| Jeff Wong |
Hi, I've been lurking here for a bit, and finally figured that I should dive in with a post. I'm impressed with the dedication all of you have. I hope I can eventually free up some time to devote to DIY projects, and maybe read the Horowitz and Hill book I bought at Mike Creek's recommendation half a dozen years ago.
I got into High End Audio in 1995 via my ex-girlfriend's Dad, who was an audiophile. My brother gave me his Sansui TU-717 Tuner a number of years ago, to which I added an IEC jack in order to use some aftermarket power cords with the unit. This tuner is one of the few things that I haven't had a chance to take a soldering iron to, other than for the IEC jack. I always thought it might be nice to replace the carbon resistors with metal film ones to lower the noise floor. But, I only recently found a schematic online; the collector in me would prefer an original, but, the practical side of me is glad to have gotten anything at all. My DIY skills and experience are limited; I've generally only done parts swaps, and no circuit design. So, please bear with this neophyte.
When I had the hood open a few years ago, I recall that there were some 8 pin chips in the Sansui TU-717. I believe the part is an RF/IF Amplifier - LA1222 (its equivalent is an ECG1227.) Does anybody know of a higher quality version (preferably a drop in replacement), perhaps made by Burr Brown or Analog Devices? Would there be any benefit to replacing this part? I've used Burr Brown Op Amps as replacements for I/V conversion in many of my other components with very good results. I have no idea if upgrading an RF/IF Amplifier will reap any sonic benefits.
I was wondering if I might be able to do a quick swap in the TU-717 in the short term before performing any major surgery on the unit. I can imagine replacing all of the resistors, maybe getting some Murata ceramic filters and popping those in, and upgrading several (if not all) of the electrolytic capacitors. I've got a list of the caps that someone else has replaced in the TU-717 with supposedly good results. At some point in the future, I'll do this with something suitable like Black Gates.
Has anyone here modified a TU-717? If so, what parts substitutions offered the most significant improvements?
Any information would be greatly appreciated. |
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| Jeff Wong |
| Thanks, Frank. I've gathered some useful info from a number of places, including that one. I've now got a list of capacitors that can be replaced that should provide better sound. I've been advised to avoid changing the RF/IF LA1222 chips. Hopefully, I will eventually get some free time to mod this unit. |
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