The 183 high plate is just a delicious sounding amp. The YouTube videos of TAG's along with the Louis Electric Cobra have sold it to me.
Interestingly/curiously, there is also a lot of mod-space with this topology; members here have converted their 183s to Bluesmasters and I like that option. The Bluesmaster is another fine sounding amp. But first things first!
The project here is to build the amp with no exotic unobtanium parts. The market for sustainable supplies of Dralorics, Q-lines and Roe (resistors and caps) is woefully thin. Speaking with a member here, we believe that manufacturers like Nick over at Ceriatone have bought up all the available inventory of typical Dumble stock. Good on him, I suppose, but it means enthusiasts like us have to dig a lot deeper in ebay to find authentic NOS parts and its reached the point where it is hardly worth the effort anymore.
However, granted it is true that a certain aspect of the Dumble tone is rooted in the parts he commonly used, I believe there is more to it, and I want to prove it, by building an amp with only modern day, commercially available parts. The more I study these topologies the more I am convinced that it is the holistic, topological configuration of parts that contributes most significantly to the tone. I would never consider myself a critical listener, and I've never had the pleasure of playing a real Dumble, but I become more and more convinced that we can find the signature Dumble tone in observing things like the phase relationship of components on the board, the geometrical engineering of the chassis, the lead dress, and simply, the use of good quality parts carefully assembled.
There can only be one 183. A dear friend here has built truly faithful reproduction of these amps down to all the period correct parts, and they are simply amazing, but I consider him a master-builder and he is not simply a curator of museum components, he really understands the circuits and with every project he undertakes he proceeds with a deep and profound understanding of the circuits in the big picture. NOS parts are a great point with which to start, it gives us the best chances of achieving a desired set of results, like building an ancient ship with the original hand-tools, but these days NOS parts are a luxury and much depends on the skill of the shipwright in the handling of the tools. It extends deep into the philosophy of building these amps, and MrD's guiding principles. He could take shit parts and make them sound magnificent. It should tell you all you need to know about the importance of all the bits and pieces that go into amps like these. It certainly speaks to me.
I love the anecdote of Henry Ford once receiving a bill of $1000 for a nut. When the engineer was asked what could justify the bill, it is said he replied that it was 1 cent for the nut, but $999.99 for knowing where to put it. It is also said, that when he heard that, Ford paid the bill.
I stand to be proved wrong here, but I believe the 183 is more than a collection of parts!
Stephen
Edit: 24/04/2023
So, for anyone who downloaded the previous schematic, version 1.3, here is the final iteration, version 1.8
This is now tested and fully up and running.
I drew up the plans for head and posted them here: https://ampgarage.com/forum/viewtopic.php?f=11&t=36152
And here are a couple of shots showing the finished article.
Enjoy
I have only one, and shifting it around for the test if i have doubt in OPT.
)
I am always a broken record over here talking up that guy lol
