[drphoto]

Ok, I don't have the 60 hz hum I got w/ the Grado, but now, even w/ TT motor off, if I run up the volume knob on the pre, I get a low frequency rumble. Again, no music, TT motor off, no walking around the room or anything. If I switch on the subs, they just go banannas and start oscillating.

I'd guessing I need that wall mount fast, or is there some other issue?

[Elizabeth]

Super bad feedback from subs to cart. You need to move the TT,  a new location were sub low freq is self canceling (a 'null' point in room where subs energy is near zero due to boundary reflections)
OR buy some subsonic filters for phono line.
Try moving the TT around with the system doing rumble. Find a spot where the rumble stops. It may be in a bad location? Also you might move subs and do same thing, look for spot that stops rumble.

[drphoto]

Oh, it's doing the rumble thing even WITHOUT the subs. But if I light them up, they go ballistic. In other words, the subs are not the cause of the problem. But because of the issue, I can't use them.

[analognut]

So if you "light" your subs up they go ballistic. I'm guessing your TT is against the wall and if your subs are also against the wall that could easily be a problem. Try moving subs out 12'' from wall and see if that helps. They should sound better that way anyway- less bass build-up in the corners. 18"-24" would be even better if you have the room. 

[drphoto]

Nope that's not it. I have the rumble WITHOUT the subs! But because of it, they go crazy.

Again....the subs are not the source of the problem.

And the subs are way out in the room, at least 4' from any wall.

I'm getting this low end noise without ANYTHING PLAYING!. TT motor not on either. So it's not motor noise.

Sorry to shout, but replies so far seem to be overlooking this.

[neobop]

Seems like somethings wrong even with the subs off. Hard to figure it out long distance. This rumble - like a low frequency hum? Check your cartridge connections and your ground wire. Could be a loose clip. Make any other changes recently?

Something is making your preamp amplify this rumble and send it to your subs. It could be the preamp, but not likely. Other sources OK? If so, and you can't find the cause, try hooking up the old cartridge and see what happens. It's probably a connection problem with the record player or a defective cartridge. If you are running separates, you could try a ground wire from preamp to amp. Sometimes that works. 

[drphoto]

I'm running a Rega table, which puts the ground through the shield of one of the output leads. (the left one if I'm not mistaken) So there's not much I can do on grounding, short of ponying up a couple of hundred bucks for a OL rewire kit.

This is a total mystery. It's a low frequency noise/rumble. Not a 60 hz hum. I'd say down around 40hz or maybe lower.

[drphoto]

It would all make sense, if I was playing music. Low end feed back means the need for better isolation.

But this happens w/ nothing playing, hell it happens w/ the TT motor off and the arm parked, which is what makes it such a mystery.

[Elizabeth]

 My next guess is you have some vibration coming in through the house foundation you do not notice BUT the cart registers.
The ONLY solution I could offer is to BUY subsonic filters for the phono interconnects.
KAB RF1 is a $170 rumble filter. Others also available for less. Not as common as a separate connector as used to be available. Several phono preamps offer a rumble filter.
Used to be able to buy cheap little gizmos that went right in interconnect lines.
PS try putting finger (Very lightly) on stylus tip. Does the rumble stop?
Try isolating TT base, put it up on telephone books.. does the rumble change?

[drphoto]

Yeah, I think that KAB gadget might be my only solution.

I know $170 isn't a ton of money, but it's starting to add up fast. I'm gonna go broke trying to run a midfi deck. You'd think that any pre w/ a phono input would have a rumble filter. I know all the mass market stuff from the 70's did, like the Marantz 1060 I had in high school.

At least the Denon does have enough output to work w/ my MM phono stage.

[neobop]

It would all make sense, if I was playing music. Low end feed back means the need for better isolation.

But this happens w/ nothing playing, hell it happens w/ the TT motor off and the arm parked, which is what makes it such a mystery.

Not such a big mystery. The same thing can happen when there are bad connections between cartridge and preamp. I assume you have checked all the clips, RCAs etc to make sure none are loose. Sometimes when changing cartridges, 1 of the wires can get disconnected from the clip. That happened to me a few weeks ago. That's why I suggested you see if the old cart still works OK.

I doubt if a rumble filter will solve this. A subsonic filter will help with TT rumble below the audible band, usually while playing a record. I'm not sure exactly what the problem is, but from your description, a filter would be a band aid approach at best. Maybe that $ would be better spent on the re-wire.

Other than that, I don't know what to tell you. I never had a Rega arm. Seems like a stupid way to wire one. Some bargain.
neo 

[bacobits1]

It sounds like something is being excited before the Turntable if the table is not even on or the stylus on the record. It has to be in the Preamp and amp combination when the pre is in phono position. Is it doing any of this with another source like CD? You may be getting something vibrating the tubes?

I had a similar problem for a long time when using the HSU VTF3 MKII with various tables and cartridges, and sizes of rooms, they were all my High Output MC's. The last one on my P5 and a Dyna 10X5.
In this case I was running the 10X5 at 100 Ohms loading on MC to get the gain I wanted (it likes over >1000 Ohms) on a tube Phono pre and accentuating the lows way too much at that setting. On certain bass heavy songs the sub would excite the whole room and flutter wildly. I always had to turn the sub down. It never did it on CD. I just got rid of the sub and got full range speakers and no more problem.

Yours is something a bit different so it has to be a reaction of the Preamp set at Phono and amps combination. Since you are running 2 subs I doubt you could isolate any reaction completely. I also tried the KAB Sub Sonic Filter a few years ago it did not work. At that time I was using a Benz Glider High Output. 

See if you can Isolate that Preamp and stop possibly tube ringing.
The only suggestion I have.

Good Luck.

D

[Wayner]

The Denon DL-160 is a high output, MC cartridge. What preamp are you using and what inputs are you using? If you have it in the MC input (usually 60db of gain) then the stylus and cantilever are acting like a microphone (too much gain). This cartridge should be put into the MM input (about 40db of gain) to match up with the higher output of the Denon.

Wayner

[neobop]

This problem seems a little more mysterious. From the loading thread:
 
"Ok, since I've come back to vinyl, I've seen mention of 'load' matching. I'd never heard of this 30 years ago, when I had my first Thorens.

 My pre list an input impedance of 47kOhm, which is same as the Ortofon 2M Blue.

I'm really leaning toward the Denon DL-160 as everyone says it has a huge soundstage 
but I've seen no specs on impedance.  Anyone know? Does it matter that much?"

The only way you're going to figure this out is troubleshoot. Surely other Rega owners have used this cartridge successfully. Do you own a multi-meter?
Did you try the old cartridge? Please hook up the old one again. You're not going to get anywhere theorizing. 1 loose cartridge clip can do exactly what you described. If you need to tighten a clip, use something like a big pin inside the clip and gently squeeze the clip with your needlenose. The pin will ensure that you don't accidentally crush the clip.
neo

[sts9fan]

I personally think rumble filters are good with vinyl and subs.  Mine goes a bit wacky without it.
I also think you should find out exactly what the issue is before you spend another dime.

[Wayner]

This problem seems a little more mysterious. From the loading thread:
 
"Ok, since I've come back to vinyl, I've seen mention of 'load' matching. I'd never heard of this 30 years ago, when I had my first Thorens.

 My pre list an input impedance of 47kOhm, which is same as the Ortofon 2M Blue.

I'm really leaning toward the Denon DL-160 as everyone says it has a huge soundstage 
but I've seen no specs on impedance.  Anyone know? Does it matter that much?"

The only way you're going to figure this out is troubleshoot. Surely other Rega owners have used this cartridge successfully. Do you own a multi-meter?
Did you try the old cartridge? Please hook up the old one again. You're not going to get anywhere theorizing. 1 loose cartridge clip can do exactly what you described. If you need to tighten a clip, use something like a big pin inside the clip and gently squeeze the clip with your needlenose. The pin will ensure that you don't accidentally crush the clip.
neo

neo, I think because it's a high output MC, it's loading should be around 47K, but as you say, it may be necessary to fool around with it. However, I think it's just going to cut-off the high end.

I personally think rumble filters are good with vinyl and subs.  Mine goes a bit wacky without it.
I also think you should find out exactly what the issue is before you spend another dime.

I agree. Your going down the vinylphool hi-way right now and you have to solve this before spending more money (unless that is no object).

Wayner

[carbonfiberone]

When listening to the feedback try to unplug the TT at the wall outlet

[bacobits1]

From Denon's site
    * Type: Moving coil (MC)
    * Output: 1.6 mV high output designed for MM inputs
    * Channel Balance: 1dB Max. (1kHz)
    * Channel Separation: 25 dB Min. (1 kHz)
    * Output Impedance: 160 ohms
    * Suggested loading: 47K ohms
    * Stylus: 0.07 x 0.14 mm special elliptical solid diamond
    * Cantilever: Aluminum
    * Frequency Range: 20 Hz to 50 kHz
    * Tracking Force: 1.6g ± 0.3g (1.3~1.9g)
    * Compliance 10 x 10-6 cm/dyne
    * Weight (Mass): 4.8g


If you are tracking too low you will get woofer problems.
Recommended Load impedance over 47k ohms
So, you have it loaded correctly in the MM output.

What are the gain numbers on the Preamp MM setting?

D

[neobop]

I only posted OP's loading post to show that he is using MM stage.

All the VTF, filters and tracking or isolation suggestions don't apply. This happens when record is NOT playing. Just the hook-up causes low frequency noise that turns into oscillation.

AFAIK this can be caused by moving the cartridge too close to some preamps with internal power supply. More likely, it's a bad connection between the cartridge and preamp. Less likely, a problem with the phono section of the preamp or a defective cartridge.

I'm telling you, the exact same thing happened to me when I changed cartridges and a wire broke off a cart clip. Because the clip has heat shrink on it, you couldn't see that it was broken off.

This can be checked with a meter or continuity tester. Please don't test with the cartridge hooked up. Pull your cables out of the preamp and check between the RCA plugs and the clips. Rt ch RCA center to red clip. Rt ch RCA outside to green clip. Lf ch RCA center to white clip. Lf ch RCA outside to blue clip. When you're checking a clip, for example the red, put your probe at the RCA end on the other connection for that ch, the outside, to make sure they don't cross conduct.

Without more information we're guessing. I suggested you hook up the old cartridge to eliminate possibilities. You might want to try that first.
neo

[Wayner]

If he has the thing plugged into MC with 60db of gain, he has turned the coils of the cartridge into microphone! If one of the wires is off or broken on the cartridge, there should be a "buzz" sound and one of the channels with the broken or loose wire will not play music. He could also have some wires swapped.

Yes, need more information.

Wayner