Cayin Soul 170P Tube Power Amplifier

Cayin Soul 170P Tube Power Amplifier

The Cayin Soul 170 C/P amplifier combination continues the design language of the Soul family.

Cayin presents its new flagship models in the Soul series, which now occupy the top spot in the portfolio of the renowned tube specialist. For the first time in the Soul series, a Class A circuit is used, giving the Soul 170P exceptional power and control. In bridged mode, the power amplifier delivers up to 120 watts RMS – more than enough to drive even power-hungry loudspeakers.

Class A Push-Pull in the Soul 170P

The Cayin Soul 170P is a versatile tube power amplifier that can be operated in either mono or stereo mode. For the first time in the Soul series, Cayin employs Class A amplification, which, in conjunction with the four TUNG-SOL KT170 tubes in a push-pull configuration, ensures exceptional performance and musicality. The amp delivers 60 watts RMS twice as a stereo power amplifier and up to 120 watts RMS as a mono power amplifier in ultralinear mode.

The Soul 170P features two selectable levels of negative feedback, allowing for fine-tuning of the tonal signature. An integrated Dynamic Auto Bias servo circuit precisely regulates the operating conditions of the tubes, extending their lifespan and ensuring operational reliability. This is further enhanced by the soft-start function and protection circuitry of the power amplifier. Should the power tubes ever need replacing, the Auto Bias servo circuit allows for this entirely without manual intervention.

The warm, vibrant sound of the Soul 170P inspires enthusiasm and creates an atmosphere where music is not only heard but also felt. Experience the unique combination of technical precision and musical expressiveness.

What makes this amplifier special is its pure Class A architecture with four powerful TUNG-SOL KT170 tetrodes operating in Class A push-pull configuration. This results in exceptionally clear and natural sound without compromise.

Flexibility is guaranteed by its operation in both stereo and mono modes: In stereo mode, the amplifier delivers a powerful 60 watts per channel with ultra-linear response, while in mono mode it provides an impressive 120 watts – ideal for loudspeakers with high power requirements. Additionally, two selectable NFB levels (high and low) allow you to tailor the sound signature to your individual preferences.

The Soul 170 P is crafted with the utmost care, continuing the design tradition of the Cayin Soul series. Internally, every connection is hand-soldered point-to-point to ensure maximum reliability and optimal signal transmission. This masterpiece of craftsmanship impresses with its quality down to the smallest detail.

Whether in your home listening room for the perfect enjoyment of your favorite albums or in demanding audio setups for true music lovers – the Soul 170 P will make your sound system shine and bring every note to life.

Tubes & Circuitry

At the heart of the Soul 170P are four TUNG-SOL KT170 beam tetrodes in a Class-A push-pull configuration. The amplifier also features the following components:

• Voltage Amplifier Tubes: 2 × 12AU7

In the voltage amplification stage, two JJ 12AU7 tubes perform the initial signal amplification, providing the necessary voltage boost before the signal is passed on to the power amplifier stage. Their low distortion and noise levels guarantee stable and precise signal processing.

• Driver Tubes: 2 × 6SN7

The JJ 6SN7 tubes used in the driver stage are known for their musical expressiveness and powerful drive. They lend the sound both emotional depth and analytical clarity.

• Rectifier tube: 1 × 17AX4GT

This classic rectifier tube supplies the driver stage with a stable DC voltage, ensuring reliable operation and a refined sound with the characteristic warm tube tone.

Flexible Operating Modes for Maximum Versatility

The Soul 170P offers two clearly defined operating modes: In stereo mode, it delivers 60 watts per channel in ultralinear operation, ideal for classic two-channel setups. Alternatively, mono mode with 120 watts is available, enabling a powerful, high-performance single-channel configuration. Switching between stereo and mono operation is simple and straightforward via a secure switch on the rear panel, ensuring quick and flexible use in a variety of listening situations.

Negative Feedback Circuit

The Soul 170P utilizes precisely tuned negative feedback to balance sound quality and naturalness. Cayin's engineers implemented moderate negative feedback that strikes a balance between control and musical vibrancy.

The "Low" setting opens up the soundstage, enhancing expressiveness and emotional depth. The "High" setting, on the other hand, provides tighter control, greater precision, and a more analytical sound. This allows the Soul 170P to adapt flexibly to a wide range of speakers and musical styles, unlocking its full potential.

Dynamic Auto Bias

The Cayin power amplifier features a fully integrated Dynamic Auto Bias servo, enabling the replacement of the KT170 output tubes without manual adjustment. This system continuously monitors and regulates the operating condition of each tube, ensuring precise matching and thus guaranteeing optimal performance. Simultaneously, it protects the tubes from overload and extends their lifespan—for reliable operation and maximum efficiency.

Component Selection and Internal Construction

• The amplifier is meticulously hand-assembled with point-to-point wiring, minimizing signal loss and effectively reducing crosstalk and interference. Key components include:
• Silver-plated internal wiring for optimal conductivity
• Aluminum alloy feet with anti-resonance properties for vibration damping
• Individually hand-wound toroidal power transformer and wideband EI output transformers

This precise selection and manufacturing of components guarantees clear, unadulterated sound reproduction with maximum reliability

Dynamic Automatic Bias

The Soul 170P features a fully integrated servo circuit for dynamic automatic bias, enabling seamless replacement of power tubes without manual adjustment. This system precisely regulates the operating state of each KT170 tube, ensuring optimal tuning and extending tube life—all while maintaining operational reliability and tube longevity.

Protection Features at a Glance:

• Smooth tube start-up thanks to a 60-second soft-start circuit
• Precise control of protection mechanisms by a microcontroller (MCU)
• BMI indicators for power tube failure detection and automatic

Safety Circuit Activation

These integrated protection features ensure reliable and safe operation by detecting and preventing potential damage early on.

Connections

The device offers versatile inputs with one XLR and one RCA connector, allowing for flexible connection to various audio sources. For speaker operation, 4 Ω and 8 Ω impedance outputs are available to ensure optimal compatibility with different speaker models.

Cayin Soul 170P Tube Power Amplifier

• Tube complement: 4× TUNG-SOL KT170, 2× 12AU7, 2× 6SN7, 1× 17AX4GT
• Rated output power, stereo mode: 2× 32W (RMS, triode mode) / 2× 60W (Pure Class A)
• Rated output power, mono mode: 64W (RMS, triode mode) / 120W (RMS, ultralinear mode)
• Frequency response: 8Hz – 70kHz (-3dB, RCA/XLR)
• Total distortion: 0.2% (1W/1kHz) Less than 2% at rated output power
• Signal-to-noise ratio: 105dB (RCA, A-weighted) 102dB (XLR, A-weighted)
• Input sensitivity: 820mV (NFB: LOW)
• Input impedance: 18kΩ
• Output impedance: 4Ω, 8Ω
• Input connectors: 1 × RCA (pair), 1 × XLR (pair)
• Dimensions: 430mm × 420mm × 239mm
• Net weight (W × D × H): 37.5kg
• Power consumption: Max 420W