So here is a VRDN out of a Wayne‘s BA2018 linestage, that seems to be… not working?
Symptoms were a dead channel and loud hum, when replaced with an identical build into the same setting, the line-stage is brilliant again…
My problem is that the PSU looks perfectly intact, and the measurements are spot-on and stable like a rock…
To isolate the problem, do I look after what and where?
Thank you
Symptoms were a dead channel and loud hum, when replaced with an identical build into the same setting, the line-stage is brilliant again…
My problem is that the PSU looks perfectly intact, and the measurements are spot-on and stable like a rock…
To isolate the problem, do I look after what and where?
Thank you
Attach labels to each VRDN voltage regulator board: SN_1 and SN_2 or other phrases that unambiguously identifies which board is which. FIRST and SECOND. ALICE and BOB. Whatever you want.
Now read the story below, paying attention to the italicized phrases.
Does this give you an idea about an experiment you can try? What hypothesis does this experiment test?
Now read the story below, paying attention to the italicized phrases.
- The first time board SN_1 was attached to the linestage, there was a dead channel and loud hum
- Board SN_1 was removed from the linestage
- The first time board SN_2 was attached to the linestage, the sound was brilliant
Does this give you an idea about an experiment you can try? What hypothesis does this experiment test?
Thanks to both Rayma and Mark!
I shall do as advised, and get this process as organized as possible… which of course requires a bit of preparation, so I‘ll need until monday or so until I‘ll have some docs prepared.
Just two things:
- ALICE and BOB, haha, like that!
- vrdn-1 was installed a few weeks ago and has been playing very nicely. (Probably just as nice as vrdn-2.)
david
I shall do as advised, and get this process as organized as possible… which of course requires a bit of preparation, so I‘ll need until monday or so until I‘ll have some docs prepared.
Just two things:
- ALICE and BOB, haha, like that!
- vrdn-1 was installed a few weeks ago and has been playing very nicely. (Probably just as nice as vrdn-2.)
david
The story of my 2 VRDN
Mark, thank you for all your inspiration inputs.
There are basically 2 VRDNs, both built identically (initially meant to be used for a dual-mono-thing).
VRDN-1 I'd call Clyde
VRDN-2 I'd refer to as Bonnie
(this as a reference to the perforated chassis-floor—calling it Verdun 1/2 would have seemed a bit, unrespectful to the VRDN)
First, I build the Wayne's BA-18 linestage and connected it to a Salas I-select board, with a PEC 25K pot. = Perfect operation with various DAC's as input, and ACA and F4.
What has changed?
This is a kind of problem I hate: Not being able to reconstruct what the error was/is.
Actually it's better than anything broken, but it lefts me out
Now I am redoing everything that was tucked in in a clumsy way (new back-plate, rewire everything from VRDN to output)
()
Mark, thank you for all your inspiration inputs.
There are basically 2 VRDNs, both built identically (initially meant to be used for a dual-mono-thing).
VRDN-1 I'd call Clyde
VRDN-2 I'd refer to as Bonnie
(this as a reference to the perforated chassis-floor—calling it Verdun 1/2 would have seemed a bit, unrespectful to the VRDN)
First, I build the Wayne's BA-18 linestage and connected it to a Salas I-select board, with a PEC 25K pot. = Perfect operation with various DAC's as input, and ACA and F4.
- I swapped the POT with a 10K Elma relay-based attenuator board. = Perfect operation with various DAC's as input, and ACA and F4.
- I grounded the WLS, with a CL60 thermistor. = Perfect operation with various DAC's as input, and ACA and F4
- Installed the cinemag CMOQ4 for more gain = One channel gone, loud hum.
- Removed cinemags = no change.
- Removed everything but VRDN-1 and WLS = no change
- Swapped VRDN-1 with VRDN-2, ground floating = good.
- Swapped VRDN-2 with VRDN-1, ground floating = good.
What has changed?
- Cinemags are out of the circuit
- WLS ground is not connected
- VRDN-1 + VRDN-2 ground-planes ar not connected
This is a kind of problem I hate: Not being able to reconstruct what the error was/is.
Actually it's better than anything broken, but it lefts me out
Now I am redoing everything that was tucked in in a clumsy way (new back-plate, rewire everything from VRDN to output)
()
Verification and debug is usually messy and often confusing.
Try "X" -- it doesn't work.
Try "Y" -- it works!
Try "X" again -- now it works!
Try "Y" again -- it still works!
Now you have a choice. You can (attempt to) figure out why "X" didn't work the first time. Or you can decide that you really don't care what went wrong the first time, what you do care about is: it's working now.
You can decide to completely ignore the fact that thousands of DIYers have successfully included Cinemag transformers in their builds. There's mountains of evidence that Cinemags work extremely well -- just not in YOUR project build. You can leave it out and don't bother to figure out why.
You can also ignore the fact that "X" and "Y" are identical copies of the same board. One worked and the other didn't -- who cares why this happened? Then, without any changes to the boards, both worked -- who cares why?
Try "X" -- it doesn't work.
Try "Y" -- it works!
Try "X" again -- now it works!
Try "Y" again -- it still works!
Now you have a choice. You can (attempt to) figure out why "X" didn't work the first time. Or you can decide that you really don't care what went wrong the first time, what you do care about is: it's working now.
You can decide to completely ignore the fact that thousands of DIYers have successfully included Cinemag transformers in their builds. There's mountains of evidence that Cinemags work extremely well -- just not in YOUR project build. You can leave it out and don't bother to figure out why.
You can also ignore the fact that "X" and "Y" are identical copies of the same board. One worked and the other didn't -- who cares why this happened? Then, without any changes to the boards, both worked -- who cares why?
So truely true…
Although it would be interesting (to a limit) to investigate why it didn’t work, but (learning curve aside) i consider it counterproductive to try to redo the fault I made [emoji4]
As for the cinemags, I again blame myself not the trannies—and this situation is different: they haven’t yet worked so it very much seems worth the effort to do it right this time!
Although it would be interesting (to a limit) to investigate why it didn’t work, but (learning curve aside) i consider it counterproductive to try to redo the fault I made [emoji4]
As for the cinemags, I again blame myself not the trannies—and this situation is different: they haven’t yet worked so it very much seems worth the effort to do it right this time!