I would like to join the others in thanking you for posting your very enjoyable YouTube videos. It was surprising for me to see that you came up with the same conclusion I did a number of years back questioning the need for a driver section in a single-ended tube amplifier if one will be using an active preamplifier. I too have been experimenting with this over the years and have made a few single-ended amplifiers without a driver stage. In most cases I did integrate a gain control for each channel on the amplifier to compensate for the difference in tube section gain found in most tubes. These controls are usual small screw-set potentiometers since the is no need for me to adjust them unless I notice a channel in-balance. I am currently working on a project to easily compare 6L6, EL34, El37 output tubes as well as 12XX7 preamp tube utilizing a modified Chinese single-ended stereo tube amplifier that will allow me to quickly switch between two tubes using the same mono input to hear in real time the various tube differences. It is also useful in selecting the lowest noise preamplifier tubes for use in either the phono or the first preamp stage. I think it could also help in selecting the best phase inverter tube. Thanks again to you Skunkie and all of the other Forum members. Joe in Virginia
Thanks!
It has taken a number of years to build my collection of Dumortier tube gear and even more to accumulate all of the DIY parts I have in my basement. Now, my challenge is to find homes for 80% plus of the stuff in my basement as I work towards simplifying my life and ensuring that I do not leave too much of a mess for my family to deal with when the time comes.
I purchased an A12 and was surprised how good it actually sounded right out of the box. I think someone at the company has been looking at your videos and has taken steps to improve the design for better performance. I am sure there are may thing I will be doing to further improve what is a real bargain for those interested in the hobby. I was so impressed with the looks and physical build quality that I just ordered an A50 before they start going up in prices.
Please feel free to contact me at any time should you feel I may be able to assist you in any was as you continue with your projects and great videos.
Joe in Woodbridge, VA
www.dumortier-us.com.
PS - Should anyone be interested, there is a great electronics training course on my website produced by the U.S. NAVY under the tab "NEETS". It is free and very comprehensive.
That is some great looking gear!!!