Component Upgrade/Mods to share?

Your going about this the right way, seeking advice from those who have done the work and succeeded.

Unfortunately, my early days of parts swapping yielded spotty results. The quality of the parts is not always the determining factor for success.

A perfect example being when I tore apart Snell type A speakers. I upgraded all the internal wire, crossover caps and resistors. I used the exact value for the caps and resistors. No errors were made, the parts simply were not a match for the design and they were returned to the original parts.

On the other hand, I have had equipment designers suggest parts that they knew would improve their circuit. Every time the modification was begun from an informed source, the results have been wonderful.

You will need to list the equipment to get the suggestions flowing.

One of the things to look out for when parts swapping is that you know what value you are looking at. A resistor of say 1k ohms at 5% tolerance may be 1050 or 950 ohms. If the designer used his resistors based on measured values and not printed values, you may be substituting a precision 1%resistor of the wrong value. Sometimes it might make a difference and sometimes not. The same could be true for any component. The unit will still operate, but the sound might be degraded, or it may be improved. People that are experienced know which way to go when parts swapping. But, if you never do it, you will never get experienced. Sometimes you just have to jump in and do it. A good method is to try a part, let's say a resistor, that has a 10% tolerance rating. Not too critical. Get some precision resistors, some at the exact printed value, some a little higher , and some a little lower, all within the 10% tolerance rating. Try different values and see what, if any, difference in the sound may be. Also, the brand and type of these passive devices can sound different, so you may want to try a few different brands too. With caps, you need to get the right type and/or orientation or you're goint to screw up. Polarized, non-polarized, elecrolytic, film, etc., with polarized you must get the orientation right,by lining up the marked conductor with the place it should go. With some caps, particularly in power supply filtering, larger Farad ratings can be better, or even "piggybacking" additional caps over existing ones is common. Get some reading material and give it a try.

Twl is right on. The failure rate on parts is down right frightening. Most would rather have parts returned than to test each one to make sure that they meet spec. This despite the fact they give themselves rather generous tolerances. Some manufacturers (Dunlavy comes to mind) sorts and matches parts prior to manufacture and then indiuvidually fine tune each finished piece to match a reference model. AlbertPorter I belive the early Snells ( when Dr. Snell was at the helm)were treated the same way. Mixing and matching parts by reputation can be risky. I'll make another food analogy that will humour some. If one just follows a recipe with out considering the ripness (or lack there of) with out compensation they will never excell as a chef (it is chemistry and physics after all). IMHO fine tuning with lesser parts can yield better results than better parts with out fine tuning. While using the best parts and best skills should bring out the best (It SHOULD be easier too). It's more important whats comes out than what goes in. Unless you access to extensive test equipment and know how to use it, mods may be entertaining and educational,but not necessarily an upgrade. Another consideration is whether your work even, if sucessful is devaluing your initial purchase. Many people are turned off to purchasing self moddified used products. You may even void the warranty. With all that negativeity I encourage you to try. That's how this hobby started in the first place. It should keep manufacturers on their toes knowing that people are going to inspect their work and see if their getting their money' worth. Please share your decision/results with us.