Timewave DSP

Timewave DSP-9 and 599zx

Received the correct TDA-2003 audio IC and some electrolytics for the DSP-9 today and tested it out.  Sounds like new with some new filter and coupling caps.  Will be great for some of the smaller rigs.  I used Digikey # 497-2161-5-ND  which is TDA-2003H.  The H means horizontal and it is actually vertical mount but this just means you have to bend the leads.  I put the leads in the board and bent the whole IC up bending all the leads at once.  This is not a big deal.  I also changed C38, C28 the large output coupling cap and the power supply filter.  Both of these were showing some leakage on the Heath C-3 Cap tester.  I also changed the input coupling cap to the IC and a couple of other 10uf in the audio amp circuit and two other 10uf coupling caps.  The two large caps tested a bit leaky on the tester the smaller ones seemed to test ok but I changed the obvious audio coupling caps anyway.  Sound like new now.  I like the 599zx better but the -9 does a very good job for the features that it does have.  Service is still available but it would have been $70 for the factory to change the audio IC.

Timewave DSP-9

Took the old Timewave DSP-9 out to look at again.

DSP-9 Top

The Audio output on this is a 'chipamp'  TDA2003 and when it went bad I ordered a TDA2006 because it is a pin equivalent but it did not work so I put it aside.  I looked at the data sheets for the two chip amps and it although they are 'pin' equivalent there are major differences in the circuit that the chips want to see according to the sample circuits provided by the mfg.  By changing some of the values I could tell the chip would come to life but sometimes it was oscillating and it would only run for a few seconds before overheating and shutting down.  Now I notice that DigiKey does have some of the older TDA2003 in stock and I think I will try to get the original replacement before attempting to change the circuit to get the newer TDA2006 to work.