Upgrading specific components in a tube amplifier

Thank you for your replies. 

The audiophile gentleman I was talking about upgraded the capacitors to Arizona Capacitor Blue Cactus and resistors to Audio Note Silver Tantalum/Niobium 2 watt. Since this person is to specific I was wondering if the components had a significant and positive effect on the sound overall. 

I am still reflecting on purchasing the Yamamoto VT-52 amplifier and I have been told that they are absolutely astonishing but the tube sockets could be improved, that's why I also asked about those. 

In your experience, do such modifications lead to noticeable improvements in sound quality, or do they risk altering the original design in ways that might not be beneficial?

To answer the question.... It can, and It can.  Different components and manufacturers can have a different sound.  I've messed around with many different pieces of equipment over the years.

For example.  I have an older Dared MC-7P preamp that I picked up at a yard sale a few years ago.  This is a Chinese tube unit that sold for around $800 new 15 years ago.  It came with some crappy capacitors in it.  I replaced them with Mundorf and Clarity caps.  Oh, what a positive difference it made.  

Then I had a Classe Model 70 amp that sounded very nice.  Smooth, warm, good resolution, but a bit soft in the upper treble.  Someone recommended that I replace the several of the electrolytic caps with foil and teflon caps. As it was already showing it's age, I went ahead and recapped the amp.  It went to hell.  Bass got muddy and the treble went from soft to agonizingly bright.

So, the lesson I learned is that audio engineers sometimes make choices for specific reasons.  Sometimes it is for manufacturing issues or costs, sometimes for managing the sound or voice of the equipment. 

Do your research, ask questions,  take pictures and document your changes, in case you have to reverse what you did.  Don't be afraid of contacting the manufacturer and ask questions.  You will be suprised at what they may tell you to go ahead and do (or not do.)  Designer Nelson Pass is famous recommending upgrades to his older designs.  Same with Steve McCormack and the guys at Conrad Johnson.

And make sure you are making modifications for the right reasons. Are you doing it because you want to have fun and enjoy the hobby?  Are you making a repair and it is an opportunity to possibly improve a short coming? Are you dissatified with the piece of equipment?  [Would it be cheaper to sell the gear and invest the money (including what you might spend on parts and labor) into something better.  Can you afford to write off the investment in the equipment you are modifying?  (Somethimes it can be real hard to sell modified equipment.)]  

Just my 2 cents... wait, better make that a nickel since they want to stop making pennies, lol.

- Jeff

Different resistors and capacitors are popular for different applications.  Figure out which resistors and caps you're looking to upgrade, post the values and where they are in the circuit, and current brand, and you'll get some good recommendations.

Upgrading parts can certainly be worthwhile, and can be audible, but what you prefer is always subjective. Be aware that some caps take some time to burn in, and don’t always sound better immediately.

For me, recent mods started with adding a VTA board to my Dyna 70s. In addition to a different driver stage, those mods also beefed up the power supply. At the same time, I upgraded the coupling caps, resistors, and internal wire. It’s tough to be certain what contributed to specific changes, but the whole amp sounded better across the board to me. Switching to a solid state rectifier followed.

Tube rolling can lead to some significant audible changes too, and while not usually inexpensive, they don’t typically involve any modification, assuming the amp will accept the tubes types you try, so it’s easy to experiment if you’re willing to obtain the tubes.

Lastly, my tube amps are now bi-amped, have an inline high pass filter before the amps, and only power the midbass and tweeters from ~ 60hz up. The woofers go through an active low pass crossover and are powered by a SS amp below 60hz. Relieving the smallish tube amps of the responsibility of powering larger woofers in the lowest octaves most definitely led to improved clarity, and in my case was relatively easy and affordable to do.

Once again thank you very much for taking your time to write so thorough responses to my inquiry. 

 

Are you doing it because you want to have fun and enjoy the hobby?  Are you making a repair and it is an opportunity to possibly improve a short coming? Are you dissatified with the piece of equipment?  [Would it be cheaper to sell the gear and invest the money (including what you might spend on parts and labor) into something better.  Can you afford to write off the investment in the equipment you are modifying?  (Somethimes it can be real hard to sell modified equipment.)]  

Relevant and necessary reflections that I believe one should carefully consider oneself before proceeding with these major adjustments.

Figure out which resistors and caps you're looking to upgrade, post the values and where they are in the circuit, and current brand, and you'll get some good recommendations.

As I mentioned I'm considering Yamamoto Sound Craft VT-52. It is supposed to be an astonishing amplifier made of high quality craftsmanship.

After reading the article of switching components here and there, I started wondering how that would work on a Yamamoto amplifier. II have a pair of Audio Note speakers, entry-level, although they may be upgraded to AN SPe/HE very soon. Then I started to play with the thought of changing bits of Yamamoto to Audio Note components (capacitors, resistors and perhaps tube sockets as I heard Yamamotos aren't the best) to see if you could improve the amplifier a tiny bit. Perhaps it could also promote synergy with my speakers, who knows... 

The intent is not to have a Yamamoto amplifier that becomes a clone of Audio Note but rather, identify if there are components within the Yamamoto circuit that could be improved.