Alternative AC Adapter for Amplifier

Check our new Geekzone Price Comparison web site for electronics prices in New Zealand.

Forums › Gadgets, robotics, home automation, electronics › Alternative AC Adapter for Amplifier

networkn

4755 posts

Uber Geek

Trusted

Subscriber

Topic # 112703 17-Dec-2012 20:50
Hi There! I bought a bit of electronics (headphone amp) and the recommended AC Adapter is this: https://www.jaycar.com/productView.asp?ID=MP3059&keywords=MP3059&form=KEYWORD Is it likely this is the only suitable bit of kit for it, or is some equivalent going to provide same level of power? Anyone know where I could find a more cost effective alternative?

RunningMan

1332 posts

Uber Geek

Reply # 733903 17-Dec-2012 20:55
Does it need the full 15VAC / 1.5A of that supply? What are the power requirments for the amp itself?

networkn

4755 posts

Uber Geek

Trusted

Subscriber

Reply # 733905 17-Dec-2012 20:57
This is everything I know about the power requirements and honestly, though if I did some reading up it might mean something to me, at this stage, it doesn't mean much. http://o2amp.wikia.com/wiki/Power_Adapters

BigHammer

1803 posts

Uber Geek

Moderator

Trusted

Subscriber

Reply # 733949 17-Dec-2012 21:57
$36 isn't too bad if it's the right one for the job. Surely better than buying something cheap and nasty and blowing up your new headphone amp. Samsung Galaxy SII (I9100T) ROM: Omega v20.1 - XWLSD 4.1.2 JB Kernel: Philz Modem: XXLS8

networkn

4755 posts

Uber Geek

Trusted

Subscriber

Reply # 733965 17-Dec-2012 22:23
Ok I bought the Jaycar one. I thought as much but you never know and it never hurts to ask :) (Actually anyone who thinks that never met my mother) :)

richms

8811 posts

Uber Geek

Trusted

Subscriber

Reply # 733995 17-Dec-2012 22:59
Its an AC output adapter, they are getting really really rare since they have to be a transformer, and a transformer that meets the govts meddling minimum efficiancy specs is not cheap to make compared to a cheap switching supply. Some old ADSL routers used an AC wallwart so if you need to replace it, look on trademe for a junk old router for $5 or so Richard rich.ms

Niel

2466 posts

Uber Geek

Trusted

Reply # 734090 18-Dec-2012 08:38
Transformer based power supplies are still allowed, but only for certain types of products. Switch more power supplies have a reduced life and the output noise (ripple) is harder to filter out so the high purity audiophiles avoid them like the plague. In reality, ambient noise and speaker non-linearity and a number of other factors means it does not matter at all. So then we come to the fact that the one suggested is 15V AC, not DC. I cannot think of any reason why the amplifier would use AC input, so it will be rectified to DC which is 15 x 1.414 = 21V DC (+/- 10% or so for AC variation). If you want to run it off DC (and assuming the correct spec is 15V AC) then you need about 19V - 23V DC. This sounds high for a headphone amplifier, so suggest you double check if it needs 15V AC or DC. You can never have enough Volvos!

networkn

4755 posts

Uber Geek

Trusted

Subscriber

Reply # 734096 18-Dec-2012 08:53
Neil: the required specs are on the link I provided above.

Niel

2466 posts

Uber Geek

Trusted

Reply # 734220 18-Dec-2012 11:42
networkn: Neil: the required specs are on the link I provided above. Ah, was reading too fast and thought the link was a Wikipedia page on power adapters. Okay, so they need AC to generate a split supply and high enough to charge two 9V batteries in series. Now it makes sense. Let me know if you want to modify it to run off a (say) 24V DC power supply as it can be done very easily without affecting performance. You can never have enough Volvos!

networkn

4755 posts

Uber Geek

Trusted

Subscriber

Reply # 735235 20-Dec-2012 01:26
Well I have to say it has arrived and I am feeling not too happy. Firstly this thing is huge, twice the size of the thing I am connecting it to, secondly because it's the most stupid design ever. The connectors (it has 7 of them which can be interchanged) is basically 2 pins which go into two holes. They practically fall out making it pretty much useless since there appears no way to secure it more firmly in the socket!

Niel

2466 posts

Uber Geek

Trusted

Reply # 735242 20-Dec-2012 07:24
It is huge because it is an AD power supply. It would be smaller if it was a lower power rating, but they nearly do not exist in NZ any more due to energy efficiency regulations. Ten years ago those were all you got, now they are extinct. The little plugs is typical of what has been used for many years, but they should not fall out by themselves. Let me know if you want to modify the amp to take a modern DC power adapter. You can never have enough Volvos!