42tm018 Replacement, better frequency response!

[wavley]

After searching at mouser I found that there is a better transformer than the 42tm018 we all use for various projects.  The Triad TY-141P has a frequency response of 200 Hz to 15 KHz for less than two dollars more than the 42TM018.

Soon I'll get to use them in a splitter I'm building and I'll let you know how it works out.

Wavley

[Paul Marossy]

Cool. Aren't those about four or five times physically bigger than a 42TM018?

[wavley]

Maybe so, I haven't used the 42TM018 so I can't compare them, but they have a footprint about the size of a quarter so for the project I'm using them for there is plenty of room.

[Paul Marossy]

Maybe so, I haven't used the 42TM018 so I can't compare them, but they have a footprint about the size of a quarter so for the project I'm using them for there is plenty of room.

Oh, so they are much, much smaller than I thought. I must be thinking of another brand/model then, or perhaps this is a new offering.

[R.G.]

Notice that the specs are just what the manufacturer guarantees.

In my splitter circuits, I've come up with ways to drive the Xicon transformers to get low frequencies down to 60Hz, and the top end measures out at 22kHz anyway.

No doubt the Triad device is better, and might get even lower than 60Hz if properly driven, but the lowest note on a standard-tuning guitar is 82hz.

[Paul Marossy]

Notice that the specs are just what the manufacturer guarantees.

Right. Anything beyond that is kind of a no-man's land. 

The one transformer I was thinking of earlier is made by Edcor. That one is quite a bit larger physically than the Mouser transformer.

[wavley]

Well, I'm going to try building this splitter passive considering it is preceded by a space echo as a buffer.  I figured the better specs would be better for a passive device and seems to be compatible with R.G.'s circuit if it doesn't work and I need to build his.  R.G. you have a very nice circuit by the way and your articles have been quite enlightening for me for quite a while.  I've been following this board for a while but I never post because I can usually find what I need from searching, plus I'm a tech at a radio observatory so I have a building full of physicists and engineers to ask when I'm stuck, of course all the guys that know tubes are retiring but that's a story for another day another board...

[brett]

Hi

Aren't those about four or five times physically bigger than a 42TM018?

Often, transformers are made with physically large cores to transmit bass.

But also consider the fact that power transformers all operate  at 50/60Hz (ie transmit deep bass).  Large ones and small ones. To transmit this low frequency the high power ones have much larger cores than their low power cousins.  So core size is related to the lowest frequency transmitted AND the power rating.

There are three things you can do to put more bass through a transformer.
One is to go for more steel/core material.  This is a common approach. 
Two is to go for active bass enhancement, and cover the bass loss with bass boost.  To use this option, you must have spare "headroom" or also use option 3.
Option three is to lower the wattage being transmitted.  If the core is saturated at 200Hz at 0.1W, try dropping the wattage to 0.01W.  There's every chance you'll get bass transmission down to 100Hz (or lower).  Using only a fraction of the VA rating gives you the "headroom" for active bass boosting if you want to do that, too.  However, don't go too far under the VA rating (ie 10W transformer, 0.01W signal) or signal losses will be an issue.

Have a great day.



cheers

[wavley]

I think that by driving my isolation transformers with the 600 ohm output on my 501 space echo that has a low output I don't really need the extra circuitry, we'll see this weekend.  If I'm wrong, I'll be building the hum free

[R.G.]

Yeah, if you have a 600 ohm drive available, you're probably OK.

[wavley]

So I built it this weekend and it sounds great!  I can even drive it from my Boomerang+ because it has low impedance output too.  Added bonus is that I think that my amps like being driven by the transformers quite a bit more than the space echo or boomerang+

[Paul Marossy]

So I built it this weekend and it sounds great!  I can even drive it from my Boomerang+ because it has low impedance output too.  Added bonus is that I think that my amps like being driven by the transformers quite a bit more than the space echo or boomerang+

Cool!