You should check this thread:
http://www.diyaudio.com/forums/pass...ifier-distortion-measurement.html#post2753978
The attenuator here works well for me and has essentially zero issues with ground loops.
Do you mean my SemiSouth R100 powered Aleph J? It's slowly cooking, I plan on having it done by Burning Amp, hopefully sooner. I recently acquired an oscilloscope, and what little DIY time I have lately is going towards learning how to use it in a constructive way.
Owing to the disappearance of P-Channel JFETs
and tweaked by Mr. Marsh's headphone amplifier with 2N5457/2N5460 front end I worked up this board -- it will accept a pair of each of the JFETs Dick used -- they have a pinout which is DSG -- or it will accept a pair of JFETs with the DGS pinout OR SOT23 DGS devices. My preference is to have some local filter and bypass, the ability to limit RF on the front end, and an output Zobel.
and tweaked by Mr. Marsh's headphone amplifier with 2N5457/2N5460 front end I worked up this board -- it will accept a pair of each of the JFETs Dick used -- they have a pinout which is DSG -- or it will accept a pair of JFETs with the DGS pinout OR SOT23 DGS devices. My preference is to have some local filter and bypass, the ability to limit RF on the front end, and an output Zobel.
An externally hosted image should be here but it was not working when we last tested it.
I should have said DSG and DGS type parts. Some of these have Idss of 4 to 6 mA and gm of several thousand milli-Siemens -- not as good as the K174/J74 but certainly useable. You can also use the NXP N-Channel BF862 which is easily available.
Weak Bass
I did a 1-to-1 comparison of MY F5 with an Sansui vintage amp as well as the MyRef_C chipamp, while the highs and mids are better, i find that MY IMPLEMENTATION of the F5 lacks in bass.
I know that i cheaped out on the PSU caps (unknown Chinese brand 80000uF/rail) which will have a direct impact.
The question that i have is---
Is it possible that my speakers needs a higher wattage amplifier (91dB 8 ohms) for thre bass to be filling ? Right now I can go upto 60% of the volume control before the whole household bears down on me to turn down the volume.
I did a 1-to-1 comparison of MY F5 with an Sansui vintage amp as well as the MyRef_C chipamp, while the highs and mids are better, i find that MY IMPLEMENTATION of the F5 lacks in bass.
I know that i cheaped out on the PSU caps (unknown Chinese brand 80000uF/rail) which will have a direct impact.
The question that i have is---
Is it possible that my speakers needs a higher wattage amplifier (91dB 8 ohms) for thre bass to be filling ? Right now I can go upto 60% of the volume control before the whole household bears down on me to turn down the volume.
not with the F5, I guess 😀
hmm, your input cap might be too small
or if you have output cap on your preamp
alternatively you could try a bigger paralel resistor at input of F5
Yes with my F5 (60% is plenty loud) 🙂. As i said would higher wattage translate to better bass while keeping the volume level same (that is not playing louder)
The Preamp is a B1 with LDR volume control.
I have 8*10000uF (50V) per channel (chinese no-name).
The Preamp is a B1 with LDR volume control.
I have 8*10000uF (50V) per channel (chinese no-name).
Be mindful that the gain of the F5 is only 15dB, and most power amps are 26dB. Even a few tenths of a dB will influence your listening impressions.
True the Mauro Pensa myref has 31dB, not sure about the Sansui Au-719...
My F5 has 20 odd DB (200ohm feedback resistors)
Guess its time to change caps ... Panasonic TS-HA & hope for the best
My F5 has 20 odd DB (200ohm feedback resistors)
Guess its time to change caps ... Panasonic TS-HA & hope for the best
tinitus,
In phase with the other speaker? or with the tweeter on same speaker?
I would presume you mean the other speaker.
Jackinnj,
Thanks again for that tip on the Thors. Made a HUGE difference for the better.
Ron
In phase with the other speaker? or with the tweeter on same speaker?
I would presume you mean the other speaker.
Jackinnj,
Thanks again for that tip on the Thors. Made a HUGE difference for the better.
Ron
the PSU caps has a huge influence on the sound. i use mallory, and there is no lack in bass. or anything else for that matter😀😀
Thanks put in an order for Panasonic ts-ha 10000uF 50V from twisted pear audio ($15 for 4)...its $4.5 each @ digikey