Need some help with 2 problems

[SyncTronX]

(snippage) #2 In a Jung multi-loop configuration, the inner loop is set to a very high gain to increase linearity & reduce distortion.

The overall gain for the stage is set by the outer loop. In this case, the outer loop gain is figured just like any other non-inverting stage. It has an overall gain of "11".

Using this calculator:

Non-Inverting Op-Amp Resistor Calculator

I entered the following information.
R1 - 4 K ohms 1k + 3K
R2 = 1013 K ohms, 1M, +3k + 10K
V2 = 0
V1 = 1

Result:
Gain = 0
R2 = Nan
R4 = Nan

[mygearstationcom]

In case someone else needs information

Thanks for the post. It's great to be able to dig up such archived information.

I did find a Jung Calculator at Electronics Calculators When you click on the "I Know What The Resistor Values ARE. What's the Gain?" You can enter the values of the resistors.

The calculated GAIN value is 10.587727708533078. I'll take 11

This calculator takes an existing set of resistor values and calculates the gain. It can do this for either a standard noninverting op-amp gain stage (e.g. a CMoy pocket amp) or a Jung multiloop gain stage, as in the schematics at right.

If you only give values for R3 and R4, it uses the simple gain formula: G = R4śR3 + 1. If you also give the R5 and R6 values, it uses the Jung multiloop formula derived by Tophu:

G= R3(R4+R5+R6) +R4(R5+R6)

R3(R4+R5+R6) + R4R5

[Ronsonic]

So you got ahold of the finals test for this semester without answer sheet dinjya?

[Mars Amp Repair]

I know this thread is a bit old, but thought you'd be interested in knowing that both these problems came directly from the Fender Certified Tech test that they send to the warranty service centers.

I figured Fender wouldn't expect us to actually grab a calculator for either of these circuits, so I looked for the simplest way to figure the answers by rounding.

The resistive network is pretty easy to figure without any heavy calculations. the only parallel resistors that would require a calculator to figure the EXACT resistance is the 50ohm & 1.5Kohm in parallel. As an instructor used to say to us...the 1.5K is like flie shit in the pacific ocean to the 50 ohm & for estimating can be pretty much disregarded...so that leaves the rest of the ckt which is simple.

The 'Wang Chung' circuit is another issue. fortunately wayne provide the link for the calculations there. We weren't too far off as we figured the first opamp had such a high fb resistor (1m) that is was basically open loop. that left the 2nd op amp to do the gain setting. Rfb/Rg That calculation came out to about 10...pretty close to what you get when you actually plug that into the calculator.

glen

[unparalleled]

Last time I was on a course (Alpine GAIT) 1998 it took me a long time to find out the speed of sound in M/sec. (having left school in 1969)

343 M/Sec @ Temp 20 C at sea level?