Tube Regulator

[fdegrove]

Hi,

Do U had experience that use non- CT winding transformer that mix with diode(IN4007) & tube(5U4) to rectifiy in 300B amp.

If it is what I think it is than the diodes ( the silicon ones) would still benefit from snubbers.
To me, the main beauty is that it provides a slowstart as well.

Hi James,

Are you sure this is what it is called? It's not a Graetz bridge, but a Goertz bridge?

Cheers,

[valveluver]

If the noise occurs at or about 100Khz, the filter choke will take it down more so than the power supply ripple. The inductive reactance, of a 10 henry choke @ 100Khz is +j. 6,200,000. If a 100 Khz component appears on a DC supply, it is poorly designed.

[fdegrove]

Hi,

RTFM, or in other words pls. read what's said in the link I provided.

No choke is going to kill it off effectively, this is a MHz thang.

Snubb it and see,

[valveluver]

The higher up in frequency the spurious component is, the easier it is to filter. If the component is in the Mhz range a mica bypass capacitor would take it out. A .01MFD capacitor is a -j. 13

[fdegrove]

Hi,

If the component is in the Mhz range a mica bypass capacitor would take it out. A .01MFD capacitor is a -j. 13

And no, that won't be all that effective...

Once again read the info given by Fred Dieckman, digest it and just like me, you'll realise that audio is a big jungle,

A scope is a really handy tool, not a luxury.

Ciao,

[valveluver]

I have one. A 100Mhz dual trace. I have never seen what you are talking about.

There is no other way to look at ripple components.

I have a complete audio test facility

[siu sin man tho]

hi frank,

is the diodes ( the silicon ones) would provides a slowstart as well as the 5U4G.
The tubes need time to warm up the filament. Is still faster than the diode??

thanks

Thomas

[James D.]

Hi Frank,

Frank said

Are you sure this is what it is called? It's not a Graetz bridge, but a Goertz bridge?

You are 100% right! Sorry. I'm dyslexic - so this sort of mis-spelling is very common with me

You should see my attempts at learn a new language

I agree with the diodes still benefiting from snubbers in a Graetz bridge - that has been my experience with 1N4007.

Valveluver

Actually a 100Mhz scope won't capture most of this RF noise by just hooking it accross the psu rails... The noise is burst in nature and (relative to the B+) low level. It can be done using a 'B delayed' set up but it is still very difficult to sync the B delayed with the reverse recovery spike.

But then if you have 'a complete audio test facility' you have a 1GHz bandwidth spectrum analyser with 80dB range and this will show this noise very very clearly - you can then see how ineffective your suggestions at filtering these components out will be.... ( I wish they did work!!!)

ciao

James

[fdegrove]

Hi,

To give you some idea of the (lack of) effectiveness of a snubber here's a screenshot of a scope.
This is the nasty **** going on next to the snubber capacitor. The vertical voltage scale is 50 mV/div. Notice the sharp spikes of HF, almost 150 mVpk.

The diodes are your everyday IN4007s, byspassed with a 1nF cap and a 150R in series.

Cheers,

[fdegrove]

Hi,

To give you some idea about the smoothness of the Schottky diodes:

Cheers,