News: Trouble logging in? Log in from the login page.
May 25, 2019, 04:13:29 am

Author Topic: Cheap linear 230v - 9v VS Step down transformer  (Read 453 times)

0 Members and 1 Guest are viewing this topic.

Offline Paulo83

  • Newbie
  • *
  • Posts: 9
Cheap linear 230v - 9v VS Step down transformer
« on: August 14, 2018, 12:06:23 pm »
Hey all,

I have recently snapped up a used Bottlehead DAC and wanted to sound you all out on the best way to go in terms of power supply when it turns up (shipping from US to UK).

I believe it will turn up with the original 110v psu but wondered what the trade off would be between picking up a cheapish 230 - 110 step down transformer vs a cheap 230v - 9v DC linear supply like this https://uk.rs-online.com/web/p/desktop-power-supply/4006945/

While I have read a bit about the battery PSUs that were released I haven't been able to track any down for sale.

I'm not afraid of a little DIY if there are significant gains to be had elsewhere but ideally I don't want to spend much more money to get the DAC up and running.
Paul Cawley

Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 10713
Re: Cheap linear 230v - 9v VS Step down transformer
« Reply #1 on: August 14, 2018, 01:13:08 pm »
The power supply you linked to is not rated for sufficient current to power the DAC.

The cheap-ish 230-110 transformer is a good idea.  10VA would be plenty, but you'll probably end up not finding much under 50VA.

-PB
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline Paulo83

  • Newbie
  • *
  • Posts: 9
Re: Cheap linear 230v - 9v VS Step down transformer
« Reply #2 on: August 17, 2018, 12:40:30 pm »
Thanks for getting back to me. So would something like this be more suitable? https://www.amazon.co.uk/Stepdown-voltage-converter-version-240V/dp/B000H9HU5C/ref=mp_s_a_1_2?ie=UTF8&qid=1534545272&sr=8-2&pi=AC_SX236_SY340_FMwebp_QL65&keywords=230v+to+110v+transformer&dpPl=1&dpID=41ULDTS0rPL&ref=plSrch

Seems concerningly cheap! I assume it being rated to 45w isn't an issue, will the DAC just draw what it needs?
Paul Cawley

Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 10713
Re: Cheap linear 230v - 9v VS Step down transformer
« Reply #3 on: August 17, 2018, 04:40:01 pm »
The 45W rating is more than adequate for the DAC, but your suspicions about quality are well founded, I'd look for the 100W model!
Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline mcandmar

  • Hero Member
  • *****
  • Posts: 1497
  • Not all engineers are civil
Re: Cheap linear 230v - 9v VS Step down transformer
« Reply #4 on: August 17, 2018, 11:43:40 pm »
Go big, i tried the 50w converters and they used to overheat and trip the thermal protection after a few hours.  Go for a 75w or 100w.
M.McCandless

Offline Paulo83

  • Newbie
  • *
  • Posts: 9
Re: Cheap linear 230v - 9v VS Step down transformer
« Reply #5 on: August 20, 2018, 05:55:52 pm »
Paul Cawley

Offline mcandmar

  • Hero Member
  • *****
  • Posts: 1497
  • Not all engineers are civil
Re: Cheap linear 230v - 9v VS Step down transformer
« Reply #6 on: August 20, 2018, 11:03:52 pm »
Decent looking bit of kit, should do the job nicely.
M.McCandless