Overview The Jolida JD502B is a stereo tube integrated amplifier rated at 60 watts per channel into 8 ohms. Its output stage uses four 6550-family power tubes, with KT88 through KT100 types also supported according to the manufacturer, while 12AX7 and 12AT7 tubes handle voltage amplification and driver duties. Designed as a relatively powerful tube integrated amplifier, the JD502B includes multiple line-level inputs, 4- and 8-ohm speaker connections, and externally accessible bias test points and adjustments. Jolida specified a wide frequency response and a low-feedback circuit, positioning the amplifier as a practical bridge between traditional tube design and modern speaker requirements. Why This Model Matters The JD502B became one of Jolida’s more familiar integrated amplifiers because it offered enough power for a broader range of speakers than many lower-output tube designs. Its 60-watt rating, large output transformers, and readily available output-tube families made it attractive to listeners who wanted classic tube architecture without being limited to very efficient loudspeakers. It also appeals to owners who enjoy experimenting with compatible output tubes and careful bias adjustment. While different tube choices can subtly change the amplifier’s behavior, proper matching and setup are more important than chasing unsupported claims about any single tube being universally better. Highlights 60 watts per channel rated output into 8 ohms Four 6550 output tubes; compatible with KT88–KT100 types 12AX7 voltage-amplifier and 12AT7 driver tubes 4-ohm and 8-ohm speaker connections Top-panel bias test points and adjustment controls Multiple line-level inputs Who It’s For The JD502B is well suited to listeners who want a full-size tube integrated amplifier with useful power and straightforward controls. It remains important to verify tube condition, bias stability, and service history before extended use.
