For those who have decided to take the plunge and build your own guitar tube amp, please allow me to share my early projects/mistakes with you to assist get you going within the right direction. However, make sure to really want to develop your own:
You need to be fairly handy around electronics already, and aware of the risks inherent in high voltage tube electronics and the precautions to consider when concentrating on tube amps
You shouldn’t possess the expectation that you can save money… unless your time and energy may be worth nothing at all you are able probably do better investing in a completed amplifier, even from your Cayin 300B, but certainly on the open market as used
All said, though, there is a lot of satisfaction in completing and playing an amplifier you built yourself and achieving the license to further modify/tweak/voice your creation perfectly… so let’s get going:
Stumbling Through My first couple of Projects – My first project started as an AM radio, it had occurred to me that the chassis and the majority of the components was quite appropriate for an octal-tube-based Fender Champ-like single-ended amplifier and that i wished to hear the main difference in tone between real tubes and also the tube modeling in my Roland Cube amp… After studying some good tube amp books (see resources) I settled upon a plan and:
* I fought using the old transformers (insulation switching to dust when you flexed the leads), used tube-sockets, noisy potentiometers and poor physical layout (working with the old radio chassis didn’t provide optimum placement from the major components for any tube guitar amplifier)
* Found out that true point-to-point wiring isn’t the best choice for experimenting
* I couldn’t locate a non-microphonic old-stock pentode tube
* The tone sucked… with hindsight In my opinion it was because of the underwhelming, un-branded, tiny output transformer, but I’ll probably never get back to check
* Bottom-line, I learned a lot however it didn’t answer my fundamental questions on tube-tone because I didn’t end up getting an iconic amplifier as a reference at the end of the project
* I spent some frustrating evenings redesigning and reworking my first effort and after that for my second major project I broke down and got a new kit that promised a clone of any vintage Champ amplifier.
Major findings included:
Saving a couple of pennies from time to time on components isn’t satisfying when you end up investing lots of time building the project and elements of the end result look cheap (e.g. a plastic replacement for a ‘proper’ metal construction XLR Cable or worse… sacrifice tone (e.g. cheap electrolytic capacitors)
I’ve grown a little leary of un-branded chinese transformers that might not have even been hi-pot tested not to mention certified with a safety agency; and that knows what laminations, etc. are employed in the audio transformer?
Tiny chassis and cabinets aren’t the best choice for adding additional functionality for the stock circuit and extremely frustrating to work with
8? speakers and small cabinets suck tone… this amplifier sounds great once you plug it right into a proper speaker & cabinet combination
The First DIY Guitar Tube Amp Project
Using the above experiences in your mind it is time for you to summarize some considerations for the first project:
* Simple project however, not under-featured… something which will be satisfying and playable
* Physically large for easy access, simplified assembly and room to modify
* Well documented, well supported… not necessarily with user’s manuals and step-by-step construction guides, but instead with a community with active forums, or extensive web documentation, etc.
* A total kit of parts, no difficult sourcing of components
* Good quality parts with all the potential to upgrade them if desired… but moderation rules… you may want value over extravagant components to reduce your downside if your project doesn’t emerge phczif or perhaps you lose interest.
* Standard sized chassis for quick sourcing of cabinets, or Line Magnetic 518ia available from the kit supplier, or perhaps a desire, determination and capacity to build (and finish) your very own cabinetry
* With the above given due consideration my third time was the charm!
I suggest you look for an established supplier of tube-amp kits, and pick a model that fits both your taste in tone along with a satisfying list of features for your first DIY Guitar Tube Amp!