Xits X10 = liverpool half power?

[rhinson]

Glad to see a couple others as impatient as me! I look forward to doing this together with you guys...

rawnster's lower photo (one I originally posted) is not of the sadie, or the X10, there are three power tubes (unless one is a PI tube that is taller than a 12ax7?). I did not order a choke resistor or a choke yet. Thanks for the reminder colossal. Here's another photo but probably doesn't show more than we already know...

[img:800:600]http://chicagocadcam.com/ChrisHahn/schem/X10_2.jpg[/img]

that's not a third power tube----it's a 6ca4 rect. tube---used in lots of small amps including the 18w marshall, so it's probably a safe bet he's using something in the range of 18w marshall power iron for all these xits 2-el84 amps we're dissecting. rh

[rawnster]

Hey rhinson, it appears that all of the gut shots of the various xits builds contain a diode grouping that in all likelihood is for SS rectification. Why would you think there's a recto tube therein?...that is, unless the builder has incorporated an SS/tube recto switching of some kind. Or could there be something else going on?

Just curious....thanks.

[M Fowler]

Backup incase the rectifier tube goes down the diodes are there to save the day perhaps.

mark

[Ian444]

To me, it looks like all the gut shots are SS rectified amps, I can't see any actual gut shots of a tube rectified amp?

[surfsup]

Yea I didn't see a tube recto anywhere in any of the photos. I am challenging myself with the gargantuan Solen 15uF 630s. Anyone see anything critically wrong here with this layout having the Solens near their respective tube(s)...? The proposed ground scheme in green (two star grounds, one at input and one at P tranny). Most is to scale (pots, switches, IEC, fuse, chassis 8x16x2, 3.125" G10, the solens, the larger caps and ohmite resistors). Just the small stuff like small resistors, 47pF cap, etc are just drawn in as placeholders.

[Lonely Raven]

Doesn't the multiple stars have the potential for ground loops?

Wouldn't it make more sense to have the one at the far left buss through the rest and *end* by the IEC connector?

Great drawing by the way!

[M Fowler]

I would run B+5 with the other caps.

[surfsup]

Mark, would you mind elaborating on why? I read elsewhere to do it this way (which helped bigtime with my HO, btw) because its best to ground the input with the first tube's cap. I'd certainly appreciate your thoughts and anyone elses.

Also, I rotated all the tubes so pins 4-5 and 9 are all accessible from the bottom wall straight up with minimal hum loops, and easier wiring I guess, as well as put the tubes close to each B-node. What other considerations should I be thinking about at this stage?

EDIT, whoops I didn't put in the dropping resistors yet...

[angelodp]

Why the Solens? F &T @ 450v are smaller?

A

[rhinson]

Hey rhinson, it appears that all of the gut shots of the various xits builds contain a diode grouping that in all likelihood is for SS rectification. Why would you think there's a recto tube therein?...that is, unless the builder has incorporated an SS/tube recto switching of some kind. Or could there be something else going on?

Just curious....thanks.

we haven't seen gut shots of the amp with the ef86 input tube as far as i know---( i haven't seen any gut shots with a preamp tube up at the front of the amp matchless style like this amp obviously has) just the top shot-----with the ef86, p.i. tube, 2- el84's and the other tube is indeed a 6ca4 rect. tube----if you look close you can see the diff. rh

[NickC]

I like that style of tube holders in IMG_3784.jpg above, but haven't seen any like them in the online parts emporiums. Anyone know a source? Thanks!

[Lonely Raven]

I like that style of tube holders in IMG_3784.jpg above, but haven't seen any like them in the online parts emporiums. Anyone know a source? Thanks!

The guy has every detail worked on, the "tolex" the chassis, the wood...I wouldn't be surprised at all if the tube holders are custom as well.

[rooster]

Um, IMO you would be wise to avoid the Solens. Why? Because they are too 'fast', simple answer. Have you built amps with the Solens before? They are a stepping stone on the path to a bright and somewhat harsh guitar amp. Electrolytics are important in guitar amps, old school for a reason.

[surfsup]

I already ordered 'em that's why. I thought you guys were saying films were the way to go (quieter, faster), especially for higher gain. I read a bazillion posts on that. Ugh...I'll think about getting different ones. At least this was a good exercise in planning (3D wise too, tucking some under the big barrels). Here's my latest, any problems running leads under the dropping resistors running up over the rest of the components?

[M Fowler]

Some amps connect the V1a cathode bias resistor/bypass cap to the input ground as that can help with low level signals.