5Y3GT data sheet?

[bluefoxicy]

I should like to suggest that these curves show that an amp without smoothing caps would sound boggin.

Fenders liked to use 8uF power filter caps with 25uF cathode cap on the power tube, i.e. Fender Champ. In the event of strong signal, the power supply sags and the B+ of say 300V becomes a B+ of 50V or so for a small period of time, and now the amp compresses and dirties the signal a bit.

I've built a great sounding amp that used a strong 200uF filter cap set, and then 22uF and 22uF further down the power supply. It also used a 1000uF power tube cathode cap on a 6V6. This sounds nothing like a Fender though, which also does sound nice using 8uF power supply filtering and 25uF on the power tube cathode with a slow-responding rectifier causing sag.

[Wakculloch]

Appologies for being slightly cryptic, but the graphs show an increase of voltage from zero, into a purely resistive load, (as far as i can tell as the web site is vague) and is not representative of anything in a real amp. I presume they are trying to illustrate the 'sag effect'.
In my opinion they are making too much of it.
The very term 'sag' implies a long lasting and drastic drop in HT voltage.

[bluefoxicy]

Appologies for being slightly cryptic, but the graphs show an increase of voltage from zero, into a purely resistive load, (as far as i can tell as the web site is vague) and is not representative of anything in a real amp. I presume they are trying to illustrate the 'sag effect'.
In my opinion they are making too much of it.
The very term 'sag' implies a long lasting and drastic drop in HT voltage.

You're right, amps don't quite act purely resistive

Beyond that I don't know. The different rectifiers clearly have different physical and behavioral characteristics; I can only guess how this affects the amp by reading others' comments and experimenting on my own.

[Enzo]

I think it is also worth mentioning that the amp is drawing its current from the filter caps really - not depending upon the rectifier alone. The rectifiers keep the caps charged. SO when some large transient signal happens the amount of filtration is a large factor in response.

As far as I can tell, those respopnse curves tell you haw long it takes the filter cap to charge when the standby switch is first turned on. If that takes half a second or one tenth of a second, I don't care either way