cgtrox

That's the only problem with these amps. They are a hybrid of half amp and half computer. First thing is, we all know how hot tubes in a tube amp can get, which is part of their charm. Well, we also know what happens when a computer gets hot! There is a part of the "computer" that is getting too hot. First thing to try (a little ghetto, but...) get a small fan and aim it at the back of the amp while you're playing it. If it stops doing what you said, then there's your problem. Next, look for a Line 6 certified store to look at it, not a regular amp place. More than likely it is the mother board which can be replaced by a Line 6 certified repairman. Good luck bro... cgtrox B)

Okay Terry, the BIG question! (Glad to see you her btw!) Can we get SVPre's made anymore? I've been eyeballing some MKI's at a couple of places... :D cgtrox B)

Nah, he doesn't have that kind of power over there, I think he's just the marketing guy. The owners are two guys who made Strymon and I don't think they are gonna let that out as it might affect their boutique pedals that they have out now. Awesome stuff they are putting out up there! We are prolly gonna have to Area 51 it and do some reverse engineering, LOL! :( cgtrox B)

I know man! I use the Insane Blue (modern high gain) with only half or less of the gain as my main sound. I think it's modeled after a hot rodded Marshall. I use the Clean Blue (Hiwatt 100) for great rock clean tones! cgtrox B)

If it's an MKI the first thing to try is parking ALL of the knobs to "ZERO" after you have everything set (except for the MASTER VOL and PRESENCE knobs). The reason is to keep the knobs from vibrating loose from their set position. One little nudge is all it takes to get the amp going crazy on you! Or, you can try placing the head somewhere else besides on top of the cab (I'm assuming you have it there) or where the loud sounds wont affect it. I have my Marshall 2x12 cab in a case and I place my MKI on top of that for live shows. Doubles as a pick, slide and beer shelf, too! cgtrox B)

Awesome find! I love the way it makes the amp sound! I did a total re-tube as well a few years ago and I feel the same way. It's actually my main gigging amp right now, I really feel the MKI series has that little something that the MKII does not. Where did you buy it from? cgtrox B)

Be sure to match the ohms output on the amp to the cab... :VERY IMPORTANT!!: You cannot run it mismatched for long, or run it without a cab (or load) connected as it will damage the transformer. Is it a new head? Sounds like someone might have already done this and maybe damaged it. I would try the head with another cab (if you have access to one) and that will tell you what you need to know. cgtrox B)

Also try an aerosol "office supply" cleaner that blows out any debris from the amp jack before sending it to the repair shop. cgtrox B)

Or you can look at the jack itself and look at the "tongue" that sticks out or the "negative" terminal as it might bent the wrong way. all you have to do is bend it back towards the center and try the jack to see if it snaps into place and holds firmly. If not, it might be time to just replace the jack altogether. cgtrox B)

My son has his MKII on top of a Marshall sealed 2x12 cab with Celestion G12T-75's in it. The MKII has an Eminence R,W&B that gives clear mids and highs while the 75s pump out the low THUMP! Great sound and the 1x12 combo fits perfectly on top. cgtrox B)

Nice score bro! It even has the Steve Howe mojo! cgtrox B)

Here's a good read... http://torresengineering.stores.yahoo.net/maprtutse.html They actually have "matched" 12AX7 tubes! Which wont really matter on the SV, but I got them anyway! LOL! I put the 5751 in the phase inverter slot or V2 and a Tung Sol in the "power boost" slot or V1 and then a nice Mullard in the SV Pre. I also put a set of Groove Tube 6L6's in. All of this made a definite improvement on the amps tone. Not like night and day but it is noticeable. Did it about two years ago and it stills sounds great! cgtrox B)

Make no mistake bro, poking around inside a tube amp without any knowledge of it CAN KILL YOU!!!! :o So, please be careful or just better yet, let a pro do it for you. cgtrox B)

Exactamundo! There is some magic tied into the cicuit board where the tube sits. cgtrox B)

Yessir! There are four modes, STOCK, YELLOW, ORANGE and RED, Red being the hottest. I use the ORANGE setting myself. There was even one guy making a footswitch for the floor so you can change the modes on the fly. Remember, the original switches are internal and you pretty much have to take the thing apart to switch them. Which is why we all installed external switches. cgtrox B)

The HD100 model has a notch in the circuit board allowing it to be installed over the mother board. Like so.. http://medias.audiofanzine.com/images/normal/line-6-spider-valve-hd100-343436.jpg If you look at the 40W version there is no notch in the board. It is a complete rectangle. Like this... http://simulason.free.fr/switches.jpg The best way to tell if a used SV amp has an SV Pre installed is to look for two after market switches. Most guys were putting the "mini" toggles like Mesa uses. Some guys were putting more heavy duty switches, but they do have to be SPST switches. (Single Pole/Single Throw) like these from Radio Shack part #275-0634 http://www.radioshack.com/product/popup.jsp?productId=2062506 cgtrox B)

Sorry brutha, no left overs and no custom made models nor is there any plans to do so in the future. :( Keep an eye on craigslist or ebay is the only way now. Remember, the 100W model is different from the 40W version. cgtrox B)

Done! Waiting on a response... ;) cgtrox B)

Oh yes, the SV Pre! I STILL use my Spider valve MKI with the SV Pre installed as my #1 rig. It sounds AWESOME with my 2x12 Marshall with V30's and the M9 in the loop. Has all the stage volume for a mic'ed band. I wouldn't use my SV without it. I wish they would make more even by special request only! They make that series (MKI) come alive! Rick Miller who used to be a Line 6 big wig is working for Strymon now. They have grown so much in the last few years. Hmmm, maybe I can plant a bug in his ear... :) cgtrox B)

They can't put it on the internet if it isn't true... :D cgtrox B)