Can anyone solve my Violectric V222 and Sparkos op amp problem?

[Promee]

I’m a total op amp neophyte, and I am 100% out of my depth on this, so I’m hoping one of you can offer some guidance. I also posted this over on Head-Fi, so I am sorry for duplicating content, but I want to get as many opinions as possible on this!

The Problem:

I put the Sparkos SS3602 in each of the op amp slots in my Violectric V222. They made an immediately noticeable improvement in sound. Then I turned it off, and when I turned it back on, no sound. Turning it off and back on again, it works fine. This happens like clockwork. Every other time that I turn it on, the lights on the front come on, but no music.

What I have tried:

It doesn’t matter how long I wait between powering off and on, it is the same behavior. I also tried putting the original op amps back in, and the behavior returns to normal, works every time. With the stock op amp in the volume pot position and the Sparkos at the inputs, it still happens. Using the 3 SS3602s I have, I rotated each one out in the input positions, and same problem each time, so no faulty op amp. I also tried all permutations of the ground, lift, chassis jumpers (Keeping both L & R channel the same) with both the lift and ground setting for the main power jumper - no change. I have tried switching inputs and changing to a couple of different pre-gain settings with no change to behavior.

More investigation:

(Photos below) I opened the amp, and, not touching anything at all on the inside while it is plugged in, I turned the device on, and I see 11 total lights. 8 green on the main amplifiers, 2 green in the middle of the large electrolytic capacitors, and 1 red on a small vertical board in front of the other internal components. From what I have read in the manual, there is a DC protection circuit that disconnects power to the headphones if DC is detected. My theory is that a relay is activating to turn on the DC protection circuit when powering down the amp. There is a sound of a relay clicking very shortly after turning the power off, and the red light on the front board comes on for just a second. When turning the amp back on, that red light is illuminated and there is no sound. One of the green lights in the pair among the capacitors is off when this happens, but the other 9 are still on. When I turn it off again, then back on, all of the green lights are back on and the red light is gone and music plays.

Photos:

Amp is playing correctly - 8 green lights on the left, 2 on the right, no red light:

Amp is not working - no sound playing - 8 green lights on the left, 1 green light on the right, and red light on in the front:

Red light on front alternate view - amp not working - no sound:

My questions:

1. Is there a way to keep the Sparkos op amps in and fix the behavior?

2. I don’t mind turning on the amp twice each time as long as I am not harming it, and it sounds awesome with the Sparkos, so does anyone think this might be causing a problem for me down the line?

3. Can anyone explain why this might be happening?

4. Is it bad that warranty is misspelled in the manual? I just noticed that in the second photo, lol

Thanks for your help everyone!

[Polygonhell]

Contact Spakos and Violectric /Lake People.
My understanding is that the US distributor of Vio is quite approachable.

They’ll be able to give you useful advice.
I personally wouldn’t leave them in there with that behavior, the odds are the amp is faulting some protection circuit at startup. That might be harmless and it might not.
But someone familiar with the discrete opamp design and amp designs would be the only ones who could really tell you/

[Promee]

Thank you for the suggestion! I have emails out to Sparkos and to Lake People. Maybe I will also forward it to Power Holdings, the US distributor, as well.

[pennstac]

Do you have to use the power switch to get this behavior? If you plug and unplug does it work as it was in the last state? Just curious. My sense of humor was going to suggest putting a switch in the power cord, or simply turning it on every other time and not turning it on when the red light will come on. (Basically installing Schrödinger’s cat to operate as a power control).

[Promee]

That’s an interesting thought! Unfortunately, the behavior is still present when unplugging it, and that is true in both directions. Unplugging from a good start still triggers it to fail the next time after plugging back in, and unplugging it after shutting off does not prevent it from failing on next power up.

[Promee]

So Arthur from Power Holdings actually saw my post on Head Fi before I even reached out and PM’d me some helpful info! Lake People responded on there as well, but they seemed less enthusiastic about me messing with the op amps. Still they were helpful and pointed out that the light I’m seeing is in fact indicating the presence of DC in the circuit and disconnecting to save the headphones. It also appears that the effect is cumulative, and I have less of an issue if I just replace one of them. I also have been told that the one by the volume pot is probably not good to replace as it doesn’t have much to do with the audio signal and will likely cause more problems than it helps.

[Torq]

Sorry for not getting to this earlier.

For one of several possible reasons* you’re, at a minimum, putting DC on the output with the SparkOS op-amps (as indicated on the board lights) and possibly also going beyond current-limits in other parts of the circuit (indeed, the latter might cause/trigger the former).

Both are BAD.

Protection circuits are not infallible and can be sacrificial (and/or partially sacrificial … in that they can only take a certain amount of abuse, by design, before failing completely … see MOVs in surge-protectors). And if/when they fail, it’s a dead amp, dead headphones, or both.

Also, turning PSUs and the circuits they are powering on/off frequently/rapidly is bad for them, and will not make things better (I get that you’re trouble shooting, but this activity has the potential to cause other failures that won’t be recoverable without repair).

Remove the SparkOS op-amps and put the original back in.

The way the V222 is designed may simply preclude using higher-gain, higher-current or otherwise spec-variant op-amps even if they are otherwise topologically and pin-compatible.

While I would say your best bet here is just to keep it stock, if you really want to play you’ll need an op-amp with similar OR LOWER draw, gain and output than the originals to avoid this reliably … though there may be leeway between stock and something not quite as aggressive as the SS3602 - and only one parameter may be the culprit. But you’ve a good chance of killing the unit while trying to figure that out (unless SparkOS has specific, tested, recommendations that they’ll stand behind … or Violectric etc. has other info).

---

*The higher gain, alone, may push parts of the V222’s circuit to allow more current to pass, or more voltage to be present, through some filter, limiter or clamp on the V222s output that the standard parts do not. This would marry up with the problem being progressively worse as you add more of the SparkOS devices to the circuit. Though that’d be the case for too much current draw, also.

[Polygonhell]

@Promee

Lake People responded on there as well, but they seemed less enthusiastic about me messing with the op amps.

All op amps are not the same (it’s really not like rolling tubes except in the sense your swapping out a component), and depending on the design, even something as inane as changing the speed of an opamp can cause some circuits to become unstable.
Audio circuits are usually less sensitive to changes, but if the amps designer is telling you not to, I wouldn’t.

DC on the output of an AMP is a VERY bad thing, to the point it will destroy a headphone driver in seconds if it’s at all significant.

Looking at the circuit board and GUESSING, probably the only one acting as an amplifier in the circuit is the one on the top left, and that might not even be depending on the gain setting, the one top middle is just going to be handle the balanced input. And the one by the volume control is probably just a buffer to deal with impedance matching.
Not all op amps are unity gain stable and that could well be the issue here, but again if it were me I’d defer to the designer and just forget about using the Sparkos

[Promee]

Thank you guys for the thoughtful replies on this. I really appreciate the consideration. I actually had a little back and forth with Arthur from Power Holdings (the US distro for Violectric) and he says he has worked with plenty of customers who are rolling op amps with these. The consensus as he sees it is that only the XLR input op amp seems advantageous to roll. He said the other two seem to affect voltage regulation and can be a problem to mess with. He also said that while it obviously won’t be under warranty, he has a guy who he has used for years to fix Violectric amps for a couple hundred bucks when people like me have blown them up, and it’s a surprisingly painless / not as expensive as you would think process. So with that in mind, just to close the loop on this, I’m going to copy below my post from that other forum. As a side note, I’ve generally had fun over there talking about tubes and such with fellow Woo Audio owners, but it was a very different experience in the Violectric amp thread, kind of surprisingly negative. Still, I think the sonic outcome of the past 48 hours has been fantastic, and I ultimately learned a good bit and got a lot of good advice, including from the posts in this thread. And without further preamble, my other post:

Just wanted to do one last follow-up on my op amp rolling saga. I got some additional advice that I should leave the volume pot position alone completely, as it is very unlikely to positively alter sound and more likely than average to cause a problem, so back to stock for that one. Also putting the RCA / jumper side op amp back to stock. If that one is connected to the SE inputs, that will be of no consequence to me anyway, as I am only using balanced DACs at the moment, and if it is somehow linked with the pre-gain jumpers, more likely to cause problems than improvement. That leaves only the XLR position, and in that one I’m going to leave the Sparkos. As long as I don’t very rapidly turn back on after powering down, I’m not getting any triggering of the protection circuit. The lesson here seems to be that more is not always better.

Having the one Sparkos SS3602 in that position makes an undeniable change to the sound for the better for me. With the Focal Clear, this raises the slam factor on things like bass drums to another level. Otherwise, I think it sounds pretty similar, but I think the amp was already good and neutral, but it didn’t exactly wow me for the $ (I don’t yet have any super tough to drive headphones, so that might also alter the value proposition). With the Sparkos, I’m quite happy with it, and I think it is going to be a well-loved piece of my collection. If this modification does slowly increase wear and tear on the amp, I know I’ll have to pay to get it fixed or replace it, but I genuinely don’t know how much I would listen to it without that change.

So that’s going to be the compromise - 1 Sparkos instead of 3. I’m fully aware that this might be some vicious combination of wishful thinking, confirmation bias, rationalization, etc., but honestly I think it sounds better with just the one Sparkos than with all of them. Maybe having all 3 was just pulling too much current, maybe it was causing some other kind of mismatch that is way over my head, but the one alone seems to increase the slam to a pretty staggering degree. I can understand the position that it might not be good to modify these products for a variety of reasons, and I can understand if the change in sound signature might not be appealing to some people, but I just can not believe that someone with any level of love for audio gear could listen to this amp in stock form side by side with one with the Sparkos at the XLR input and not hear a difference. It may not be safe in the long term, it may not make sense electrically, and it may make the amp measure worse, but it sounds fantastic to me.