[icefox]

I know it's a bit crazy but I want to make sure it is possible before I try.

Nicolas, would you please let me know if it's possible to use 274A rectifier tube (with a 4pin to 8 pin adapter) in the power supply of the Apollo, replacing the 5Y3?

[PromitheusAudio]

Should not be a problem
the apollo power supply uses a choke input which allows many times of rectifer to be used.
Like you said if you get the 4pin to 8pin should not be a problem then

[zoltm2001]

I did tried to roll a WE 274A, 197x vintage to the Apollo. It was a jaw-dropping experience. The performance jump 3 classes, able to rival the MFA Silver Passive Pre.

Mine is an EI core Apollo. I wonder if a C-core TVC-upgraded Apollo would provide further jump.

I am so surprised how sensitive the Apollo is in terms of rectifier rolling.

[PTC]

I have a TVC with the active tube linestage and the rectifier tube in the power supply has 5 pins??? It is several years old have things changed???Peace,Paul

[zoltm2001]

I have a TVC with the active tube linestage and the rectifier tube in the power supply has 5 pins??? It is several years old have things changed???Peace,Paul

Paul,
 
I believe nothing has changed. The power supply should typically be an octal base. I use a converter to play with 4 pin rectifier tube.

If you need that PM me.

Thx

[PTC]

Anyone know where I can get one of these converters???Peace,Paul

[redabook]

Have a look at EBAY item number 320483364271. Might be what you are looking for.

[PTC]

That looks like it Thanks,Paul