Bottlehead Forum

Bottlehead Kits => Eros Phono => Topic started by: MikkelR on March 29, 2025, 03:18:40 AM

Title: Orientation of VH Audio CU-TF Caps in Eros Upgrade – 0.01µF RIAA + 1µF Coupling
Post by: MikkelR on March 29, 2025, 03:18:40 AM

Hi all,

I’m in the middle of a capacitor upgrade on my Bottlehead Eros and wanted to run a quick question by the group regarding capacitor orientation—specifically for the VH Audio CU-TF (Copper Foil Teflon) caps.

I’ve done quite a bit of soldering over the years and feel good about the install, but as always: measure twice, solder once. The guidance from VH Audio around outer foil orientation has me second-guessing slightly, especially in terms of getting it right for noise rejection and shielding.

I’m focusing on two parts of the circuit:
   1.   The 0.01µF caps in the RIAA EQ network
   2.   The 1µF 400V output coupling caps

⸻

Here’s what I’ve gathered from Bottlehead documentation:

1µF Output Coupling Cap – Between T9 (T10) and T6 (T7).
The outer foil (or negative) side should face T9 (T10), which leads to the preamp’s 47kΩ input (lower impedance).

0.01µF RIAA Cap – Between T4 (T11) and T5 (T12).
The outer foil side should face T5 (T12), which is grounded in the EQ network.

Does this match your experience? I think I have the orientation right, but before committing fully, I’d love to hear from anyone who’s used CU-TFs in this build—especially if you noticed any difference in hum/noise floor depending on foil orientation.

Thanks a bunch in advance!

Cheers,

/Mikkel

Title: Re: Orientation of VH Audio CU-TF Caps in Eros Upgrade – 0.01µF RIAA + 1µF Coupling
Post by: Paul Birkeland on March 29, 2025, 05:32:41 AM

That all sounds correct.