OHM FL Series amp |
Post Reply |
Author | |
JOLD
New Member Joined: 21 April 2021 Status: Offline Points: 4 |
Post Options
Thanks(0)
Posted: 21 April 2021 at 9:24am |
Hi guys, I have a question about one of my FL series amps , at the rear by the incoming power there is a small riser board attached and the incoming mains is then sent to the rocker at the front
look like thermistors they have 10SP AND UEI 050 one is loose and not soldered are they acting as soft start etc , the big Jamicon caps look fairly new but not tested just yet. Also looks like one or more of thermistors may have blown are they soft start as such? Probably the next question is what can i replace these with been searching but no luck yet. Maybe https://uk.farnell.com/amphenol-advanced-sensors/cl-140/ntc-inrush-current-limiter-50/dp/1707220 ??? So now found out its NTC 50 OHM 2 AMP now on the hunt for couple of transistors
Edited by JOLD - 22 April 2021 at 3:45pm |
|
hmaudio
Old Croc Joined: 03 April 2009 Location: Nottingham Status: Offline Points: 3844 |
Post Options
Thanks(0)
|
There was a few different version of the Ohm fl series amplifier. some were built by Andy Hunt Matrix amplification and i am not sure who built the others.
The Ntc thermistors are used to slow the inrush current on power up, then a relay on the pcb will close bypassing them. If they keep blowing check the relay is operating properly, you can replace the thermisistors with the same value and does not have to be the exact same make. I cannot remember the value for these but it looks like they have been changed before in your picture. The jamicon capacitors tend to be crap in these amplifiers and tend to leak after a while. The best thing to do is measure them. If you need some capacitors i have four F&T 125v 6200uf some left over from when i did mine years ago do not know the condition of them at the minute. If this is a Matrix version the best person to speak to is Andy Hunt he gave me alot of advice with these amplifiers years ago when i fully rebuilt one and changed everything on the pcb and used hitachi fets for the outputs instead of the Buz901p/ 906p fets. Jamie Edited by hmaudio - 23 June 2021 at 8:03am |
|
Nottingham based cab builder. https://www.facebook.com/HMAudio-154352667920145/?ref=bookmarks
This account is used by 2 people. |
|
kedwardsleisure
Old Croc Joined: 20 January 2009 Location: Staffordshire Status: Offline Points: 4938 |
Post Options
Thanks(0)
|
you'll probably find most matrix amps dont have an inrush bypass relay, the NTC's are left in circuit.
They can fail just through old age |
|
Kevin
North Staffordshire |
|
Post Reply | |
Tweet |
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |