Who is dying: Tubes or Caps?

Dr.Mavashi

neonderthalotonalogist
Ok, after about 45 minutes of playing at rehearsal level Laney AOR begins to misbehave a bit. Low end becomes a bit too dark and too muddy, especially when boosted with MXR line driver fore leads, and sometimes it sounds for a second i have a phaser pedal there, it kinda chokes in a swhirley way ..
 
Re: Who is dying: Tubes or Caps?

I can't make any determinations by your description.

You can tell if your filter caps are going bad by hitting a low E, with the amp as loud and clean as possible. If the note goes flat after the initial attack, the filter caps are getting a little old.
 
Re: Who is dying: Tubes or Caps?

Ignorant question: does that amp have a rectifier tube or solid state rectification? Just a guess, followed by the phase inverter tube and/or the power tubes. Obviously it's something getting quite hot after a while.

HTH

Chip
 
Re: Who is dying: Tubes or Caps?

Ignorant question: does that amp have a rectifier tube or solid state rectification? Just a guess, followed by the phase inverter tube and/or the power tubes. Obviously it's something getting quite hot after a while.

HTH

Chip

Chip,

The AOR's have a solid state rectifier. The amp is, for all practical purposes, a very hot rodded 800 series Marshall.

Jerry
 
Re: Who is dying: Tubes or Caps?

I think that if your filter caps were going you would have a persistent hum. If you have spare valves around (and if not, WHY NOT?) jut swap em out and see what's going on. Diminshed volume and phasey sounds .... to me, that sounds like all of your valves need replacing!
 
Re: Who is dying: Tubes or Caps?

Thanks guys,
Well I do have some hum issues, but I am not sure if its beyond to what some call "aor noise." Also, the amp was moded for more head room, and it has less gain than other aors, still gotta unmod this lunacy. I dont have new tubes because I am on a budget/one thing at time sort of thing, I am real metal guitarist - unemployed.
 
Re: Who is dying: Tubes or Caps?

Thanks guys,
Well I do have some hum issues, but I am not sure if its beyond to what some call "aor noise." Also, the amp was moded for more head room, and it has less gain than other aors, still gotta unmod this lunacy. I dont have new tubes because I am on a budget/one thing at time sort of thing, I am real metal guitarist - unemployed.

Hum isn't normal...ever for an AOR. Possible causes of hum in a still functioning amp include:

(1) worn out filter caps
(2) mismatched output tubes
(3) open suppressor grid resistor
(4) improperly biased output tubes
(5) open resistor in the filiment balancing array
(6) imbalanced output transformer

Any tech worth his salt will be able to diagnose what is wrong with your amp amd give you repair options. This should be covered under his standard bench fee. Explain your situation. As a tech myself, I am accustomed to musicians on tight budgets that have to do repairs in stages.
 
Re: Who is dying: Tubes or Caps?

I don't get any hum either with my two AOR 50s. I do get noise when I dime all of the gain, but that's something other than hum.
 
Re: Who is dying: Tubes or Caps?

OK, current settings

Guitar, invader in the bridge volume 8, tone 7

TS - Drive about 5, Level about 9, Tone about 9.

AOR

Presence 2
Bass, pulled 4
Mids 6
Treble pulled 9
Pre-Amp about 7
MV 4 to 6

I while I love the voicing, how it just roars and the sandy break up, every now and then I get a bit too much of the white noise typa hum with that swirly kinda choke ....
 
Re: Who is dying: Tubes or Caps?

SO ive been looking at jcm 800s for a while, i play pop punk, i dont need a whole lot of distortion but i dont want that cheap sound. i want a real, hard hitting tone and what better to get than a marshall i thought. but ive heard talk of this AOR, should i get it instead? does it "hit hard" with some distortion?
 
Re: Who is dying: Tubes or Caps?

OK, current settings

Guitar, invader in the bridge volume 8, tone 7

TS - Drive about 5, Level about 9, Tone about 9.

AOR

Presence 2
Bass, pulled 4
Mids 6
Treble pulled 9
Pre-Amp about 7
MV 4 to 6

I while I love the voicing, how it just roars and the sandy break up, every now and then I get a bit too much of the white noise typa hum with that swirly kinda choke ....

Are you using the low or high sensitivity input?

If the high one is used; what are the pre 1 and 2 settings and do you have the pull boost engaged?
 
Re: Who is dying: Tubes or Caps?

I know that swirly phasey sound you're talking about, and when it happened to my Marshall I needed the filter caps changed. Don't know if it would act the same way in your Laney, but after they were change, it didn't do it anymore.
 
Re: Who is dying: Tubes or Caps?

Are you using the low or high sensitivity input?

If the high one is used; what are the pre 1 and 2 settings and do you have the pull boost engaged?
Mine is a 6-knobber, so only on pre-amp knob. Using the Hi-sensitivity channel.
Yeah, the boosts are engaged on bass and treble:

AOR

Presence 2
Bass, pulled 4
Mids 6
Treble pulled 9
Pre-Amp about 7
MV 4 to 6
I know that swirly phasey sound you're talking about, and when it happened to my Marshall I needed the filter caps changed. Don't know if it would act the same way in your Laney, but after they were change, it didn't do it anymore.
Cool, did you change anything else besides caps?
 
Re: Who is dying: Tubes or Caps?

I know that swirly phasey sound you're talking about, and when it happened to my Marshall I needed the filter caps changed. Don't know if it would act the same way in your Laney, but after they were change, it didn't do it anymore.

My Peavey was doing that kind of thing last year, was the filter caps also. I thought maybe it was the tubes and changed them but it still buzzed and sounded like the phaser was on all the time. Apparently those capacitors should be changed around every 9-10 years and mine were the stock ones from 1983. So it's very likely that's the filter caps. I get most of my electronic components from www.mouser.com, they've got tons of stuff on there for pretty cheap so you might want to check that out. A guitar tech said it'd be like $80 to do, did it myself for less than $15 I think. Peavey said they would have done it for $50 plus another $50 in shipping for the amp. If you're comfortable soldering I'd say go ahead and change the filter caps yourself anyway, it'll be cheap and probably could use it regardless if that's the current issue or not.
 
Re: Who is dying: Tubes or Caps?

AaarG, Thank you.
I wonder which caps to get ... LCRs or F&Ts .... original were LCRs ..... plus there are JJ caps now too ...
 
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