We can not yet look into the future, but we can set the direction and aim towards the plans we set up. This page contains my present plans for the MT Audio Design home site.
Tube Amplifier Projects
I have started the 'Quadimodo' project and will finish it sometime. At the moment I am very happy with my Jadis amp and other projects have higher priority. The 'Sep Yep' project is still in the idea stage and will remain there for some time, but I have already bought the 300B's and other tubes. As it looks right now, I will use my 300B tubes for another amplifier project.
A phono amplifier with RIAA correction and connection for moving coil cartridge.
A crossover unit for the subwoofers with tubes in the high pass section. The crossover project is running and is presented in the 'MT Audio Kits' section. Since this is a rather ambitious project it will take some time to finish it. This crossover also includes a high quality preamplifier to be used with the tube amplifier dedicated for driving the ESL-63 described below.
A tube amplifier dedicated for driving the Quad ESL-63 loudspeakers. This will use two 845 tubes per channel in the output and it drives the stator plates directly!
Maybe I will also design a cheap tube amplifier, just for fun.
A friend of mine is in the building phase of this cheap amp, it is a rather unusual EL84 design and I will include some information later.
Quad ESL-63 Element Refurbishing
I have bought some damaged ESL-63 panels and together with my associate Gunilla and friend Martin, I am going to try to refurbish these. We are going to build a stretching jig and try to find a working coating procedure (the difficult part). If we succeed the intention is to offer this service to those who are interested, and the price must be reasonable. I think those who are in this business now charge too much. We are not interested in total Quad ESL-63 service because of the freight difficulties. This project is described on the page 'Quad ESL Repair' in the 'Quad ESL' section.
Printed Circuit Boards
I have deigned some PCB's meant to be used as building parts in DIY tube amplifiers. I have no need for them at the moment, which means that these are on the waiting list too. Maybe some other PCBs will appear later.
Quad ESL Tweak Page
Done! I am going to describe how I altered the Gradient SW-63 filter characteristics. I will also modify the input on the filter, the input impedance is only 22 kOhm which is a bit low for my tube pre-amplifier. Now I am running the ESL-63/SW-63 combination together with my own crossover XO-2001 (described in the 'MT Audio Kits' section) and it sounds wonderful.
Done! I shall describe the record player tweaks I have made, including the oil damped suspension, which is very interesting (at least I think so). When I find new interesting tweaks, these will be added.
A page dedicated to the Audio Note DAC Kit 1.1 has been added and this will be updated with new information and I also plan a new PCB for the output section with transformer in and transformer out.
I will probably add a room correction tweak page, and an anti-vibration tweak page.
I am very happy with my speakers, so loudspeaker construction has low priority at the moment, but I will discuss some ideas I have around speaker construction. I have a couple of ideas about dipole subwoofers, one of them an electrostatic subwoofer! In the mean time, take a look at Geert Meddens dipole subwoofer project. The link can be found among the visitors on the 'Other HiFi' links page. Since I wrote this the page 'DIY Dipole SW' has been added to the 'MT Audio Kits' section, this describes a Gradient SW-63 clone.
I hope to find the time necessary to add some more stuff on this page soon.
The links shall be updated whenever I find new interesting links, this happens of course randomly.
When I have finished the 'Quadimodo' amplifier, I will take some pictures of it. One of the reasons for the delay is that I want it to be good looking, and that Spire Audio Enclosures does not exist any longer. When these pictures are added I will also add some pictures of the rest of my system.
Other Pages Under Construction
Here are some topics that I am considering for new pages:
Anti-vibration information with some theoretical background.
Acoustic treatment with building instructions and theory.
ESL theoretical page.
A couple of more opinion pages
New topics may also pop up without warning
I shall publish these as soon as I can find the time to compile them.
This site uses frames, but if you have found this page via a search engine and do not see a frame on the left side of this page, you can use the home button to get to the main frame of the MT Audio Design site.