300DR functionally becomes a 135!

Huge - 

Straws clutching at, but have you tried to Mute/Unmute (several times) via the handset & logo in case something has got stuck, which power cycling/resets may not be 'budging'

I've had a channel drop-out on a system post a nearby lightning strike (IIRC all the buttons on the pre lit up) - thankfully, after a power-down & resting period all came back OK.

p.s. 1st time I've read the specs on a 272 -  no wonder it's such a popular bit of kit.

What about a change 282 or 252/SCDR/Chord Qutest?

Bob the Builder posted:

What about a change 282 or 252/SCDR/Chord Qutest?

I'll comment on this next weekend.

Vincé 2 posted:

Hi Huge

Clean the contacts of the Burndies sockets and plugs.

Thanks, I unplugged and re-plugged them twice before eventually proving that it's actually the 272 (despite having swapped over the interconnect leads).

OK, I've tracked the problem down - it isn't the 300DR, it isn't the 272 itself (well not exactly).

A dog eat my homework - well more like a ferret stole my music.

I replaced the 300DR with a Nait 5i using the pre-out into the AV input of the 5i.  It worked for a time and then the right channel stopped again.  I checked over all the connections, removed everything I didn't need, dressed the cables and restarted it.  It worked again.

I replaced the 300DR using minimal connections - it worked.  I plugged everything else back in and the right channel stopped.  I unplugged the interconnects to the sub's DFSP and it worked.  I checked the sub cables - no short and 100pF.  I plugged the cables back in with no connection to the sub's DSP - no right channel.  I looked and saw that I'd knocked a ferrite out of position.  I re-positioned the ferrite, it worked again.  Then I realised that I'd re-positioned the ferrite when dressing the cables with the 5i.

Just having the ferrite about 100mm in the wrong place stopped it working, the only thing I can think is that it was forming a resonant tuned circuit that was interacting with some radiated RFI in the area.  Even more weird, the ferrite that caused the problem was on the LEFT channel.

I've removed all the ferrites from all the four interconnects taking signals out of the 272, and now it seems to be fine: I'll see how long this keeps working.

This is completely bizarre.

Blimey Huge, that is indeed a very strange one! Bet you're heaving a sigh of relief.

Oh you bet.  It's almost a matter of life and death - literally: music is the main component of my suicide prevention system.

By the way. Have you done the firmware update, if not worth a try whilst waiting to get it sorted.

Yes I did that about four weeks ago - considerable improvement with the 272.

Currently it still seems to be OK.

Why just moving a ferrite should have such a dramatic effect, I still don't know.

Happy to hear that the 272 does not have to take a trip back to the shop!

Had missed that you had got it working. Woohoo

Thanks, but as an ex scientist I still want to know...

WHY?

However, as an ex scientist I also know I have to accept that if I don't have the correct instrumentation to measure something, then I can't find out about it!
I'll just have to wait and hope it stays fixed.

Huge posted:

Currently it still seems to be OK.

Why just moving a ferrite should have such a dramatic effect, I still don't know.

I can't imagine that the ferrite itself is doing anything that would shut down a channel. I'd guess an intermittent connection that is getting jostled when you play with the ferrite. But I guess you've jiggled everything to check. Most strange.

Not just jiggled, I took the plugs apart to do a visual inspection of the solder joints and I even checked them with a ohmmeter and an LCR bridge.

If you do work out how an actual ferrite is to blame, please let us know. I make judicious use of them all over the place and would hate to think there is a hidden gotcha somewhere.

I guess the real test will be, for you to replace the actual cable with an identical one and put the ferrite in the same spot. The only thing I can possibly imagine is that the weight of the ferrite just pulls an internal wire linked to a floating pin (if using HiLine or SL) a smidgen out of contact in the female DIN socket. In which case, an insufficient sprung DIN socket on the 272 could still be a root cause.

Huge,

Glad to hear your music is playing.  Hoping you have abandoned any possible plans for suicide (makes me shiver to imagine!).  Kudos to you for maintaining your sense of humor.  

Now, as to the ferrites causing this - perhaps we are all better off not knowing?  At the outer limit of science we all reach a point where we introduce "epicycles" as did Ptolemy (a modern example of which is, I suspect, black holes).

Best...

Charlie

Ohhh ferret! Sorry. Huge your typo confused me. It's all clear now.

Oh well that’s the 500 down the drain, well for the time being.

Hi Huge, nothing helpful to say  other than comment you have really found a weird one with this.     But as we are both fans of the little furry ferrous critters,  I don’t see the point of ferrites on signal IC’s unless you have some really high RFI.   I only have mix 75 on SMPS AC & DC sides & H30 on Ethernet.     I hope you have finally nailed this down,  but it does seem very strange.   

CharlieP posted:

Huge,

Glad to hear your music is playing.  Hoping you have abandoned any possible plans for suicide (makes me shiver to imagine!).  Kudos to you for maintaining your sense of humor.  

Now, as to the ferrites causing this - perhaps we are all better off not knowing?  At the outer limit of science we all reach a point where we introduce "epicycles" as did Ptolemy (a modern example of which is, I suspect, black holes).

Best...

Charlie

Actually I've applied to volunteer for the Samaritans - I'm in a minority group they seek to recruit.

Personally I believe that there are few things that are not amenable to analysis by reason and science, even if the conclusion is that there's not enough information in the system to differentiate between the possible macroscopic effects (e.g. Heisenberg's uncertainty principle and Schrodinger's cat).

(And btw, my speakers are Spendor not Kudos!  )

Winky, FZ and Mike,

First the reason for the ferrites:  with the ND5 XS and Nait XS, I found that (at least in my environment) without them all over the place, including the signal leads, there was an increase in underlying background of 'confusion' in the signal and a masking of detail.  I simply kept the ferrites when I upgraded; but I'm not sure that they give such an advantage with the 272 / 300 so I'm reviewing the situation.

In terms of mechanical stress causing a socket disconnection...

The ferrite that moved was on a cable with an RCA phono connector.  The loss of signal was noticed in a signal path that's connected through a different lead with a DIN4 connector.  It can't be a simple mechanical effect, but I still checked all the leads for shorts, dry joints and electrical inconsistencies just to be sure (all of them were OK).

This just seems so strange that initially I just couldn't believe it, so I repeated the test... twice - same result each time!
Later I may even try with a different type of ferrite (2xTDK 70s and 2xWürth ferrites instead of the 4xTDK 70s I used last time).

Huge posted:

Thanks, but as an ex scientist I still want to know...

WHY?

However, as an ex scientist I also know I have to accept that if I don't have the correct instrumentation to measure something, then I can't find out about it!
I'll just have to wait and hope it stays fixed.

Once a scientist always a scientist. I’ll be an ex-scientist when I’m pushing up the daisys

Ravenswood10 posted:

Huge posted:

Thanks, but as an ex scientist I still want to know...

WHY?

However, as an ex scientist I also know I have to accept that if I don't have the correct instrumentation to measure something, then I can't find out about it!
I'll just have to wait and hope it stays fixed.

Once a scientist always a scientist. I’ll be an ex-scientist when I’m pushing up the daisys

You can take the scientist out of the lab, but you can't take the lab out of the scientist!