2. amps-preamps
  3. 179150-111416

Finally made the transition to a tube preamp!

I was always curious about the much hyped sound that one can get from quality tube amplification. People talk about 'tubey magic', 'the golden glow', etc. I was always curious, but was reluctant to go in that direction because the received wisdom is that unless you spend big bucks (like, money you could buy used car with), tube amplification will only disappoint. The rationale is that with less than top notch tube equipment, all you get is a muddled sound with weak, flabby bass and rolled off highs.

My opinion started changing once I obtained Carver M-4.0t power amp. I bought it because I wanted a lot of power to drive my Magnepan MG-1 planar speakers. Once I hooked Carver M-4.0t to my Maggies, the sound was transformed. Not only did Maggies start singing, the very character of the sound drastically changed. Carver made that amp with the intention to emulate his flagship tube power amp, and by the way that amp sounds, I'd say he came pretty darn close. Yes, I started hearing that 'magical 'tubey' sound. Very exciting!

However, that's not what really changed my way of enjoying music. Intrigued by this encouraging discovery (courtesy of the Carver amp), I started looking for an all tubes preamp. Of course, quickly realized that without paying at least three of four grand, I won't be able to afford quality tube preamp.

Then, by accident, found an ad on the craigslist selling Dynaco PAS-4. Tempted, I offered $475.00 and next thing you know, I got the preamp. 

OK, so now, with Dynaco PAS-4 hooked into Carver M-4.0t, the sound is completely, radically different than anything I was able to hear before. This preamp is incredible. It seems to have it all: soft, sweet, mellow, liquid, golden glow sound coupled with muscular bass. It delivers almost frightening slam, and the soundstage is way larger than before.

Isn't it amazing that for less than $500.00 one can get such amazing sound? The only problem is, as I understand, Dynaco PAS-4 is quite a rare find. Allegedly, it was produced in the early 1990s in very limited quantities.

Bottom line, if you spot this preamp for sale, don't hesitate to snatch it. In my experience, it is quite amazing!

crazybookman
knotscott
948 posts
 

Where can I learn more about that arcane skill you call "roll different tubes to tailor to the sound to your liking"?

Tube rolling is optional of course, but it’s unique to tube gear and adds an element of fun and interest. Many/most (at least some) tube gear owners find that different brands of vacuum tubes...even those of the same type and similar specs, can sound different. The results can vary a lot depending on the particular circuit that’s in play, and the results are very subjective. Your system and your room will play a factor. Your system with the Maggies should be more revealing of the differences than most. You only need to please yourself, so no worries. Since you’re new to tubes, I’d spend some time with what you’ve got, get very familiar with the sound, and do some research in the process. Tubes have gotten a bit expensive since the Russian/Ukraine invasion, but there are good deals if you look.

It’s cheaper to start with the preamp and driver tubes of the amp vs the output tubes. It’s best to go in increments vs all at once so you can appreciate whatever differences there might be...it can be subtle. It’s also good to allow several hours for new tubes to burn in, so take your time with each move....it’ll give you lots of time to research and think about the next move.

There are some direct substitutions of type that are possible....just be sure to read up on which ones. Changing amplifier output tubes may require a bias adjustment, so read up on how the Carver handles the biasing....some amps have a user friendly potentiometer, others are auto biased, and some even require a resistor change, so you’ll want to check into that before changing output tubes.  You may need a simple voltage meter for biasing.  The preamp tubes and the driver stage tubes of the amp shouldn’t need any bias adjustments, which is another good reason to start there.

https://www.themasterswitch.com/how-to-tube-roll

 

This is not an absolute definitive tube comparison, but there are some interesting comments and charts...it’s something, and can’t hurt to look, but don’t be afraid to go your own way.

https://tubedepot.com/pages/tube-comparison-tool

Have fun! 😎

 

 

oddiofyl's avatar
oddiofyl
3,916 posts
 

Enjoy, welcome to the Darkside...  

ghdprentice
7,098 posts
 

Congratulations. it only gets better from where you are. Enjoy.
 

A tubed preamp was my first step into the tubed arena about thirty years ago. Since then one component after another has become tubed. Each accompanied by an increase in musicality and overall sound quality (they were always upgrades as well as switch to tubes). It has resulted in my current very satisfying system.

oddiofyl's avatar
oddiofyl
3,916 posts
 

I’m all tube and don’t think I could ever go back. Good tube equipment is very reliable, most tubes are too in my experience over the last 30 years with tube gear. I have had something with a tube in it since 93 when I bought a CAL Alpha DAC and very few tubes actually red plate or arc. Had a few loose vacuum, but overall reliable and no damage to components, except for my Anthem Amp 1. A great amp but blew a cathode resistor if a tube failed. Sonic Frontiers sent me a few and it wasn’t a big repair. Worth it given how good it sounded... and just having bought a house and having a kid then I had to keep that thing running....

bjp9738's avatar
bjp9738
67 posts
 

Sounds like a great find. Enjoy! I'm in the tube preamp, solid state amp club, too. It's a nice little glimpse into the tube world without the hassle and expense of maintaining power tubes.

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