RP-7

In principle, signal pickup using a one-piece cartridge (such as Concorde-type models) works reliably. However, there are important geometric considerations that affect tracking accuracy and fidelity, especially on compact turntables like the RP-7.

 

 

All pivoted tonearms (straight or S-shaped) inherently produce tracking angle error, which occurs because the stylus moves in an arc while the grooves on the record are cut in straight lines (tangentially). This means that a cartridge is only perfectly aligned at one specific point on the record. Everywhere else, the stylus sits at a slight angle to the groove, resulting in distortion and potential record wear.

 

To reduce this error, cartridges on straight tonearms are usually mounted at an offset angle, which tilts the stylus slightly to the side. This helps align it more closely to the groove across a wider area of the record.

 

In contrast, S-shaped tonearms, like the one on a Technics SL-1210 or RP-7000, inherently incorporate this offset angle into their geometry. This design allows many cartridges (including one-piece Concorde models) to achieve an optimal alignment by default, without manual adjustment. That’s one of the reasons Concorde cartridges are widely used on traditional DJ turntables.

 

Even on classic 12" turntables (e.g. Technics 1210 / Reloop RP-7000) with S-shaped tonearms, tracking angle error can never be fully eliminated across the entire length of a record. These tonearms are designed to minimize the error, but there will always be a compromise between the outer and inner groove alignment. Therefore, some level of distortion or inaccuracy is always present in pivoted tonearm designs.

 

 

The RP-7 features a straight tonearm and is specifically designed for 7-inch vinyl records. This results in a shorter tonearm (effective length: 164.5 mm, overhang: 0 mm), which naturally increases the tracking angle error compared to full-size (12") setups.

 

Here’s what the tracking angle error looks like:

 

With a one-piece cartridge on the RP-7:

    - At the outer groove (R = 84 mm): ~14.85°

    - At the inner groove (R = 53 mm): ~9.37°

        

- With a headshell-mounted cartridge, properly aligned to a 9.5° offset:

    - Outer groove: ~5.35°

    - Inner groove: ~0.13°

    - Straight null point (R = 53.76 mm): 0°

 

This demonstrates a improvement in tracking accuracy and reduced distortion when using an adjustable setup while aiming for optimal soundquality.

 

 

However, another critical factor for DJs is tracking stability during scratching not just sound fidelity. In this regard, the RP-7 remains an excellent choice for DJs, even when using one-piece cartridges. Its straight tonearm design offers reliable performance for turntablism and DJ techniques, and many users will prioritize skip resistance over absolute hi-fi performance.

 

Among scratch DJs, it’s common to manually angle the cartridge inward (negative offset) on S-shaped tonearms. This setup is often used to compensate for lateral forces and improve stylus stability while scratching. A classic example is a Shure M44-7 installed at a slanted angle on a Technics/Reloop RP-7000 tonearm.

 

While this can enhance tracking under aggressive use, it also introduces greater tracking angle error, which reduces sound fidelity - especially toward the inner grooves.

 

Interestingly, using a one-piece cartridge on the RP-7 (with its short and straight tonearm) can mimic this increased tracking stability, due to the naturally higher tracking angle error. However, the loss in audio fidelity still applies. You may gain some resistance to skipping during scratching, but at the cost of increased distortion and reduced stereo accuracy.

 

 

The more tracking angle error present, the greater the potential for:

- Distortion in stereo image and transients

- Uneven stylus and record wear

- Reduced clarity, especially toward the end of the record

 

While a one-piece cartridge will work and may be suitable for performance-focused DJing, it cannot be fine-tuned to minimize tracking error to the minimum. For users who value high sound quality, accurate stylus alignment, and balanced wear, we strongly recommend a headshell-mounted cartridge on the RP-7.

 

Ultimately, the decision lies with the user. Just be aware of the trade-offs between tracking stability and sound fidelity.