Recommandation for 1:6 1:8 SUT under $5K?

input designations: 3, 10, 30, 100 are for the simple minded, 

it took me quite a while until I found the actual specifics of gain that occurred at those designated positions for my FRT-4 SUT.

We want to increase a too-low signal strength

You cannot multiply a +db number

What can we multiply the signal strength by to know?

X is the symbol for Multiply

Multiply by What ____ ? How Much? what term do you use?

turns ratio is not clear to my brain

a specific number is an answer,

a FACTOR in my brain

so X Factor, the factor that you multiply by

the factor that you square

before you divide

to ascertain a result

Of Course.

Perfectly Clear

....................................

"and 4 optional X Factors (4 different windings thru the passive transformers)"

i.e. 4 different 'turns ratio'

4 different GAIN options

I forgot I made this 'SUT INFO' on this site

https://www.audiogon.com/systems/11318

I just used the term X Factor I found on this chart

then I made my own chart

@elliottbnewcombjr 

it took me quite a while until I found the actual specifics of gain that occurred at those designated positions for my FRT-4 SUT.

Turns ratio and gain (X??) are not the same thing and the two only match when the load impedance is infinite and the source impedance 0.  The chart you present seems to use gain, X and turns ratio as the same number which can lead to confusion.   The turns ratio is used for impedance calculations and the gain is the result of applying the related impedances to the turns ratio.

Consider the Altec Peerless 4722.  This transformer has 1:18 and 1:36 turns ratios.  If you feed it with a Denon 103 (40Ω) into a typical 47kΩ,  both turns ratios will give about the same gain (X) of around 23-24dB and not the expected 25dB (1:18) and 31dB (1:36).

The above case is extreme and using the X factor for calculating impedances will not assure accurate results.  Of further interest, in the case of the 103-4722 combo, many (including Mitch Cotter) find the 1:36 position to be better sounding than the 1:18 even though the 103 is being loaded at a value below its internal impedance.  

dave

Given the specs, how/who came up with 3/10/30/100 for the designations?

I'm sure they moved over to Sony's camera division, and continued their mission 

intactaudio

Tomato, Tomato, I hope you can hear the difference.

call me stubborn, persistent, but only because otherwise it makes no sense to me.

The OBJECTIVE is to increase the signal strength.

The RESULT of the OBJECTIVE, is a change to impedance (unless separate controls are provided)

you said "The turns ratio is used for impedance calculations and the gain is the result of applying the related impedances to the turns ratio."

I'm saying, in SUTs like mine (impedance is not a separate control), the impedance is the result, I call it 'resultant impedance'.

In my world, GAIN (shown as a ratio), i.e. 1:20.68 is a shorthand way of saying x-factor of 20.68. You refer to 1:20.68 as 'turns ratio', I, and the chart refer to it as X-Factor

In my world, they are the same, and the only way you can know the 'resultant impedance' is to start with the x-factor and then do some calculations.