Hi
I use two of these G2 amplifiers (one per channel) to drive two home-built ‘bass modules’ each with a single Dayton Audio DC-160-woofer. Long story short I put them (and the bass modules) in to my main system which consists of Tannoy R2 floorstanders, 2 x BK Gemini II sealed 10 inch subwoofers (one per channel), Arcam A28 amplifier, Arcam D33 DAC and Naim CDSi CD player. They really have helped with stage height, punch and music generally coming alive.
However, and it’s a big one, if the Arcam amplifier is switched on, when I switch the Nobsounds on at the wall (both switched off on their own switches on the amps themselves) it clicks the Arcam into protect mode. I did this once with the volume turned up and it sent a big pop through the main speakers + BK subs and I had to turn the Arcam off at the wall to get it out of protect mode. I have tried both Nobsounds individually and they both do it, yet nothing else does this on the same wall socket. The Arcam uses a different socket. Clearly I don’t want to damage the Arcam (which cost much more than the Nobsounds). I assume that the Nobsounds send something up the RCA cable and into the preouts of the Arcam when they are powered on at the wall, despite the fact that they are switched off themselves! I assume this is also happening when the Arcam is off but I just don’t know about it. I am concerned that the amps are not safe, certainly for those units upstream of them!
Is anyone else aware of this issue with this design of subwoofer amplifier? They do not seem to do it in my office system using a different main amp (AVA). Is there anything else I could try/do to stop this happening? I have just got the system pretty much exactly as I wanted it. The alternative is to replace the Nobsounds with something else that has an adjustable LPF such as 2 x BK electronics plate amplifiers or a single Dayton Audio APA 150. Unfortunately, short of cheap Chinese amps, we don’t seem to have the same choice of off-board LPF amplifiers in Europe/UK as is available in the USA - the OSD amplifiers don’t seem to be available for example.
Any advice on this would be greatly appreciated.
Regards
Alex
I use two of these G2 amplifiers (one per channel) to drive two home-built ‘bass modules’ each with a single Dayton Audio DC-160-woofer. Long story short I put them (and the bass modules) in to my main system which consists of Tannoy R2 floorstanders, 2 x BK Gemini II sealed 10 inch subwoofers (one per channel), Arcam A28 amplifier, Arcam D33 DAC and Naim CDSi CD player. They really have helped with stage height, punch and music generally coming alive.
However, and it’s a big one, if the Arcam amplifier is switched on, when I switch the Nobsounds on at the wall (both switched off on their own switches on the amps themselves) it clicks the Arcam into protect mode. I did this once with the volume turned up and it sent a big pop through the main speakers + BK subs and I had to turn the Arcam off at the wall to get it out of protect mode. I have tried both Nobsounds individually and they both do it, yet nothing else does this on the same wall socket. The Arcam uses a different socket. Clearly I don’t want to damage the Arcam (which cost much more than the Nobsounds). I assume that the Nobsounds send something up the RCA cable and into the preouts of the Arcam when they are powered on at the wall, despite the fact that they are switched off themselves! I assume this is also happening when the Arcam is off but I just don’t know about it. I am concerned that the amps are not safe, certainly for those units upstream of them!
Is anyone else aware of this issue with this design of subwoofer amplifier? They do not seem to do it in my office system using a different main amp (AVA). Is there anything else I could try/do to stop this happening? I have just got the system pretty much exactly as I wanted it. The alternative is to replace the Nobsounds with something else that has an adjustable LPF such as 2 x BK electronics plate amplifiers or a single Dayton Audio APA 150. Unfortunately, short of cheap Chinese amps, we don’t seem to have the same choice of off-board LPF amplifiers in Europe/UK as is available in the USA - the OSD amplifiers don’t seem to be available for example.
Any advice on this would be greatly appreciated.
Regards
Alex
Many thanks. I have drawn a basic diagram of the power, signal and speaker level wiring from the Arcam A28 amp downstream to the BK subwoofers and Nobsound G2 amps/passive bass modules. Hopefully it is clear enough to follow. I made one error when I started colouring the speaker wires (should be CC green) red instead of green. The black lines are power and the red lines are pre out/signal level RCA connections. I use Y splitters (on per channel) from the Arcam amp so that all four bass amplifiers (subs + Nobsounds) receive a signal from the left or right preout pair. I tried the Nobsounds without the Y cables and they still did the same thing!
The Arcam amp and the Nobsounds come off different wall sockets but to the best of my knowledge the actual house main is the same. I have also included a picture of the system to give you an idea how it is all laid out.
If you have any questions or ideas, please let me know.
Sorry that the pictures are upside down!
Regards
Alex
The Arcam amp and the Nobsounds come off different wall sockets but to the best of my knowledge the actual house main is the same. I have also included a picture of the system to give you an idea how it is all laid out.
If you have any questions or ideas, please let me know.
Sorry that the pictures are upside down!
Regards
Alex
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Thanks for looking. Just to clarify, both G2s are only wired via RCA from the Arcam’s preouts. I use Y splitter cables on the Arcam’s preouts so that the two BKs and the two G2s receive their signal at preout level thus system volume is controlled by the Arcam only. The only items linked to the Arcam’s speaker outputs are the two main Tannoy speakers.
Regards
Alex
Regards
Alex
I’m certain the issue is coming from the G2s. My guess is that they somehow let a big ‘switch-on surge’ through even when they are powered off. It was a loud pop/bang the time I had the volume on the Arcam up. I’m guessing that they lack something on their inputs to stop this switch on surge go upstream through their RCAs - they were cheap but they would be so much better for me at least if they spent just a little more making them ‘safe.’ It’s a real shame as otherwise they performed flawlessly but I dare not risk damage to my other components.
I’m waiting to hear back from BK Electronics ref their plate amp options but the ones they list on their website are overkill power-wise, even though price-wise they are good value. Another option would be using a standard stereo power amp (e.g. Arcam, Cyrus et al) and use a MiniDSP or Dayton DSP-LF (X2 - one per channel) to set crossover/phase etc. I will start another thread on this for user’s experiences of these products.
Thanks for your help and suggestions.
I’m waiting to hear back from BK Electronics ref their plate amp options but the ones they list on their website are overkill power-wise, even though price-wise they are good value. Another option would be using a standard stereo power amp (e.g. Arcam, Cyrus et al) and use a MiniDSP or Dayton DSP-LF (X2 - one per channel) to set crossover/phase etc. I will start another thread on this for user’s experiences of these products.
Thanks for your help and suggestions.
OK, bit of an update, I tried swapping a few bits about and putting a G2 on the same power strip as the Arcam amp. Net result,I still get the amplifier going to protect. However, when it did this I was looking at the Arcam’s display and it read “DC Offset” when it clicked in and out of protection mode. I assume that means that upon switching on at the wall, the Nobsounds send DC up the RCA cable. I’m no expert, but I assume that is not good.
Any ideas of a solution short of getting new sub amps?
Edit: I have just tried the same on my Arcam A18 amplifier in the office (connected the same way) and no triggering of the protection relay or message using the same Nobsound G2. It’s a mystery.
Any ideas of a solution short of getting new sub amps?
Edit: I have just tried the same on my Arcam A18 amplifier in the office (connected the same way) and no triggering of the protection relay or message using the same Nobsound G2. It’s a mystery.
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