Search found 11528 matches
- Mon Feb 18, 2019 8:54 am
- Forum: Everyones Projects
- Topic: remote hv power supply
- Replies: 3
- Views: 64
Re: remote hv power supply
I use the Lumburg ones in the Ref Phono.
- Sat Feb 16, 2019 12:07 pm
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
1) with a DC heated DHT using Andrews DC board, is there a benefit to using virtual cathode resistors When this question was asked, my answer was "as there is no disadvantage to doing so, and some theoretical justification, then may as well" Now there is a downside, that justification is removed. 2...
- Fri Feb 15, 2019 9:52 pm
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
And used Schottky diodes.
- Fri Feb 15, 2019 5:18 pm
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
Bet it wont be easy to "prove" given that you expect it willI would expect the bridge to impact the sound, but should be easy to prove

- Fri Feb 15, 2019 5:00 pm
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
No external power, so the led lights IF the difference between the voltages at the ends of the resistors differs by more than 3 diode drops plus the drop over the current limiting resistor. Interesting, but wouldn't that be directly in the music path ? Yep, thats it, throw a cap across it of you li...
- Fri Feb 15, 2019 3:39 pm
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
You could try a LED inside a bridge rectifier. ok quick bit of googling and ... Capture.PNG Is that something like what you had in mind ? No, literally a LED inside a bridge rectifier. Rectifier with ac terminal one to each resistor cathode, LED with dropper resistor between the bridge + and - term...
- Fri Feb 15, 2019 1:35 pm
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
You could try a LED inside a bridge rectifier.
- Fri Feb 15, 2019 11:49 am
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
Yes, you are trying to detect when the two currents are different, you have two equal resistors, one in each current with a common tail, if the currents are different, the voltage at the top of each resistor will be different.
- Fri Feb 15, 2019 10:11 am
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
In that case you may as well just compare the voltages on the top of the to sense resistors. What is unknown is will it trigger with a audio signal.
- Fri Feb 15, 2019 8:56 am
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
It would light the LED's when you turn the amp off.
- Thu Feb 14, 2019 5:00 pm
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
Well, you can connect to the cathode resistor without grounding anything which I think is what you are asking.
- Wed Feb 13, 2019 11:45 pm
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
These sort of isolated supplies can be great for providing a floating supply from a existing DC supply.
https://uk.rs-online.com/web/p/isolated ... s/3965174/
https://uk.rs-online.com/web/p/isolated ... s/3965174/
- Wed Feb 13, 2019 3:14 pm
- Forum: Everyones Projects
- Topic: Niobium - Valve pre for SS Power Amp
- Replies: 48
- Views: 3788
Re: Niobium - Valve pre for SS Power Amp
The electrostatic screen is to prevent capacitive coupling between the primary and secondary. Doesn't affect hum field.
Just try rotating one of the transformers and see if the hum changes.
Is it hum (50Hz) or does it have edges? (100Hz+charging)
Just try rotating one of the transformers and see if the hum changes.
Is it hum (50Hz) or does it have edges? (100Hz+charging)
- Wed Feb 13, 2019 3:11 pm
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
- Wed Feb 13, 2019 2:24 pm
- Forum: Everyones Projects
- Topic: Warning LED when valve stops conducting - a little SS help needed
- Replies: 120
- Views: 1191
Re: Warning LED when valve stops conducting - a little SS help needed
Transistors never fully turn off. I would consider the resistor on the same side as the LED.