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gareth magennis gareth magennis is offline
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Default Pultec EQP clone problem

On Friday, 5 March 2021 at 06:38:12 UTC, wrote:
geoff wrote:
===============

I would be curious to see the oredrs of harmonics and if they altered
over freq.


** I now have a jpeg image showing exactly that for you.

VERY clearly.

Where can I email it ?


...... Phil


gareth magennis wrote:
===================


These are screenshots of the Pultec clone ringing:
https://imgur.com/Ou0BGml

and with 100 Ohms in series with 0.01uF:
https://imgur.com/jaLv5Dz


** Nothing unusual with either.


The ringing is outside the audible range.


..... Phil



The ringing isn't necessarily the problem. The problem is that under certain conditions the unit oscillates at 90Hz, a phenomenom I still have not witnessed, but this has been confirmed by the company as a known issue with this early production unit.
The ASSUMPTION is that the ringing is somehow the cause of the 90Hz oscillation, and reducing the ringing will solve the problem.

The company issued a mod to tackle the 90 Hz problem, but we don't know what that mod is, or whether it is designed to reduce the ringing, or whether the mod adresses a different issue altogether.


Gareth.