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The short cord goes from the guitar/jack to the Match Box Input (top/jack). The Match Box Output (bottom/jack) cord goes to the Pre-Gain Input on the Amp.

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Since Peavey Electronics first introduced the Session500 steel guitar and fiddle amplifier back in 1980, we have been the only company to offer an interesting solution to the problems that are encountered when using potentiometer based pedals for controlling the volume of the amp. Although our “volume pedal” or “pre eq patch” point has been a standard feature on every steel amp since the Session500, players may not be aware of this unique method of “inserting” their volume pedal into the circuit on the various models that have been introduced since that time. On the Session500, this insert point was labeled “PEDAL-IN & OUT”. On the Vegas 400 and the Nashville 400, it was labeled “PRE EQ PATCH-IN & OUT”. On the Session400 Limited, this insert point is labeled “PRE EQ PATCH-SEND & RETURN”. On our latest models, the Session2000 and Nashville1000, this insert point is labeled “PRE EQ PATCH-SEND & RETURN”. Although they are all labeled with different names, the purpose and results are the same.

A typical volume pedal patch is made between the guitar and the amplifier input. However, doing so could cause the tone of the guitar to change as the pedal is moved up and down with changing volume requirements, because this patch introduces a varying resistance as seen by the guitar pickups. The Peavey pedal patch allows the user to insert a volume pedal into the active pre-amp circuit, thus increasing the performance of the volume pedal. Because the volume pedal is patched in after the first pre-amp stage, no signal degradation occurs regardless of the pedal volume setting. The volume pedal changes only the volume without affecting the tone or character of the guitar voice.

This is how the circuit works. When an instrument signal is routed through either the high gain or low gain inputs (10db gain difference between the two types), it is routed through a first order high-pass filter that blocks DC into and out of the first operational amplifier (IC chip) for protection. A 20 hertz low pass filter is in place to provide better signal to noise ratio of the circuit. In this first stage of the circuit, we have designed in various electronic component circuits to reduce noise so that it won’t be amplified through the remaining signal path. When the audio signal hits the pre gain control potentiometer, the level of the signal that is to be routed through the remainder of the circuit is dependent upon the setting of this control. At this point in the circuit, the signal is routed out of the OUT jack via shielded cable, through the volume pedal and back into the circuit through the IN jack using a second shielded cable. NOTE; When the volume pot is in the fully up position (no sound), the wiper of the pot is sent to ground. When the volume pot is in the fully down position (sound), the signal is then audible through the circuit). The pedal volume pot acts in the same fashion as the PRE GAIN control on the amplifier. The IN jack is of the “normaling” type, which remains closed until a ¼” plug is inserted for the returned signal. At this point in the circuit, additional noise filtering is applied and a 1.56Mhz. low pass noise filter is employed to shield radio frequencies from entering the circuit. In addition, a high pass filter blocks frequencies below 10 hertz.

At this point in the circuit, a second first order high-pass filter blocks DC current into the second gain stage before signal is routed through the remainder of the preamplifier.

This “pedal patch” is exclusive to Peavey steel guitar amplifiers and it works! If you have any questions, please contact me toll free in the U.S. at 1-877-732-8391 or by e-mail at mikebrown@peavey.com

I haven't yet finished experimenting with where to patch in a clip-on tone control so that it doesn't suck off the Hilton pedal highs. From Mike's description above it seems like it might work either patched into the pre-EQ or in the FX loop.

As far as where to locate the external tone control, I haven't ever seen anyone use a clip on tone control(but there may be one available). There is a possibility that anything in the signal path can degredate the audio signal and sometimes there is no way around it. I can't really say that I have to readjust tone controls using either the Nashville 400, Nashville 112 or the Nashville 1000 amps when switching between C6th and E9th. But it's not that often that I take a stab at the C6th neck either.

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Allen Harry
Emmons SD10
Nashville 1000

I have a battry powered Behringer pedal (embarrassed emoticon) but I think its still "passive" in that it doesn't have a preamp, as such, in it (?). I plan to get a proper pedal soon, and I'd value any input before I choose which type.

Jeremy

[This message was edited by Jeremy Threlfall on 06 October 2006 at 07:24 PM.]

If you introduce any other type of device into this chain, you may cause unexpected impedance changes...you might like it better, or not. You'll have to be the judge. The experimental variations are endless and no one, not even our Guru, Mike B., can predict the results.

The newer Goodrich and Hilton pedals are designed to correct impedance matching when used between the steel and the amp's guitar input. These pedals were not designed to be used in the 3 cord setup. Again, inserting any other device in this chain may, also, cause unexpected impedance changes...you may like it, or not. You'll have to be the judge, again.

Impedance changes, like we're talking about here, equate to tone changes. These are all low signal level and low voltage devices, so no harm will be done with common sense experimentation. If you find a combination that you like, go with it. But, understand that the same setup, using similar, but different devices, will most likely yield different results (tonality).

I don't claim this is the best hookup for an active pedal, only that it is available and that some players might like to try it.

Actually, IMHO, the best setup, from the standpoint of matching impedances, would be to use only the active vol. pedal (Black Box optional) between the guitar and amp input, then use a multi effect box (ProFex or Pod, for example) hooked into the effect loop, or preamp in/out jacks. All the impedances would be correct and the maximum sonic accuracy would be achieved.