DIY Audio Projects Forum
http://diyaudioprojects.com/Forum/

unbalanced dc connected inverter
http://diyaudioprojects.com/Forum/viewtopic.php?f=9&t=6541
Page 1 of 1

Author:  Danielk [ 29 May 2019, 11:19 ]
Post subject:  unbalanced dc connected inverter

Hi,
I am building a williamson amplifier with a dc connected inverter. Now when i measure the sine waves on the plate and on the cathode of the inverter tube, the plate has a much higher amplitude then the cathode. And this is off course amplified again through the rest of the amp. I built it exactly like the w5m heathkit, with a 22k plate and a 22k cathode resistor. I have no idea why this is happening. Please, any help is appreciated.

Daniel.

Author:  Suncalc [ 29 May 2019, 14:50 ]
Post subject:  Re: unbalanced dc connected inverter

I'm assuming that you're talking about a concertina phase splitter. First a question: How is it biased (fixed or self)? Second, how is it loaded at the outputs. It's important to remember that the concertina has wildly different output impedances at the two ports. Loading can have a significant effect on the performance. Could you post a schematic?

Author:  ILoveHiFi [ 29 May 2019, 16:55 ]
Post subject:  Re: unbalanced dc connected inverter

I had one R&D test in transitor amps where the transitor concertina phase splitter did not work. I went to a Diffrential op amp and it worked perfectly as wanted.
A very werid phenomona that I'll probally never understand

Author:  Danielk [ 30 May 2019, 01:05 ]
Post subject:  Re: unbalanced dc connected inverter

willamson schematic: http://www.r-type.org/articles/art107e.jpg
w5m schematic: https://www.tremolo.pl/Firmowe/HEATHKIT/W5M.GIF
The power section is from the st70 with kt88s.

i found out what was the problem. the preamp and phase splitter are an exact copy of the williamson amplifier or the w5m. I found that the voltage to the splitter was much to low. The plate of the splitter just had no room. I replaced the r6 which is 22k with a 2.7k resisitor and now the amplitudes are exactly the same. and it sounds very good. :P

Author:  ILoveHiFi [ 30 May 2019, 04:25 ]
Post subject:  Re: unbalanced dc connected inverter

:up:

Page 1 of 1 All times are UTC - 6 hours [ DST ]
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/