Hi Jack,
Sorry this is long.....
Is the issue you are facing at low or high volume? If it is only at high volume you can suspect the power amp and/or speakers. You may be running out of head room with 50W. If it is there even at low volumes then it is to do with the preamp. If your distortion level is OK at lower levels you may need to reduce it at higher volumes when the power amp distortion comes in.
The first Laney Pro Tube 6 knob amps had 3 12AX7 preamp tubes and were very similar to the Marshall JCM800.
The slightly later version still had 6 knobs but had 4 12AX7 preamp tubes. They were still essentially mid gain amps like a JCM800. One half of the additional tube was not used but there was an additional stage - half of a 12AX7 after the tone stack. This is said to based on the Lee Jackson mods that were done in the 80’s. This is discussed elsewhere on this forum:
Lee Jackson mod
http://forum.metroamp.com/viewtopic.php ... 047#p89606
The AOR series you have came after that and made use of the unused half of a 12AX7 as high gain drive boost before all the other preamp stages. This is much higher gain than a JCM 800.
Actually this AOR circuit the circuit is more similar to the Marshall JVM basic boost stages (if you remove all the fancy channel switching and midi etc). So you can try the mods suggested for those amps on the JVM forum:
http://jvmforum.com/phpBB3/viewtopic.ph ... 52&start=0
There is one other:
http://music-electronics-forum.com/t1845/
“I recommend to replace the 100K VR1 with a 1MEG and replace the 2 100K resistors with a single 470K.”
The easiest way to do that without taking resistors out of the board is to remove the 100K resistor in parallel with the first pot. Then disconnect the wire going to the high end of the pot and add a resistor in between that lead and the connection on the pot where the wire went before. One 100K stays on the PCB so you the extra resistance you want. As the resistance is increased you get a tighter, less compressed sound but you lose some gain. You might want to try a separate pot first though temporarily as the original has the additional push-pull switch for the channel switching.
The LAR MAR PPIMV mod you mention might not therefore give you what you want as this is to get more distortion from the phase inverter of lower gain amps. You might end up with an even more mushy distortion on a high gain preamp.
The general idea of voicing on high gain amps is to reduce the bass going in to prevent a loose compressed low end and to cut the very high frequencies on the way out to avoid fizzy distortion. I suspect that your issue is too much bass going in – please try the capacitor Joey mentioned first.
The controls on the 8 knob AOR’s are quite interactive so it can be quite tricky to dial in the exact sound you want. What are the settings you have tried? The preamp 1 volume is after the first gain stage and gives a brighter sound. The preamp 2 volume is after the second gain stage and gives a warmer sound.
Please try reducing the gain a settings – there is so much available on an AOR that at maximum settings it can be compressed (remember you have one more gain stage than an JCM800 going in).
These amps are great but really overlooked so they are cheap on eBay etc. I really don’t thing it is worthwhile spending a lot on Mercury Magnetics transformers, high quality capacitors etc. as you won’t get your money back and the stock transformers are fine IMO (Joey also thinks so). There are so many things to fine tune first to achieve the sound you want.
No offense but I don’t quite understand why anyone would prefer the diode clipping 2205 sound to the all tube sound of a Laney AOR. OK I’m more of a classic rock fan and I have a Marshall JMP 50W Master Volume amp as well as a Laney. If that is the sound you want for metal why not try solid state pedals in front of the amp with the AOR boost on the lower setting (that’s about 3 tube JCM800 territory where pedals are often used to boost).
This is what has been said about the 2205/2210 on this forum:
http://forum.metroamp.com/viewtopic.php ... 58#p341018
Re: Hey Joey Voltage 2210 help needed.
by jerrydyer » Fri Feb 25, 2011 2:01 pm
well it just blows chunks all together. Ive got two of them here and they both suck big time. I just want them to sound like 800's with more gain. These things are dumb. fizzy flabby bass, no sustain. I dont know who thought this was a good idea.
Re: Hey Joey Voltage 2210 help needed.
by joey » Fri Feb 25, 2011 6:25 pm
Second, I would play with that second stage with the 470K plate load/marshall's ghetto compressor. I would maybe try 100K plate load there, and an unbypassed 2.7K, instead of the diode/10K, and see if that is enough.
After that you can try to play around with the diode clipper right after. it is the same symetrical w005 array as whats in their 2100/4100/jmp etc...