one do i get? help!

 

[Blackmore]

If I were you I would buy at least 150W, however 300W would be the best choice. I have one 300W from 240V to 120V to drive my tube amp. I have understand how bigger the capacity of transformer, how better/easyer it can work. And for the future you can always buy another amp which uses more than 60W. My is 180W

Quote:

Originally Posted by TempleOfEar right... actually, your post was way too technical for me . They do have step-up transformers like these http://www.goldenshop.com.hk/AI-trad...m/m_stepup.htm I'd need 60w+ one if I'm to get G & W 2.6. I really can't decide between it and BADA 12 tho. 12 has that cool futuristic look going for it but G & W seem to have more positive reviews going for it.

 

[edisonwu]

I have some experiences with some kind of step-up transformers. some are good, but some could be bad. It is always taking a chance. You can still add up a power conditioner right after the BAD transformer. Ask your dad if he can find one in china. they make good transformers at low cost. But you'r still need to watch out.

 

[lini]

TOE: The step-up/down units using conventional transformers usually work quite well. How do these work: Well, it's either really just a conventional transformer with 1:2/2:1 ratio, or what we over here call "Sparschaltung", which is cheaper, but doesn't offer galvanic isolation and just taps the primary winding (= there is no secondary winding in a Sparschaltung-transformer, it's more like a voltage divider...) - i.e. the non-Sparschaltung models are a tad safer (and also a bit better in attenuating disturbances on the power line), but that usually doesn't matter...).

Especially for an amp, you should indeed go a good bit higher than the nominal power rating in order to provide a reserve for possibly higher load on turn-on and also not to choke dynamics. On the other hand, it makes no sense to go insanely high, 'cause from experience the more powerful models often also tend to produce a lot more audible acoustic hum.

However, audible acoustic hum from the transformer can also be a problem with the transformer inside the to be stepped-up/down device itself, foremost when a transformer designed for 50 Hz is operated on 60 Hz (or vice versa) and isn't nominally rated for both. But even if the specs claim 50/60 Hz compatibility, one might in practice experience louder acoustic hum with the non-native frequency. So your milage may vary here - though one might regard acoustic transformer hum in a headphone setup more as a beauty flaw than a real problem, anyway (granted, K1000-owners might differ here...

)...

Greetings from Hannover!

Manfred / lini

 

[Vicks7]

hi all, sorry to chime in here but does anyone have an idea what size step up transformer (110v to 220v) I would need to drive an MPX3 SLAM and a CD Player with plenty of headroom. I am currently using a small step up up transformer for each but I think the transformer for the MPX3 SLAM is not poweful enough as the attenuator needs to be turned to beyond 3 o'clock to get a decent sound level.
many thanks

 

[jmmtn4aj]

Quote:

Originally Posted by TempleOfEar right... actually, your post was way too technical for me .

Its quite simple really, so long as you've learnt basic physics. A transformer works by having a steel loop and two wires coiled around it opposite of each other, like so:

Power is supplied into the primary coil in the form of an AC current at a certain voltage, and the voltage that this induces in the secondary coil depends on the ratio of the number of turns in the primary coil to the number of turns in the secondary coil, called the turn ratio. A transformer with a turn ratio of 2:1 is a step-down transformer, i.e it lowers the voltage.

A transformer with a turn ratio of 2:1 can have 200 turns in the primary coil and 100 turns in the secondary, or 600 turns in the primary coil and 300 turns in the secondary. If the supply voltage is 240V, a transformer with a turn ratio of 2:1 will (ideally) half the voltage to 120V. Vprimary/Vsecondary = Nprimary/Nsecondary, where V is the voltage and N is number of turns.

Similarly a transformer with a turn ratio of 1:2 is a step-up transformer, hence a supply current at 240v to the primary coil will (ideally) result in a 480v current in the secondary coil.

Of course in a practical transformer there's this thing called the efficiency rating, because real-life transformers loose power when functioning due to heat, hysteresis, winding (coiling wires produces an inductive reactance effect, the AC version of resistance (well okay, it's a little more complicated than that) ) , etc. All this and the fundamentals of how transformers work is past the 'basic' level

 

[Blackmore]

As for the CD players, they are like between 15-20W. But Tube Amps are different story. My amp uses 180W so SLAM can be the same. Buy 300W one and he can drive both

Quote:

Originally Posted by Vicks7 hi all, sorry to chime in here but does anyone have an idea what size step up transformer (110v to 220v) I would need to drive an MPX3 SLAM and a CD Player with plenty of headroom. I am currently using a small step up up transformer for each but I think the transformer for the MPX3 SLAM is not poweful enough as the attenuator needs to be turned to beyond 3 o'clock to get a decent sound level. many thanks

 

[vberch]

I needed to drive a powered 120W output subwoofer that was brought over from Germany and I was told to buy a 700+W transformer. I ended up buying a 1000W transformer from Ebay. It's better to be safe then sorry. It was around $50 shipped.

Quote:

Originally Posted by TempleOfEar I'm about to buy Bada 12 or G & W 2.6 in china (my dad is down there) And I figure getting a power transformer is no big deal next to saving hundreds of dollars for the amps. But I wonder, is it safe? how do power transformers work? will they be as reliable and as pure as feeding actually 220v to the amps? thanks and sorry if I seem like trolling with these 'my dad's buying me a chinese amp!' threads but this is the only day he can do that cuz of his schedule and the window of time is closing...

 

[badmonkey]

Should one care about the difference between a regular autotransformer, and an isolating transformer? The latter are more expensive - is the extra cost going to make a difference running a headphone amp?

 

[mattigol]

as lini suggested, maybe an isolating transformer will do double duty as a power conditioning device.

 

[gaijin]

I killed the power supply of a pretty expensive cd player using a 110>220V transformer.

 

[zipdisk]

Step-up/down transformers have been used for many, many years; there is nothing mysterious about them. In general they are as safe as other parts of the electrical systems . If you are worried, then I suggest you buy one from a reputable/estalished company, and make sure that it is certified (e.g., UL, etc). Also make sure that it is rated to handle more power than you will need. This will give you an additional safety margin. I would also suggest you use a power conditioner after the transformer to take care of electrical trash that the transformer may produce (if you find you need it).

 

[badmonkey]

I see the word "may" used a great deal in this thread