What's wrong with my ljm_ljm L25D board ?

[FraserSoft]

PSU

Alec,

along does sell them too - that I've used before. It was the dual AC/DC voltages that Cristi's model offers that made them more appealing once I started using SMPS in my builds. Both will work - it just depends what secondary low-voltages you have available to power them, AC or DC.

Rick

Unfortunately I don't have spare voltages available the transformers I have used are 500VA toroidal that were originaly in my Musical Fidelity Dr Thomas amplifiers. Two out of the three blew up due to an unstable Musical Fidelity pre amp and the transformers are only 46-0-46 AC, the boxes are big enough to build a small psu for the boards though so that's probably the route I will go.
Alec

 

[redjr]

... the boxes are big enough to build a small psu for the boards though so that's probably the route I will go.
Alec

I've had to do that before too - build a lower voltage PSU to power it. Good luck. Cristi is great to work with too.
Rick

 

[TheDealer]

Can I realize Dual DC adding with seal lead acid batteries ?

So guys,

I got a tip from a member but not sure if this could work. Can I add to power supply 2 seriell 12 V SLA batteries ? This would mean that I add 12 V+/V- to the current 59 V+/V-.
So I can reach at least 70 V+/V- and know finally if the not working board was reasoned by undervoltage.

But the first step made me unsure. I have connected only the 2 seriell batteries to the V+/GND/V- points of my powersupply an from here to the monoboards. PSU not powered (only battery voltage).
Measuring the monoboards showed me continued voltage drop from 12,5 V to 7,8 V (and still falling). Here I disconnected the batteries from system. Is it generally not recommended to realize VDC increase that way I did ?

 

[FraserSoft]

Power supply

So guys,

I got a tip from a member but not sure if this could work. Can I add to power supply 2 seriell 12 V SLA batteries ? This would mean that I add 12 V+/V- to the current 59 V+/V-.
So I can reach at least 70 V+/V- and know finally if the not working board was reasoned by undervoltage.

But the first step made me unsure. I have connected only the 2 seriell batteries to the V+/GND/V- points of my powersupply an from here to the monoboards. PSU not powered (only battery voltage).
Measuring the monoboards showed me continued voltage drop from 12,5 V to 7,8 V (and still falling). Here I disconnected the batteries from system. Is it generally not recommended to realize VDC increase that way I did ?

If you are going down the route of using L25 modules why not build a proper power supply. I now have 3 stereo amplifiers using L25's and also bought 3 of these kits for the + & - 65volts 68pcs 80V150UF matrix Power supply kit for L20 L15D L20D L25D Power amp board | eBay these are fed with 3 500va toroidal transformers 45-0-45 volts AC. The only thing I am waiting for now is 3 speaker protection boards as there is a bit of a squeal from the speakers on switch off.

 

[Paladinxxx]

I have the squeal problem at switch off as well... but only on one channel. The other channel just shuts off with ought any noise. I'm running +72 0 -72 Vdc 30,000uF per rail.