Modifications to integrated tube amp: experiences?

Hello Knowledgeable Audiophiles,

I am seriously considering having my Onix SP3 modified.
(I don't know why people sell these amps. I love what it does.)
Does anyone have any experience with the modifiers out there (e.g. Parts Connexion, Hot Rod, or others)?
Who would you send your amp to?
I await your replies and thank you.
What I'm really looking for here is recommendations and experience with so I can decide who best to do the modifications.
I would recommend Kyle does great work..I can't be happier with my Cary PH-302.Located in Califorina
i actually did some mods to my sp3. the unit out of the box has a very warm and enjoyable sound. i added .1 sonicap platinum bypass caps to the coupling capacitors on the power tubes, and on the pre tubes (12ax7 i believe) i replaced those with .1 sonicap platinums. if i were to send it off i would have also had them replace the rectifier with something better, but doing it myself, it was a difficult part to get to.

i noticed increased air and clarity up top and the unit sounded significantly more detailed.


i will tell you this now, none of the mods i had done will change this amp as much as rolling some tubes through it.
12ax7 to the GE triple mica 5751's made a bigger difference to the sound than the mods i did. also changing the power tubes to the valve art 350b made a definite change for the better. it can all be very system dependent though.

if you search my name on the av123 forums you can find some detailed posts and pictures regarding the mods that i did.

good luck and happy listening :)

Please save me some time.
Where did you get your tubes, particularly the GE 5751 & 350B's?