To open a thor TA 1000 MK II you first...

Below is both an update and resolution for other’s, to the issue I have encountered twice now in normal use of my Thor TA 1000 MK II line stage preamp. It’s remote sensor (located beneath the base of the preamp) wasn’t well enough engineered so it can be pushed up into the body of the unit now and then. Negating the remote functionality of the unit almost entirely. Some forethought should be given to moving it about by resting it onto a smooth level surface in the interim. Packing too is a consideration, and forming a pocket into the dense foam which supports the carriage will likely prevent this occurrence.

I was contacted by a member who supplied the following info for opening the preamp.

I asked:
That thing in the hole in the center (formerly) covered up by a paper sticky tag is really an Allen set screw/bolt?

Reply:
“It is an allen or should I say was before they purposely mangled it. If you can't get a bite on what's left with a hex key you can either use an "easy out" or just drill it out very carefully as my friend did.”

I said:
Hmmm…. What possesses someone to purposely mangle a main point of entry? Locks only keep honest people honest anyhow.

I find no other screws or fasteners under the body of the unit... my friend said, even the 3 BDR cone footers don't have exposed screw heads and we couldn't figure out if they were glued on or what.

So the feet just turn out counter clockwise? as well as does the
uh, large ‘drilled out allen’ in the direct center of the preamp underneath in the center of the 3 cone footers?

Reply:
Yes all counter clockwise. Mine removes the threaded stud and feet
altogether. On my friend's unit, the feet come off first then their studs need to be removed. We've taken these apart and though they are electrically the same there are a few layout and component differences.

I asked:
Removal of the tubes is needed too accomplish this task?

Reply:
It’s probably a good idea though not absolutely necessary.

I said:
I'm figuring not much play or allowance or distance/space is gonna
be gained here as all the ins & outs, and controls are still wired
up, but there ought to be a couple inches or so within which to maneuver about, right?

Reply:
The bottom plate is fastened to standoffs inside and I'm thinking the only thing wired to it will be the remote sensor. I would think there is a clear connection to disconnect the remote sensor from its board somewhere there. If not I'm pretty certain there is enough extra wire to access it comfortably.

I said:
Absolutely my most sincere thanks for any and all info here... I'm
scared of trying to fish out the remote sensor, something may be pulled off or broken off in the doing.

Reply:
It took me a long time to decide to take it apart. Paul did a pretty good job keeping it mysterious. I thought they had a special press set up to dis-integrate it.

… I hope this helps out anyone else who has one of these remarkable preamps in overcoming perhaps it’s sole design shortcoming.

If you’ve found another way to access your Thor amp, or preamp, or found out some other item that bares passing along, here might be a good place to do it.

FOLLOW UP

"Grab It", that's all you need to do.

AS Dave posted initially opening a Thor MK II is not insurmountable. In fact, it’s not hard at all to do.

This purposely ruined set screw and the absence of supportive information on the Thor products seems the rule rather than the exception, as I’ve found from several others they too have this gnarled screw instance with their Thor components. Go ahead… peel back that sticker and see for yourself.

But…. There is a solution!

A small innocuous device called a “Grab it” and a good slow speed hand held bi-direction drill, surely does the trick in no fuss no muss, and virtually, no time. Inserting the Grab its cutting edge into the screw and using the reverse feature of a drill, it will cut a conical shaped hole well into the set screw. You don’t have to go far either. In fact the set screw began to back itself out during the cutting portion of the extraction process.

The Grab it bits come in varying sizes too. A set of four can be bought online for $20 + shipping. I got mine at Lowe’s home improvement center.

Slipping out the tiny Grab it bit from the drill, turning it around, and re-inserting it back into the drill, you now have the extractor end at the ready. Insert it into the just cut cone and slowly apply some reverse torque from the drill motor. Violin! That once enigmatic conundrum of a fastener should no longer be an issue!

On some models the feet also need to be removed. Mine did. A rag of sorts and a pair of very strong hands, or channel locks will suffice there. However, on some the studs within the feet will thereafter need removal too. On mine the studs were more attached to the feet than to the chassis so turning out/off the Black Diamond Racing Cone footers was good enough. You’ll note if you have to do this by how the feet are apportioned over the base plate, or simply on it, as removal will needs be done IF they cover the outer perimeter of the plate and body of the unit too by their own girth.

These Thor units, were singular blocks of aluminum at one time, and then whittled out to form a more or less one piece concern. Consequently, the base plate is quite tightly fitted to the circumference of the unit’s body. Inserting a small screw driver into each of the holes and gently prying up a bit here and a bit there will relieve the bound plate and access is then granted!.

You’ll have to dig further down from here on your own. I went no further as my issue was then at hand. I will say there’s scant little in there that’s visible right away, and more layers need to be peeled to really get into the workings of the unit. I had no such desires. … It might well have been that honesty thingy I spoke of earlier. It may have also been, that “Let’s leave well enough alone” too. I’m a big fan of the latter option generally speaking.

I simply needed a very minor technical task to be done. I asked several experienced, audio designers, and technicians, and was either refused flatly, delayed with their answer for weeks, or found the price tag for the exercise inordinate. The latter, IF I agreed to send it off, was to be done by those who had no working knowledge of Thor equipment. I’ll not name then here.

Only one person offered to accommodate me with my issue but even he couldn’t get to it for a fair amount of time. I was grateful for his intervention and offer of assistance, yet felt if at all possible to avoid shipping the unit.

So I waited and wondered and worried and pondered… and then hit the uh… Screw it, switch and began a thread inquiring about a step by step opening procedure…. And one finally came along.

But with such great fear in place, I put off doing it for an extremely long time anyhow.

Thanks much Emoonie for the help. And thanks also to “Grab It”.

The remote aspect of the MK II is now working just fine BTW.

Many times, things that seem very technical are not and a quick look see might just be the ticket to remedying the situation.

Thanks again to all those who have been of help to me, and I hope this is of help to another. If nothing else, those Grab it bits are the real deal and mighty handy things to have around!

PLEASE be careful with any metal chips generated by using an easy out or the 'grab it'. Any chips get in the wrong place and ZAP! You may want to have a vacuum cleaner standing by with a small tip.

Good thought there... and we did. The info acompanying the Grab It bits says as much too.... Drill... remove debris.... drill.... remove... etc.

Also, the keener the hand and eye, the better set the hole will be and it's best set to the center of the item being removed.

Thanks very much.