Tube Phonostage Causing Rumble and Noises

Are you using RCA interconnects

Your phono amp is reproducing low frequency signals coming from your turntable, its support, and the room.

You could try springs under the turntable. 

If you can’t sort it out, try a rumble filter.

Ok, I apologize for this.
 

How loud is your subwoofer set? Typically  the correct settings to have them correctly integrated is the crossover very low, speaker dependent, but 40hz and volume 10 - 20%… I mean basically turned way down to correctly fill in the trail off of your main speakers.

I have sat down to listen to someone’s high end audio system and immediately jump up and crank their sub woofer down that is cracked up to 80% with a crossover at 120 hz because it is squeezing the sound stage nearly out of existence.

Rumble filter needed to attenuate everything below 20hz. In the past preamps often had this as a switchable option. My RGR 4 has it and I leave it engaged.

+1 Could it be that simple? Sounds like a feedback loop.

How loud is your subwoofer set?

When the phonostage is idle, there was just rumble.

Thanks for the feedback. I asked Jim White about the rumble filter and he said it was a bad idea. I set the sub volume at around -20 dB. Crossing over at 35 Hz for the Apogee and 85 for the LS3/5 A. Definitely not loud.

No issue with the rumble/noise playing the DAC (Bricasti M1 Series II).

I am using XLR throughout except the tonearm cables.

I don’t have issues using the I/o with the Apogee. Maybe it’s because the frequency response is 25-25k Hz and the I/O is generating subsonic frequencies under 20 Hz.

One issue with LP records is the need for the RIAA equalization curve. Due to the technical requirements of vinyl record recording, for playback, the RIAA curve boosts bass +20 dB and cuts high treble -20 dB to compensate for the polar opposite frequency adjustments made when the master was cut.  This means that rumble and any imperfections in the record will be magnified.

Over at the Propeller Head Plaza section at Audio Asylum (where geeky stuff is often discussed) a fellow posted some screen shots of spectrum analysis he did on various phono cartridges.  On one set of images, the 20 Hz background noise was about -70 to -80 dB, but when you dropped down to 10 Hz, the background noise increased to -39 to -48 dB.   Therefore, if you are running a subwoofer with a turntable and have a phone preamp & amp system that is linear in the sub-bass, it is very easy to end up with playback problems.

Since the problem persists after tube swapping, I am beginning to suspect there are defective parts in the unit.

when lightning strikes twice, it cannot be just coincidence. Before I acquired the I/O, I got a Rhea Signature. The minute I turned it on, my jaw dropped to the floor seeing the speaker driver cones being pushed all the way out. It was a scary scene. I took the Rhea to a local tech. He did some measurements and concluded the Rhea was generating subsonic frequencies. I informed my distributor about the issue and he didn’t believe me. I took the Rhea to him and he witnessed his diver cones got pushed out all the way. He immediately promised a replacement and I opted for the I/O.

Can anybody offer some information about subsonic frequency coming out of a tube phono that is caused by failed or defective parts?

Thanks.

Thanks misstl. Jim White did mention RIAA curve boost. Jim also said it was impossible to eliminate the rumble to zero although I was assured the rumble was eliminated before I paid for the service. I don’t mind a little rumble but no one can listen to records while the entire room is shaking.

This is most puzzling.

One more idle thought -- turntables are mechanical devices and subject to wear over time -- just like your car tires and anything else mechanical. Might be worth trying a different turntable or two (preferably relatively new) in your setup and see how that affects things. It could be you have a worn bearing or some other issue, such as a suspension problem, as others have mentioned.

Not as bad as yours, but I had a version of this occurring when playing my turntable, utilizing the built in tube phono stage in my preamp.  The solution for me is to turn off the subwoofer that is near my turntable when playing vinyl.  No problem leaving the 2nd sub on that is some distance away.

You might try turning off your subwoofer/subwoofers as a test.

Thanks again misstl. I get the rumble when the turntable is not in use.

my turntable is about 6 or 7 years old. Lightly used because I listen to digital most of the time. 

Thanks, jetter. If I can’t resolve the issue, that’s the only option. Luckily Aesthetix makes good phono. It is just as enjoyable with or without a subwoofer.

To me, the primary issue is not whether I use the sub or not. I am deeply concerned that the I/O is generating a subsonic frequency that could damage speakers with cone drivers, like what happened to the Rhea.

I assume you mean by not in use as not playing a record but still connected and selected as the source. If this is the case, your table/cartridge is picking up subwoofer output and amplifying it somehow. Airborne or structural. Fit Nobsound springs under sub to decouple from floor. Or, if you disconnect the tonearm connection into the phono, and it’s still causing rumble from sub, then, yes something is amiss with the phono amp. Can you verify if this is the case? There is an unlikely possibility that components in the unit are microphonic. Given that you’ve experienced this with 2 units, it’s likely something else is going on unrelated to the phono amps.

I get the rumble when the turntable is not in use.

Feedback.  Isolate the turntable.  Move the sub farther away from the table.  

If you want to try a rumble filter, I can send you one to try out.  I believe it is an RF-5 I purchased from KAB.   I used it for years until I bought a Technics SL 1200G.   My previous VPI Prime and Scout needed the filter.   I can send it to you and if it works, we can talk price.  If it doesn’t, you can send it back.  If interested, send me a PM. 
 

Bob

@bpoletti is correct. Your turntable is sitting in a “hot spot”, a zone where bass frequencies are being amplified. If it’s near a corner, try moving it.

@agharion "I get the rumble when the turntable is not in use."

You've got me confused. Until now I thought the thread was completely about rumble while playing LPs.  Here's a line from your original post: "As soon as a signal was passed from the phono, the sub went crazy, it produced some subsonic noise that made the room shake. I then connected the phono to a tube integrated amp and I heard a loud distorted noise through my LS 3/5A."

So, I'm not sure where you go from here. You've got a ton of suggestions so guess you just keep experimenting. Have you brought in a different phono preamp to find if the issue is still present?

If moving the turntable and/or subwoofer does not work, your cheapest option, as others have pointed out is to install the KAB RF1 subsonic filter.  However, this will require that you insert the filter in between the phonostage and the amplifier and will require an extra set of RCA cables.  If you are using XLR connection from your phonostage to amplifier, then it becomes a little bit more cumbersome and will require xlr to rca converters (male and female). The RF1 filter can also be connected directly to the tape-loop if your preamp/phonostage has this option.

Other options include getting an isolation platform like HRS, SRA or Minus K depending on your budget.  And if all else fails, then get a phonostage with a built in subsonic filter. 

As an fyi, I had subsonic issues from my very first turntable, likely due to my suspended wood floors. In the initial stages, I did have to replace the driver on my REL subwoofer.  Subsonic rumble can lead to equipment failure over time if not mitigated properly.

@OP You indicate that there is no rumble when the Aexthetix phono stage is played via your Apogee. It's not impossible that the sub is reproducing frequencies that are below the bandwidth of the Apogees.

In terms of fault finding, you should borrow an alternative phono stage from your dealer - preferably solid state.

If that eliminates the problem then you know that the issue is interaction between the turntable/sub/phono stage.

Tubes are microphonic and the IO is relatively unusual in using tubes for all of its gain so the issue is, pardon the pun, amplified.

You need to use a subsonic filter. Many of us use them. They operate below human hearing and will solve your problem. @stereo5  was kind enough to offer you one to try. You should do it as your next step and potentially save yourself a lot of grief and expense. Springs won’t fix this. 

Do you have a modem or internet satellite (like an Orbi) close by?  I notice that my phono pre-amp meters have activity when the Orbi satellite is close by.

Hi Noromace, not in use means not playing and still connected to the select source.

my turntable is far away from a corner and the sub is at least 5 ft from the turntable.

At this point, I probably should try the rumble filter. I will give KAB a call tomorrow to get more info. Stereo5, did you mean RF-1 because I don’t see RF-5 on KAB website.

I appreciate everyone’s advices and help. Thank you all.

Do your tubes have tube dampers? It probably won't cure the problem you are having, but if the issue is microphonic tubes, damper rings may help.

Another thing to look at. A friend of mine had a terrible noise issue with his phono stage. It was later discovered to be a bad dimmer switch on the same AC circuit. You should try plugging the phono stage into different outlets to see if this is a noisy power issue.

Try changing out your interconnects. 

Hi dmguragno, thanks. I just moved the phono power cord to another receptacle.

I had an experience that a defective receptacle caused my power amp to overheat.

@agharion

If your rumble occurs with needle out of the groove, that is not turntable feedback! And it does indeed point to the Io Eclipse as a culprit for generating this unwanted LF noise. The needle has to be in groove to test for table feedback issues. I used the needle in groove, at rest, to test many many times in my "problematic" small room rig.

It’s a lot of money to have invested in that Io. I’d try to borrow another phono stage to really nail it down to the Io. Heck, maybe buy a Hagerman Trumpet MC - it sounds great for the money ($1289), might surprise you, works with almost any cartridge, won’t cause this horrible noise, and is handy to have around as a backup and sanity check.

But yes, the KAB rumble filter should "fix" this problem, but if it’s being generated by the Io I wouldn’t keep that phono stage in there regardless. My problem in my small room rig was feedback based, and the KAB did indeed resolve it (I went through 2 of these KAB’s actually; the 1st unit was defective) - though I don’t feel it’s quite 100% "sonically transparent" as claimed. However it is indeed good, and FAR better than dealing with the issue you describe. In the end my issue bugged me enough that I vowed to resolve the feedback issue itself, and eventually did. I now run happily without the KAB filter. I don’t think with all you’ve invested, you should tolerate a phono stage generating rumble. The fact that the company sent it back like this is a huge strike against.

And just philosophically, I don’t consider tubes capable of producing up to 80dB of phono gain without inviting massive noise issues. That’s why everyone else uses a JFET stage or SUT for MC gain. I’m sure it’s a nightmare selecting and re-selecting low noise tubes.

Hi mulveling, thanks. I will certainly look into the Hagerman.  If I can’t resolve the problem, getting the Hagerman at $1289 sounds like a good option.

I was interested in the Pass Labs XP-27 but the price is way up there. From my experience with Pass, they offer superb customer service. I have their XVR-1 crossover. The balance started to skew to the left a couple of years ago. They replaced the 4 attenuators but the problem came back after a few months. The took it back two more times and the same problem still persisted. They took it back for the fourth time and arranged for me to ship it directly to Nelson Pass. Nelson fixed it in less than a week. I only paid for the attenuators ($60) and first time shipping. They didn’t charge me anything after that. That’s good service.
 

I’m curious if you have a hot spot and the turntable is sitting on the peak of a standing wave.  
 

I would try to move the turntable forward off the wall or just anywhere.  Also consider bass absorption on the front wall.

i had not a rumble, but a low, loud, buzz (or hum!? No clue what he right term is) that would gradually appear (especially listening to “sticky fingers” Riling Stones)  if my volume was too high using the turntable.  It wasn’t coming off up the turntable, either.  This is a super-isolated VPI Avenger Titan, siting on a 3 inch slab of hardwood with rubber feet, sitting on a Symbol Audio table.

i read somewhere that the cause could literally be sound vibrating the stylus or cartridge.

I had extra GIK bass trap panels and lined one up right behind the audio cabinet, just sitting on the floor with about two feet sticking up so it absorbed the “bounce” off the back wall.  Immediately went away.

i then did a cleaner install.

i had not a rumble, but a low, loud, buzz (or hum!? No clue what he right term is) that would gradually appear (especially listening to “sticky fingers” Riling Stones) if my volume was too high using the turntable. It wasn’t coming off up the turntable, either. This is a super-isolated VPI Avenger Titan, siting on a 3 inch slab of hardwood with rubber feet, sitting on a Symbol Audio table.

i read somewhere that the cause could literally be sound vibrating the stylus or cartridge.

I had extra GIK bass trap panels and lined one up right behind the audio cabinet, just sitting on the floor with about two feet sticking up so it absorbed the “bounce” off the back wall. Immediately went away.

i then did a cleaner install.

@davetheoilguy I recently started playing with VPI turntables, and really love them BUT they are more susceptible to a ~ 100Hz resonance, in my experience. I first perceived this as a background rumble / hum / buzz which became more pervasive with higher playback SPL, and thought it was a ground loop - but upon further investigation, confirmed it was indeed feedback!

It’s a combination of the plinth and tonearm. I’ve experienced it with Aries 3 and Avenger Reference, on a Critical Mass Systems rack and Platinum filter. In my case, the issue got FAR worse with the 10" 3D arm wand. With the Fatboys (both uni and gimbal) the problem is mitigated enough to no longer be a concern. The 10.5i metal arm is actually quietest of all (its problem resonance is much higher in frequency but also much lower in level), though the Fatboys do sound better overall. The original 3D arm was just unusable in my small room. In fact, at a high enough volume it could be triggered into runaway feedback - fortunately I’m quick on the mute button! You could destroy your speakers otherwise.

I’ve read a couple other instances of this issue with the original 3D arm, but it doesn’t seem to be well known overall.

With my Clearaudio magnetic bearing (CMB) decks, there are no problems with 100Hz (drum beat like) frequencies, but they can be hell at subsonic frequencies (visible woofer flapping), unless you have truly excellent support underneath them.

Again, I don't think any kind of table feedback is OP's issue since he says it happens with needle out of groove. The cartridge coils form part the "constrained" layer between vinyl groove / cantilever on one side, and damper / suspension on the other side. When stylus is lifted out of groove, it cannot generate signal. 

Thanks everyone for your feedback and advices. I think I will take the easy way out, ie play records without the sub.

Thanks a million.

@mulveling 

“With the Fatboys (both uni and gimbal) the problem is mitigated enough to no longer be a concern.”

Sadly, this is also the Fat Boy — Kevlar 3D printed.

I also have the Esoteric Grandioso turntable.  Same issue when I used the Van den Hul Frog Gold cartridge, so I think it’s the cartridge, which is otherwise lovely.
 

I two huge SVS PB 16 ultras and Bowers 800 (Diamond) to fill a big space and I like to listen loud.

I measured and had an off the charts standing wave peak about 1.5 feet off the front wall.

Regardless of what is picking up the feedback, the base trap solved the issue.

@davetheoilguy 

Interesting - still so many surprises and lessons to be had in this hobby! That's cool you were able to isolate the problem to standing waves, and resolve with acoustic treatments. I *think* the majority of my issue here was structure-borne energy, so that is indeed different (moved rack around a lot trying to avoid the worst of standing waves and structure-borne energy). I've recently had the Frog Gold on the Fatboy here. And agree - it's such a lovely, well balanced cartridge!

@mulveling 

I’d love to say I’m an acoustic genius, but I figured out it was a standing wave because every time I went to look at the turntable to figure out what was going on, the sound would rapidly fade (and my heart would start beating way too fast, which I figured out was relevant later).

A very Heisenberg’s cat situation.  I’d look and the sound would go away.

Eventually it dawned on me that my body was breaking up the wave.  Did a little trial and error and then tests to confirm.

The weird heart rate is a classic symptom of intense subsonics, which I knew from working in a haunted house when I was a teenager.

This whole OP issue is odd.

@davetheoilguy - the Frog is relatively high compliance for a moving coil and favours arm's on the lower end of effective mass range, so if there is a problem, it's more likely to be in matching of the arm and cartridge than the cartridge per se.

The phono stage is fine. It sounds like the subwoofer is way too sensitive. I would disconnect the sub and any crossovers and see how things run. Remember, records always produce a little rumble. If all is back to normal you have a subwoofer problem, if not than you will have to start eliminating units one at a time. Other sources do not produce a lot of very low frequency garbage like a record does and may not excite the problem. 

@yoyoyaya 

The 3D printed tonearm is one of the Van den Hul recommended tone arms for the Frog Gold and vice versa.  In fact, they market together.  The mass of the 12 inch dual pivot is 12.5g.  They sound wonderful together.

Also note that the problem (as stated above) reproduced with the cartridge on the Esoteric Grandioso with its TA-9D tonearm which is a radically different design.

And there is no fault invovled, except the odd acoustics of my room and my tendency to listen at high volume.  I suspect any sensitive cartridge would have had feedback.

Thanks Davetheoilguy. I thought from your post that the Frog was gone before the Esoteric arrived but of course the Esoteric arm is a different kettle of fish altogether. The Frog is a great cartridge - I owned one for ten years - replaced by a Crimson XGW Stradavarius.

And there is no fault invovled, except the odd acoustics of my room and my tendency to listen at high volume. I suspect any sensitive cartridge would have had feedback.

I’m a very loud listener too. The various problems with feedback and phono stage noise become exponentially worse as we raise volume. It’s vinyl playback on "hard" mode (extra hard if you also use a sub), but worth it. The KAB filter is the easy fix (but not perfect) if you don't feel like doing too much experimentation. 

I was getting noise from my McIntosh MP1100 tubes, turned out to be my router.  A cheap Faraday cloth from Amazon placed on top of the glass on my MP1100 eliminated it all.