• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

AC Heater for better Sound quality? Waste of time or worth a try

Jump to Latest
#141
Rod Coleman said:
Hi Rich

The original diodes you have were on a board marked 300B - and I think that's why they are under-rated. The types I use will give much lower drop ar high current (the only place it matters!).

With PSUD2, the built-in type 1N5828 comes close, use that for your estimates; 1N5822 is nearer to the 300B version

PSUD2 PT voltage is the unloaded voltage - easy to measure
Click to expand...
The board was not fitted by me so that may be the case, or it could have been the board that were used and the diodes selected for the circuit.

Thanks - I have remodelled with the 1N5828 diodes and used the low drop model I can find on the drop down.
Now things look nearer to what I measured on the original, however it seems like I don't really have any headroom - or even enough?

Thoughts?
 

Attachments

  • Screenshot 2022-10-20 at 13.20.01.png
    Screenshot 2022-10-20 at 13.20.01.png
    833.9 KB · Views: 53
#142
tonescout said:
The board was not fitted by me so that may be the case, or it could have been the board that were used and the diodes selected for the circuit.

Thanks - I have remodelled with the 1N5828 diodes and used the low drop model I can find on the drop down.
Now things look nearer to what I measured on the original, however it seems like I don't really have any headroom - or even enough?

Thoughts?
Click to expand...
sorry wrong screen shot see here
 

Attachments

  • Screenshot 2022-10-20 at 13.28.13.png
    Screenshot 2022-10-20 at 13.28.13.png
    757.3 KB · Views: 85
#143
I may have misunderstood your message Rod, do you mean the diodes you sent are represented by 1N5828 and the existing diodes in the board marked 300B are 1N5822, if so I may still skinny my way in!
 

Attachments

  • Screenshot 2022-10-20 at 14.06.23.png
    Screenshot 2022-10-20 at 14.06.23.png
    380.6 KB · Views: 41
#144
Can't be sure based on that, but the only accurate way to proceed is to build it to the plan.

Remember, the output does not have to be 10.0 on this valve - adjust it down... The current will also go down; the rectifier output will go up, (and lifetime goes up)
 
You must log in or register to reply here.
Top Bottom