mojotom wrote:
10n input cap could be smaller like 4n7,
I agree. The first coupling cap along with the first cathode bypass cap are critical to tune the bass response of the amp. But I would start with the 10n and tune downward if necessary. It also depends on how much gain you play at - more gain, more early bass cut.
mojotom wrote:
Matchless uses 1n2 on the Liverpool
mojotom and Colossal - ??? There are two different tube stages with two different caps and a shared/common cathode resistor in the schematic you flagged - not what you suggest at all. Which is to say that I still think that there is some switch to go between the two caps and we can't see it.
FWIW, in all the schematics available for the Matchless product, the combo .1 + 22uf does not exist on a single 12AX7 triode. Only on the Clubman will you see it (the combo) and only then on a triode/pentode tube, a different critter and here perhaps needing different results.
Are we reading the same schematics?
Most people stall out when fixing a mistake that they've made. Why?
Wow...I gotta get more sleep. You're right. I was blindly looking at the cathode and didn't even notice it was a pentode input Of course there is 0.1uF there. Previous post edited.
I believe Azatplayer did try paralleling an 0.1uF to the first stage in his test circuit. Perhaps he will comment on the outcome.
I did Dave, yes. Its a pretty subtle change, but a welcome one.
My test circuit is for all sakes a AC30, started as a rocket but crept towrds AC30. Ive done the 110K grids, using a larmar and leaving the grid leaks in, and REALLY like the result.
Now it has the paralleled cathode .1 cap with 22uf cap, and i like that too.
I have not had to turn down the treble or cut at all, but theres a little more life in there, kinda more chimey goodness than making it any brighter. I like it.
Im gonna have a go at this schemo, soon, just waiting on a PT.
Rooster, I was talking about the Matchless 15w because they used a 1MA drive and a bigger cap on the input.
As far as the .1 bypass cap go, I remember finding one along with the 22µ on a lot of Matchless and badcat DC30 based, and on the top boost input. It was not used in the old Matchless era amps.
Anyway it's rafraiching to see something different on an EL84 based amp, I tried to find more information on the Komet 19 but nothing usefull. This one
seems even better from the video.
Are you all ok using two power resitors between PT secondary and diodes ?
look strange to me.
OK, its possible that it stops some potential scratchyness at V1, something noticable as you turn your gtr volume up and down. In other words, if you have a leaky electrolytic at the V1 cathode perhaps bypassing it with a poly cap will prevent/overcome this. ?? Speculation here as I don't use or see the need for the added cap. As to altering the sonics noticably, I say a blind test is in order - and by more than one player?
But yes, looking at the pic you posted mojotom, its possible that cap is there in parallel I suppose. That's a Badcat, right? Well, here I will only add that building an amp from a photo is not for everybody. Didn't someone say they bought one of these amps at the start of this post?
Most people stall out when fixing a mistake that they've made. Why?
WHen I have read about bypassing the elect bypass cap with a small plastic cap it is said to change the feel, suppose to make it quicker whatever that means.
Probably a try it to see if you like it type thing.
Or perhaps it helps tame any fizzies.
Has anyone at amp garage picked up this amp yet? (X10) I would love to find out whats under the hood(PM). Nice sounding amp. A year on the waiting list is a long time to wait for one of these amps. I'm thinking of an 18 watt(EL84) amp for my next build. Suggestions or Schematics for a similar amp would be appreciated. Thanks. db
DustyBadlands wrote:Has anyone at amp garage picked up this amp yet? (X10) I would love to find out whats under the hood(PM). Nice sounding amp. A year on the waiting list is a long time to wait for one of these amps. I'm thinking of an 18 watt(EL84) amp for my next build. Suggestions or Schematics for a similar amp would be appreciated. Thanks. db
Dusty,
Not sure if you saw it or not some pages back, but between a few of us, a reasonable approximation of the schematic was deduced and posted from some gutshots of the X10. A remaining unknown is what voltage the PT is operating at, but we can probably make some decent assumptions there too. Azatplayer has tried out the PPIMV/grid leak pair hybrid conditions in a voxy amp he has with good results. The PT is Mercury and they will not tell you anything about it because it was wound specifically for an OEM but it is not their Tone Clone brand so may not be the typical Vox/18W 290V value.
Azatplayer has done some extensive experimentation taking the information from this thread and building a test platform. He has done some really cool work in this regard. But from what he said, there are still some things that are eluding him from "getting it right". We've got 90% of the details worked out however, the voltages are key of course and since the Xits X10 transformers are proprietary wound by Mercury, we will not know anything about the working voltages until someone is able to get inside one and take some measurements (and confirm that last miserable dropping resistor value!).
azatplayer wrote:I ended up ordering one... the price at the time was really good, theyve since gone up with the demand.
Still have to wait till at least years end for it.
That was actually Azatplayer, so my guess is that he is still on the waiting list for his! Man, that must be nice to have an absolute avalanche of orders! Xits was backordered for something like 24 weeks within a few weeks of announcing the preliminary price and availability (and Greg V's demo). It's a great amp for sure though.
Of course there is 0.1uF there. Previous post edited.
