[icefox]

Curious if there is any user here has any experience to share on rolling the rectifier tube in the seperated Power SUpply of the Apollo pre-amp?

[tanchiro58]

U50 is an excellent choice but rare to find one.

[zoltm2001]

Hi tanchario,

Thx for your reply. I understand that you have been a happy user for a quite heavily mod Apollo. Your suggestion carries a lot of weight .

BTW, I have gone down the path of toying with 80 rectifier tube with the 4pin to Octal adapter. I found the rolling of rectifier tube yields more change that the 6N1P.

[tanchiro58]

Hi tanchario,

Thx for your reply. I understand that you have been a happy user for a quite heavily mod Apollo. Your suggestion carries a lot of weight .

BTW, I have gone down the path of toying with 80 rectifier tube with the 4pin to Octal adapter. I found the rolling of rectifier tube yields more change that the 6N1P.

I sold my modded Apollo to a new owner and he also agreed with me that using U50 rectifier tube and PC189 to replace stock 6N1P the sound has more resolution, sweet midrange and dynamic low bass than before.

Cheers,
Tan 

[zoltm2001]

Is the PC189 a pin-to-pin replacement to 6n1p? What brand of u50 and PC189 that you found most match? In my current setup, I found the low-end of is a bit lean, I would like fuller bottom as I am using a pair of Maggie 3.5, high tends to more prominent at time.

[tanchiro58]

Is the PC189 a pin-to-pin replacement to 6n1p? What brand of u50 and PC189 that you found most match? In my current setup, I found the low-end of is a bit lean, I would like fuller bottom as I am using a pair of Maggie 3.5, high tends to more prominent at time.

As you know I did completely modify my Apollo by replacing all stock caps and resistors with high quality caps like Rubycon for PS, BGs and Mundorf for input tubes and resistors like Riken and Tants.

For PS I use Osram U50 and Siemens PC189 for tube stage. They matched pretty well with high quality components I mentioned above. I got plenty of efficient mid-and tight low bass.

Thanks,
Tan

[zoltm2001]

Hey tan,

One key question that I would appreciate your guidance, is PCC189 a pin-to-pin replacement to 6N1P? Do I need to add some resistor here and there?

[tanchiro58]

Hey tan,

One key question that I would appreciate your guidance, is PCC189 a pin-to-pin replacement to 6N1P? Do I need to add some resistor here and there?

The answer is no pin to pin to replace 6n1p directly with pc189 because you need to change some resistors under tube sockets and B+ voltage.

Here is the thread about my modification with Nick's suggestions:

http://www.audiocircle.com/index.php?topic=48674.0

Good luck,
Tan