Woops Wrong test LP. This one
https://www.amazon.com/HIFI-NEWS-Test-Producers-Cut/dp/B00KMCL1PE
Sub Sonics and woofer pumping
I have a VPI prime on bear claws sitting on a maple base. Floor is concrete. I use a Nagaoka MP500 cart with going to an ARC PH3se phono pre, then to a Herron 1A preamp. Amp is an ARC Classic 60. Speakers are Thiel CS 2.4’s.
I get pretty aggressive woofer pumping with vinyl.
I’ve lubed my bearings on the table.
my alignment is spot on.
Tracking force at the upper limits of cart.
I’ve added the 2nd pivot point to the 3D arm.
I’ve even switched out the counter wt to a much heavier unit and added a comparable head shell weight to change the total mass of arm. To no avail.
None of these things have had any effect in reducing the pumping.
I REALLY don’t want to use a rumble filter.
I’m left with the conclusion that the cart may not be a match for the arm, even after adding all the extra mass.
Any thoughts or solutions.
I get pretty aggressive woofer pumping with vinyl.
I’ve lubed my bearings on the table.
my alignment is spot on.
Tracking force at the upper limits of cart.
I’ve added the 2nd pivot point to the 3D arm.
I’ve even switched out the counter wt to a much heavier unit and added a comparable head shell weight to change the total mass of arm. To no avail.
None of these things have had any effect in reducing the pumping.
I REALLY don’t want to use a rumble filter.
I’m left with the conclusion that the cart may not be a match for the arm, even after adding all the extra mass.
Any thoughts or solutions.
Showing 4 responses by mijostyn
Last_lemming are the woofers pumping at normal listening levels or just when you turn it up? The Nagaoka is very stiff and we really do not know where you are. It would help if you could get the Hi Fi News Test LP. Then we can know for sure. It also is a lot of fun to test other parameters. Very Useful. Here, https://www.amazon.com/Tonearm-Headshell-Cartridge-Weights-turntables/dp/B01B8ONJVI and https://www.amazon.com/Ultimate-Analogue-Test-Lp/dp/B001GBA71Y/ref=asc_df_B001GBA71Y/?tag=hyprod-20&linkCode=df0&hvadid=312149562874&hvpos=&hvnetw=g&hvrand=501746434509243117&h |
Last_lemming, are you saying this occurs with more than one record?? the lead in grooves seem to be the noisiest park of the record. If this is just one record you have either a warp or a low frequency pulse at one point on the record. No big deal. If it is happening with every record you have a much more serious problem with the bearing or platter. The Cartridge is doing what it is supposed to do. If you are worried about the tonearms resonance frequency get a test record and check where it is. Very easy to do. |
Last lemming, you have several problems culminating in amplification of rumble. The most significant one is that you are using a very stiff cartridge in a uni pivot arm. Your resonance frequency is too high and you are amplifying rumble inherent in records. You will need to add mass to the head shell. In order to determine how much you will need a test record with resonance tracks like the Hi Fi News Analog Test LP. You want to get that resonance frequency down below 10 Hz. Uni pivot arms are a problem because they have a third degree of freedom and a third resonance point, the rotary one. The best way to avoid issues with rotary resonance is to use a compliant cartridge like an Ortofon 2M series cartridge. They run around 20 X 10-6 cm/dyne. The Nagaoka is 8.5 X 10-6 cm/dyne. It is a great cartridge but it was designed for a heavy gimbal arm. I think you can get the rumble down to acceptable levels by tuning the system. If you can't then there are only three solutions, change the cartridge, change the tonearm, get a rumble filter. My preference would be a new arm. The Nagaoka will work perfectly in an Ortofon arm and they are relatively inexpensive. Soundsmith sells a dandy set of graduated head shell screws. Put the heaviest (Stainless) screws on and tell us what happens! |