custom-built tube amps

I found a Sansui AU-125 tube intergrated/power tube amp at a flee market. I paid the guy $50 and acted like he was robbing me. I never took tube amps seriously and figured I use it for tinkering...You know, with Sansui's great reputation for Amps (wink,wink). While nearly ruining an already neglected amp I retubed with a matched quartet of Svetlana 6l6gc's. Much to my surprise even this sorry state the sound stage and upper to mid frequencies where very impressive. I have been a fan of Musical Concepts mods and their sister company Musical Design for years. I have a custom built single ended, class A output stage modified x-Hafler DH220 that has humiliated many store brought pedegree (hi-end) amps. So I decided to go to the well once again. I sent the amp and it's schematic to John at Musical Concepts (Musical Design), and a year later and $1250.00 more I recieved the amp back. It has Cardis Binding posts, custom built pure tube phono stage, rebuilt power supply and much more. The end results was a stunning 35wpc tube amp that is rivaled by only the best hi-end tube gear selling at more the 2 or 3 times the price. Don't discount the custom built option.

Like all things consumer, caveat emptor (may the buyer beware). In the last 5 years, a huge number of "new" companies have come up like mushrooms, all offering tube equipment alledged to be "the worlds best" etc., etc. I am sure that a number of these companies are owned and run by skillful, qualified, passionate people who design, produce, and stand behind their products. I am also sure that many of these companies have been set up just to take advantage of the new commercial "opportunities" that exist in the new tube revival. Talk to the owners, find out how long they have been in business and how man items they have produced. Watch out for newcomers, high voltage can kill!

Advances in tube circuit design in the last 30 years are almost non-existent; after all the SE triodes date from the '30s. So every competent technician can copy an old design, use high quality modern parts and come out with a decent tube amp. Many of the minor manufacturers are doing just that. The only difficult part of the design are output transformers, and the good ones are terribly expensive. So you can really do a fine DIY tube amp, if you do not electrocute yourself with the high voltages ;-) Making a great tube amp though, is extremely difficult.

I am back for hobby to build tube single ended amplifier
Balance input and output what are the good tubes
Kindly advice

I love this, a thread from 1998!