Rectifier Tubes Hum?

[Ribboz]

oh maybe I said it wrong. The sound is after shut down.
I just said all that about standby so you know I'm shutting it down properly :D

[Dmoney]

after shutdown I hear nothing through speakers,
But i do hear the valves tinkle and such for a while. It's probably just the cooling on the mechanical parts. stuff contracting as it gets cooler. 

[Ribboz]

after shutdown I hear nothing through speakers,
But i do hear the valves tinkle and such for a while. It's probably just the cooling on the mechanical parts. stuff contracting as it gets cooler. 

That would make sense. :) Alrighty, I just wanted to make sure nothing was wrong :D

[jpfamps]

the weber copper caps are meant to emulate the recto valves they replace.
I'm thinking of getting a GZ34 replacement to use as a "spare" GZ34 since the amp I built uses a GZ34 and has no other rectifier.

They also do a straight diode replacement. The GZ34 emulator is meant to replicate the sag etc... I'm not sure how true it is.

If that is the case, you'd have switchable diode rectifiers with one setup emulating valve sag. in theory.

My amp that I built uses a GZ34. It doesn't feel saggy at all.

As HTH said you don't get much sag with a GZ34. In fact unless you are using a transformer that is massively over speced you will probably get at least as much sag from the mains transformer as a GZ34.

Regarding the copper caps, having taken one apart (!!) they simply have solid state diodes in them with cement box power resistors to increase the impedance of the supply so that the B+ drops under load a la valve rectifier. The also have a varistor in them to limit in rush current.

Personally I avoid using valve rectifiers as they are more expensive than solid state rectifiers, less reliable (and it would seem to me that modern valve rectifiers aren't as robust as old ones), and the sonic sag effect can cheaply be replicated using a power resistor in the HT.





 

[HTH AMPS]

I will note that I've had the same Weber Copper Caps for over ten years now, so they're robust and do work as advertised.  In that time you'd likely go through four or more GZ34s (judging by current production standards).  I started using the Weber CC as the GZ34s in my Selmers kept dying halfway through a set and I wasn't prepared to spend £50.00 or more on a NOS one (pricing at the time), especially when its not really a 'tone' thing like NOS preamp and output stage valves (which ARE worth the extra cash imo, ymmv).