I'll have to try the TDK,But try these too,I'm very impressed.I remember you saying that about the maxells,They are very good but these sonys sound crisper, to me anyway.Sounds like you need to upgrade,If you can afford to keep your 424, keep it for ideas then record your finished ideas on a better deck.I have a vintage 246 which I think is the coolest 4 track, a 238 which I use exclusivly for live gigs, and the mother of all potastudios, the 388 which I'll never part with. They all have their place in my home studio