noise reduction circuit/chips USER SERVICABLE on 238 8-track??

[Cratinus]

i have fried 3 of the "Dolby S" noise reduction chips on my loyal 238S Syncaset
recorder. i returned the unit to Tascam for service only to find that the specific
Dolby chips that they used on the 238S are no longer available. although the unit
is fully operational WITHOUT the noise reduction engaged, i was wondering if
i might be able to install some "substitute" chips,..perhaps replacing all 8 with
something else "Dolby-related". i've never seen any schematics on the unit
(but i could probably find some somewhere). in fact,..i really didn't know that the
noise reduction aspect of the recorder was simply a collection of 8 Dolby S "chips"
of some kind till the Tascam folks told me so. perhaps it's not worth the trouble.
the unit sounded BRILLIANT (for a cassette multitrack) until the chips went astray,
at any rate. if anyone has any tips, recommendations or resources please let me
know. cheers.

[frederic]

I wouldn't go this route.

Your best bet is to purchase a used dolby encoder/decoder for your recorder and not disassemble the circuit boards.

Tascam made the same exact encoders found in your 238 as an external device, and every so often I see them on digibid and e-bay.

Originally posted by Cratinus
i have fried 3 of the "Dolby S" noise reduction chips on my loyal 238S Syncaset
recorder. i returned the unit to Tascam for service only to find that the specific
Dolby chips that they used on the 238S are no longer available. although the unit
is fully operational WITHOUT the noise reduction engaged, i was wondering if
i might be able to install some "substitute" chips,..perhaps replacing all 8 with
something else "Dolby-related". i've never seen any schematics on the unit
(but i could probably find some somewhere). in fact,..i really didn't know that the
noise reduction aspect of the recorder was simply a collection of 8 Dolby S "chips"
of some kind till the Tascam folks told me so. perhaps it's not worth the trouble.
the unit sounded BRILLIANT (for a cassette multitrack) until the chips went astray,
at any rate. if anyone has any tips, recommendations or resources please let me
know. cheers.

[Cratinus]

frederic, thanks for the response. do you know the name or model # of the Dolby
encoder/decoder that you referred to?? also, are these SINGLE channel or EIGHT
channel devices?? let me know if you can. thanks.