Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

Help with Symetrix 544 power transformer
Help with Symetrix 544 power transformer
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 21st August 2020, 06:52 PM   #1
spoontex is offline spoontex  Spain
diyAudio Member
 
Join Date: Feb 2016
Default Help with Symetrix 544 power transformer

HI,

I friend have an old Symetrix 544 comp. But the power transformer is burned. So, I need a replacement, the problem is that I have no idea what type of transformer is. The manual have some schematics, but is unreadable. The only that can help, maybe are the voltage regulators.

78M12
79M12

78M15
79M15

Anybody can help?

Thanks.


https://i.ibb.co/mBz2fcL/IMG-20200821-193448494.jpg
  Reply With Quote
Old 21st August 2020, 07:23 PM   #2
duncan2 is offline duncan2  United Kingdom
diyAudio Member
 
Join Date: Mar 2013
Location: Scotland.
As this is a small transformer and the regulators have a 500ma limit then a transformer with an output of 20 volts + and 2 amps + would do.
  Reply With Quote
Old 21st August 2020, 07:28 PM   #3
spoontex is offline spoontex  Spain
diyAudio Member
 
Join Date: Feb 2016
So, I need a 20v with CT and 2 amps. I think that will be hard to find a pcb mount transformer with the same pin spacing... or you go directly with a toroidal?


Thanks.
  Reply With Quote
Old 21st August 2020, 07:49 PM   #4
spoontex is offline spoontex  Spain
diyAudio Member
 
Join Date: Feb 2016
Screenshot-20200821-214309 — ImgBB
  Reply With Quote
Old 21st August 2020, 08:18 PM   #5
duncan2 is offline duncan2  United Kingdom
diyAudio Member
 
Join Date: Mar 2013
Location: Scotland.
There are plenty of "pin through " PCB transformers online at say 24 volts ,if you cant find an exact mechanical match you can drill the PCB to suite and reroute the connections watching you don't interfere with the copper on the other side.


Do NOT !!! try to bend the pins to fit --you have been warned.
  Reply With Quote
Old 21st August 2020, 08:32 PM   #6
spoontex is offline spoontex  Spain
diyAudio Member
 
Join Date: Feb 2016
What do you think about this one?


https://www.hammfg.com/files/parts/pdf/229D20.pdf



Thanks for the advice.
  Reply With Quote
Old 21st August 2020, 08:39 PM   #7
PRR is offline PRR  United States
diyAudio Member
 
PRR's Avatar
 
Join Date: Jun 2003
Location: Maine USA
Help with Symetrix 544 power transformer
After voltage: as a first crack, get one the same *size*.

I doubt this is 20-24V @2A, maybe nearer 0.5A, but it has been a while since I fondled transformers for pay.

EDIT: we can scale the size of the original against the DIP chips with 0.1" pin spacing. The original seems to be about 2/3rd of the linear dimensions. So it is probably 0.3X the weight and the VA. Which puts it near 12VA-15VA, or 48V 0.3A.

Working the other way: 2 dozen(?) chips at 5mA-10mA each is 150mA-200mA DCwhich suggests a 0.3A AC rating.
Attached Images
File Type: gif spoontex-544-42.gif (87.7 KB, 46 views)

Last edited by PRR; 21st August 2020 at 08:54 PM.
  Reply With Quote
Old 21st August 2020, 09:40 PM   #8
duncan2 is offline duncan2  United Kingdom
diyAudio Member
 
Join Date: Mar 2013
Location: Scotland.
Quote:
Originally Posted by spoontex View Post
What do you think about this one?


https://www.hammfg.com/files/parts/pdf/229D20.pdf



Thanks for the advice.

If it fits I would choose that one too.
  Reply With Quote
Old 22nd August 2020, 09:02 AM   #9
spoontex is offline spoontex  Spain
diyAudio Member
 
Join Date: Feb 2016
Today I mounted two toroidal transformers in series ( 12V 1A each one ), for checking voltages and power consumption.



The voltage regulators works are expected. And the power consumption, measured in AC on each secondary winding of transformers are 34mA more or less, so with two windings they are 170mA more or less. It's possible?


If I check the voltages and power conumptions rigght, a transformer with 12-0-12 and 0.5mA it's enough.



I'm thinking on put an external transformer like the ones on mixer consoles, only for avoid drilling pcb and other botched job.


Behringer PSU6-EU – Thomann Espana


Behringer PSU5-EU – Thomann Espana



And this is a photo of the multimeter:


https://i.ibb.co/rfCb0WZ/IMG-20200822-105618084.jpg

Last edited by spoontex; 22nd August 2020 at 09:06 AM.
  Reply With Quote
Old 22nd August 2020, 09:37 AM   #10
duncan2 is offline duncan2  United Kingdom
diyAudio Member
 
Join Date: Mar 2013
Location: Scotland.
It obviously needs less current than I thought , personally I am not keen on using external power supplies for a PCB intended for a mains transformer due to pick up of external radiation due to the long leads used to feed the PCB but if you are happy with it its your choice .


A "botched job " is only that if it is not thought out and "rushed " I would still fit a soldered in mains transformer it just requires thought on the layout .
  Reply With Quote

Reply


Help with Symetrix 544 power transformerHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
WTB: symetrix digio kipman725 Swap Meet 0 4th November 2019 10:03 AM
Symetrix 302 mic preamps FS Jack Hidley Swap Meet 0 26th November 2012 12:57 AM
Newbie Question - Power Transformer vs Isolation Transformer SparkyPete Tubes / Valves 10 2nd November 2012 06:13 PM
symetrix kamskoma Solid State 0 11th February 2006 05:25 PM
Symetrix Compressor limitors for sale Zero Cool Swap Meet 3 8th May 2005 12:31 AM


New To Site? Need Help?

All times are GMT. The time now is 12:11 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki