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Arm resonance and other questions..

Hello to all out there! I have recently acquired a Rega 25 with a Dynavector Dv-20x and its running threw a Monolithic ps-1, hc-1 power supply combo. This replaces my old luxman. Why did i not do this years ago!!!! It sounds MUCH! better in every way than my Adcom gcd-600 cd player. I will be putting a Heavy weight on and play with the endless other things i can do (keeps me off the street at night). But i digress(perching to the choir). I do have two questions.
When i put the needle down on on a record with the sound off i here the normal sound of the needle playing the groove, but it is much louder at the bearing end than the cartridge end. Is this normal? do i need to try and dampen the arm, or this part of Rega’s thing and i should stop being anal and stop listening to the turntable with the sound off! ( girlfriends suggestion)
The other question is ...... I just bought a Dave Brubeck “Time Out” Columbia “six eye” mono (cl-1397) that looks clean, black and little played.... $10. Very excited, i come home, go strait to the turntable, give it a dusting, carbon brush it, ....ahhhhhhh looks good for a first play, drop the needle, quickly sit down ........ Well, its like sticking your head in a bowl of rice crispes ..... no make that like dragging a rake down a gravel road. Not just the random clicks, pops, and hiss of a dirty groove but a constant, and it gets louder and softer with the music. clearly not just dirt! ............... I slump in my char and a tear comes to my eye. I have not cleaned it properly yet but i have a sinking feeling this is not the problem. The odd thing is that listening threw the gravel every thing sounds wonderful. Bass is full and tight and the cymbals ring clear .... and i can here the brass. All better than either of the other Time Out’s i have ....... i think??? Is it posable to damage the groove so that it sounds like its raining pebbles and still have everything else sound fine?? Any thoughts on what this could be??

Thanks....... Bill
bkcme

Showing 2 responses by twl

twl
3,251 posts
 
The arm does resonante with the energy fed back into it from the cartridge. This happens with any arm, but it is not a great thing. A little damping can help, especially at the headshell. Try some self stick felt on the headshell and on the sides of the cartridge itself. Not alot of it. This worked for me.

As for the Brubeck album, it's trashed. The sound of the grinding getting louder and softer with the music, is the tipoff. Played on a "vinyl lathe" as I call it. Nothing can be done about it.
twl
3,251 posts
 
Bill, there is a fine line in the amount of damping that should be done on an arm. If you do too much, it sounds dead. I recommend starting at the headshell, and even the cartridge. I used some self-stick black felt from Wal-Mart. I cut some very small pieces, and stuck them to the sides of the cart, and on the headshell. On the Rega arm, the finger lift is quite lively, so it should be damped. Also a 1/2" wide ring of felt around the arm about 1/3 of the way out from the pivot is a good start. This 1/3 point is the "ring" point on the Rega arms. That is about all you'll need, and you might not need even that much. You'll know if you do too much, because it will start to sound dead. I highly recommend doing the HiFi mod. The other really great mod, is the HeavyWeight counterweight from Expressimo Audio. A world of improvement for only $90. You can make the HiFi mod yourself by following the directions on my thread. You will not believe the improvements from that!

Yes, it is all about lateral movement control. And yes, a singing arm is not good, but as I said, you can go too far. I don't know the exact reasons, but some "liveliness" in the arm is good for sound.
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