Bass is lacking/tubby on old Philips 212

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".

The turntable and arm usually have nothing to do with the frequency response. I would suspect the pickup and the preamp. Check the following:

1. Is the cartridge wired out of phase? This causes severe diminution of the bass notes, because the pushing of one speaker is canceled by the pull of the other speakers. (If the other sources sounded the same way, I would suspect the speakers out of phase). Try trading the wires to ONE channel.

2. Are you using a standard phono preamp? If not, the RIAA de-emphasis curve is missing. A microphone input is flat, but a phono preamp has de-emphasis to undo the pre-emphasis (bass cut, treble boost) on the record. The pre-emphasis reduces noise and increases playing time.

3. There are 4 different kinds of pickup cartridge. Each needs its own kind of phono input:
- Ceramic (also crystal)
- Magnetic (moving magnet)
- Moving coil
- Electret (condenser)
Make sure you have the correct type of phono preamplifier.

4. Check the rest of the audio chain.

5. One possibility for the tubbiness is a tonearm resonance. This is hard to cure by any method except using a different pickup. But I have never seen this in that Philips.

Thanks for the advice.

I will check to see if the cartridge wires are connected to the proper pin.

The lack of bass was not present on my old DP 12 Mitsubishi table with a Grado Prestige Black cartridge, but it was not terrifically tight on that rig either. I am using an RIAA phono amp built into my AMC integrated and have it set for Moving Magnet cartridge, so that should be OK. The other option for a setting is Moving Coil, but that does not sound as good as the MM setting.

The rest of the audio chain sounds fine on two different digital sources and my tuner, so I think it is something going on with the TT/cartridge/tonearm/phono amp system.

Suspecting cartridge head or tonearm resonance, I explored using Blu-Tack in various applications in response to a suggestion from someone on another forum. Here is what I found:


"OK - I tried applying Blu-Tack 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 Blu-Tack 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 again for your input on this.