Room acoustics and treatment isn't a slap something in the room and it's good. It is an exact science and the better you invest in a measurement mic, and some practical and useful methodology to room treatment, the better
Too much bass from my Octave V70SE
Hello all. Has anyone experienced too much bass from an integrated tube amp? I just added an Octave V70se to my set up. I've also added some room treatments. Which consists of cork wall tiles covering entire wall behind my system, and behind each speaker i have stacked a 24x24x5" bass trap with a 24x48" skyline diffuser on top of the trap and a 24x24" absorber/diffuser on top of that. The room is multi purpose so I did the best i could with the treatments. My main set up is Anthem avr, bluesound node, anthem mca325 amp, rega p8, and a Schiit Skoll phono stage. After the added room treatments I find that i listen predominantly with the ARC room correction turned off. So the treatments definitely helped.
Now to the Octave. I added the integrated tube amp because I wanted to mainly use it with my Rega. I added a switch however that allows me to switch from the Octave to the Anthem so while I'm streaming through the node via my avr , I can switch to either amp. The Octave is really really good. A noticeable improvement over the Anthem amp which I really like but at more than double the price it should be better. Ok, no problem there. The problem arises when I run my Rega straight to the Octave via the Schiit Skoll. Bass is very strong. Too strong on alot of tracks. At about 50% volume i start to get what I'll describe as low frequency feedback it gets really bad the more I turn it up. This dose not happen if irun the Rega through my Anthem set up. My guess is that the stylus is starting to vibrate do to the bass. I have an isolation platter under the rega and iso acustic feet on Rega itself. Also isolationpucks under my speakers. Which I forgot to mention are Paradim founders 120h. I also stacked some large cushions in the corner behind my right speaker. The left one has open space behind it. I've tried moving the Rega off of the council and further away but same thing happens. Keep in mind that this is a no issue while running through my anthem rig. The volume has to get pretty loud for the problem to show itself but as the volume goes up I starr to notice a slight LF noise which gets exponentially worse as the volume goes up. Why? Can it be the tubes that make the Octave bass heavy? The phono pre? Is the Octave itself that sensitive to vibration? Im at a loss.
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Sofia, much thought and consult with GIK and more thought and measurements with my ARC were taken. One dose the best with the conditions and resources that one has. Im sure tweaking will be done, but in my post I did state that I'm listening primarily now without room correction enabled where as before it was almost always on. So I guess I did ok....thanks |
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@sandrodg73 You might have better success getting your concerns addressed if you repost in the correct forum, i.e. "Amps Preamps." |
Tube microphonics is a possible culprit. That would account for the difference between the results with the Octave vs those with the Anthem. The phenomenon you describe is also compatible with microphonics. Tap the tubes on the Octave gently with the eraser end of a pencil with volume set at the threshold of where you start to hear the problem. Gently. |
@sandrodg73 Wrote:
See here Mike |
it is odd to me that you say on one hand that tapping the tubes with a pencil eraser has no effect and on the other hand measures, you have taken to reduce the possibility for acoustic feedback into the amplifier seem to help. The difference between the anthem amplifier and the octave amplifier, so far as I can see from afar, is tubes. So if isolating from acoustic feedback is helping, then it must be in someway the tubes or the circuit that is resonating in response to airborne energy. That adds up to microphonics. Anyway, I am otherwise stumped. in the end, what is important is solving the problem, not necessarily understanding the source of the problem. So I am glad you are getting somewhere. |
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Thanks guys. Great article ditusa. Makes sense. I guess ultimately I have a vibration issue which leads to feedback at higher volume levels. So its probably negatively affecting SQ overall even if its not completely obvious at lower volumes. So plan of attack is an iso table or feet under the Octave( and probably tube dampeners too), some better bass traps in the corners, better iso feet for my speakers, and after I've done what I can physically ill run ARC on the towers themselves to hopefully fix the frequencies that I'm not able too. This has been quite the process picking an amp, treating room, and dealing with this issue. My cables are a mess. Im looking forward to resolving the issue, dressing all the cables and actually spending time enjoying my new toy, not evaluating.
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