Slaving a Plexi Project

[Bronco]

Without the load box and just the attenuator, the signal would still be too hot or too high to use effects? Does this sound right?

Not true...I use a THD Hot Plate set to load and have used its lineout signal directly to wet effects > power amp... works just fine; signal is not too hot whatsoever.

[jnewlyn]

Hmm. I'll get this figured somehow.

[908ssp]

Guitar signal less than 1 volt called instrument level. Guitar amp input less than 1 volt.

Effects loop 1 to 10 volts called line level. Effects loop 1 to 10 volts, rack effects 1 to 10 volts. Power amp inputs 1 to 10 volts. Attenuator output from the line out jack 1 to 10 volts. Amp's line out 1 to 10 volts.

[jnewlyn]

Guitar signal less than 1 volt called instrument level. Guitar amp input less than 1 volt.

Effects loop 1 to 10 volts called line level. Effects loop 1 to 10 volts, rack effects 1 to 10 volts. Power amp inputs 1 to 10 volts. Attenuator output from the line out jack 1 to 10 volts. Amp's line out 1 to 10 volts.

Well fuck, that's pretty simple. Thanks for that 908ssp.

So what does the Jose Load Box do because didn't Ed come out of that to his flanger, EP-3, etc. Those would be instrament levels. NO?

[908ssp]

I wasn't clear stomp boxes work at instrument level and rack effects work at line level. So it is possible that he needed more voltage reduction to put instrument level stomp boxes after the amp. And if he wanted to go in the second amp through the front he'd have to drop to instrument level.


There is also some over lap as some stomp boxes have enough head room to handle more than 1 volt and many output controls on effect loops have level controls that either switch low level around 1 volt or can be dialed back to near 1 volt.

You might remember some discussion about effect loops being too hot for a stomp box. Some Line 6 effects have switches on them for either line or instrument level. Instrument level is usually harder to achieve clean noise free results. Line level works better for loops and effects as it has more head room.

[jnewlyn]

There we go. Now I'm getting it. That's what I was after. I think its been said that he used his delays, flanger and stuff after that first head. This of course all before the SDE 3000's and the rack stuff.

So what Mark is doing is great for the slaving thing but if he wanted stomp pedals or EP-3, he would have to knock down further. That's what I was thinking the Jose thing did.

[dirtycooter]

Some digital delay pedals and stuff made today you can stuff a -10 signal into with little or absolutely no problem but generally you need a variable line level output control and get the "make up gain" from the second amps volume-I do it all the time with delay pedals and use them like rack processors.
Works awesome and adds a shit ton of other delay options rather than being limited to just rack stuff-not to mention cheap!

Also you'll find stompboxes being "unity gain pedals" they will not have the coloring some rack processors do since there is no extra gain circuitry in them like input and output controls that are active-but you have to have to be careful not to overload the inputs of the stompbox and really use your ears since they don't have clip lights or LED's and make sure the second slave amp is capable of getting the weaker signal coming out the other side of it back up-the essence of an AMPLIFIER in its truest form really. Sometimes depending on the amp its hard for it to amplify such a weak signal at times and may require a crap load of reserve wattage.

I use the Crown CE 2000 and changed the jumper internally [they are labeled Z 100 and Z 200] on its in-puts to be optimized for a -10 signal instead of it expecting a +4 or hotter signal-this gives me a ton of un-colored reserve wattage too using this specific amp and it is far from overkill really. An Ebtech line level shifter will work the same also in some applications for -10 and +4.
Keep in mind though most stomp boxes from years ago expect -20 instrument levels.

Don't know about older mxr pedals or other non-delay type fx though-been wanting to try a chorus pedal this way and I feel I can get it to swing just fine when I try it though.

[jnewlyn]

. Good to know. I'm gonna try this re-amping thing myself soon with my 50 and 100 watter. What I do like about the Idea is that you can have a more consistent tone at different volumes.

[leadguy]

I'm going to try and find a suitable transformer, b/c if I can put the transformer after the load in my UA and before the variable line out, I think it will effectively be the same thing as what you've described. I'm pretty sure there's enough room in there to do this.

Thanks for the help!

http://www.jensen-transformers.com/datashts/6110kb.pdf" onclick="window.open(this.href);return false;

what about this one?

Seems to be ok. The orange and red wires need to be connected together on the output.

[StuntDouble]

I'm going to try and find a suitable transformer, b/c if I can put the transformer after the load in my UA and before the variable line out, I think it will effectively be the same thing as what you've described. I'm pretty sure there's enough room in there to do this.

Thanks for the help!

http://www.jensen-transformers.com/datashts/6110kb.pdf" onclick="window.open(this.href);return false;

what about this one?

Seems to be ok. The orange and red wires need to be connected together on the output.

woohoo; kickass! So theoritically I could wire this between the load and the lineout of my attenuator and it should bring the voltage down to suitable levels for slaving?

[leadguy]

Jensen make good quality transformers.
Have a look at the pdf file page 2 down at the bottom or this http://www.jensen-transformers.com/as/as012.pdf" onclick="window.open(this.href);return false;

The 2 ends of the load resistor would connect to the transformers blue and green wires of the transformer and the end of the voltage divider line out pot P1 would connect to the yellow wire of the transformer and the end of resistor R1 would connect to the brown (ground) wire of the transformer. The orange and red transformer wires connect to each other. All grounds should be soldered to one main ground connection point.
Multiple different ground connections can lead to ground loop noise.
Also the transformers shield black and white wires go to ground.



Transformer is a 4:1 step down transformer. 10k secondary on amp 1's side and 600 ohms primary on amp 2's side
P1 is a 250k voltage divider pot (from Jose load box)
R1 is optional and is around 680 ohms
R1 stops the P1 pot value ever going to 0 ohms.

[leadguy]

The Jensen JT-6110K-B transformers input voltage specs.
It can handle an input voltage of around 15.4 Vrms or a peak to peak voltage of around 44 volts so I'd say it's ok for the Marshall output of say 30 volts.

Maximum Input Level at 20 Hz = 15.4 Vrms (+26dBu)

Voltage peak = Vrms × √2 = 15.4 x 1.4142 = 21.77

Peak to peak voltage = Voltage peak X 2 = 43.54

[leadguy]

http://www.gearslutz.com/board/high-end ... g-box.html" onclick="window.open(this.href);return false;

"The Jensen JT-6110K works great and you will NOT overload the input.
This is the one I use on the JM-410 I build.
Works great...
And yes it is not cheap...
But the title of the this thread is "Best Reamp""

[StuntDouble]

Cool; I'm debating whether to try and mod my attenuator or start from scratch and build a Jose Load Box.

What ohm value do I need for the resistors? I'm guessing 4 ohms if I go with 2x 200w wired in series and 8ohm for 1x 300watt?

[leadguy]

Should be ok. The watts for the load resistors should be twice or more the rated watts of the amp IMO just to be safe. The more watts the better for handling heat.