Ready-to-Run (RTR) SSR DC Speaker Protection and Delay GB

[jwjarch]

Just placed my pre-order as well! Thanks X!

xrk971 - 4 units - USA
pinnocchio - 2 units *Pre-order Placed*
Vunce - 2 units - USA *Pre-order Placed*
Miggie78 - 2 units - FINLAND
gary s - 4 units - AUSTRALIA *Pre-order Placed*
WTL- 2 units - AUSTRALIA *Pre-order Placed*
ppap64 - 2 units *Pre-order Placed*
drpro - 2 units - USA *Pre-order Placed*
Alarudin - 2 units - SINGAPORE
Ripcord - 2 units - USA
Myint67. - 4 units - Singapore (depends on price )
ravid - 2 units - India *Pre-order Placed*
darrr - 2 units - Poland *Pre-order Placed*
Avtech23 - 2 (maybe 4) units - Australia
necplusultra - 2 units - Dominion of Canada
gannaji - 4 units - USA
Amplitude - 2 units - Denmark
esprit - 2 units - UK
hirscwi - 4 units - USA
yoaudio - 4 units - USA
kamco - 2 units - USA *Pre-order Placed*
Baobei - 2 units - UK *Pre-order Placed*
Kokanee - 4 units - Canada *Pre-order Placed*
Abanico - 2 units - Spain
vasilis - 4 units - Greece
astromo - 6 units - Australia *Pre-order Placed*
mlloyd1 - 2 units - USA
markus22ch - 6 units - Switzerland
redjr - 2 units - USA *Pre-order Placed*
gtose - 2 units - USA *Pre-order Placed*
jwjarch - 4 units - USA *Pre-order Placed*
gktaudio - 6 units - USA *Pre-order Placed*
quadtech - 2 units - USA
livingstone - 4 units - RUS *Pre-order Placed*
Bare - 2 units - Can
Quan - 4 units - Aus
MD_Stryker - 2 units - USA
tuyen - 2 units - Australia *Pre-order Placed*
evanc -2 units -USA *Pre-order Placed*
tcpip - 6 units - USA *Pre-order Placed*
Pilcom - 2 units - AUS *Pre-order Placed*

 

[xrk971]

What's the advantage of this over a mechanical relay design?

No arcing which degrades contacts - and at worst, can weld contacts shut. No bounce, no noise, no mechanical wear - last forever.

No added distortion as I have shown.

 

[xrk971]

I just got the headphone amplifier version of this circuit to work.

Cheap as Chips OPA1688 Low-THD Muscle Amp

1.00Vpp into 51ohms, Akitika 2ppm 1kHz source, FFT with SSR (4.4ppm THD):

Without SSR (4.2ppm THD):

 

[JOIMONF]

I just got the headphone amplifier version of this circuit to work.

Cheap as Chips OPA1688 Low-THD Muscle Amp

1.00Vpp into 51ohms, Akitika 2ppm 1kHz source, FFT with SSR (4.4ppm THD):

Without SSR (4.2ppm THD):

[/QUOTE

 

[JOIMONF]

No arcing which degrades contacts - and at worst, can weld contacts shut. No bounce, no noise, no mechanical wear - last forever.

No added distortion as I have shown.

I'd like to read reported in first as best sounding, more transparent, detail, and refinement than mecanical relay. Those specifications reports must come in second place, as a confirmation that nothing weird is added as a background

 

[astromo]

What's the advantage of this over a mechanical relay design?

Mechanical relays (generally) have a higher failure rate (due to moving parts) than a solid state "switch". Relays can arc and weld their contacts so that they get "stuck on". Bound to be more to it but that's my simplistic take.

 

[Vunce]

I'd like to read reported in first as best sounding, more transparent, detail, and refinement than mecanical relay. Those specifications reports must come in second place, as a confirmation that nothing weird is added as a background

Besides the advantage that a SS Protection circuit has no moving parts to wear or degrade over time, I thought the bigger advantage over a relay based circuit is it adds nothing. It has no more or less transparency, detail or refinement than the amplifier itself. I think the posted measurements lead in the direction of proving this correct.

 

[quan]

Just placed my pre-order as well! Thanks X!

xrk971 - 4 units - USA
pinnocchio - 2 units *Pre-order Placed*
Vunce - 2 units - USA *Pre-order Placed*
Miggie78 - 2 units - FINLAND
gary s - 4 units - AUSTRALIA *Pre-order Placed*
WTL- 2 units - AUSTRALIA *Pre-order Placed*
ppap64 - 2 units *Pre-order Placed*
drpro - 2 units - USA *Pre-order Placed*
Alarudin - 2 units - SINGAPORE
Ripcord - 2 units - USA
Myint67. - 4 units - Singapore (depends on price )
ravid - 2 units - India *Pre-order Placed*
darrr - 2 units - Poland *Pre-order Placed*
Avtech23 - 2 (maybe 4) units - Australia
necplusultra - 2 units - Dominion of Canada
gannaji - 4 units - USA
Amplitude - 2 units - Denmark
esprit - 2 units - UK
hirscwi - 4 units - USA
yoaudio - 4 units - USA
kamco - 2 units - USA *Pre-order Placed*
Baobei - 2 units - UK *Pre-order Placed*
Kokanee - 4 units - Canada *Pre-order Placed*
Abanico - 2 units - Spain
vasilis - 4 units - Greece
astromo - 6 units - Australia *Pre-order Placed*
mlloyd1 - 2 units - USA
markus22ch - 6 units - Switzerland
redjr - 2 units - USA *Pre-order Placed*
gtose - 2 units - USA *Pre-order Placed*
jwjarch - 4 units - USA *Pre-order Placed*
gktaudio - 6 units - USA *Pre-order Placed*
quadtech - 2 units - USA
livingstone - 4 units - RUS *Pre-order Placed*
Bare - 2 units - Can
MD_Stryker - 2 units - USA
tuyen - 2 units - Australia *Pre-order Placed*
evanc -2 units -USA *Pre-order Placed*
tcpip - 6 units - USA *Pre-order Placed*
Pilcom - 2 units - AUS *Pre-order Placed*

Removed myself from the list as longer required. Thanks.
Quan

 

[potstip]

What do you think about this beautiy is this have same logic?

 

[potstip]

What do you think about this beautiy is this have same logic?

 

[xrk971]

Those look very nice - possibly similar topology. Looks like dual comparators - closer to the HPA SSR protection circuit that I have above.

 

[potstip]

After a little bit more investigation Accuphase using mosfets (k160f10) for speaker protection and as mentioned here below they have significant advantages over solid state relays.

ESP - MOSFET Solid State Relays

I also check high end yamaha amplifiers they also use mosfets.

Br...
Erkan

 

[jhofland]

The solid state relay aspect of this circuit does, in fact, use high current capable MOSFETs.

 

[jhofland]

SSR protection circuit testing

Tom Christiansen suggested that the circuit be tested under load connected to a low distortion amplifier. I acquired one of his Modulus 86 amplifiers that is capable of 40W out into an 8 ohm load. My test setup uses an Akitita low distortion 1 KHz oscillator as a signal source and a first generation Focusrite 6i6 connected to the amplifier via a 10:1 attenuator. Using REW to measure the apparent distortion. I first tested it without the SSR protection circuit and adjusted the input to drive the output to just above 18VRMS into 8 ohms.
The first plot shows the results. There are no apparent distortion products above the noise of the test setup.
I then added the SSR protection circuit between the amp output and the load and repeated the measurement without making any adjustments to the Focusrite input. The second plot shows the results. The banner showing the REW setup happens to override the 1KHz peak of the plot, but the harmonics, or lack thereof, are apparent. There is no discernible difference in the output harmonic content with or without the speaker protection circuit in place.

 

[aive]

Nice one!

 

[avtech]

xrk971 - 4 units - USA
pinnocchio - 2 units *Pre-order Placed*
Vunce - 2 units - USA *Pre-order Placed*
Miggie78 - 2 units - FINLAND
gary s - 4 units - AUSTRALIA *Pre-order Placed*
WTL- 2 units - AUSTRALIA *Pre-order Placed*
ppap64 - 2 units *Pre-order Placed*
drpro - 2 units - USA *Pre-order Placed*
Alarudin - 2 units - SINGAPORE
Ripcord - 2 units - USA
Myint67. - 4 units - Singapore (depends on price )
ravid - 2 units - India *Pre-order Placed*
darrr - 2 units - Poland *Pre-order Placed*
necplusultra - 2 units - Dominion of Canada
gannaji - 4 units - USA
Amplitude - 2 units - Denmark
esprit - 2 units - UK
hirscwi - 4 units - USA
yoaudio - 4 units - USA
kamco - 2 units - USA *Pre-order Placed*
Baobei - 2 units - UK *Pre-order Placed*
Kokanee - 4 units - Canada *Pre-order Placed*
Abanico - 2 units - Spain
vasilis - 4 units - Greece
astromo - 6 units - Australia *Pre-order Placed*
mlloyd1 - 2 units - USA
markus22ch - 6 units - Switzerland
redjr - 2 units - USA *Pre-order Placed*
gtose - 2 units - USA *Pre-order Placed*
jwjarch - 4 units - USA *Pre-order Placed*
gktaudio - 6 units - USA *Pre-order Placed*
quadtech - 2 units - USA
livingstone - 4 units - RUS *Pre-order Placed*
Bare - 2 units - Can
MD_Stryker - 2 units - USA
tuyen - 2 units - Australia *Pre-order Placed*
evanc -2 units -USA *Pre-order Placed*
tcpip - 6 units - USA *Pre-order Placed*
Pilcom - 2 units - AUS *Pre-order Placed*



After much deliberation and trying to persuade the domestic finance director, I'm sorry but I'm gonna have to drop out of this one. The US-AUS exchange rate / timing just isn't quite right for me at the moment.

Best of luck with the test unit.

 

[xrk971]

No worries Avtech!

The exchange rate is rather miserable for Oz at the moment - so I appreciate all the support we get from folks down under even more.

 

[xrk971]

Very nice work Jan. Can you click the THD analysis button so that we get the inset window showing % HD from various components up to H9?

That Mod86 is indeed one clean amp at high power.

 

[astromo]

What do you think about this beautiy is this have same logic?

According to one Accuphase product manual, yes:
http://accuphase.com/technical_information/e-650_technical_information.pdf
They're using a MOSFET based switching philosophy.

 

[Bonsai]

Very nice!!