Tube Regulator

[valveluver]

I will admit that vacuum rectifiers may sound different. I see them as introducing intermodulation distortion due to poor regulation. If you like the distortion, it is a good thing.


The information, on the high speed diodes just confirms my theory. The switching artifacts are above 120 hz and thus removed by the filter components.

As far as seeing it on a scope the ripple, on my 400 volt supply, is less than 1 volt. The regulation holds within 2 percent.

[analog_sa]

Valveluver

SS rectifiers exhibit wide band switching noise which on it's own is very likely inaudible but mixed with you favourite music in different stages of an amp will contribute to 'electronic glare'. Your best bet is to compare sonics of SS and vacuum rectifiers and decide for yourself. If it sounds the same consider yourself lucky - one less worry in your audio designs and less chances of developing fully-blown audio paranoia Make this decision based on your own ears, not Frank's or Joel's.
This type of noise is certainly measurable but not easily visible on a scope - we're talking narrow spikes with lots of hi-freq content but low repetition rate. And of course this has no resemblance to innocent 50/60Hz hum which even the less gifted seem to be able to hear

cheers

peter

[James D.]

There is a lot of stuff in the link Frank that references articles on the problems caused by the reverse switch off spike that diodes exhibit and the hf noise that this causes in the psu....

What does this sound like and how does it affect the audio?

Typically this is wideband noise that might extend down into the middle of the audio band but most of the energy is at 100KHz up into the multiple MHz region. These high frequencies are typically not attenuated by the psu components, for instance psu chokes parasitic capacitance shorts the choke out at these frequencies. They are then injected into the audio circuits where they modulate / mix with each other and the audio signal. They are normally relatively low level so this acts to 'grunge up' (technical term ) the sound in valve amps without feedback and in valve or ss amps with trans-stage feedback they really coursen the sound and extend the higher order distortion components leading to rapid listening fatigue...

hope this helps

ciao

James

[analog_sa]

The filter components (chokes and caps) generally don't do much to very sharp noise spikes. Nor do regulators unless they still work in high MHz region. If what you non-believers say is true a vac rectifier can easily be emulated by SS and a series resistor but practice shows this to sound terrible.
Valve rectifiers are clearly audible even after extensive regulation. Once i built a phono-pre with a transformer supplying way too high voltage. It burnt the excess in multiple RC/LC filters and used a ridiculously large main filter cap - 3300uF. This cap was being charged through nearly 100kohm resistor and still the character of the rectifier was clearly audible.

cheers

[Jay]

Originally posted by analog_sa
And of course this has no resemblance to innocent 50/60Hz hum which even the less gifted seem to be able to hear

But 100/120Hz is not innocent. I saw him did it!

[siu sin man tho]

hi,

very sorry for the non-sense questions.

can anybody told me what is the meaning of

SS rectifiers.



thanks

Thomas

[James D.]

Hi Thomas,

ss rectifiers are solid state or semiconductor diodes such as 1N4007 etc.

ciao

James

[siu sin man tho]

thanks james.

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


In hong kong somebody say that this can low the internal resistance.
Is it right??

thanks

thomas

[James D.]

Hi Thomas,

I assume you are talking about the Goertz Bridge? A Hybrid bridge rectifier configuration. There is quite a bit on the web about it a google search with find a few references.

I am building one at present with BYV26Es and an 83 to power my 6B4G pp amp. I ahve a cheap source of good quality psu transformers but the ht windings do not have a centre tap so I'm using ss BR at present and want to see if I can hear the difference with an 83 in the circuit... more later I'm sure.

I have just tried it with a BYV26E bridge and that sounds very good - much better than 1N4007 with snubbers and, surprisingly, better than the 5U4 psu that feeds my sons 2A3 PSE amp.

So I say try it - you may well like it...

One observation - that is often made and just as often overlooked! All these implementations are system dependent.

I'm sure with different transformers etc. the 5U4 can sound better than the BYV26Es... And I know in some circuits that the 1N4007 with snubbers can sound as good as a GZ34 - not evry circuit but certainly in some...

ciao

Jmaes

[siu sin man tho]

thanks James,

I had another experience is compare one EZ80 parallel with one 5U4 in my power amp.

it look like to low down the power supply resistant.
& change the EX80 to 417a can change to sound quality, Do U try it already.

thanks

Thomas