An actual Symasui starting up...
The start-up event is slow enough, hence it makes no sound. Here's a scope capture of the turn-on and settling of my Symasui IPS test board. Offset goes to just over 1.5V and actually takes a full 6 seconds to be within normal amplifier specs, and some more time following that to fully settle into 'negligible' territory. I never looked at it in this manner, now I'm curious to see the others behaviour at the moment of switch-on.
The start-up event is slow enough, hence it makes no sound. Here's a scope capture of the turn-on and settling of my Symasui IPS test board. Offset goes to just over 1.5V and actually takes a full 6 seconds to be within normal amplifier specs, and some more time following that to fully settle into 'negligible' territory. I never looked at it in this manner, now I'm curious to see the others behaviour at the moment of switch-on.
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OK. If it is an issue it should addressed now because Jason just sold a bunch of the Symasui boards and folks will be building them. Besides, 1u and .1u caps are easier to come by than 2.2u caps.
I'll add too that I'm powering this with an SMPS outputting +/-45V and the on-board shunt regulators (resistor values) have been set-up for the test PSU output. It is also a loaded OPS, 8 Ohm resistive.
Edit: A turn-on transient isn't at all uncommon and generally with relay protection delaying speaker connection not a hazard or even an actual fault. Some designs just do it more than others. I have never tried a non-servo symasym so I can't offer any comparison. Obviously there's some settling occurring on start-up, but the behaviour seems normal afterwards.
Edit: A turn-on transient isn't at all uncommon and generally with relay protection delaying speaker connection not a hazard or even an actual fault. Some designs just do it more than others. I have never tried a non-servo symasym so I can't offer any comparison. Obviously there's some settling occurring on start-up, but the behaviour seems normal afterwards.
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Shorting R3 has no effect. I can delay the speaker turn on time with the Arduino to work around this if it's not going to cause any problems but on mine it has 10 seconds to settle as the soft start comes up, then a short delay again before the speaker relays activate. That's quite a long time to settle. It just had me worried when I lost a set of outputs, then saw this happening.
I'll do the same check with Wolverine, Spooky and CFA-XH. Some servo IPSs and some not. None of mine make any noise on start-up, but that doesn't mean there is no slow transient occurring.
It will be a couple of hours before I'm back at the bench to run the tests.
I tested open /closed on all of them. AND .6V at the lifted ground.
The IPS's in question might be
limited to just the Sym/spooky.
Issues that need to be tested/explored.
-Cap values
-12V supply verification (correct voltage - enough current to settle quickly).
-servo reference - the "big" one. I corrected this on the Kypton-V. The
reference resistor on the servo should go the same EXACT ground as the
NFB resistor. With a VFA servo , just a few mV's can be a volt !
Simple workaround ... remove D1/2 , jumper R3. If a lifted ground is wanted,
put it at the input jack. 😱😱
PS - I actually considered this fault factor with the "kypton V".
A max ground fault of .6V (diodes) on either the spook or Sym give exactly 4 V @ output.
OS
The IPS's in question might be
limited to just the Sym/spooky.
Issues that need to be tested/explored.
-Cap values
-12V supply verification (correct voltage - enough current to settle quickly).
-servo reference - the "big" one. I corrected this on the Kypton-V. The
reference resistor on the servo should go the same EXACT ground as the
NFB resistor. With a VFA servo , just a few mV's can be a volt !
Simple workaround ... remove D1/2 , jumper R3. If a lifted ground is wanted,
put it at the input jack. 😱😱
PS - I actually considered this fault factor with the "kypton V".
A max ground fault of .6V (diodes) on either the spook or Sym give exactly 4 V @ output.
OS
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WAY ahead of you
Nope , wolverine in/NFB have the same reference (blocker cap).
CFA-X has cap's and low-Z NFB - very little issue.
This is a VFA issue - Sym/spook only. Eliminating the lift (D1/2-JUMPER R3) at the IPS
will eliminate this error.
OS
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I've had it idling for half an hour and it just tripped my DC protection. Everything appears okay. My first thought was another set of outputs popped but it's up and running fine again.
check everything that is slow to change (like capactors) for bad ESR ,
defects , reverse polarity.
The IC and discrete's would settle in an instant (or go pfftttt)
without "slow passives" to interfere.
The only other thing that could create "squirrly-ness" is outright
instability/oscillation.
OS
defects , reverse polarity.
The IC and discrete's would settle in an instant (or go pfftttt)
without "slow passives" to interfere.
The only other thing that could create "squirrly-ness" is outright
instability/oscillation.
OS
The only thing missing from Valery's protection circuit is a datalogger. I have no idea which channel tripped it. Do you think it would be wise to hook a dummy load on? This may have been a fluke thing with the protection board too. This is it's maiden voyage as well.
Jeff, just as a bold idea...
Last time, I had my protection triggered randomly, when I had the wire, connecting G1 and G2 grounds not soldered well on one side. It looked like soldered, but had no connection. So IPS board ground was floating slowly, provoking DC offset also growing slowly, until protection tripped just above 1V DC. Just try to check your grounding...
Last time, I had my protection triggered randomly, when I had the wire, connecting G1 and G2 grounds not soldered well on one side. It looked like soldered, but had no connection. So IPS board ground was floating slowly, provoking DC offset also growing slowly, until protection tripped just above 1V DC. Just try to check your grounding...
I'll check it again. I should have hooked the scope up and let it record what was happening. Every time I look at the meter it's reading 4mV on both channels. Nothing is overly warm (other than the 12 volt regulator on the protection board). Other than the first 30 seconds after start-up and that one protection circuit trip out of the blue these things seen perfect. Once I get the overcurrent protection going I want to load them down and warm them up.
I just got home so I hooked up the Symasui to a 5P OPS. Initial start up cold with the input shorted and no load on the output I saw about 2.2V on the output and it took maybe 6 to 10 seconds to settle to 3mv. I shut it off and waited about a minute and restarted it and saw about the same thing. I then hooked an 8 ohm load and tried it again. I still see the same thing except it maybe settles a little quicker. To be honest I don't remember hearing any thump, but I imaging 2V probably moves the speaker a little. I'll try changing the values to the same as the Krypton and see if that makes much difference. I still don't see how this behavior could damage the outputs. Really strange that it took out a whole side. I've never had that happen and I've made a lot of mistakes. 😱
I'm thinking the output may have failed from another issue. When I get a chance I'll dissect that output board an see what I can figure out. 2 volts DC won't likely be heard but your woofer cone will likely be pushed out pretty far.
Hi Thimios,
FYI,
FISCHER ELEKTRONIK - SK 56/ 150 SA - HEAT SINK, EXTRUDED
SK 56/ 150 SA - FISCHER ELEKTRONIK - HEAT SINK, EXTRUDED | element14 Philippines
Sounds as if an integrated power OPS and a microprocessor board for sensing and control initially would be a good to great help.
Yes it would. Datalogging would be great as well. It would likely be inexpensive to build. Just need a talented coder.