I have revised my proposed Aleph J build to comprise monoblocks. My plan would be to place each amplifier adjacent to a speaker. In order to turn them both on from a single source, I would like to have a relay in each monoblock that, when activated, connects the mains to the power transformer. I would power the relays through a single low voltage (5 to 12 volts dc depending on the relay) power supply in its own chassis placed next to my line stage (I am not sure if it would require a linear power supply or if an SMPS would suffice).
My first question is whether my idea makes sense or is there some fundamental flaw with my thinking?
My second question is whether the cables running from the relay PS to each monoblock need only have two wires (V+ and return) or three (also protective earth). I would think that I would not need that third wire because the monoblocks will each be earthed, but would appreciate any insight anyone could give me.
Also, I thought I might as well run the current for the relay through a thermal switch attached to the heat sink on its way to the relay. That would provide a simple method of thermal protection, but is it overkill? Does the temperature of the heat sink pretty much stabilize over time, or might it increase if the amps were inadvertently left on overnight for example?
Finally, does anyone have any thoughts on what would be a good relay to use for this purpose? Would 10 amps be sufficient? I understand that SS relays require less current, but that they leak some voltage. Should I avoid that type for that reason?
Thanks for any help anyone can give me.
Jazzzman
My first question is whether my idea makes sense or is there some fundamental flaw with my thinking?
My second question is whether the cables running from the relay PS to each monoblock need only have two wires (V+ and return) or three (also protective earth). I would think that I would not need that third wire because the monoblocks will each be earthed, but would appreciate any insight anyone could give me.
Also, I thought I might as well run the current for the relay through a thermal switch attached to the heat sink on its way to the relay. That would provide a simple method of thermal protection, but is it overkill? Does the temperature of the heat sink pretty much stabilize over time, or might it increase if the amps were inadvertently left on overnight for example?
Finally, does anyone have any thoughts on what would be a good relay to use for this purpose? Would 10 amps be sufficient? I understand that SS relays require less current, but that they leak some voltage. Should I avoid that type for that reason?
Thanks for any help anyone can give me.
Jazzzman
I think long term you will much prefer the convenience of having the auxillary supply inside the amp.
I use this with the 12vdc trigger from my preamp, works fine...
Amazon.com: Iot Relay - Enclosed High-power Power Relay for Arduino, Raspberry Pi, PIC or Wifi, Relay Shield: Electronics
Amazon.com: Iot Relay - Enclosed High-power Power Relay for Arduino, Raspberry Pi, PIC or Wifi, Relay Shield: Electronics
I can see the appeal of the idea, but I would think one is better off with longer amplified signal wire than longer un-amplified signal wire.
-Michael
I think I used the wrong word to describe what I am trying to do. I did not mean a wireless remote control, I was referring to a wired switch placed next to my preamp. When I build a new preamp, I might include an arduino to provide wireless capability.
Thank you, etet. That looks promising. Could it handle the current of two Aleph J monoblocks and a line stage?
I'm using a wireless remote plug for my living room amp, and it has been working just fine for many years. I was using it with Aleph 5 before, and current was not an issue. You probably do not have to build one, you can find adequate one on Amazon if your goal is just remote power on/ off.
It's rated at 30 amps, probably twice your circuit breaker rating. I'm running my Aleph J dual mono and two 300 watt subs without any issues.
Jazzman, did you get your J build problems sorted? I'm guessing not since you are talking about monos.
My project has gone through so many combinations and permutations that I can’t count them. I always end up in the same place - trying to come up with a way of handling the heat. The monoblocks will allow me either to place each one on top of the woofer box of my Martin Logan’s, or place them on the edge of my audio cabinet (heat sinks with nothing over them and only the floor under them). Someone (it may have been Russellc) suggested using connectors on all the amp inputs and outputs to facilitate swapping amps using the same chassis and power supply. This thought encouraged me to try the Aleph J first, then perhaps the F6 later.
Answering the original question - yes, can be done with a simple relay driven by external voltage. There are more clever/sophisticated solutions, but a relay will work, they do in my amps
I like a single-button-on approach, so my DAC powers pre-amp(s) via a mains out socket and power amps by 12VDC
You need to take care of turn on thumps, if your amps do this
Watch out for flyback diodes built into relays, you will need to mind polarity in this case
Use heftier relays I would suggest, or have a good soft start circuit
On attached photo you can see a relay glued next the switch and parallelled to it. DC wires from a 2.5mm socket not yet installed on the photo
I like a single-button-on approach, so my DAC powers pre-amp(s) via a mains out socket and power amps by 12VDC
You need to take care of turn on thumps, if your amps do this
Watch out for flyback diodes built into relays, you will need to mind polarity in this case
Use heftier relays I would suggest, or have a good soft start circuit
On attached photo you can see a relay glued next the switch and parallelled to it. DC wires from a 2.5mm socket not yet installed on the photo
Attachments
I assume that this is your 1st FW clone build, i can share my experience. I also build monoblock, where AlephJ was my 1st FW clone build, but i gave the board away to my friend.
now on each chassis there are J2 and M2 on each side of the heatsink with neutrik powercon to switch between board. you can refer to this post
Separate Power Supply for First Watt Amps
I also had same idea to build remote trigger for my audio gear and already got this kit by my local diyer (you can search if any similar item ebay/aliexpress) where this relay will be trigered if any audio source coming.
but I have not install it yet, i don't think it's necessary because my audio gear won't stay 24/7. now i just use traditional method by pressing the rocker switch
Attachments
2 Pico, it just dawned on me what you meant. I could just wire an on/off switch (to be placed by the line stage) to the mono blocks, each of which would have its own relay and auxiliary power supply. Am I correct that, if wired this way, I would want to include a protective earth connection to the box holding the on/off switch? Could I just use a wall wart as the auxiliary supply?
I could go further and include the audio detection module suggested by gadut in each mono block to trigger the relay and avoid the manual switch altogether. I suppose with this approach, in order to warm up the amplifier I would have to start playing music. I assume that the audio input to the amplifier would be in parallel with audio fed to the audio detection module.
The other approach would be to use the IOT relay suggested by etat. If I used that approach, would there be any problem with using a wall wart to trigger the IOT device?
Thanks a lot to everyone for your thoughts on this.