I made a preamp actually a 26 preamp.
However when i hooked it up it buzzes not hum(50hz or 100hz). How do i get
rid of this buzzing. ITs rather annoying. Sound is good though.
Preamp is like this.
Separate power supply feeding 300V and 0 V and battery supplying 6.3 volts and 0 volts. THis feeds into the 26 preamp.
THe preamp has a ccs and another ccs feeding gas diodes. Like gary pimm stuff
Grounding is done at incoming rca input single point.
The output is a mufollower feeding a C-core preampoutput trans. This is grounded to rca input too.
I have not twisted the fillament wires yet and shield it as well as the B+ wires. WOuld this help?
ANy suggestion to how remove the buzzes?
Cheers
Nicholas
However when i hooked it up it buzzes not hum(50hz or 100hz). How do i get
rid of this buzzing. ITs rather annoying. Sound is good though.
Preamp is like this.
Separate power supply feeding 300V and 0 V and battery supplying 6.3 volts and 0 volts. THis feeds into the 26 preamp.
THe preamp has a ccs and another ccs feeding gas diodes. Like gary pimm stuff
Grounding is done at incoming rca input single point.
The output is a mufollower feeding a C-core preampoutput trans. This is grounded to rca input too.
I have not twisted the fillament wires yet and shield it as well as the B+ wires. WOuld this help?
ANy suggestion to how remove the buzzes?
Cheers
Nicholas
Quote:
Just to remind you that 26 requires 1.5V not 6.3V
Too much heater and you hear a ting and the bas***d is gone.
I'm sure he knows it😀 Its just a typo
Just to remind you that 26 requires 1.5V not 6.3V
Too much heater and you hear a ting and the bas***d is gone.
I'm sure he knows it😀 Its just a typo
Check out my thread. There is some good information there even if no one bothered to address the original question. Kevin was good enough to supply information on his #26 tube line stage which has prompted me to bid on a set of used high dollar UTC HA 133 transformers that I will never get.
Check out this thread.....Aikido using a #26 tube?
Check out this thread.....Aikido using a #26 tube?
It was used with a ccs.
I grounded one end of the fillament. That help to lower the buzz. But the buzz come and goes and so is the intensity. From time to time the buzz goes tolerable to loud.
Thanks
I grounded one end of the fillament. That help to lower the buzz. But the buzz come and goes and so is the intensity. From time to time the buzz goes tolerable to loud.
Thanks
Do you have grid stopper resistors on the 26? (1K works fine right at the grid pin) The erratic buzzing noises you seem to be describing are often a symptom of oscillation. Also check the CCS's to make sure that they are not oscillating.
I have used the 26 in a number of designs and it is quite prone to pick up external fields due to the large surface area of the plate and the relatively high rp.. I shield mine with shields I made out of fairly thin brass sheet formed into a circle and soldered together, this slides onto the envelope of the tube and grounds to the chassis.
I have used the 26 in a number of designs and it is quite prone to pick up external fields due to the large surface area of the plate and the relatively high rp.. I shield mine with shields I made out of fairly thin brass sheet formed into a circle and soldered together, this slides onto the envelope of the tube and grounds to the chassis.
I have not twisted the fillament wires yet and shield it as well as the B+ wires. WOuld this help?>
YES - you must do that. I found that out with my 26 preamp. Big difference.
YES - you must do that. I found that out with my 26 preamp. Big difference.
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