Weak/tubby bass on old Philips 212 TT

I have an old Philips 212 electronic TT that I have been restoring. It has new lights/sensors, a new belt, and a new Grado Prestige Blue cartridge.

Replacing the belt made a huge difference as the old one was either too big or stretched out compared to the replacement, resulting in poor speed control and PRAT. Now with the table placed in my cabinet on a heavy wooden block, I'd have to say the sound in the mid to upper registers is really good with depth and air around female vocals and guitar, and good pace. Not the nth degree of high treble extension, but detailed and sweet lower treble and midrange - surprisingly good compared to Rega P2 and P3 tables I have been auditioning recently with stock Rega cartridges.

But the bass from the Philips just isn't up to the same caliber as the higher registers. It is weak and a bit tubby through both headphones and speakers compared with the two Regas mentioned and my Cambridge Audio CD player. Not terrible, but now clearly the weakest part of the overall presentation. I am a bit surprised by this because Grado Prestige cartridges have a reputation for relatively strong bass for the money.

The cartridge is aligned as close to square in each direction as I could desire without shimming - the tonearm's fixed VTA results in the cartridge being tilted a bit up at the front - a condition I would think would increase the bass response relative to rest of sound spectrum. I adjusted the overhang with a protractor. The cartridge is set to track at the recommended 1.5 grams and the anti-skate is set for an elliptical stylus, although adjusting this a little either way makes little difference in the sound. I am using the MM phono preamp on my AMC 3050a integrated amp with some minor modifications (12 gauge power cord and high quality plug, HiFi Tuning fuses, silver jumpers).

Question: are there any simple tweaks I can try do to improve the bass response on this table/arm/cartridge combination? I realize the arm is not the last word in rigidity with it's plastic cartridge insert, and I am suspecting that is where the problem lies. Any suggestions appreciated short of "get another table".
Try placing the block on some isolation devices such as cones. If the block is sitting directly on the cabinet it will transfer vibrations to the table. Isolate the block from your cabinet as well as you can.
Thanks Stanwal, I'll try that.

The reason I think the bass problem is within the TT system is that it's present even with the the headphones on and the speakers turned off. Perhaps need better way to drain vibration away from the platter and arm, but the Philips arm and platter are suspended together and separated from the plinth.

Wondering if there are ways to dampen resonant vibrations on the tonearm itself???
An old trick was to use SMALL amounts of something like BLUTAK. Can be placed between cartridge and head shell. In my former days as a dealer I was once sent a similar substance to try by an accessory co. Or on counter weight, this is my idea and I haven't tried it so you can blame me if it doesn't work. I use to use a 212 but it was too long ago to remember anything specific, it was a well respected unit in its day.
I will try the blutak too.
Put footers on the table.A soft material may agrivate the bass problem.Decouple the base under it also.

OK, I looked at your system pics, I get the idea.
OK - I tried applying blutack in various places on the turntable and here is what I found:

-placed between the hard plastic feet and the underlying wooden block - bass was more pronounced, but not necessarily cleaner; some loss of air and spatial cues in the treble; "plastic" or rubbery sound to midrange - NOT HELPFUL

-very small amount placed in spots between plastic cartridge carrier and head shell where they clip together - cleaned up bass with very slight loss in dynamics - HELPFUL

-small strip placed between cartridge and plastic carrier before screwed together - at first - cleaned up bass, but some loss of air and space in the treble and more of that "plastic" sound; over time treble problems and midrange went away and bass remained tighter - HELPFUL (suggest blutack moved away from contact points between cartridge and carrier under pressure from screws and now acting as "glue" to provide better bond between surfaces)

-small dots placed on either side of counter weight - cleaned up bass a little bit with no other adverse effects - HELPFUL

-small dot placed on top of head shell - dulled sound - NOT HELPFUL

-small dot placed on center of tonearm - robbed bass and space from sound - NOT HELPFUL

I do not currently have the resources to invest in brass footers or other isolation devices for the TT base or the wooden block, but will investigate this in the future.

Thanks for your input.