Quote1. Regarding the power supply: My intention is to hook this up to a 8Ω cabinet. So, are you saying that the original wall-wart will not be enough? If this is correct then, what are the specs for the proper PSU?
I think earlier you had mentioned increasing the power. You don't have to, but it can handle a larger power supply if you want. The max the output op amp can handle is 20W and 44Vdc. For an 8 ohm load, you should be able to go up to 44V. However, my earlier warning was if you are going to try a 4 ohm load, then stick with 34Vdc because obvioulsy the current will be larger for a 4 ohm load than for an 8 ohm load. Increasing the power supply to 20W won't make a huge difference but it will be slightly louder at maximum clean output.
Quote2. I thought phatt's advice about removing the diodes meant the gain pot is still working and you still get some distortion, you just get less distortion or "cleaner" distortion. However, from your last post, if I understand right, are you saying the gain pot becomes inactive and you basically lose ALL distortion this thing can produce? If that's the case, then no this is not what I am after. I do want the versatility of having a Gain control before my Volume. Question is can this Gain control be more gradual in response and smoother in performance?
Essentially yes, but it is a bit more complex than what I explained. The diodes clip the output of the first stage and cause harmonic distortion. If you remove them you can still get distortion from overdriving the amp. But the purpose of the first stage is merely to overdrive the clipping diodes when the gain is set high. In my opinion the best solution is to simply reduce the maximum gain of the first stage so that the gain pot becomes more usable. However, you can try both solutions and see which one suits your needs.
Quote3. The 24V 600mA wall-wart powers your MA007 right? Are you using it as is or you modified it and play it through a different speaker?
Is this the MA007 ? Is it made of plastic? I'd be curious how it sounds!?!
Yes. I did not mod the new wall-wart. My original intention was to mod the original wall-wart with a different transformer but it turned out to be simpler to just replace the whole wall-wart. Yes I have the MA007. I actually have two. One that I moded and I bought another to compare the original sound. They are different. But I don't have the ear to really say which is better. The moded one is slightly more powerfull with clean sound and my volume and gain controls are more usable. I also moded the tone stack to give it a brighter sound. And I put a large filter cap to reduce the humm.