If that's what you want, check out no romance's springs under turntable thread. Nobsound will get you almost all of what you get with the big buck stuff for $35.
Woofer pumping possibly due to tube amp when playing vinyl
I am moving this issue to this forum because of what I discovered this weekend.
I’ve been trying to figure out why I have woofer pumping when I play vinyl, and for the last two weeks I’ve been messing with my vinyl rig trying to figure out what is causing the issue. The woofer pumping seems to be more prevalent with the vertical up-and-down movements of the tonearm regardless of which turntable is being played. It appears it happens more at the outer edge of the record then the inner grooves. I assume this is because record is more warped at the outer edges. The woofer pumping happens even in quite passages, so it’s not noise induced vibration affecting the turntable.
I have used two different turntables to try to figure this out, one is a pioneer PL 530, and the other is a VPI prime. both with different carts. Also, I have verified that all the carts being used on these turntables work well together with their respective arms.
However, it is not the turntable or cartridges.
Things I can say for certain, it is not the turntable because I switched turntables with different cartridges to confirm this, and I still get the woofer pumping. It is not a phono preamp because I’ve switched several phono preamp‘s, solid state and tube, and I still get the woofer pumping. It appears it is the tube amp that may be at cause. It’s the only component left of the chain.
I have a Audio Research Classic 60 amp. I got the amp used but it came with a new set of power tubes I don’t recall if I changed the four smaller driver tubes, I also change the four large capacitors to new capacitors and biased the amp.
The interesting thing is, with the TT’s I tried, it is the right channel that pumps more than the left channel, regardless of the variety of different cartridges tried, all aligned with AS Smartractor.
To be certain it was limited to vinyl playback, I plugged in a CD player and I do not get the woofer pumping at all. So I have a couple theories (1) the TT is just transferring subsonic frequencies from the records, ALL records I play do this. Please remember, this is from the two different turntables being used, one a VPI prime belt driven, and the other a pioneer PL 510 Direct DrIve, or (2) there’s some weird thing going on at the amp that I cannot explain.
My question is, if there is something going on with the amp could it be a tube issue, or capacitor issue, or a biasing issue. If so what is the most likely culprit. Or I guess something else altogether.
In the end I’m rather tired of chasing this ghost, and I would rather not use a subsonic filter if possible. If I do have to use a subsonic filter I want the most transparent one if such a thing exists. I’ve heard mixed results about the KAB unit.
I’ve been trying to figure out why I have woofer pumping when I play vinyl, and for the last two weeks I’ve been messing with my vinyl rig trying to figure out what is causing the issue. The woofer pumping seems to be more prevalent with the vertical up-and-down movements of the tonearm regardless of which turntable is being played. It appears it happens more at the outer edge of the record then the inner grooves. I assume this is because record is more warped at the outer edges. The woofer pumping happens even in quite passages, so it’s not noise induced vibration affecting the turntable.
I have used two different turntables to try to figure this out, one is a pioneer PL 530, and the other is a VPI prime. both with different carts. Also, I have verified that all the carts being used on these turntables work well together with their respective arms.
However, it is not the turntable or cartridges.
Things I can say for certain, it is not the turntable because I switched turntables with different cartridges to confirm this, and I still get the woofer pumping. It is not a phono preamp because I’ve switched several phono preamp‘s, solid state and tube, and I still get the woofer pumping. It appears it is the tube amp that may be at cause. It’s the only component left of the chain.
I have a Audio Research Classic 60 amp. I got the amp used but it came with a new set of power tubes I don’t recall if I changed the four smaller driver tubes, I also change the four large capacitors to new capacitors and biased the amp.
The interesting thing is, with the TT’s I tried, it is the right channel that pumps more than the left channel, regardless of the variety of different cartridges tried, all aligned with AS Smartractor.
To be certain it was limited to vinyl playback, I plugged in a CD player and I do not get the woofer pumping at all. So I have a couple theories (1) the TT is just transferring subsonic frequencies from the records, ALL records I play do this. Please remember, this is from the two different turntables being used, one a VPI prime belt driven, and the other a pioneer PL 510 Direct DrIve, or (2) there’s some weird thing going on at the amp that I cannot explain.
My question is, if there is something going on with the amp could it be a tube issue, or capacitor issue, or a biasing issue. If so what is the most likely culprit. Or I guess something else altogether.
In the end I’m rather tired of chasing this ghost, and I would rather not use a subsonic filter if possible. If I do have to use a subsonic filter I want the most transparent one if such a thing exists. I’ve heard mixed results about the KAB unit.
Showing 5 responses by millercarbon
paulgardner-
@millercarbon Can I ask where you got a carbon fiber outer ring clamp? I need one!Everyone does! Took mine to CES one year, compared with a bunch of em, its a great clamp. DJ Casser must have been impressed, he copied it, and so his stolen from me copy is as far as I know the only one on the market. Mine being DIY and a one-off. Its made from some BDR Shelf material that was left over after making the Miller Carbon turntable. https://systems.audiogon.com/systems/8367 DJ died about a dozen years ago, his heirs seem to be keeping the company alive but its not like it was. Far as I know BDR is only sold through Music Direct. I would call and ask if they can make you a record clamp. It will cost a lot. It will be worth it. Only clamp I know better than mine. Better made, better sound. He stole the design but give the man credit, he also perfected it. If they can't do that the next best would be order one of the Round Things with the threads going all the way through. Make sure your spindle is threaded to use this. Otherwise you need a collet type clamp. Which let me know, it can still be done its just more work. But a Round Thing, you can see them in my System pics, they are round and almost the right size. A little small but still better than every other clamp on the market. Then either dish it out like I did, or get an O-ring the right size to go around the perimeter so it pushes the record down from the outside area of the label. Then put a washer, or a small O-ring, near the spindle. That is the key. To push the record down from the center to the outside edge of the label, so when its clamped down the outer edge of the record contacts the platter first. This works just amazingly well. I really don't know what's wrong with the people here. They're talking about anti-skate, and every single crazy thing a guy could possibly imagine that can have nothing to do with it, while stubbornly refusing to see the one thing that will. Ignore the herd. Get a clamp. You will see. |
Wrong on all of it. You tried three different clamps. If none of them are designed like I said you could try a hundred more and it won’t prove a thing- other than that a lot of record clamps are of poor design. Which is why I made my own. There are some good ones out there. I described exactly how they should look and work. Get one and use it. Problem solved. |
I can’t discount your thoughts about the clamp, but how would this affect the outer edge of the record where there is no clamp. I’m right about everything. All you have to do is read what I write. last_lemming: how would this affect the outer edge of the record where there is no clamp. millercarbon: My record clamp is dished out inside, so as its clamped down it presses the record down onto the platter from the outside edge in. Got it? From the outside edge in. last_lemming: I use a heavy record weight - which I know you say is no good - but it firmly holds the record onto the deer hide mat.Where did I say deer hide mat? millercarbon: as its clamped down it presses the record down onto the platterSee? Platter. Not mat. Platter. Ditch the deer hide mat. last_lemming: I’ve also tried several matts to no avail. Yes, because that is part of the problem. Ditch ALL mats. |
Lord. Of course its the turntable. Specifically, its the way the record is clamped to the platter. ALL records, if you just plop them down, are going to produce some degree of the very low frequency energy that you see as woofer pumping. When I play records, any volume, there is plenty of bass and no woofer pumping. Without filters. Horrible idea! Look at my system. Please. Took the time to post the pics for a reason: so everyone can learn. Study, observe, and learn. Please. https://systems.audiogon.com/systems/8367 Look close at the platter. Notice the black ring around the spindle? Looks like a washer. Its not. Its carbon fiber. Its hard to take a picture from an angle that shows every detail clearly so you have to really study it. Which you should do! Totally worth the time. See how thick the washer is? A record placed on this is held just very slightly higher than the surface of the platter. If played like this, or if any record was played on this same table without the washer, just sitting on the platter, there would be all kinds of woofer pumping. Because at the scale of amplification we use even near invisible amounts of vertical motion at the record translate into a totally obvious pumping at the woofers. The fact you mention being able to see the tone arm move AT ALL tells me you’re not even close to doing it right. So the next step after placing the record on the washer that holds it too high is to clamp it down. My record clamp is dished out inside, so as its clamped down it presses the record down onto the platter from the outside edge in. Fully clamped the record is absolutely flat on the platter. Its clamped so flat that when the clamp is released its like its been suctioned down onto the platter, which you can tell because when the clamp is released the records stay down for a second until air comes in and it pops up. This is what you want. Its not your amp. Forget about that. Waste of time. Don’t move your table. Its embarrassing how far off track some of these ideas are. Look for a good clamping system. Clamp. Not weight. Clamp. |