Feb 20

Peavey Vypyr 15 Mods from Petr

Vypyr 15

Vypyr 15 Amplifier

The Vypyr 15 Watt model is about as stripped down as Peavey could make it to minimize production costs (thus resulting in the low price that they are sold for).  Still, it is possible to get the same sound out of it that you get from the much larger Vypyr 75.

Peter (Petr), an EE turned IT guy from Chekoslovakia has designed a MIDI card that can be installed in the baby Vypyr which opens up a lot of

Petr's MIDI Schematic

Schematic for Petr's MIDI modification.

capabilities in this little amplifier.  The circuit to enable this is rather simple and the finished package is quite small, but the end result goes a long way towards making the littlest Vypyr act more like its big brothers.

Making this mod is a simple task for an EE, but it is way out of the capabilities of someone who dosen’t know the difference between a soldering gun and a soldering iron.  Installation requires cutting a hole in the amplifier’s metal housing to provide access to the 8 pin DIN socket.  Then holes need to be drilled in the case to allow mounting the circuit board (with insulators) so that the socket lines up with the holes.

Installing this mod requires cleaning out the solder holes on the DSP board to install the socket for the MIDI board’s ribbon cable.  This requires the use of a ‘solder sucker’ and some good skill with a soldering pencil.  You will also have to solder a surface mount resistor onto the Vypyr’s DSB board if you plan to use the MIDI to connect your Vypyr to a foot pedal (like the Sanpra).   It should be noted that dependable MIDI connectivity to Vypyrs is a bit dodgy and that some MIDI interfaces seem to be unable to provide enough current to drive this interface.  Check out the list of known-good MIDI interfaces on the Peavey Vypyr Forum.

I did encounter this problem with the board that Peter supplied, but he was very helpful in helping me diagnose the problem and helping me get to a functional solution.  You may also want to note that long MIDI cables seem to make the problem worse (this is usually a low current problem and long cables make things worse fast).  Don’t spend money on an interface with long cables on the MIDI side.  The shorter the better.

Petr's MIDI Board

Petr's MIDI Board

Having a MIDI input on the Vypyr 15 not only makes it capable of firmware updates and using a foot pedal.  It also makes the stomp boxes and looper available using MIDI commands through the new interface.

A little known fact is that ALL Vypyrs are the same when the output is connected to the headphone jack.  I run both my Vypyr 15 and my Vypyr 30 directly from the headphone out into my mixer, then use the PA speakers for the real sound.  As I’m using a couple of 15″ PA cabs, the sound from both is way beyond what anyone would expect from such inexpensive gear.

If you are interested in trying out Petr’s mod, send him an email (drieg321_@_gmail.com Remove the underscores – added to minimize SPAM).

His web site has been down for a while, but I noticed the other day that he has a new web site up at:

Link Removed – Petr’s site appears to have been hacked. Please make sure you have proper protection before going to his web site.

Safe copy saved on this site:
Peter’s Web Page

Will relink once it appears that the problem has been addressed


  1. Glen my sanpera is going into infinite restart loop often…..

    I searched peavey forums, found many results

    some says its a faulty firmware

    some say the midi board is faulty

    some say the power delivered is not enough(i can’t say if this is true, since My house is very poorly earthed, but fr power conditioning I’m supplying the amp through the computer’s UPS)

    I mailed Peavey with this video(the problem I’m having)to them,

    they replied,

    Unfortunately, we do not have a list of service centers for other countries. I suggest contacting your distributor for that information. They can be reached at galaxydigital@vsni.net.
    I can tell you, however, that the problem is likely a bad cable, or within the amp itself. When you find a service center, tell them to replace R2 on the MIDI board with a 1.1k resistor.

    Can you tell me if its the right direction to proceed……

  2. Jan


    nice to find the diagram of the modification. Can you send me the specifications of the used parts? (R2, R3, R4, C1, C2, C3, C4, D1, U1)

    1. Glen


      Petr should be asked for the component values. His email is drieg321_@_gmail.com (remove the underlines). I know that he regularly changes out components to improve the dependability. In particular, R1 and R2 need to be adjusted depending on the current that different brands of MIDI devices can provide.

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