Edit Mar 28, 2023: Schematics for Rev 2.3 that have the bonus low capacitance PSU PCB:
Edit Dec 4, 2022: GB5 interest list here - please sign up and 30 units needed for production to commence.
https://www.diyaudio.com/community/threads/rtr-ssr-speaker-protection-gb5.392399/#post-7186273
Edit March 14, 2021: Easy Peasy instant off anti turn off thump mod here:
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
Edit Jan 25, 2021: the Gen 2 RTR SSR schematic and notes on use is here. Specifically,
Details on how to connect the power supply and how to use the instant off bonus controller board.
Edit Dec 16, 2020: the GB interest list for the Gen 2 of the RTR SSR has kicked off. They will handle up to 150v or 300w into 8ohms, the speaker negative is isolated from power supply ground to allow use with bridged amps, and there is an external open collector logic pin to instantly shutdown the SSR. $47ea, professionally assembled and fully tested. Free shipping in USA.
GB interest list here:
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
Edit Oct. 22, 2019: The full production run has been delivered. They look great!
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
Edit Oct. 15, 2019: Here is a photo of the sample unit we tested before we gave the OK for the full production run:
Edit: Oct. 15, 2019: We just received news that all 120 units of the first production run have been completed. Should be shipping them out soon.
Jhofland has developed a superb, simple, compact solid state relay (SSR) DC speakere protection and turn-on delay circuit that is similar to the one used in the ABBB amp. JPS64 did the layout on this, and together, we now have a very nice SSR protection circuit that works "like a wire". It uses very compact SMT parts and the whole board is only 75mm x 35mm per channel. An assortment of connection options are availble ranging from usual spade Fastons to Molex Minifit 4-pin locking jacks, or even plain old soldered flying leads. The circuit uses a topology designed by Jhofland to sense a small DC offset via an opto-coupler isolator and a comparator. The comparator drives another optoisolator to activate back-to-back ultra-low RDson MOSFETs as the SSR. A second comparator provides the 3 second time delay when powering on to avoid turn-on speaker thump. The circuit is powered from the conveniently available +ve DC rail of the amplifier's PSU (range is circa +20v to +100Vdc). The supply voltage is reduced and regulated to a constant value on board via a regulator for consistent performance despite variations in the supply rail voltage.
Initial testing of the SSR DC Protect circuit revealed that when it is on, it truly acts and measures as if it were a piece of high current wire. No noticeable artifacts in the time domain were visible on an O-scope, and FFT's also revealed that it had no effect on the harmonic distortion profile either.
Specifications:
The best part of all is that we will be offering this as a proefessionally built and fully-tested, ready-to-run (RTR) unit. The user just has to solder on his/her own choice of spade terminals or Molex Minifit Jr connectors, or flying leads, the +ve supply via a JST connector or flying leads, and then go and use it.
Thanks to Jhofland for the design, and JPS64 for the layout.
3D render of intitial version for testing and verifcation:
Photo of verification build with Faston connectors:
O-scope screenshot of signal at 100wrms into 8ohms with (yellow) and without (blue) - they are indentical and thus perfectly overlaid. Test with Hafler Class AB amp and resistive load:
Edit Aug 7, 2019: New data with VHEX+ amp for 40Vpp into 8ohm load (25wrms) showing harmonic distortion components from H2 through H5 vs Frequency and THD for case without SSR Protection in place:
Same data with SSR Protection in place:
Comparison with overlay of above THD data for both cases:
Comparison of THD vs Power into 8ohm load with and without SSR Protection in place:
Typical FFT without SSR Protection in place at 25wrms into 8ohms:
Typical FFT with the SSR Protection in place at 25wrms into 8ohms:
No added distrotion as shown by test with 40w into 8ohm load with and without RTR SSR using Tomchr's ultra-low distortion Modulus86 amplifier:
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
For more technical details of this test, see this post:
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
Update August 7, 2019: Pre-orders are now being taken from my shop here. Price for fully built and tested unit is $40ea with Free Shipping in the US; $10 shipping to Canada; $15 shipping to everywhere else.
Update July 29, 2019:
Current interest list shows almost 100 units. Looks like this is a definite go! Latest render with voltage regulator IC and transzorb diode for protection:
With vertical Molex Minifit Jrs:
With Faston spades:
Schematic of pre-production unit:
Edit Dec 4, 2022: GB5 interest list here - please sign up and 30 units needed for production to commence.
https://www.diyaudio.com/community/threads/rtr-ssr-speaker-protection-gb5.392399/#post-7186273
Edit March 14, 2021: Easy Peasy instant off anti turn off thump mod here:
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
Edit Jan 25, 2021: the Gen 2 RTR SSR schematic and notes on use is here. Specifically,
Details on how to connect the power supply and how to use the instant off bonus controller board.
Edit Dec 16, 2020: the GB interest list for the Gen 2 of the RTR SSR has kicked off. They will handle up to 150v or 300w into 8ohms, the speaker negative is isolated from power supply ground to allow use with bridged amps, and there is an external open collector logic pin to instantly shutdown the SSR. $47ea, professionally assembled and fully tested. Free shipping in USA.
GB interest list here:
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
Edit Oct. 22, 2019: The full production run has been delivered. They look great!
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
Edit Oct. 15, 2019: Here is a photo of the sample unit we tested before we gave the OK for the full production run:
Edit: Oct. 15, 2019: We just received news that all 120 units of the first production run have been completed. Should be shipping them out soon.
Jhofland has developed a superb, simple, compact solid state relay (SSR) DC speakere protection and turn-on delay circuit that is similar to the one used in the ABBB amp. JPS64 did the layout on this, and together, we now have a very nice SSR protection circuit that works "like a wire". It uses very compact SMT parts and the whole board is only 75mm x 35mm per channel. An assortment of connection options are availble ranging from usual spade Fastons to Molex Minifit 4-pin locking jacks, or even plain old soldered flying leads. The circuit uses a topology designed by Jhofland to sense a small DC offset via an opto-coupler isolator and a comparator. The comparator drives another optoisolator to activate back-to-back ultra-low RDson MOSFETs as the SSR. A second comparator provides the 3 second time delay when powering on to avoid turn-on speaker thump. The circuit is powered from the conveniently available +ve DC rail of the amplifier's PSU (range is circa +20v to +100Vdc). The supply voltage is reduced and regulated to a constant value on board via a regulator for consistent performance despite variations in the supply rail voltage.
Initial testing of the SSR DC Protect circuit revealed that when it is on, it truly acts and measures as if it were a piece of high current wire. No noticeable artifacts in the time domain were visible on an O-scope, and FFT's also revealed that it had no effect on the harmonic distortion profile either.
Specifications:
- PCB size is 70mm x 35mm and the M3 screw mounting holes are 62mm x ~26.5mm
- Requires > +19vdc power supply (can use +ve rail from your amp) and internally regulated to 15v
- Fully tested for 100w rms continuous load into 8ohms (MOSFETs are rated for up to 154w into 8ohms)
- Fully tested to handle 48vdc continuous DC fault
- 3 second turn on delay
- For a 48vdc fault, turn-off time is 25 milliseconds, 1.5v thrreshold
The best part of all is that we will be offering this as a proefessionally built and fully-tested, ready-to-run (RTR) unit. The user just has to solder on his/her own choice of spade terminals or Molex Minifit Jr connectors, or flying leads, the +ve supply via a JST connector or flying leads, and then go and use it.
Thanks to Jhofland for the design, and JPS64 for the layout.
3D render of intitial version for testing and verifcation:
Photo of verification build with Faston connectors:
O-scope screenshot of signal at 100wrms into 8ohms with (yellow) and without (blue) - they are indentical and thus perfectly overlaid. Test with Hafler Class AB amp and resistive load:
Edit Aug 7, 2019: New data with VHEX+ amp for 40Vpp into 8ohm load (25wrms) showing harmonic distortion components from H2 through H5 vs Frequency and THD for case without SSR Protection in place:
Same data with SSR Protection in place:
Comparison with overlay of above THD data for both cases:
Comparison of THD vs Power into 8ohm load with and without SSR Protection in place:
Typical FFT without SSR Protection in place at 25wrms into 8ohms:
Typical FFT with the SSR Protection in place at 25wrms into 8ohms:
No added distrotion as shown by test with 40w into 8ohm load with and without RTR SSR using Tomchr's ultra-low distortion Modulus86 amplifier:
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
For more technical details of this test, see this post:
Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB
Update August 7, 2019: Pre-orders are now being taken from my shop here. Price for fully built and tested unit is $40ea with Free Shipping in the US; $10 shipping to Canada; $15 shipping to everywhere else.
Update July 29, 2019:
Current interest list shows almost 100 units. Looks like this is a definite go! Latest render with voltage regulator IC and transzorb diode for protection:
With vertical Molex Minifit Jrs:
With Faston spades:
Schematic of pre-production unit:
Attachments
Last edited:
RTR SSR Protection GB Interest List (you are free to remioe your name or change qnty if the price isn't what you expected it to be):
xrk971 - 4 units - USA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
xrk971 - 4 units - USA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
xrk971 - 4 units - USA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
gary s - 4 units - AUSTRALIA
WTL- 4units - AUSTRALIA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
gary s - 4 units - AUSTRALIA
WTL- 4units - AUSTRALIA
Updated list after your last post X - this GB looks good!
xrk971 - 4 units - USA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
gary s - 4 units - AUSTRALIA
WTL- 4units - AUSTRALIA
TOTAL = 26 boards.
xrk971 - 4 units - USA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
gary s - 4 units - AUSTRALIA
WTL- 4units - AUSTRALIA
TOTAL = 26 boards.
xrk971 - 4 units - USA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
gary s - 4 units - AUSTRALIA
WTL- 4units - AUSTRALIA
ppap64 - 2 units
TOTAL = 28 boards.
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
gary s - 4 units - AUSTRALIA
WTL- 4units - AUSTRALIA
ppap64 - 2 units
TOTAL = 28 boards.
Updated GB interest list.
xrk971 - 4 units - USA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
gary s - 4 units - AUSTRALIA
WTL- 4units - AUSTRALIA
ppap64 - 2 units - CANADA
drpro - 4 units - USA
TOTAL = 32 boards.
xrk971 - 4 units - USA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
gary s - 4 units - AUSTRALIA
WTL- 4units - AUSTRALIA
ppap64 - 2 units - CANADA
drpro - 4 units - USA
TOTAL = 32 boards.
It is designed to trip with greater than +/- 1.5 volt dc. The signal is lowpassed through an RC network with about a 0.22 time constant. So I would expect about a second duration at this offset. For deviations greater than 1.5V the duration will be correspondingly shorter.
Updated GB interest list.
xrk971 - 4 units - USA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
gary s - 4 units - AUSTRALIA
WTL- 4 units - AUSTRALIA
ppap64 - 2 units - CANADA
drpro - 4 units - USA
Alarudin - 2 units - SINGAPORE
Ripcord - 2 units - USA
TOTAL = 36 boards.
xrk971 - 4 units - USA
pinnocchio - 6 units - CAN
Vunce - 4 units - USA
Miggie78 - 2 units - FINLAND
Nautibuoy - 2 units - UK
gary s - 4 units - AUSTRALIA
WTL- 4 units - AUSTRALIA
ppap64 - 2 units - CANADA
drpro - 4 units - USA
Alarudin - 2 units - SINGAPORE
Ripcord - 2 units - USA
TOTAL = 36 boards.