Jelco SA-750L

[sony6060]

The Jelco SA-750L has a dampening oil option. I understand a cup is filled with the supplied oil. If the tone arm will perfectly track the worst warped records, what is the benefit?

 

[marcmorin]

The Jelco SA-750L has a dampening oil option. I understand a cup is filled with the supplied oil. If the tone arm will perfectly track the worst warped records, what is the benefit?

Its to control the resonate amplitude of the cart.

 

[sony6060]

Its to control the resonate amplitude of the cart.

Oh. How does one set it up, or is it 'one size fits all' deal.

 

[AudioSoul]

I have owned the 750L. I never added the oil, I never felt the need to with a DL-103R cart. But that being said, if you hear any frequency anomalies start by adding a little oil at a time until it goes away.....

 

[sony6060]

I have owned the 750L. I never added the oil, I never felt the need to with a DL-103R cart. But that being said, if you hear any frequency anomalies start by adding a little oil at a time until it goes away.....

I have a DL-301MKII and hear no issues either without oil.

 

[EWizard]

I added the oil to my 750D fairly recently, and the bass seemed to tighen up some.
The good thing is that they supply enough oil that if you want to remove, you can, and add more later if you want.
I kind of like the sound with the oil.
Using a DV 10x5 with mine.

 

[marcmorin]

Oh. How does one set it up, or is it 'one size fits all' deal.

The easiest way would be with a frequency test album. First find the resonate frequency, second, note the amplitude of that resonate frequency, tune that amplitude as needed. The most notable would be as mentioned, how well the bass fares with adding damping. As that amplitude will reach further up the frequency range than expected.

 

[2526]

I bought my 750D used, but with box, instructions, tools, etc., but no oil. What type of oil would one use, or should I try to contact a Jelco dealer? Thx

 

[marcmorin]

I bought my 750D used, but with box, instructions, tools, etc., but no oil. What type of oil would one use, or should I try to contact a Jelco dealer? Thx

silicone oil in 500,000cst. 300,000cst may also work in a pinch

 

[dlaloum]

Something else to keep in mind...

the low frequency arm/cartridge resonance - which exists with all arms and cartridges regardless of the matching... matching simply shifts the frequency at which it happens- will intermodulate with higher frequencies generating Intermodulation Distortion.

This is subtle and hard to identify - but its removal does improve the sound (both subjectively and objectively).

Best way to get rid of it (or rather minimise it) is damping.

This is normally provided in most setups by a combination of the damping built into the stylus suspension, and the natural friction in the bearings and lubrication of the arm.

More sophisticated arms like the 750d provide a mechanism for increasing or decreasing the damping.... this also allows them to put better bearing with much lower friction as the damping is now provided by a differing mechanism...

If the resonant frequency is too high on your setup (12Hz and up?) then damping will provide immediately noticeable improvements in the bass...

If the resonant frequency is too low, damping will reduce sensitivity to warps and footfalls.

And regardless of res F. damping is likely to improve tracking and reduce IMD...

Just remember that a little damping goes a long way... don't overdo it!

bye for now

David

 

[sony6060]

Thanks all.

 

[VinylSoul]

I didnt have any fancy oil for my Sumiko MMT, so i bought something like STP and installed it. Great improvement in the sound of the 8MZ.

 

[marcmorin]

I didnt have any fancy oil for my Sumiko MMT, so i bought something like STP and installed it. Great improvement in the sound of the 8MZ.

STP is about as thick as 500,000cst. Much cheaper......although has an odor.

 

[gusten]

Besides the odor, the silicone oil is used because it will keep a stable viscosity over time, and it´s close to a Newtonian fluid.
gusten