We are going to kick off a new series about turntables this week. We will start with the basics of turntable design in the first article of the series and then cover setting up a turntable from scratch in the subsequent articles.
Part 1 - Understanding Turntable Design
As you delve into the world of turntables, you might face a daunting task.
Once you step beyond the entry-level turntable range, there is a myriad of options - you have the choice of turntables and platters, tonearms with varying lengths and makes, and an even bigger choice of phono cartridges.
Once you have chosen the different components, you would need to complete the following tasks before you can even begin to listen.
1. Assembling the turntable - the plinth, motors, platter and arm boards (where applicable)
2. Installing the tonearm to the turntable
3. Installing the cartridge
4. Optimising the position of the cartridge
5. Optimising the position of the tonearm
6. Adjusting the tracking force
7. Adjusting the anti-skate
If you are new to the world of turntables, you might be better served with an “all-in-one” turntable that comes fitted with the tonearm and cartridge - all ready to go.
In our extensive range of turntables, we have a number of favourites that do exactly just that:
- the Project Debut range which includes the Debut Carbon DC and Debut Espirit DC SB, with the latter providing one touch speed selection to switch between 33 and 45rpm, an acrylic platter to reduce ringing and vibrations and the Ortofon 2M Red cartridge, which offers a big step up from the OM-10 cartridge on the Carbon DC.
- the Audio Technica LP120 which is inspired by old school DJ turntables, fitted with a S shaped tonearm for cue-ing, the Audio Technica ATH95 cartridge and variable speed controls and reverse play
- the Audio Technica LP5 which shares the similar technology but in a more discrete package. The LP5 uses a more refined J shaped tonearm and the ATH95MX extended range cartridge
With these turntables, you can skip steps 2-5 since they come pre-fitted with the tonearm and cartridge and just start from Step 1 (which is highly simplified for such models), then move to step 6 and 7.
So why would someone then choose to complicate matters and pick a turntable that is more complex to assemble?
To truly appreciate turntable design, we first have to see how they work.
With records, music information is stored within tiny traces and cuts inside a record groove. When the stylus of the cartridge moves over the grooves, it vibrates.
The stylus is connected to a small electro-magnet - which converts the vibrations into electric signals. These signals can range from 100s of micro-volts to 100s of mili-volts. Much lower in levels than the signal that comes out of your CD player or DVD player. That is why you need to connect the cables from your turntable through a phono pre-amplifier which boosts the signals to about 1-2V and normalises the equalisation to offset the EQ done during the cutting process. The phono pre-amplifier can be built into the turntable itself, in a standalone box or built into an integrated amplifier.
A well-designed turntable thus need to address the following:
- minimising vibrations and resonance from external sources which might create erroneous vibrations on the stylus
- ensuring a constant speed
- minimising tracking errors
- using spring suspended platters - like with LINN’s designs
- using very heavy a.k.a. high-mass platters - like with ProJect Signature and Acoustic Signature designs
- using inert materials less prone to ringing for the platter - like acrylic or vinyl in ProJect turntables or brass/gold silencers embedded inside the platters like Acoustic Signature
- using inert and lightweight materials for the tonearms such as carbon fibre used in Acoustic Signature and ProJect turntables, so the vibrations from the record grooves are more easily picked up
- using heavy support bases and plinths with spikes and/or dampening materials to cushion the turntable
- using a belt drive system to reduce the transfer of vibrations from the motors to the platter and from there to the records and stylus. You can also use a flywheel/pulley system like with ProJect Signature which isolates the vibration even further.
Ensuring Constant Speed
The higher end turntables often come with quartz controlled speed controllers to ensure a constant and consistent speed to the motors. Acoustic Signature also provides upgraded linear power supplies to the speed control systems which take the noise down even further.
A direct-drive motor like the Audio Technica is capable of very consistent speeds with a slight trade off in transference of vibrations from a direct-coupled motor
Minimising Tracking Errors
Ideally, the tonearm should always be tangential to the circumference of the groove. When you first set the cartridge up, you align the cartridge to be tangential at 2 points using the protractor/alignment kit.
However, outside of these two points, the tonearm angle is slightly off from the ideal tangential position. The deviation from ideal can be greatly minimised by using a longer tonearm, as shown in the chart below.
This is why you will find that the higher end turntables often have longer tonearms.
As you can see, designing a good turntable is not a trivial process. Companies like Acoustic Signature, Linn and Pro-Ject spend a great deal of time and resources on optimising their manufacturing processes to deliver state-of-the-art designs. Don't be worried if you aren't comfortable assembling the different components. We can help you set up the turntable optimally when you get them from us.
Here are some of our favourite turntables:
- inert platter built from recycled vinyl material
- 2M Silver cartridge
- Project 9cc evolution tonearm (more rigid construction than the carbon tonearms in the Debut range)
- DC motor with quartz precision speed controls
Pro-Ject Xtension 10
- inert platter from recycled vinyl and reinforced with aluminium for high mass
- Project 10cc evolution 10” tonearm with better tracking
- DC motor with quartz precision speed controls - with adjustment of 0.1rpm for more accurate speeds
Acoustic Signature XXX
- Choice of carbon fibre tonearms ranging from 9” to 12” with adjustable arm base
- immensely heavy plinth for incredible resistance to vibrations
- high mass metal platter with optional silencers made of 24k gold or brass.
- choice of external linear power supplies for more accurate speed control
- entire turntable weighs 50kg
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