Hey there lads, Just wondering if I can use a mesa lonestar preamp circuit, with a OTS/HRM style Pi and amp section.

I'm working on a project where i've stripped most of the bells and whistles from this circuit:
http://www.schematicx.com/view-schematic/mesa-boogie-lonestar-schematic/

gotten rid of the thick/thicker switch, added brightness, got rid of reverb section, and the buffered loop section, plus the switching matrix. Essentially I've just got two basic channels now and the output feeding in to the D-style PI.

My question is, will this match, or will there be impedance problems?

Jim

yeah, I've been told that too; My experience is different though.

The 'air-leaking' symptom presents as a way brighter purple, almost pink, and yeah, the tube doesn't work at all well.

My old man, a valve amp tech from waaaay back tells me its just the electrons charging particles or the very small amount of gas that's in there, be it nitrogen, oxygen, neon, whatever.

certainly not an indication of a dud valve.

Back to the mod though, it seems to be rounding itself out a fair bit, and I've noticed with the tele, and the humbucker in the lapslide this amp is sounding orgasmic; the strat's pickups must be to blame.

To get around this i'm using a stage 3 booster from this guy:
http://www.guitarpcb.com/apps/webstore/products/show/1275488

With a few mods to kill some of that higher freq.
I really recommend this boost, it gives quite a nice clarity to the signal, which i find is need after a few pedals that suck tone.

I was gonna say, yeah, nothing will work fine. I've been running my amp out of its cab for a few weeks while i tweak the insides etc. Not a single cycle of noise at present..

that being said, I'm sure there would be a situation where you'd want that shielding there; large club with lights etc nearby, also if you have a c-lator etc on top, that would induce noise without that shield.

Thanks for the input JD0x0,

I'll try just piggybacking the 390's on that side, that'll give 780pf close enough, these components are hard to get at my local here in aus, so ordering them in takes  few days.
 

I've been noticing a blue haze developing in the output valves too, I've read a lot and apparently it doesn't mean anything, it looks cool though...

hmm, well first of all its not a local feedback loop, i was quite tired when i posted that yesterday, its just a pair of 390pf caps across pins 1 - 3 and 6 - 8 like the ots standard.

as for the speaker, i'm using the wgs 12-65, its just in the fender performer combo which i'm using as a cab till i get a decent couple'a days off to build my 2x12 dumble style. The other speaker is the wgs veteran 30 apparently the two sound quite nice together...

the ice pickyness is only on really loudly plucked or picked notes, the pickups i'm using are probably to blame, they are a set of klein's, with scooped middles similar to a certain pop musician's specs, but i've never been entirely happy with them, also i don't know if i've got the right sized and or type of tone capacitor in the guitar itself, as lowering the tone makes it sound a little like a half cocked wah.

hmm...

another aspect is this amp has probably got around 20 hours on it with a pair of jj 6L6's and three jj 12ax7s

I threw a nos "Ei" yugoslavian valve in there that i've had since i can remember (at least 26 years) so its gotta be my old mans from a radio or whatnot, which made the cleans nicer.

I dunno, i'll post a clip or two tomorrow when i can be funked.

thanks for the feedback, even though, i now feel like i've messed with something i didn't need to.

Howdy Lads, ladies,

I've just spent a grand total of 2 minutes installing this and i've gotta say a world of difference is made.

I put in the two 390pf capacitors, as a local feedback in both of the sides of V2.

It's killed that ultra horrible treble my bluesmaster is getting, and now the treble trimmer is at 12 o'clock, my clean treble is at 2 o'clock, and the amp is singing.

This is really simple and i encourage everyone with a hrm blues to try it if they are unhappy with the fizz on the overdrive channel...

I used dielectric polystyrene caps from element 14:

http://au.element14.com/lcr-components/fscex-390pf-1-630v/capacitor-390pf-630v/dp/9520775?Ntt=952-0775


I should add here however that I am using 6V6's instead of the 6L6's supplied. IMHO the 6V6's provide a wider varitey of tones at in-my-loungeroom levels.
 



Next I'm going to try 100k plate resistors on all the 12ax7s, then maybe start playing with that 47k slope resistor.

Jimbo.

I'd be getting a pair of these bad boys, solid as a rock, and much nicer feel than the ceriatone supplied ones. (less 'crunchy')

http://shop.ebay.com/?_from=R40&_trksid=m570&_nkw=3pdt&_sacat=See-All-Categories

the blue ones are better.

source: been building pedals for years...

Thanks Exocet, definately be reading up on that data! 

you're not exocet from MTAU forums are you?

Welcome to the club sir. I trust you will enjoy the beast!

Hey lads, long time lurker first time poster...

I found a 'dumble/two-rock' schematic somewhere that was hand drawn, and was apparently the innards of a two-rock custom reverb.

The preamp section, from what I could work out (terrible diagram) was similar to the OTS, but had 100k plate resistors...

What does increasing the voltage on the plates do for the tone?

as a side note, are there any resources for learning what mods do what? I've got experience in solid state amplification, more of a hifi background, so I do kinda know what I'm doing, but these terms like 'snubber' 'bleed' etc are all new to me.

Thanks in advance.

Whoa that was quick, what a good bloke!

Cheers man!

Erwin, I've just taken delivery of a hrm bluesmaster, would you mind slinging a copy of that schem my way? Jim (at) wheresmyspaceship (dot) com

Thanks in advance, could we call this the 'Erwin mod'?

Yeah its not a sovtek 5y3 is a genuine GE nos 5y3.


I really have no idea what the problem is.

I can't remember, although I'm pretty sure its not. There is a good chance its a NOS Ge 5y3, I'm at work atm, wont be able to check til i get home.

I read somewhere that if the PT gets hot, like really hot, then its looking like a short somewhere internally...

So I've finished my ceriatone 5e3 build, looks stunning, sounds even better, only problem is, today i was playing quietly, clean, vol less than 1, etc, and after about 20 mins of playing i leant down to switch the amp off, leaning my hand on the power transformer, The transformer was cooking, like burn your hand hot.

I've measured the heater voltages, as i've only got a cheap dvm i don't trust measuring the HT, but they are at 6.45 volts, which seems normal to me.

As i said, sounds just like a saggy old 5e3 should sound, but gets really really hot.

This obviously isn't normal, anyone got any ideas as to what it could be?