Xits X10 = liverpool half power?

[Ian444]

The X10 circuit has a roughly similar topology to the Fender Blues Junior circuit, which uses a 10:1 voltage divider after the third gain stage. Looks like there is plenty of gain on tap, especially to drive EL84 which don't need much. Just food for thought. The Fender uses a 220K series resistor to drive the PI. Might shed some light on the subject, or might not. Fantastic job you guys are doing.

[Masco]

Looks to me like an AC-15CC with one extra gain stage, sans reverb and trem.

[Andy Le Blanc]

I like that solution, it also looks like a simple mod with wider applications.

[pamaz67]

I like that solution, it also looks like a simple mod with wider applications.

As far as I've seen ( and done) the preamp can run from really clear to heavily distorted tone.
I agree that this preamp, coupled with different power amps and with a few tricks on the supply, could be an interesting base to get a wide range of sounds , with an easy and functional front end.
The first thing that comes to mind is making a mixable output stage a la egnater/brunetti with a couple of 84 and a couple of 6v6

[pamaz67]

my layout ( not definitive but almost there....) I don't have any trick for the front led, as in the definitive version I think I'll stick to the traditional jewel.

[pamaz67]

the board

[surfsup]

Paolo, i was thinking about using a jewel too because i'm not sure how the faceplate thickness will affect mounting the LED but i stuck with the LED for now since i have the passives mounted already.

Your 220k is under the red shrrink on the pot's wiper and the small blue resistor on the board next to the 10k is the 82k?

[pamaz67]

Paolo, i was thinking about using a jewel too because i'm not sure how the faceplate thickness will affect mounting the LED but i stuck with the LED for now since i have the passives mounted already.

Your 220k is under the red shrrink on the pot's wiper and the small blue resistor on the board next to the 10k is the 82k?

correct: the 220k is soldered directly at the pot lug under the red shrinking tube, and the small res is 82k ( 100k in the last revision ).
Don't want to stress anybody , but to me ( and waiting for your point of view once you'll listen) I'm almost convinced that the preamp resistors couple are 220k-2k7. and 100k-1k5. This couple is giving more sparke and a more decise attack. And in my amp the effect is very evident.

[surfsup]

Haha, here we go again with the RC combos...

Are you back to 25uFs for the caps?

My radioshack 30w is not hot enough to solder turrets. I treid. I hope my new iron shows up monday to start soldering.

[pamaz67]

The only reason I say that , is that the x10 is just an ac30 with half the power tubes and one more gain stage after the traditional preamp.. In an ac30 the first tube shorts the 2 cathodes from brilliant and normal input with an 1.5k resistor. If we think to divide the thing is like having the 2 cathodes with a 3 kohm resistor each. Therefor, 2k7. That's IMHO

Yes 25uf. As I have raised the PI and pre tube voltages the sound has dried a lot, so the 25 uf gave it a little more of body.

[surfsup]

Are you using the RC filter between the two 220ks before the MV? I don't see a RC combo there.

You have a pushpull on your first Vol pot. I couldn't find normal 1M pots and actually have three pushpull pots for Vol Treb Bass. What can I do with them? I see you have what looks like a small capacitor on the vol pot. Is that basically your bright switch? I never used a pushpull pot before.

[pamaz67]

no rc flter at the moment, as i prefer to choose more refined components than placing that filter.
Now I'lll try to swap a few brand and type of resistors and capacitors to set up correctly the whole thing.

[Gaz]

no rc flter at the moment, as i prefer to choose more refined components than placing that filter.

What do you mean by this?

[azatplayer]

I think he prolly means, he'd rather tweak the tonestack to get the cut desired than add a cut control of sorts.

[pamaz67]

no , no tweaks to the tone controls, but just a choice of the correct set of components to have no piercing sounds.
I don't feel the need for a hi cut control as the treble tone control can darken enough the hi range.
Just as an example, using some old allen bradley resistord( and philips mustards if necessary.) here and there to soften a little the sound.