Bottlehead Forum

Bottlehead Kits => S.E.X. Kit => Topic started by: alanchongth on May 31, 2025, 05:20:31 PM

Title: S.E.X 2.1 CS4 – Resistance Check After Changing Output Impedance
Post by: alanchongth on May 31, 2025, 05:20:31 PM

Hi everyone,

I just reconfigured my old S.E.X 2.1 CS4 amplifier's output impedance from 8 ohms to 32 ohms. When I performed a resistance check, I found that terminals A7, A8, B7, B8, C1, C2, C4 and C5 all show values around 60–62Ω.

According to the manual, these four terminals should be marked as "*", which I understand means they should show no resistance or remain open. Could anyone help me understand what might be wrong?

Before the change, the amp was still working fine—just a bit noisy when turning the volume knob.

Thanks in advance for any advice!

Title: Re: S.E.X 2.1 CS4 – Resistance Check After Changing Output Impedance
Post by: Paul Birkeland on May 31, 2025, 06:52:19 PM

If the tubes glow, then I wouldn't be too concerned with those readings.  They may also change with no tubes in the sockets.