Intact Audio

As promised, here's the schematic for the inductive passive tone controls.

-Steve

The "other" frequency selective use for attenuators is inductive based tone controls. Attached is a LTSpice simulation of a set of tone controls based on this concept. The Treble consists of one tapped inductor (boost side) of 1mH+1mH+4mH+4mH+4mH+4mH (=100mH total) and 30 ohms. (lower resi...

This is one of those "no R, no C" designs. I've attached the schematic gif file as well as the LTSpice ASC source file. Note that you need the include files modeling the tubes too, see SPICE thread for those files.

A lot of this is on Duncan Munro's site, but for more or less completeness, here's how to add tube Spice modeling to LT Spice. In the swcadiii directory (that's the default where all the schematics you create reside - usually under "Program Files" and LTC or whatever) place the include fil...

cool... so are you sticking with the 300mhy for the choke???

10-20 ohms DCR OK???

Yep that looks good!

Ya know, this is going to be pretty cool. I don't recall EVER seeing a Loudness comp circuit made with no capacitors!

Steve

#1 showed the peak at 8K that steve saw. 2&3 were the same. this suggests to me that spice indeed puts the lumped capacitances in series, and taken to the exterme, you could end up with infinite inductance and near zero capacitance if you couple together enough discrete inductors in spice. Pret...

Interesting. The nasty test, of course, is one 300mH, 3000 ohm 1000pf "inductor" in the bottom leg. Nasty resonance at about 8kHz. That's actually one of the nice things about Spice... keeps you from stepping into the bigger pieces of cow doo-doo. However, it can also usually tell you how ...

do me a favor and send me your file (or attach it here as a zip) so i don't need to spend an awkward hour trying to redraw it to figure out what you need for an inductor. having a dedicated freeware spice like LT spice would be a cool learning tool! Hi Dave, Yep, that's a fully featured "non-w...

Hi again Dave et al, Here's the "PSpice" netlist you asked about... keyed in the circuit and ran it under PSpice (produced the same output) ... ; lr loudness circuit translated to PSpice V1 1 0 ac 1 R1 1 2 1k ; source resistance ; note - node 2 is "0dB" net L1 2 3 50H RL1 3 4 400...

what would be the effect of the L of the autoformer increasing with signal level? i would think that the nonlinearity of the 1X1 would compress the extremes as signal goes up. Here's sim with inductor values increased 1.4 times (70H, 7H etc) Incidentally, this was done under (free for the download)...

Hi All, For my next project, I'm going to do a fully integrated amp... phono, line and power amp. Now I'm one of these wierd characters who actually uses (and likes) "loudness" compensation. In a previous project, I did an experimental LR RIAA phono (no capacitors in sight anywhere) and it...