Simulating Rotel RB850 in LTSpice?

I've found sense resistors unnecessary to monitor CCS outputs because if you hover over the collector pin of the CCS transistor you'll get an icon looking somewhat like a black owl (or maybe cat?) with a circle underneath it. Left clicking this will give you the collector current. It works for all transistor terminals.
Yes, that works for me too.

But LTSpice is meant to (and documented to) give currents in wires - you simply hold down the 'alt' key, and left-click.

A normal left-click on a wire plots voltage, but holding alt is meant to plot current. And (indeed) when I hold down alt, the display says (on hover) click to plot current.

But clicking does nothing.

EDIT; I'm using LTSpice XVII, under Wine/Linux.

Hence my "sense resistor" workround. :(

I'm at a steep part of the learning curve at the moment (circuits, amplifiers, spice), so this isn't my biggest problem!



BugBear
 

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...LTSpice is meant to (and documented to) give currents in wires - you simply hold down the 'alt' key, and left-click.
EDIT; I'm using LTSpice XVII, under Wine/Linux....

That last may be the "key" detail.

Alt-LeftClick is a rarely used action in Windows (very useful; but rarely used).

A moment on Google reveals that under Linux the Alt may do something different (move window) unless you specially tell it otherwise.

Alt Key Functionality broke in Wine program

By the question we may guess this is not consistent across all Linux GUIs.

And yes, putting in a zero-V battery is an old-old-old technique to force SPICE to print-out the value of a current. Nominally neater than a "small" resistor, though it does look funny with batteries all over "doing nothing".
 
In case anyone is interested, I've attached my LTSpice file, the circuit of one channel of a Rotel rb850.



THIS DOES NOT WORK.

(and I'm not asking for help making it work, not yet anyway).


BugBear

There is a missing connection node at the vas collector.

Note that LTC spice has a "browse" option that automatically/easy fixes .lib directives. BTW, thanx Mooly for this lib.
 

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https://www.diyaudio.com/community/threads/sound-quality-vs-measurements.200865/post-2830898
The colleague also tried to measure the distortion of the first period and found different distortions introduced by different amplifiers.
https://www.diyaudio.com/community/threads/sound-quality-vs-measurements.200865/post-2824957
sardonx


"I can show you six areas in the JC 2 where I can change parts that will change the sound but not change the measurements"
Thats' a quote by Richard Schram, president of Parasound, on the JC2 preamp, the production version of the Blowtorch, designed by no other than the famous John Curl.

Watching what to measure! If you measure THD then you really won't see anything. Distortions must be measured by the compensation method. The nature of the distortion is most affected by the change in group delay (tPD - time Propagation Delay).
 

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