Kaz, still there? :) On Sat, Oct 20, 2018, 23:23 Pilau Tigered wrote: > Haha, I didn't expect a lightning fast response! > > Thanks for sharing the specifics of what you changed. > > You're talking about "10.Upgraded 4 opamps to socketed Burr Brown > OPA2604APs. These will yield better > S/N performance and increase overall gain and warmth." > > Well that good to know. I'll update the doc. Regardless - will making the > modification being mentioned reduce noise? Will it affect the sound at all? > > And finally just out of curiosity, which components surrounding the > op-amps affect the gain? I'm not looking to increase gain, but I'm happy to > learn :) > > Thanks a lot! > > Tom > > On Sat, Oct 20, 2018, 20:28 Kaz Kylheku wrote: > >> It's hard to say without some A/B comparison, with another unit, if that >> is more noisy than normal, but the MP-1's are not known for being quiet. >> That's why there are these "noise mods" out there. >> >> I basically changed every op-amp that passes audio to NE5532. For the >> quad in the EQ section, I used a MC33079. Just desolder the old, solder in >> the new; repeat bunch of times. It's good to do just one or two at a time >> and confirm the work after each one. Don't play the "which of these 11 >> op-amp chips I changed at the same time is bad/mis-soldered" game. >> >> BTW in that doc you linked to, step (10) claims falsely that fancy >> op-amps will give the unit more gain; that is not true. The gain is >> determined by the other components in the op-amp circuit! It will be the >> same. We're definitely not looking for more gain by swapping op-amps, and >> it would be wacky if that happened. >> >> On 2018-10-12 08:27, Pilau Tigered wrote: >> >> Hey Kaz, good to hear from you. >> >> So are you saying that level of noise is just how this device is? >> >> Modding/upgrading the MP-1 is definitely worth it! In that note, do you >> think you could maybe share what exactly you changed with the opamps? >> >> On Fri, Oct 12, 2018, 18:23 Kaz Kylheku wrote: >> >>> Stock ADA MP-1's are noisy. In your Youtube video, nothing strikes me as >>> odd, other than the buzz when the audio interface is used. (I concur that >>> it is probably a ground loop.) >>> >>> I haven't done anything to my MP-1 in a bunch of years now; just >>> enjoying it daily! >>> >>> When I ripped out all the audio-passing op-amps and replaced them with >>> better ones, it really cleaned up. I couldn't believe I could just put down >>> the guitar on a stand, mute the strings and walk away. >>> >>> Those ADA people created a lot of future work for hobbyists by creating >>> a great design, and then stuffing it with some crappy components. But for >>> some of us it is worth it. >>> >>> On 2018-10-10 06:03, Pilau Tigered wrote: >>> >>> Hello Kaz and the ADA MP-1 mailing list! >>> >>> I have recently acquired a used ADA MP-1. The unit is rather noisy and >>> it has a faulty front input plug. These issue led to hours of research and >>> discovery, including finding out about this mailing list and Mr. Kylheku >>> (among other leading figures in the mp1 technical community) >>> >>> ** I'd love it if someone could help me debug and locate the source of >>> the issue ** >>> >>> I have also put together a list of information and >>> mods/upgrades/refurbishing instructions and other technical resources for >>> the ADA MP-1: https://tinyurl.com/ada-mp1-refurbish-upgrades, feel free >>> to check it out >>> >>> Pilau >>> >>> >>> >>> >> >> >> >