Just getting my gear set up in a new place.
Signal in reverse order: Royds Minstrels, Chord SPM900, passive preamp (pot in a box style), DAC TDA1541A on an Arcam Alpha board with Lampizator output, Shiga Black.
Had issues with my Shiga Black not playing and so for the last couple of days listening just from my phone connected to preamp with no problems.
Just got the Shiga working again (when I first put it together managed to pull some through hole playing out which tore a pad from its trace - the solder jumper I had managed to make to the trace got disturbed in transit so I had to remake the connection (better job this time I hope))
Got everything plugged in again. Powered on. Click the input selector over to DAC. There was a pop at the speaker and no music. The power lights on the front panel of the amp dimmed over a couple of seconds and I noticed a red led on inside the amp which is not usually on (see pic). When I turned the input to DAC the volume was pretty high on account of it being set for my phone. The DC output from my DAC ranges between 3.5-4.5v.
Unplugged everything from the amp. Powering on after leaving it to sit for a while it powers on but 1-2 secs after the aforementioned led comes on and the power lights dim again.
What do you think has happened? Obviously some kind of protection. How do I recover from here?
Thanks for help in advance
Signal in reverse order: Royds Minstrels, Chord SPM900, passive preamp (pot in a box style), DAC TDA1541A on an Arcam Alpha board with Lampizator output, Shiga Black.
Had issues with my Shiga Black not playing and so for the last couple of days listening just from my phone connected to preamp with no problems.
Just got the Shiga working again (when I first put it together managed to pull some through hole playing out which tore a pad from its trace - the solder jumper I had managed to make to the trace got disturbed in transit so I had to remake the connection (better job this time I hope))
Got everything plugged in again. Powered on. Click the input selector over to DAC. There was a pop at the speaker and no music. The power lights on the front panel of the amp dimmed over a couple of seconds and I noticed a red led on inside the amp which is not usually on (see pic). When I turned the input to DAC the volume was pretty high on account of it being set for my phone. The DC output from my DAC ranges between 3.5-4.5v.
Unplugged everything from the amp. Powering on after leaving it to sit for a while it powers on but 1-2 secs after the aforementioned led comes on and the power lights dim again.
What do you think has happened? Obviously some kind of protection. How do I recover from here?
Thanks for help in advance
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Ok. Went away, made and ate dinner. After having a long rest the amp will power on, relays click, green leds light, seems stable.
I know that some amps don’t like DC on the input - is this one of those amps? So I’m guessing there are capacitors on the input that soak up the DC and when these get full it triggers the protection that I was experiencing. Not being plugged in for a period allows this DC soak to trickle away so the protection is not triggered?
Obviously I am shy about just plugging it back in where it was and firing it up again.
The passive pre (stepped attenuators) is relatively new and I did not have much playtime before it all went in the freight, prior to that a NAD C150was on preamp duties - I presume this was able to clean the signal of DC from the DAC before it went to the power amp?
Was it because the volume pot was cranked too high?
Do I need bigger output caps on the DAC -currently 2.2uf?
I know that some amps don’t like DC on the input - is this one of those amps? So I’m guessing there are capacitors on the input that soak up the DC and when these get full it triggers the protection that I was experiencing. Not being plugged in for a period allows this DC soak to trickle away so the protection is not triggered?
Obviously I am shy about just plugging it back in where it was and firing it up again.
The passive pre (stepped attenuators) is relatively new and I did not have much playtime before it all went in the freight, prior to that a NAD C150was on preamp duties - I presume this was able to clean the signal of DC from the DAC before it went to the power amp?
Was it because the volume pot was cranked too high?
Do I need bigger output caps on the DAC -currently 2.2uf?
I have not been able to find any useful info online about this amp.
It was Chord’s first production amp. There is only a post on the Chord FB page. I’ve emailed the company to ask for any more info but had no response (this would be at least 12m ago probably longer).
It was Chord’s first production amp. There is only a post on the Chord FB page. I’ve emailed the company to ask for any more info but had no response (this would be at least 12m ago probably longer).
Panic over. I think it’s obvious from this conversation with myself that I don’t have bleeping clue about any of this. Know enough to be dangerous, that’s me.
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