18W Guitar Tube Amplifier

Ok, well, another bonus page!

Recently completed a guitar tube amplifier and speaker cabinet build.  Schematic chosen is that of a TMB variation on an 18 Watt Marshall 1974 series tube amplifier design.  There are a dozen variants floating around on the web.  Check out first plug-in video on YouTube at the bottom (yeah, I got a little excited when the dial was turned only to about 4 or 5).


Back of Head and Cabinet

Completed Amp Head and Speaker Cabinet

Below are images of cabinet construction for the Head and Speaker:









Below are images of the electronics which operate through and drive the various tubes (transmit, modify and amplify the input sound from the electric guitar):

parts from various online sources

preliminary chassis layout

most of chassis layout before turret board

partially done turret board

near final chassis

near final chassis


final amplifier build


Images of the final build:


Modification to final build (speaker grille cloth changed to more 'period' look with black&tan cloth):

And 50W power attenuator added to the back of the cabinet (18 watts is a lot of power and this amp is too loud at anything above '4'):


 Video of first plug-in and 'test':



Video demo of amp sound:



Comments

Post a Comment

Popular posts from this blog

Process - Dying & Lacquer

Image
The cautions expressed in countless YouTube videos are well founded here.   Careful prep and wearing gloves are certainly ‘musts’. You might also wonder, if you reviewed the post chronology, why so much time had passed between this and the previous blog post.  Mostly this was in order to allow the lacquer (clear coat) ample drying time - 2 weeks seemed like the expected duration, and I essentially adhered to this.  It was also given that I had little experience using dyes and preparing a surface for lacquer and polish.
Read more

Process - Electronics

Image
Soldering the pups was actually one of the most relatively easy aspects to this entire build.  There are good wiring diagrams online, but I really relied on my intuition and a good multimeter.  The switch was the hardest part, only in that there are 8 terminals coming from it while there are only three leads connected to it!  And I wanted to ensure that the forward position went to the neck pup and the rearward position went to the bridge pup.  I easily isolated which terminal did what.  After realizing that each pup connected to two terminals, it was easy to work out which ones would have the right pup active in what position - including both at the middle switch position.
Read more

Lessons Learned

Image
Ok, so every project ends with lessons learned.  If it doesn't, you aren't working hard enough or you have been doing it too long and need to move on to something else.  Me, on the other hand, I end most projects with plenty of lessons; though I try not to, I make mistakes!  And while not always sure that I will try again and benefit from the experience, there is no point in repeating what is avoidable.  I often try new things and move on to the next project, so mistakes are common along the way.  Here's how you can benefit from mine.
Read more