#1
Anyone know why a valve amp loses top end when cranked past halfway?
I play a Les Paul through a Laney AOR50 mk.2 into a 2x12 cab with Celestion G12T-75 speakers.
Amp settiings are...Bass on halfway, middle on halfway, treble up full, prescence up full, preamp up full.
At low volumes the sound is nice and clear. Turn the master vol up to 12 o clock the sound goes to mud. I only use the classic gain channel.
My guitar tech fitted new valves and adjusted the bias. He also removed "the negative feedback".
Any ideas chaps?
Thanks.
#2
hmmm.

Well, if new power tubed didn't fix it then I'm not sure. When you say top end do you mean treble or gain? How you crank the pre-gain to 10 I'll never know. Isn't that fizzy as all get out? Maybe there is a bad solder joint or scratchy pot or something. Also, maybe ask Bostonrocks, he owned this amp once and it had some issues but I don't remember what they were.
#3
Quote by frosty22
Anyone know why a valve amp loses top end when cranked past halfway?
I play a Les Paul through a Laney AOR50 mk.2 into a 2x12 cab with Celestion G12T-75 speakers.
Amp settiings are...Bass on halfway, middle on halfway, treble up full, prescence up full, preamp up full.
At low volumes the sound is nice and clear. Turn the master vol up to 12 o clock the sound goes to mud. I only use the classic gain channel.
My guitar tech fitted new valves and adjusted the bias. He also removed "the negative feedback".
Any ideas chaps?
Thanks.



hey, I owned an AOR for a while. Great amps. lots of problems though. here are my suggestions.

First of all take it to your tech and have him look over all the insides. Especially capacitors. those will have much with the mud if they're going bad (they probably are, it's a 20 + year old amp). Turn down your gain. the gain on this amp gets very very muddy up high. you NEED to change the speaker. I put a Celestion Vintage 30 in my mine and it was HUGE. it sounded much clearer and way less fizz.

also your setting down low might sound good like that but the EQ will respond differently when it's louder.

try this.

Preamp 1 at 11 o clock and preamp 2 at about noon. set your bass at about 2 o clock and your mids at about 3 o clock. treble at just above noon. and your presence at about 9am.
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#4
I have tried the Laney through a 2x12 with Celestion Greenbacks, also a 2x12 with Celestion Vintage 30s and the sound is still muddy when cranking the master past halfway.
It also doesnt matter how much or little I alter the mid or bass controls.
I only use the "Classic gain" channel . I find thats got more crunch than channel 2.
#6
Wait? WTF? Did he remove the negative feedback circuit?
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#7
Quote by mmolteratx
Wait? WTF? Did he remove the negative feedback circuit?

Wtf indeed.

What I'd do is:
1: Reconnect the feedback circuit
2: Try replacing capacitors, and I'm not talking about the power supply caps (although changing those isn't a bad idea anyway, it's something that's worth doing from time to time). It could be the speaker but when the problem is frequency response, capacitors should be the first port of call. They aren't very expensive so it's a cheap and easy thing to rule out of the equation.
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