Replacement resistors in vintage equipment

[sssmokin99]

Suppose you were going to go through not only the power supply, but the amp driver boards in a 30 year old receiver or amp. You already have decided to replace the electrolytics and some other parts, check solder joints, etc. You want the thing to work reliably and sound its best for many more years, and so have decided to replace the resistors. All of them! Now, what type would you use? I have read many opinions, and some differ as to the type of circuit (i.e. amplifier versus R.F.). Anyone who has done this care to offer guidance? I should add that I am looking for that sweet spot of cost/performance, the most bang for the buck. Obviously, the largest cost of this is your own time. Many thanks for your thoughts!

[rulerboyz]

The only place I've ventured with this idea was in the phono section of a Pioneer A7 integrated amp. As an experiment I changed the resistors that were related to the signal path with resistors available from Parts Connexion. There was definitely a change in the phono section sound, however I'm not sure how much of a role, if any, the new resistors played.
For the most part I used PRP (Precision Metal film resistors). In the very first resistors after the RCA jacks, I used the more expensive Riken resistors.
I also replaced the stock RCA input jacks with the audionote chassis mount jacks and connected them to the circuit board with a light gauge solid core silver hook up wire and cardas solder. I also did this to one of the Tape out jacks so that I could compare the stock versus the "upgraded" jack. I could hear a difference in sound from that one single upgrade alone when quickly comparing between the two outputs.

I think it's going to be generally controversial, the idea of changing the resistors in vintage solid state. It's a lot of work for maybe zero difference. It's probably going to be the least likely part that would play a role in changing the amp's sound.

[Fred Longworth]

The general rules are: (1) the higher the resistance of the resistor, the more noise may be reduced by replacing it; (2) the lower the level of the signals being processed at the point in question, the more benefit you'll get from replacing resistors.

We use metal film 1% devices, usually Xicon devices, available from Mouser.

Fred

[sssmokin99]

Thanks for this good information, guys. This will possibly be a project for one of those snowed-in days! (not a problem in your neck of the woods, Fred!)

[Tube Radio]

I too use 1% metal film resistors from Mouser and have not had any problems yet.

[avionic]

If your into a little reading about resistors..http://www.aikenamps.com/ResistorNoise.htm I use mil-spec'd metal film Vishay / Dale.

[jblmar]

I replaced all 102 resistors on my Marantz 3650 preamp board. I had a noticeable, constant hiss. Replacing the resistors with the original parts listed in the service manual got rid of the problem.
BTW. The SM calls for (for the most part) carbon, 5%, 1/4 watt resistors.

Ron

[SPL db]

:lurk: