ISO transformers

[jettrocker]

Hi.

I wanna build a box that is similar to the Palmer PLI-01 Isolation box.

Looking at Jensen Transformers. But there is so many to choose from..
Can someone point me in the right direction which ISO transformer is correct to use?
http://www.jensen-transformers.com

Thanks!

[jettrocker]

Jensen JT-11P-1   

[R.G.]

There is no generally-correct isolation transformer for all tasks. Even for coupling audio, there are differences depending on what is driving the transformer and what is receiving the signal. For instance, it is very, very difficult to make an isolation transformer that will isolate a guitar signal because of the peculiarities of the guitar pickups and controls.

What are you coupling to what?

[jettrocker]

There is no generally-correct isolation transformer for all tasks. Even for coupling audio, there are differences depending on what is driving the transformer and what is receiving the signal. For instance, it is very, very difficult to make an isolation transformer that will isolate a guitar signal because of the peculiarities of the guitar pickups and controls.

What are you coupling to what?

Its a guitar (buffered) that drives the signal and its a guitar amp that receiving the signal.. Im using more than one amp so I need isolation.

[wavley]

There is no generally-correct isolation transformer for all tasks. Even for coupling audio, there are differences depending on what is driving the transformer and what is receiving the signal. For instance, it is very, very difficult to make an isolation transformer that will isolate a guitar signal because of the peculiarities of the guitar pickups and controls.

What are you coupling to what?

Its a guitar (buffered) that drives the signal and its a guitar amp that receiving the signal.. Im using more than one amp so I need isolation.

Check out RG's Hum Free ABY, it will do exactly what you want it to.  The transformers are cheap (like $3, I used the $6 Edcor version because I was getting fancy)  His actively driven transformer plan works wonderfully and pretty much guarantees consistent results for anything plugged into it, high input impedance and it pretty much looks like a pickup to the amp.

[therecordingart]

Jensen makes a great product, but my butt puckers a little bit any time they are mentioned because that price is brutal. Edcor is a good option. Inexpensive and good, but their lead times can stink.

[wavley]

Jensen makes a great product, but my butt puckers a little bit any time they are mentioned because that price is brutal. Edcor is a good option. Inexpensive and good, but their lead times can stink.

The down side is that the Edcor, while it sounds a bit better to my ear when playing Baritone Guitar/Bass VI and is harder to saturate the core, is easily 4 to 6 times the physical size of the transformer R.G. spec'd, I used the Triad version of the transformer R.G. recommended because it had a little bit better low end response spec and it was the same price.  Sounded great for guitar, a little strangled on the low end of the Bass VI and I could get the core to saturate with a hot signal and the Bass VI, so I swapped out for the Edcor and it sounds great.  Lead time is a little long because they make them as needed.

[R.G.]

If you're going to be putting bass through them, definitely go with the Edcor. I got the cheapie transformers to work for guitar, but they poop out about 60Hz, not enough for low - E on bass.

[jettrocker]

Thanks for you replies. But I'm looking for a very simple solution like the Palmer but with better sound. I have the Palmer but I don't like the way it colors the sound. Im wiling to pay for Jensen but need help which one is right for me. Found this schematic that is similar to what I wanna build. http://www.jensen-transformers.com/as/as013.pdf

Jensen JT-11P-1 is used there.. Is Jensen JT-11P-1 also the correct one for a "Palmer clone"?

[wavley]

Thanks for you replies. But I'm looking for a very simple solution like the Palmer but with better sound. I have the Palmer but I don't like the way it colors the sound. Im wiling to pay for Jensen but need help which one is right for me. Found this schematic that is similar to what I wanna build. http://www.jensen-transformers.com/as/as013.pdf

Jensen JT-11P-1 is used there.. Is Jensen JT-11P-1 also the correct one for a "Palmer clone"?

Any passive transformer is going to color your tone.  If you drive it with an effect with a good always on buffer it will probably be fine, my Boomerang+ Phrase Sampler will actually drive an Edcor fine.  The JT-11P-1 has a 10k input impedance, that's quite a bit lower than the 1M that we all generally try to hit for uncolored tone.  Trust me, I've been down this road of breaking ground loops with iso transformers... R.G. has a great and fairly simple solution.  BYOC has a kit that looks very much inspired by the Hum Free ABY, you could get the kit for less than the Jensen transformer costs.