Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Grantorino on November 22, 2025, 01:27:24 pm

Title: Amplifier Lag - Carlsbro 60 T.C
Post by: Grantorino on November 22, 2025, 01:27:24 pm

Hello there EL34 World.

Following on from the restoration and the HF oscillation fix here:

https://el34world.com/Forum/index.php?topic=33140.msg368489#msg368489

A carlsbro 60 T.C. now restored with a full recap and ‘speed-up cap’ mod, biased well, stable. (Thanks again)

When making sudden jumps in  dynamics - guitar volume at 10/10 on the bridge pickup switching to 1/10 on the neck - the amp momentarily lags as if the power dips before recovering.

Is this behaviour expected of the design and part of ‘vintage character’? If no, can it be improved?

This is with the gain channel volume control at maximum and the eq settings at midway, with no limiter.

Schematic is attached.

Thanks to anyone interested.

Title: Re: Amplifier Lag - Carlsbro 60 T.C
Post by: pdf64 on November 22, 2025, 04:39:08 pm

Possible blocking.
The 0.47uF cap feeding the V4 LTP is 20x higher than typical, the 0.22uF at the other grid is twice the typical value.