Vypyr and VIP with effects loop mod

[vypman]

J_fury68,my question is a little off topic but i have a vypyr 30 and i was going to send it in to peavey for a midi board repair because when i hook it up to my sanpera II the presets and bank buttons lock up my vypyr sometimes when i press the footswitches too fast for preset and bank changes,i also have a vypyr 75 and when i use the same sanpera II with it i do not have the lockup problem?

I think someone posted years ago about this problem being a resistor in the midi circuit board that needs to be changed,if you know what resistor needs to be changed and what value it is,can you post a photo of it and also info on how to replace it?

[Lactose]

J_Fury68,

I am attempting the mod. I got the resistor off very easily; for anyone who is interested check this video out for another method of removing these tiny surface mount resistors which does not require any modifications to an iron tip. https://www.youtube.com/watch?v=8JM4oCpWnjU

I have wired up what I think is correct according to your schematic. However, I am not quite sure of two things.
1) Which post is the tip and which post is the ring on you schematic?
2) Do I need to wire anything to ground? I am not sure why the return jack has only 1 wire connected to it. In your screen shots I see you have wired something to the posts on the board, but since you said you had to repair your amp I am not sure if that is part of the mod or apart of your repairs.

My amp will power on but I get a very very quiet signal. I just think I have not wired up the components properly. It is possible I have a bad connection some where I will check all the solder.

Any help out there? Cheers.

[j_fury68]

In this circuit all wiring goes through the tip. The ring is grounded through the jack to the chassis. As far as the wire on the "post" I think you are referring to the blue wire attached to the corner of the board with one of the screws that help hold the board in place. I can see how that would be confusing. This was me being paranoid about grounding when I was performing the mod and it is not necessary. It is very important at this point for you to check things with an ohm meter. Test without the jacks and potentiometers in the circuit. At the terminals that you added in you shouldn't have any continuity between them, the meter should be OL (out of limits) or I for infinity. Then from one of your terminals (can't recall which...you will just have to probe around) to one side of C79 you should have continuity of less than an ohm. Then from the other terminal you should have the same continuity to one of the pins on U14 and again just probe around on U14 until you find it. If you check all pins on U14 and C79 and don't get at least one pin of U14 and one side of C79 with continuity of less than an ohm then you have a bad solder joint at R82 ( the resister you removed). If you have continuity between the two terminals that you added then you have bridged solder at R82 and must remove it and try again. If you can send any pictures of your project this may help me see what you have going on. You can either post them here or send me a pm and we can converse through email. Best of luck to you.

[Lactose]

Thanks for getting back to me so quick.

Okay I tested for continuity as you described; no connection at the resistor and I got my appropriate resistance values at C79 and U14 from the respective leads. I then connected everything to the ring as you described. Now the amp plays at a normal volume! However, when I plug anything into the jacks I get lots of noise. I do not understand your statement about the grounding. To me the noise sounds like a grounding problem. In the photo I have shown the setup pulled outside of the chassis (when testing everything is inside and screwed down). I labelled the pots S and R for send and return. Note the black and red wires are coming from the chassis are the leads into the DSP.

What am I doing wrong? Also, I noted which wires had continuity on C79 and U14. Is this how you tell which wire is send and return?

Thanks,

Lactose

[j_fury68]

I think we are making some progress so this is good. Full volume with nothing plugged in to the loop is good. Just to be clear on grounding...our signal from amp will leave the dsp and enter the send pot then to the tip of our cable, out the tip of the other end and through the return pot and back to the dsp The ring of your cable will be connected through the jack to the metal enclosure of the amp. I added the blue wire to make the connection from ring to enclosure while the jacks were not physically connected to the amp as you have them in the picture, otherwise this connection is not needed. I can't see the jacks well enough in your picture to tell, but please compare them to the attached picture. They need to be "switching jacks". If they aren't this will cause you problems. And finally, Yes the send wire will be the one with continuity to C79 and return wire with continuity to U14.

[Lactose]

Aha! I need stereo jacks. I am using mono instrument jacks. I will switch them out and check back in after. My local RadioShack seems to be going out of business and they now have weird hours. I may need to order them from ebay so it may be a few days before I get back to you.

Your help is much appreciated.

[j_fury68]

Actually these are a mono jacks. A regular stereo jack will not work either unless it is "switching" as well. Search "mono switching jack" on ebay and you will see what you need.

[Lactose]

Got my switching jacks in and I am please to report a smashing success! Thanks for developing this awesome mod and taking the time to help all of us out.

Lactose

[j_fury68]

Congratulations! This is actually a challenging mod that requires a bit of skill not to make a mess of things. I am always glad to hear good feed back. I am interested to hear about any good combinations of effects used with the vypyr so please share when you have opportunity.

[Rocco Crocco]

My amp tech quoted me a price of $80 to do this mod, provided nothing weird happens while he's working with the surface mount technology used in the amp. I forwarded him the PDF that Fury put together (thanks for doing that, brother!)

Seems reasonable to me, so I am dropping it off Friday. I'm pretty stoked.

[Rocco Crocco]

My amp tech quoted me a price of $80 to do this mod, provided nothing weird happens while he's working with the surface mount technology used in the amp. I forwarded him the PDF that Fury put together (thanks for doing that, brother!)

Seems reasonable to me, so I am dropping it off Friday. I'm pretty stoked.

Ok here's an update. I got my Vypyr back from my tech about 10 days ago. It's important to mention that I had didn't want the additional pots that were a parts of j_fury68's plans. In lieu of using the 50k pots, my tech simply installed 27k resistors in the circuit instead.

Anyway, I hooked the loop up at home and it seemed to work fine. However, at rehearsal last week, at much higher volumes, I noticed that there was a significant volume drop (roughly 30%) when the effects loop was hooked up. This was when the effects were bypassed even. I was not thrilled with this development. Not the techs fault, IMO. I asked him to deviate from what j-fury designed, which was known to work.

This is what the mod looked like when I pulled the chassis...


As you can see the two jacks are installed with a resistor connected to the orange wire, and another resistor connecting the two jacks.

I PM'd this pic to j_fury and let him know the issue I was having. He suggested I remove the resistor running between the two jacks and insert a wire instead, which I promptly did. It now worked perfectly. I tested at high volume and there is no volume loss when the loop is in use.

I initially wanted this mod to insert a clean boost pedal for solos. Today, just for fun, I hooked my Line 6 M13 Stompbox Modeler to the amp using the four cable method, inserting time-based and modulation effects into the loop. Sounds incredible. Using the Twin amp model with the dirt pedals from the M13 produces some great sounds. I am a happy camper!

Anyway, wanted to thank j_fury for this thread, and for his help in troubleshooting my amp. You're a good man, brother!

[frac82]

does this "fx loop mod" even work on tube Vypyr 60? if yes, where can i get the pdf with BOM, schematics and pictures? thanx.

[j_fury68]

does this "fx loop mod" even work on tube Vypyr 60? if yes, where can i get the pdf with BOM, schematics and pictures? thanx.

Yes it will work with the tube 60. I have a tube 60 with installed effects loop and works just fine. Page 2 of this topic you will find a "how to guide" in PDF format. Good luck!

[frac82]

Yes it will work with the tube 60. I have a tube 60 with installed effects loop and works just fine. Page 2 of this topic you will find a "how to guide" in PDF format. Good luck!

thanx j_fury68, please excuse me for asking again but even tried first with "search this topic" function with no success; i clearly didn't use it well!

[propbeanie]

j_fury68 post with pdf link

There's little numbers in the lower-right & upper-right of multi-page topic "threads" that you can click on to take you to a particular page. There's 6 pages here thus far.