Note #1: Any input is welcome. I especially went to hear about your experiences with 300B and 6N6P valves.
I am about to build Tom Christiansen's "Damn Good" 300B valve amplifier. It will be customized to support headphones.
Note #2: I like to call tubes "valves". That's what they were called when they were invented.
I own a Schiit Lyr, a Schiit Bifrost (uber) and LCD2 cans. The Lyr is a hybrid amp that has a SS output and a valve pre amp. It utilizes 6DJ8 valve variants. After collecting for a while I have settled on La Radiotechnique 1965 E188CC’s and 1959 Valvo, Hamburg PCC88 D getters. I’m delighted with these and I’m done rolling Lyr valves. (I still love the thread) Hence, I am moving to an all valve amp. I also like building things so Tom Christiansen’s DG 300B filled the bill.
Tom provided me with a great deal of assistance redesigning a valve tester. It's now based on the EICO 667. This is a parallel project to the 300B build. (I will also update the progress on this thread.) Tom's an EE that specializes in precision analog circuit design and has designed amplifiers at National Semiconductor. The power supply is, IMO, the most critical component in audio gear, double that for valve audio. I am a hopeless bumbler that is trying to learn electronics along the way. I do have decent intuition.
Before finding Tom's site I was bumbling my way around different valve tester design. I was working with various transformers and getting nowhere, but I learned a lot. That led me to Tom’s power regulation products. The 21st Century Maida Regulator, for high voltage, and the Filament Regulator for, well, filaments.
21st Century Maida Regulator:
The one I built.
I built both of them complete with 0805 package SMD components. I never thought I could do that but after watching Dave Jones EEVBLOG solder series, it wasn’t too difficult. They both work great! They fixed a lot of design issues and provide nuts-on voltage from the secondary’s. Both the Maida and the Filament Reg are used in the 300B build. The best suggestion I got from Tom is to scrap the tester design I was working on before I electrocuted myself. It utilized an autotransformer with mains in the circuit. The EICO 667 design is bumbler friendly.
The schematics, BOM’s, and complete circuit explanations for all Tom’s designs products can be found at his site. http://www.neurochrome.com/audio/ There’s enough information that you can build your own boards. It’s much easier to buy them from Tom for a modest price. The BOM’s have DigiKey part numbers for every component.
I will fill ya’ll in on all the costs along the way. I don’t expect this to be a bargain basement amp. But come on’ the board is only $165 and that includes the $25 Maida board and the $20 Filament board. A very reasonable first expenditure.
On with the build.
Note #3: I have decided to call it the "Damn Fine" 300B
I will not stray away from the 300B BOM (much). So here are the 300B components I've ordered so far.
Power Transformer: ClassicTone 40-18069 $122.00
Output Transformer: Electra-Print custom wound L3500. 5K ohm @ 100ma to 60 ohm, 10 Watt. This will support my LCD2’s $200 each. Two required. $400
That IS more than enough for a first post, and if you’ve read it, I appreciate it.
I had a suggestion to put the schematics in the first post.
You will see these again.
Edited by sceleratus - 8/17/13 at 8:50am