Brad McGowan
Well-known member
I have an Otari MX55 1/4" machine in my studio that has been very reliable. The transport is great and handles the tape beautifully. The autolocator is very precise too. I like everything about the machine, expect I really feel that the sound could be improved.
Last fall I rebuilt a Dynaco PAS3X preamp and turned the phono preamp into a 15ips NAB tape head preamp. However I ran into problems with grounding issues. I also wasn't able to get the low end right, but that was likely due to miscalculations on my part. However, even with the bad hum/buzz I could sense a dramatic improvement in sound quality. The depth and detail was immensely improved. It was hard to go back to the stock electronics after hearing that.
So what I'd like to do is create tube record and repro electronics to replace the stock electronics. I can leave all bias and erase functions on the stock Otari board. I'm thinking I just need to bypass all the audio electronics, amp stages and EQ stages that are on the stock boards and insert a higher quality signal path, which can be housed in an outboard enclosure. All tube would be my preference. I actually have this old Teac all tube reel to reel with electronics that are based on the Ampex 350. I’m wondering if I could somehow marry those amplifiers and EQ circuits to work with the Otari. I have schematics for all this stuff thankfully...for both the MX55 and the Teac.
Does anyone have any experience doing this kind of thing? I've seen The Tape Project stuff and have read accounts on the Bottlehead forums regarding mods for the Technics RS1500. That's actually where I got my inspiration to convert my Dynaco. However, I've never heard of anyone doing an upgrade on the record electronics as well.
Is it as simple as just finding the appropriate points in the circuit to bypass the stock electronics and then plugging in the upgraded outboard electroincs?
Would anyone be interested in creating a project that could be adapted to work with a variety of tape decks? Or perhaps one of you guys would be interested in designing something for a fee?
thanks,
Brad
Last fall I rebuilt a Dynaco PAS3X preamp and turned the phono preamp into a 15ips NAB tape head preamp. However I ran into problems with grounding issues. I also wasn't able to get the low end right, but that was likely due to miscalculations on my part. However, even with the bad hum/buzz I could sense a dramatic improvement in sound quality. The depth and detail was immensely improved. It was hard to go back to the stock electronics after hearing that.
So what I'd like to do is create tube record and repro electronics to replace the stock electronics. I can leave all bias and erase functions on the stock Otari board. I'm thinking I just need to bypass all the audio electronics, amp stages and EQ stages that are on the stock boards and insert a higher quality signal path, which can be housed in an outboard enclosure. All tube would be my preference. I actually have this old Teac all tube reel to reel with electronics that are based on the Ampex 350. I’m wondering if I could somehow marry those amplifiers and EQ circuits to work with the Otari. I have schematics for all this stuff thankfully...for both the MX55 and the Teac.
Does anyone have any experience doing this kind of thing? I've seen The Tape Project stuff and have read accounts on the Bottlehead forums regarding mods for the Technics RS1500. That's actually where I got my inspiration to convert my Dynaco. However, I've never heard of anyone doing an upgrade on the record electronics as well.
Is it as simple as just finding the appropriate points in the circuit to bypass the stock electronics and then plugging in the upgraded outboard electroincs?
Would anyone be interested in creating a project that could be adapted to work with a variety of tape decks? Or perhaps one of you guys would be interested in designing something for a fee?
thanks,
Brad
