Yes, but it may mean that the anti turn off thump feature may not work as well. Try it and if there is no bothersome thump on turn off you are good.
If you have lots of 47uF caps out them in series back to back (Positve to positive etc). That will halve the cap value to 23.5uF.
If you have lots of 47uF caps out them in series back to back (Positve to positive etc). That will halve the cap value to 23.5uF.
I could do 2 in series, starting at the positive rail and connecting " +, -, +, - not the positive to positive as you stated above. This would indeed give a 23.5 uF value. Will see if I have 4 47uF/ 63V caps to make this work.
Thanks again
Thanks again
If you connect them positive to positive (or vice versa) you have a bipolar or no polar cap for free.
My board arrived in the mail yesterday, now have a question.
Going to use in a class A Sissysit amp, but to drive very power hungry headphones.
Wondering if and how to adjust the DC offset trip point to something lower than 1.5V?
Was thinking something around 0.5 or 1.0 VDC. Probably closer to 0.5.
I can change out SM resistors, figure that will be required. Need to place a Mouser order, so I can buy whatever I need with the order.
TIA
Randy
Going to use in a class A Sissysit amp, but to drive very power hungry headphones.
Wondering if and how to adjust the DC offset trip point to something lower than 1.5V?
Was thinking something around 0.5 or 1.0 VDC. Probably closer to 0.5.
I can change out SM resistors, figure that will be required. Need to place a Mouser order, so I can buy whatever I need with the order.
TIA
Randy
I have a SSR headphone protection circuit made just for headphones. It’s pretty easy to assemble if you can do basic SMT parts.
https://www.etsy.com/listing/971912371/ssr-headphone-protection-pcbs?click_key=01201391821312372668eff65fb7242f997d9a97:971912371&click_sum=159bf2c4&ref=shop_home_active_12
For the speaker SSR threshold level to be set to a lower value - will require some calculations. Let me ask Jhofland if he has suggested values. What would you like the threshold to be? 1.5v should not destroy a headphone. You might want to keep it to allow deep transient bass kick drums.
The threshold is controlled by an RC circuit R102 and C102. When DC charges this up there is a time constant and this powers an LED in an optoisolator. The output of the optoisolator feeds a comparator. R104 is a 200k resistor that sets the trip point of the comparator. One could make this value larger to force the reference voltage divider to a lower value. Something like 200k to 300k might make it trip at a lower voltage. Depends on where you want it. Changing R102 to a smaller value will let the RC charge up faster for a quicker response.
https://www.etsy.com/listing/971912371/ssr-headphone-protection-pcbs?click_key=01201391821312372668eff65fb7242f997d9a97:971912371&click_sum=159bf2c4&ref=shop_home_active_12
For the speaker SSR threshold level to be set to a lower value - will require some calculations. Let me ask Jhofland if he has suggested values. What would you like the threshold to be? 1.5v should not destroy a headphone. You might want to keep it to allow deep transient bass kick drums.
The threshold is controlled by an RC circuit R102 and C102. When DC charges this up there is a time constant and this powers an LED in an optoisolator. The output of the optoisolator feeds a comparator. R104 is a 200k resistor that sets the trip point of the comparator. One could make this value larger to force the reference voltage divider to a lower value. Something like 200k to 300k might make it trip at a lower voltage. Depends on where you want it. Changing R102 to a smaller value will let the RC charge up faster for a quicker response.
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Thanks. I have one of you headphone protection boards too, but it has a common ground and I didn't want to tie the output lows together at your board (even if they are ground).
1.5V seems high to me for headphones, maybe its just me being overly cautious.
Randy
Think I will retract my question.
I just calculated that 1.5V into my 50 ohm cans will generate 45 milliwatts. Not enough to worry about.
And I'm pretty sure the DC offset will be very low, and go much higher than 1.5V if something fails, the entire point of this board.
Thanks
Randy
I just calculated that 1.5V into my 50 ohm cans will generate 45 milliwatts. Not enough to worry about.
And I'm pretty sure the DC offset will be very low, and go much higher than 1.5V if something fails, the entire point of this board.
Thanks
Randy
HI
will the board be ok to use in my Groundsound coolback 600 i use to of the 3 amp so it is about 400w in 8 ohm
i hope it will be good for power of bang (can come from my preamp )
is the board a pair
Best Bjarne
will the board be ok to use in my Groundsound coolback 600 i use to of the 3 amp so it is about 400w in 8 ohm
i hope it will be good for power of bang (can come from my preamp )
is the board a pair
Best Bjarne
400W into 8ohms is 160vpp. The BSC0402 MOSFETs in the SSRs are rated 150v. However, they are installed back to back so technically, I think they should be able to handle higher peaks. I will let Jhofland answer. They are sold per pair enough for stereo amp.
it will be good if they are big enough to cover my amp it is 200w amp .. and i use 2 of them .. so it is total 400 min
If the amp is 200w per channel then it’s fine. I thought you meant 400w per channel. 200w into 8ohms is 113Vpp which is well under 150V rating of the mosfet.
sorry i am not so good to this English .. the groundsound coolback 600 have 3 piece 200w amp and a dsp i use only 2 of them so it is total 400w in left channel
and 400w in right channel
and 400w in right channel
Is each amp module no more than 200w? The question is if it can output 400w into a single 8ohm channel.
now i see the problem the best is to have one SSR for every amp module so it is 4 piece SSR is that right
so will the SSR only see 200w amp module
so will the SSR only see 200w amp module
If you have a 4 channel amp then you need 4 SSRs. If the two channel run in bridged mode then one can be shared and assuming it is referenced to ground, the voltage is still fine. If you can get the I get al PSU rail voltages from the manufacturer (or measure it yourself) that would be the best way to know.
Just recived the boards ..just fine
just to be sure max voltage from my supply to feed the board ( i have 70vdc on the supply) is this to high
Best Bjarne
just to be sure max voltage from my supply to feed the board ( i have 70vdc on the supply) is this to high
Best Bjarne
Hello! What a cool speaker protection solution, would work perfectly for my amp build! Any news as to when the board would be available again?