re-amp / reamp circuit using readily available transformer (s)

[effbiae]

hi,

thanks for all the help i've got so far in this forum.

i found a reamp schematic here:
  http://www.jensentransformers.com/datashts/11p1.pdf

but i'm wondering if anyone has a design based on easily available parts?

thanks in advance,


jack

[amz-fx]

Check this out:

http://www.muzique.com/lab/patent1.htm

regards, Jack

[R.G.]

Note that even with a high quality transformer and impedance matching, passive transformer setups will likely cause treble loss because the matched impedance can't be high enough.

In these cases, the transformers are 10K on the guitar side. Jensen has thoughtfully matched the transformer impedances with suitable resistors on secondaries, but the reflected impedance is still a problem with raw guitar signal, I think

If you have a high impedance buffer on the guitar side, suitable for driving that 10K impedance that the guitar side sees reflected, it's a good idea though.

'Course, if you have a buffer, driving long cables and amps is not a problem either.

[effbiae]

'Course, if you have a buffer, driving long cables and amps is not a problem either.

forgive my ignorance, but are you saying that a buffer does the same job as a 'reamp'?

thanks in advance,


jack

[Gus]

Jack

   Interesting read.  I think it would be fun if you posted that at The Lab.

  Did you read one Aron posted in the lounge?


Gus

[R.G.]

forgive my ignorance, but are you saying that a buffer does the same job as a 'reamp'?

No, not at all. I was just pointing out some more considerations that have to be made when you drive anything with a guitar pickup.

In this case the reamping relies on the transformers to get to low impedance. That's good, but since the transformers are modest impedance when operating into a matched load (about 10K I believe) then you're loading down the treble end of the guitar signal. A buffer helps with that.

[Dai H.]

I think there is some confusion possibly stemming from the term "reamp", so (assuming I'm correct) I think a Reamp refers to the product of this name which is meant for matching a line out to a gtr. amp input and there is no gtr. signal involved (at least not a "live" one). (The idea IIRC was to record a "raw" gtr. signal on tape, then use it over and over to record with without having to play the same thing again and again to be able to experiment with mic placement, efx. etcetera)

[Plectrum]

I think there is some confusion possibly stemming from the term "reamp", so (assuming I'm correct) I think a Reamp refers to the product of this name which is meant for matching a line out to a gtr. amp input and there is no gtr. signal involved (at least not a "live" one). (The idea IIRC was to record a "raw" gtr. signal on tape, then use it over and over to record with without having to play the same thing again and again to be able to experiment with mic placement, efx. etcetera)

Yep, I was getting confused there too; a "re-amp" is used to match a balanced line output from a console into a guitar amp or pedal input.
I'd also like to know the best solution, active or passive.

Grant

[R.G.]

Ah. That clears it up a bit. If it's just matching from balanced line output to guitar level, that's different.

In that case what you want is a 600 ohm balanced input transformer that's terminated in a matching impedance  on the secondary, then attenuation down to guitar levels on the secondary and series impedance to fake guitar pickup impedance.

It might be easiest to run the signal in series through a pickup (sans guitar) in the box with the transformer and some real guitar control circuits. That might get pretty close.

Otherwise you could fake the guitar's impedance by inserting Rs, Ls and Cs to get the right mix.

[Joe Kramer]

Hi!

I used an Edcor PC10K:10K transformer in the Jensen reamp circuit with happy results.  The Edcors sound good and are definitely priced right.   

http://www.edcorusa.com/transformers/pc/pc10k-10k.htm


Regards,
Joe