VBITNGC building & comment

[loek]

I found that my relay voltage was a little high: 8,5V for a 5V type so i added a LED in series with the relais.
Nice red if the circuit is on...

[CarlosT]

Do LEDs introduce noise?

[Franz G]

Do LEDs introduce noise?

In this situation, driven by the filament/relay voltage: No!

Franz

[wim]

Originally posted by loek
I found that my relay voltage was a little high: 8,5V for a 5V type so i added a LED in series with the relais.
Nice red if the circuit is on...

Good point Loek,

I shall measure my relais voltage too, and adjust it
if necessary.

What i found in this design and also in the previous design (from Digi and Franz), is that turning the pot that increase or decrease the delaytime of the relais is not working properly; whatever the position of the pot is, the time stays the same (about 25 seconds). For me its perfect, but why does't work this pot? What is your experience Loek, or someone else?

I have the VBITNGC working, and the first experiences are good. When time comes i will connect it to my regular audio system. I will report the results. I have the earlyer system (Digi and Franz) playing for about 9 months, ans i like the sound!

Succes building and playing to all of you!

[loek]

Hi Wim, i did not have a pot that size yet so i used a 47k resistor and with C17=100uF the delay is 30 seconds. so i keep it this way.
I can short the 47 k and count...
edit:
Did it and then it is 25 seconds, so it works as it would be...
Loek

[wim]

Thanks for your info Loek, I leave it also as it is, good to me.

[Sir_John]

Originally posted by loek
Hi Wim, indeed unbelievable, but i know a very nice supplier in the neighbourhood.
I connected the transformer for the heatingsupply, C20 is 1uF poly, R9 is 120 ohm and adjusted the output to 6,3 V.
It works! I placed the tube and inspected the voltage with a scope and found that the regulator is oscillating.
So i removed the 1uF and placed a 10uF elco: clean picture.
Display 100mV and 1uSec/div.
That are my findings.
Loek

This is very interesting. Have anyone else who finished this amp found this or something else? Actually, who has it really finished? Franz? Digi? GeWa? If you guys finished it, post some jpegs here!

[wim]

There is another strange thing i found with this design (the first desing from Franz and Digi and the second design too): With no source connected there is a loud brrrrrrrr in the speakers. When i connect a source (CD-player) there is no brrrrrrr. I can live with it, but is is strange.

[DJ Exprice]

Anyone figured out where the schematic file is?


(I don't mean to sound annoying...but I really want to make one of these because I think that they will sound amazing!)

[loek]

Not so difficult if you check the last posts: post 420.
Wim, normally there has to be a resistor from grid to ground.
If you leave the input open there is no "leaking resistor " for the grid.
You can connect a resistor (1Meg) parr. to the inputconnector.
Maybe this will help.
good luck, Loek