Building a 300B push-pull / Newbie question

If you are on a budget, you have a number of challenges, but if I were you I would avoid amps that use an input transformer if cost is an issue. You can build a phase splitter circuit that if done right can sound better than a transformer for a lot less money!

Best place to ask this question is Audio Asylum's Tube/DIY forum and also diyAudio's Tubes/Valves forum. There are plenty of PP schematics in the archives and you'll find a lot of people with extensive experience in just this sort of thing.

Here is the schematic and the assembly diagram from the late Dr Gizmo

As to whether you can make an equivalent amp on a budget, I dunno. Good transformers cost a lot of money and the 300B's ain't cheap, either.

The most important thing besides parts, is properly laying out and assembling the amp so that hum and other issues are minimized. It takes a little experience or a lot of help to get this right. Personally, I'd go with a kit for a first project. You could end up wasting an awful lot of money and end up with a mediocre or bad amp.

One person to check with would be Kevin Carter of K&K Audio. He makes reference level components and also sells kits. He has a PP 300B schematic and PP kit that is easily modified to handle it. It probably won't be cheap, he uses Lundahl transformers, but it will be amazing. Here's a post on his forum about PP 300B amp from a few years ago. Post a question there, Kevin is quick to respond and is great at support.