top of page
Vacuum Tube Audio Gear
Forum Posts
wb2tkr
Feb 10, 2022
In Questions & Answers
Hi All: I am looking for a recommendation on schematic drawing software for use on a Mac. It would be great if it is very easy to learn and use as at 78 my ability to learn and store information is not what it once was. If Mac software is not recommended, I can use Windows based software. Thanks in advance for the help - Joe in Virginia
0
2
94
wb2tkr
Feb 04, 2022
In Show and Tell
I received my A50 2 days ago and started playing with it. Here are my initial impressions and progressive improvements (I have not started on the Skunkie modifications yet). The initial sound of the amplifier was very "thin" and not at all dynamic. I replaced the rectifier with a 5AR4 and heard a significant improvement overall. I then switched out the 6SN7s for USA Sylvania and the 300B for a Sophia mesh plate. Each of these swaps resulted in a much cleaner, crisper, dynamic and fuller sound. Overall I would say it made a 300% improvement to the sound to my ears at least. I did no THD testing yet as I was more interested in the sound and did not want to be swayed by numbers. I will do the Skunkie recommended mods one at a time and listen to the results. Once I am satisfied with the amps I will run thru a full series of performance tests and publish the results on this forum. Prior to this, the other thing I will be looking at is converting the tube supply to a solid-state design. I know this will raise many eyebrows and I do not wish to get into an extensive debate about the virtues of one vs the other. I will share how I feel about the sonic difference. There are at least four highly regarded amplifiers, the McIntosh 240 and 275 as well as the Marantz Model 8B and 9, all use solid-state rectification. I have not read any suggestions regarding converting them to tube rectification. Joe in Virginia
1
28
388
wb2tkr
Jan 31, 2022
In Questions & Answers
Can anyone provide me with a link to download audio analyzer suite? I seem to be having difficulty finding it. Joe in Virginia
0
5
123
wb2tkr
Jan 29, 2022
In Introductions
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
0
2
36
wb2tkr
Jan 27, 2022
In Show and Tell
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
0
2
48
wb2tkr
More actions
bottom of page