Xits X10 = liverpool half power?

[Gee]

One more thing is that the X10 is now shipping with a 12au7 in the V2 position. Wonder why?

[johno]

Has anybody looked at this circuit/amp any more in a lately? I have looked through the thread and at the gut shots and while most of this seems fairly straight forward a few things still seem a little weird to me.

A couple of things that jump out is that they appear to be switching the neutral for power. Seems a little dangerous. If I remember how this main switch works, is that it is a 3 position with the middle being off and one direction full ON and the other position being standby. It also looks like they may be lifting the Filter Caps from ground to put this thing in standby???? Both seem really wierd switching techniques to me. I am missing something (although that could be very likely)

I am having a hard time seeing the diodes (bands) in the rectifier circuit, but could this be a full wave bridge because the Power Transformer does not have center tap? I probably need to give that some more concideration but just was thinking about that as I started this reply

I have included a gut shot for reference

[img:800:531]http://www.fatsoundguitars.com/store/am ... -guts3.jpg[/img]

[Masco]

Azatplayer has supposedly ordered one of the x10's. Hopefully, he'll be giving us the skinny when he has given it a once over.

Seems like it should be any day now....

[johno]

Masco,

Thanks for the input ... although I am not actively working on (this) amp right now, I am still very interested in making "something" like this so educating myself on some of the things that make this one tick would be helpful when I get my 2-EL84 on the bench.

Hopefully we will "hear" some more (little pun intended)

By the way, you can tell from my post count, that I have not been active in this forum ... it is just at this point in my hobby building career I don't have much to offer, and not to steer this thread off topic, I do want to take a second to the many who have posted ... it is fun to learn here. THanks

[M Fowler]

I was told that the Xits builder injured his hand and amps have been delayed as a result.

[surfsup]

I just listened to the clips, this does sound great and I'd like to build this next...too bad it is not fully documented with a schematic.

[M Fowler]

Well Colossal worked up what info we could figure out we will have to be patient until some one someday posts the info.

[Masco]

I was told that the Xits builder injured his hand and amps have been delayed as a result.

Yes, I heard this too. What a drag, the guy was just getting on a roll.

I've seen a different photo/guts shot of another Xits model and I must say that this guy is doing some really neat construction techniques. The threaded control panel thing, the covering, it's really unique. Total amp art.

[surfsup]

MFowler, I'll check it out this weeknd. I'm willing o experiment and if all that's missing are some accurate values for dropping resistors, it could be fun for a newb like me. This amp is perfect too, on power and size, I have a 10inch cab.

Though I'd love at least an fx loop...

[surfsup]

One more thing is that the X10 is now shipping with a 12au7 in the V2 position. Wonder why?

I just read the 76 page thread at TGP on this amp and people are getting theirs now. Someone brought one into a shop to get the "cleans a little more headroom" and they swapped the tubes to a 12at7 and it sounded better. I think the conversation continued to give this as the reason for the 12au7, Xits finally settled on. But that was many many posts ago.

[surfsup]

BTW there is a directory of more X10 photos (albeit an X10 "special") here:

http://www.fatsoundguitars.com/store/am ... 416175157/

1k5W ohmites at the PS secondary:

[img:800:531]http://www.fatsoundguitars.com/store/am ... guts-6.jpg[/img]

Looks like two 10k dropping resistors after the 22k

[img:800:531]http://www.fatsoundguitars.com/store/am ... guts-7.jpg[/img]

[img:800:531]http://www.fatsoundguitars.com/store/am ... guts-2.jpg[/img]

[Colossal]

@ surfsup
Thanks for the updated link to the photo gallery!

@ All...

I've updated the draft schematic with the revised values revealed from these new photos and enclosed here. Please let me know if you see anything that needs correcting. I'm not sure what that Sprague 225P series 474k orange drop is doing on the far left of the board. There used to be a diode that supplied DC to the indicator LED in its place.

Also, does anyone see evidence of a 1k choke resistor between B+1 and B+2?

[EDIT 3/8/11] SCHEMATIC REMOVED. UPDATED AND MOVED TO PAGE 8

[surfsup]

Colossal, for (1) on your schemo, you have unconfirmed 220k grid leaks for the PI, and if I see correctly in the last photo I linked in my prior post, the 220k values are fairly easily read, with two 100k above them on the board.

[Colossal]

Colossal, for (1) on your schemo, you have unconfirmed 220k grid leaks for the PI, and if I see correctly in the last photo I linked in my prior post, the 220k values are fairly easily read, with two 100k above them on the board.

The deal with the 220k/220k grid leaks on the board are indeed confirmed values, yes, but note that they ar in parallel with a LarMar (Ken Fischer Type II) master volume. The Lar Mar is a dual-gang 250kA pot with 2M2 resistors between the leg and wiper (giving it 220k). So the total grid leak value <i>if</i> the 220k/220k pair on the board are grounded is 110k. Martin Manning wrote earlier on the impedance presented to the PI with this arrangement. We just didn't know if the fixed 220k/220k pair are grounded but I think it's reasonable to assume that they are; hence the comment on the schematic.

Thanks dude!

[Masco]

The note w/ the first photo in the directory says "Sadie in X10 clothing".

So, were not really looking at X10 guts, but a Sadie instead?

Strange looking coupling cap coming off of V1's plate.