What transformers to run your mix through

[Gold]

The perfect termination resistance is one that can produce a square wave without overshoot and ringing and have flat tops.
600 ohm is good number for 1mW 0dBu, keeping those VU meters happy.
Outside of that I see no point in 600 ohm lines.

My apologies for being pedantic but if you are using 1 m/W as a metric the other part should be dBm. The other part is 1mW/600 ohm (with the meter properly terminated) is +4dBm.

 

[Cqwet Dbdfte]

Happily I don't need to use VU meters, but Sqrt(0.001*600)=0.77459666924
Like 1mW @ 600 Ohm = ~ 0.775V
Unloading the 600 Ohm source from a 600 Ohm load would increase the voltage, not sure what the numbers are for "unloaded", some load is still present.
The telephone company ran very long analog lines so impedance matching was important. The 600 Ohm number may have been impedance of free conductors in air.

https://en.m.wikipedia.org/wiki/Line_level#cite_note-handbook-2

...has +4dBu at 1.228Vrms.
Again, I don't care.

 

[JohnX]

Add one 600 ohm resistor across the two output terminals. See an earlier message of mine about really dialing in the perfect termination resistance.

I’m getting ready to start assembling this updated box utilizing your suggestion of the resistor to reduce ringing.
I get a little bit confused when making my switch selections so if it’s OK, I’d like to ask you what the correct choice would be
The box is two channels (stereo) and will have three separate outputs
1 - my normal “main” outputs
2 - a secondary output that is extremely Lofi and lacking in high frequency
3 - this position will activate your resistor to reduce ringing (which may be most noticeable in which position 1)

Would I be looking for a 4P3T on-on-on switch?

 

[AlgoRhythms]

Sure. personally, I prefer a nice rotary pot over a toggle switch. with the positions I need.

 

[JohnX]

Sure. personally, I prefer a nice rotary pot over a toggle switch. with the positions I need.

As do I.
Your suggestion occupies the middle position, and although it’s subtle, I like what it does. I used 620 ohm resistors.Thanks.

Just out of curiosity, if I wanted more of a drastic effect, would I use a higher value resistor?
(please keep in mind that I have no test equipment here. I can only go by hearing.)

Now I have 3 different tonalities on one color box.

 

[AlgoRhythms]

Adding more resistance will eventually roll off top end. How much and where that occurs I can't answer.

You could substitute a nice variable resistor, say from 300 ohm to 3k, or something like that. Since the effect is subtle, this would let you dial in a sound that works for you.

 

[JohnX]

Adding more resistance will eventually roll off top end. How much and where that occurs I can't answer.

You could substitute a nice variable resistor, say from 300 ohm to 3k, or something like that. Since the effect is subtle, this would let you dial in a sound that works for you.

What would be the most efficient way to accomplish that in a dual channel box? Would I be looking for something like this?
https://a.co/d/1C54rgX

 

[AlgoRhythms]

One variable resistor pot per channel

 

[JohnX]

One variable resistor pot per channel

I see.
I don’t think that would be practical for my use of these boxes because I am running mixes through them. Not sure how I would ever know if I had the same settings on both sides other than visual.
I suppose it could be workable if they had detents.
Thanks

 

[AlgoRhythms]

you could build two rotary switches, each with fixed resistor positions. that are matched. 8 steps?

then left and right would be the same.

 

[JohnX]

you could build two rotary switches, each with fixed resistor positions. that are matched.

I do love rotary switches.
I don’t know what it is about them but I just do.