Dynatron HFC 100 - audio output please help! - UK Vintage Radio Repair and Restoration Discussion Forum

PineconeKay · 6th Nov 2025, 11:08 pm

Hello! Firstly, apologies for my limited professional vocabulary and jargon.

I encountered an issue with HFC100. It appears to be similar to the closed thread from 2016.

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In short: when plugging speakers into the right output, whether Speaker A or B, there is no sound. Left size work well.
The balance control is set to the mid position.
Cartridge check suggested in the old thread also came out ok.

Is there anyone who would have any suggestions as to why that might be?
And if there is a way to fix this?

Uncle Bulgaria · 7th Nov 2025, 11:51 am

Have I interpreted you post correctly: when playing a record, the left side reproduces correctly and you hear what you expect to hear, but there is nothing on the right? Is there any hiss or buzz at all from the right loudspeaker if you turn the volume up without a record playing? The noise on both left and right should be equal.

By 'cartridge check OK' you mean you have touched the pins in turn and you get an equal buzz from the left and right loudspeakers alternately when two of the pins are touched?

If so, the wiring running from cartridge to loudspeakers is OK and there doesn't seem to be a reason for your symptom other than an internal cartridge/stylus fault. Have you checked the stylus?

What is the cartridge's model?

6th Nov 2025, 11:08 pm	#1
PineconeKay Diode Join Date: Nov 2025 Location: London, UK. Posts: 1	Dynatron HFC 100 - audio output please help! Hello! Firstly, apologies for my limited professional vocabulary and jargon. I encountered an issue with HFC100. It appears to be similar to the closed thread from 2016. In short: when plugging speakers into the right output, whether Speaker A or B, there is no sound. Left size work well. The balance control is set to the mid position. Cartridge check suggested in the old thread also came out ok. Is there anyone who would have any suggestions as to why that might be? And if there is a way to fix this?

7th Nov 2025, 11:51 am	#2
Uncle Bulgaria Dekatron Join Date: May 2016 Location: Cornwall, UK. Posts: 3,004	Re: dynatron hfc 100 - audio output pls help! Have I interpreted you post correctly: when playing a record, the left side reproduces correctly and you hear what you expect to hear, but there is nothing on the right? Is there any hiss or buzz at all from the right loudspeaker if you turn the volume up without a record playing? The noise on both left and right should be equal. By 'cartridge check OK' you mean you have touched the pins in turn and you get an equal buzz from the left and right loudspeakers alternately when two of the pins are touched? If so, the wiring running from cartridge to loudspeakers is OK and there doesn't seem to be a reason for your symptom other than an internal cartridge/stylus fault. Have you checked the stylus? What is the cartridge's model?