Intact Audio

Place your generic files here as starting blocks for others.

a parafeed linestage with a 76 and a 2:1 output.

Hopefully its of use, a standard three stage RIAA stage, with inverse RIAA on the input.

Usefull for finding the effect of changing the RIAA values.

LT spice file for the 14 step autoformer.

A Passive Inverse RIAA made up from an RC network. The maths is courtesy of Jim Hagerman's paper "On Reference RIAA Networks" output can either be -40db or -60db.

cheers,

-- Andrew

This allows easy changing of the L, C and cathode bypass.

This is from Nickel Core over on the asylum. The discussion is about the cap across the secondary.

If you download LTspice and run this file you should get immediate results.

This file demonstrates the effect of distortion cancellation between driver and OP stages in a SET amp. The circuit is not intended to be an optimum design for DIY but highlights the benefit of finding well-matched tubes and careful selection of their operating points.

Since most of the distortion is generated by loading of the OP tube, less linear driver tubes operating at lower current tend to work best. The increased distortion created by these conditions is 180 deg out of phase with the OP giving rise to some cancellation, mainly in the lower harmonics.

In this DC coupled example, the local NFB caused by the OP tube's RK also plays a role to help completely cancel lower order harmonics. Change the operating points to see the effect using fft to view.

You will need the attached file dmtriodep.inc in case you don't have it.

A cap / IT coupled 3 stage amplifier where the bias is stepped in the driver stage to see if there are any harmonic cancellation effects in such a setup.

Simple tuned choke file to look at the harmonics created.

Dave, this is consistent with my findings in the real and Simmed world. Definitely worth a try and perhaps some experimentation with lower C and L values.

Naz