And have wires ready .....

In addition to the C3G, I am also adding some of other signal tubes the RCA/ NU 6F8G, RCA/ Sylvania 5692 for test drive listening on my WA5  

While I am working with the WA5 external AC power switch，got the C3G tubes delivered and test drive run, the tubes in sliver grey pins and look brand new in original box.

Have all parts ready, look nice, it is a tight arrangement with this compact box                         

I ended up getting one Furutech AC IEC Inlet, one Furutech FPX CU and one Synergistic Research TESLA Plex SE duplex receptacle                    

Got my Alum case delivered today, not in top quality, but nice enough              

A refined diagram for the external power switch, added SW3 to further limit the startup current which could be usable for my WA22/ WA6 SE and other lower power Woo amps (ON=WA5, OFF=WA22/ WA6 SE). The AC OUT green indicator now also only shines when the Soft-Start Resistor was bypassed by the...

  Note that the “hum” appeared only when WA5 connected to AC power and power OFF, it just gone after power up WA5. That is not a big problem,  in fact no impact on sonic effect or quality during listening but just annoying.   In my previous experiment, disconnected the Neutral wire from AC...

Planned to have the alum case pairing with a Furutech IEC and two US type sockets .....        

And finally managed to get an alum case in black at the right size with sockets for a IEC inlet and 4 US power outlet. I am going to add the soft-start resistor,  SW1 & SW2 and power indicators inside this lovely case. It seems smart and consistent with my WA5 in black    

For better sonic effect, the circuit for full AC power connections related to SW1 will use special SCC wire.     Also for safety, replaced the Soft-Start resistor with two 1K Ohm, 50W alum shell resistors to be connected in parallel (effective as a single 500 Ohm resistor).  

Had the parts ready for DIY the external AC power switch for my WA5, it would take some weeks work,  I could not find an alum case in black colour, anyway, hope it would not look odd when putting aside WA5 PSU.                    

  That makes sense in my case, as I like playing the tube rolling games (I would change tubes for some every 3-4 listening sessions) with substantial power-on/ power-off cycles, and in fact, during the past 3 months since open box my WA5, I already had my WA5 run over 100 cycles (yes, I almost...

With the result from previous experiments for Soft-Start Resistor and the scenario of AC “hum” noise experienced while WA5 power off, I worked out a diagram and decided to DIY an external power switch as shown for my WA5 to life safe tubes and get rid of the “hum”.   It is simply composed of a...

More about the AC power supply for WA5, I experienced noticeable “hum” noise when the WA5 connected to AC power, but after power up, it just gone and in fact no impact on sonic effect or quality during listening. Disconnecting everything from signal inputs, changing tubes and headphone could not...

Also confirmed that my WA5 V2 version has a refined design for rectifier connection, it also used the center tap of the 5V-0-5V, the rectifiers on WA5 may consider working independently in a parallel configuration.         Also check the difference in rectifiers wiring in pics from...

What these videos tell? In this case, the stable condition 0.4A = 0.22A for tubes + 0.18A for other components before the B+ in place. The tubes on my WA5 may be suffering an initial "cold" current over 0.7A (actually higher, maybe over 1A), but they only need about 0.22A in total under normal...

Confirmed that adding soft-start resistor is feasible, I end up making it into a resistor in 450 ohm (= 9 x 50 ohm, 20W in serial).        And check my experimenting videos without/ with the Soft-Starter Resistor. AC current measured during my WA5 power up in initial 40 seconds. Note...

I am adding a resistor and a power switch in the AC power circuit to simulate a power soft-start for WA5 and managed to experimenting a best delay interval before bypass the resistor, it seems working (a 3-4 seconds delay before supplying WA5 with full power is feasible) that limited the startup...

WA5 Soft-Start & External Power Switch   A simple DIY adaptor to facilitate learning the AC electrical behaviour of my WA5, four AC current were measured with 220V AC supply at initial power up, just before the completion of standby countdown, just after the standby and WA5 run stable some...

Have my third pairs WE300B Tube Register, vintage tubes in their 1950s, tested at NOS level, D getter with code USN-CW.            

Got unboxing and Tube Register another WE300B pairs in their 1960s with double D getter, both tested at NOS level. Just have a trial drive for an initial impression, I would record the difference with the 1950s pairs in the Impression Register after I got into serious listening session.    ...

Look like that is the case, though not necessarily spending more big bucks, after the first month trial run, I am adding back one by one what I had done on my WA22 & WA6 SE, to have the stock WA5 turned into an "optimized" configuration. There are still work at the AC power supply for further...

Have some interesting DIY work on my WA5 today ...... LOL   And just completed a follow up session ...... Yeap! What a difference in sonic effect (clarity, resolution of tone, dynamic response), feel like adding another upgrade! SWEET!