Introduction

[jpsimons]

Hello, just joined diytube. I haven't built anything for myself, at least not yet, but I wanted to share where I'm at in my hi-fi quest.

Back in I dunno 2001 I made my first foray into hi-fi, getting a new Rega P3 turntable for $900 which at the time was a lot of money for me. Then in 2007 I got curious about tube amps and bought one of Tom McNally's Darling amps on eBay. Then I had to get some high efficiency speakers at Hawthorne (the local hi-fi shop in Seattle), which were Klipsch KG4 with horn tweeters and rear-firing woofers. I was super happy with this setup for years. Sweet midrange, lots of presence, but lacking some detail and weak in the rhythm section.

So this year I tried a Dared 300B amp. Didn't like it. Then I found a used Fi 2A3 X amp on Audiogon and I'm really digging it. It came with Sovtek 2A3 tubes which I didn't care for at all, but TJ mesh 45's sound pretty good, and the JJ 2A3-40's that I just received sound great. Seems like the 45/2A3 platform is very flexible with "tube rolling" options.

As for DIY, I did study EE in college for awhile before I switched to comp sci, but I was mostly doing digital not analog. How does one start? Find a well-known schematic and build it? Do most of your do-it-yourselfers know a lot about analog L-R-C kind of circuits?

[mesherm]

I already had an electronics backround and experience with kit building but was only interested in solid state until I bought a cheap S-2 tube amp kit.
From the sound of that amp I was encouraged to continue with tubes and came across Shannon's DIY 35 and this forum. Then I started picking up beater Dynaco amps and tubes from ebay and fixing/modifying them. Then I graduaded to designing and building my own amps from scratch starting with PP and ending up with SET 300Bs ands 2A3s. I would suggest getting GlassWare Audio Design TubeCad as a minimum. I have that plus the SE and PP design software. It may seem confusing at first but eventually you will learn how to use them effectively. Also PSUDII for designing power supplies is very handy and free. The book Building Valve Amplifiers by Morgan Jones is good to have also. John Broskie's Tube CAD Journal contains a wealth of tube design information. Finally you have all the helpful folks here at diytube. Be warned though that tubes can be a very addicting and expensive hobby. I have four very large tube caddies filled with vacuum tubes most picked up on ebay. NOS tubes never loose value though.

[zippy1540]

I would say just get a schematic and start building. that's what i did after lurking on the forums for a while. I'm still learning but so far i've built the diytube st-35, a SE 6em7 setup, Copied a Decware Zen, built a clementine then used the front end of a clementine to feed a PSE 6s4a setup. Every time i ask multiple questions on these forums then start slinging solder-apply the juice and hope for no smoke. so far i've been lucky. Every amp i build seems to sound better than the last one and i learn more about designing amps with every try. My latest PSE 6s4a amp i tried something new for me using the lm317 setup for 26.5ma for each tube. The sound is amazingly clear and tight. Any questions you have i would post them on this forum. everyone here is incredibly helpful. Just be careful of those Capacitors, don't get Zotted.

[jpsimons]

Sounds like it's a journey not a destination. I have this dream of the perfect amp that has all the detail and authority in the rhythm section, but also has that quality of "roundness" where the sounds come across as mixed-together and integrated (like how the best sound at a music venue/bar is in the back), a sound that's music rather than just a bunch of hi-fi sounds. I think for now I'll just keep tube rolling with my Fi X, but ultimately I'll set up a workbench and tinker. Since I'm in an apartment at the moment I'll probably wait until I get a house with a basement to start breadboarding and soldering.

[msmpe]

Hi jp

I've found there are three elements in a tube amp that strongly influence the sound of the amp. The tubes are the first, hence the process of "tube rolling". You can try differnt brand tubes both in the power stage and in the signal processing stage.

The other two are the output transformers (OPT) and the coupling caps (CC). Not too many pepople "roll" different OPT in/out of their amps due to the expense and effort. But still a worthwhile exercise if you can swing it.

The CC however are pretty easy to do - usually just a matter of unsoldering (or cutting...) the origianl CC and soldering in some new ones. With this notion you can try Auricap, Musicap, Jensen, Vitamin Q, Blackcat, Solen, oil in paper, and many others. Each one will have a marked effect on the sound of the amp. In fact, when I build my amps, I place a two tag solder strip right next to the plate of the predecessor tube and solder my coupling cap there (make it the last component to solder in at that location) so if I want to change it, it is readily accessible. Just keep the value (.22 uF for instance) same as the original. This also gives you a good excuse to get a soldering iron, solder, desoldering braid, dykes,etc.

Good listening and enjoy