mcentee2

This is a link to the v2.9 thread, page 87 from April 2020. References to the bright cap are clustered around a page or so earlier all the way through to beyond 100 I think. Google teases out more places it is mentioned. Lots to learn.

A helpful user on TGP mentioned that the real Plexi modelled in Helix had it's bright cap removed. This would explain exactly the differences I heard with the block vs my SV20 Preamp :) I have even more confidence in the other preamp blocks now :)

My SV20 has TAD preamp tubes, and Marshall only used one of the many flavours of Plexi preamps as their template, so I bet the Line6 reference is actually different to my SV anyway. They are close though compared to a lot of the other preamps. My other favourite at the moment is the Princess for a really thick juicy clean that the SV itself just can't get :)

Thankyou, it is indeed a complex thing. I thought the same as you purely by reasoning that I read somewhere Line6 only modelled the Hi inputs, and advise to use a vol/gain reduction block to imitate the low inputs before the amp. This meant if you did "jumper" the two remaining jacks there would no 3rd jack for the guitar, lol, so it must be modelled via a split Y cable into both High jacks :) Having done some listening this afternoon comparing preamps to the SV20 jumped as above and using the Normal Low guitar input, the Helix Plexi jump and bright preamps are not too far from my SV20 but are darker in character, less sparkly. The JTM45 is even closer, but the standout winner is the Who Watt, near enough spot on.

Which jumped and guitar in arrangement do the Jumped models follow? I have a Marshall SV20 jumpered from Bright Low to Normal High, and plug my guitar in to either Bright High or Normal Low as the mood takes me. Does the Helix Plexi Jumped model cover this, or some other arrangement?