- Joined
- Feb 16, 2019
- Messages
- 2
- Karma
- 0
- Gear owned
- Tascam 414mk2, 488mk1&2
Hi Folks, I need some help diagnosing a problem I’ve encountered with a 488 mk 2. I bought a 488 on eBay after looking for a long time. The one I got is in A1 condition everything works on it, faders feel like new, no wow or flutter that I can hear, pots smooth no crackle, recorder section works just as it should, play/ record/ erase heads look brand new no signs of wear. I really think this thing has been in a closet for 20myears and before that only had cursory use. The problem with it is with channel 03, with nothing plugged into the line/ mic input and the trim level turned right down there’s quite a noticeable hiss when I monitor it through either 1/2 or 3/4min the monitor section. The hiss becomes a really loud static hiss/crackle as the trim is turned up. I can still record onto the track from another input and when I switch it to tape it plays back perfectly with no noticable increase in background hiss, likewise I can monitor it through tape cue. I got a copy of the service manual for this model and when I look at the block diagram there’s a preamp first in the signal chain in either the line/ mic or multi mix input. Is it likely that the preamp,is the issue, what would cause it to fail, could it be its solder joints or us there another more likely suspect. I’m aware that there are some issues with this model re one of the tape mechanism gears binding due to the lubricant solidifying and the belts tend to degrade, would you recommend changing these pre emptively . I’m based across the pond in Northern Ireland half way between Belfast and Dublin on the east coast.