Does it get very loud very quickly?
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Does it get very loud very quickly?
I recall years ago coming across a similar issue that was solved via a cable swap, the fact you have tried several with no change shows its not that. It was a very long shot though.
I have however had problems with kit with very high output overloading inputs which manifests in a similar way to how you described. Sometimes companies are not totally honest with their specs. First time I tried a Chord DAC 64 many years ago it overloaded the input on the amp I was using at the time. That company subsequently changed the amp design to accommodate higher output sources.
Some modern highly compressed and loud CDs can tip things too, what is just on the edge of being ok with normal CDs can be overloaded by this type of CD.
I agree. I wonder how long the mkI version was available and why it's been superseded by the mkII. Even so, how would it even get to market if it can't handle 2V? And where in the chain is its volume control? If it was the first thing the signal encountered it would be a simple matter to turn it down to prevent overload.
On the assumption that it's only quite small/light, maybe it wouldn't be a bad idea to send it to Jez for checking out and/or repair.
That's the crux of it, where's the vol control? Indeed as I suggested it should not have got to market if it can't handle the standard 2V output of the sources 90% of customers will be using with it!
I wasn't for a moment suggesting that the op send it to me for any tests, more just a throwaway comment that as in 90% of such cases it would be dead easy and take minutes if one was present with suitable test gear to see it for ones self. If the op really wants me to check it then I can do that but would need the source as well as the headphone amp and if I found a problem I would have to modify it to suit I guess. It may be not an overload problem but a case of the headphone amp oscillating when it sees a certain source impedance or combination of that and output level. Another possibility is that the source doesn't like a capacitive load it sees in the headphone amp and oscillates.... Without an oscilloscope the op would never know.
Just to update, I'm currently using a Tisbury passive (mk2) and going through that there is no distortion either. I've got it set at 0db on the dip switches and plugged into ouput 2 which is set to looped. In my limited knowledge, I take it that it's basically acting like a tape out as it's sending the input (DAC) straight to the output, taking out the volume pot?
I can only assume there is some kind of incompatibilty between my DAC and headphone amp (could be the oscillating maybe like you mention Jez). Very strange indeed.
Yes, it's strange that it works fine with the Tisbury and the other peramp, but not when the DAC goes straight to the headphone amp - the signal level should be the same in all cases.
Well, well, well... Just had an interesting development. Having lived with the Tisbury a few days, I like the sound so am leaving it in place for a few weeks before switching back to the active to compare.
Anyhow, I've been connecting up all sources and while doing so, I left a set of IC's in the 2nd output of the DAC still going into the active pre. Now, when I went to listen, there was now distortion coming through the speakers! After more fiddling with cables to see why this was suddenly happening I found that by removing the 2nd set of DAC outputs the sound returned to normal. I haven't yet re-tried the headphone amp because I am sure when I did before I still had both outputs active but I will report back when I do.
If it turns out it's the DAC at fault, why would having IC's plugged in both outputs cause this distortion? Surely it's designed to output to both otherwise why have them? (btw, the active pre was not in use when this distortion occured).
Yep, just tried the headphone amp straight from the DAC, without having the 2nd set of IC's connected and no distortion at all. Looks like it's the DAC at fault.
Bit annoyed about this, looks like I'll have to send it back to Arcam.
Anyone know what the problem might be?
Just found this in the manual:
''The D33 DAC provides a pair of unbalanced audio
outputs on standard RCA phono connectors and a set
of balanced audio outputs on male XLR connectors. All
audio outputs are available simultaneously, allowing
multiple devices to receive the D33’s output signal.
However, to maintain the cleanest possible signal path
the pair of unbalanced outputs is not individually
buffered. This means that if two amplifiers are
connected, both must be powered on to avoid degrading
the signal.''
Could that be the issue? I shall have to try both amps on and see whether the problem goes away.
could wel be.. yeah try both on.