Audio Research Reference 5SE modifications/bypassing output caps


The output coupling caps in the ARC Reference 5 SE preamp are 10 microfarad caps which do not appear to have smaller bypass caps.  There has been some discussion of whether these caps are teflon or hybrid caps.  I do not have direct knowledge of the composition of these caps, but my experience with other tube amps/preamps has been that the sound of even high quality coupling caps can be improved with smaller bypass caps.  Has anyone bypassed these 10 microfarad output coupling caps with high quality caps such as VH Audio CuTF caps and if so was it worth the effort?
Ag insider logo xs@2xsoundhound
I find bypass caps work better (if at all) only with larger caps (>= 5uF).

That's a rough guideline. Bypass caps are kind of unique in that you can increase the total cap value all you want to without affecting the "response" very much, and indeed, in some preamps with smaller bypass caps (2-4uF) adding significant capacitance may indeed be a good thing.

I do worry sometimes if there is a difference, whether it is an important one or not, or a good one or not. Too many audiophiles get seduced by "different."

So I have not bypassed those in particular, but I have bypassed other 10uF caps with a "budget" copper film cap to good effect. Why don't you try them? I use the Audyn TruCopper 0.1uF caps. If they do nothing for you, then I suggest no other cap will either.

Best,

E


I know the older Ref and LS preamps that used the WonderCaps had multiple value bypass caps stacked on the output coupling cap.

My guess is that they judged whatever they are using now wouldn't benefit from it.
@monoogan Reminds me, a lot of the latest generation caps like Mundorf Supreme use exotic windings to achieve much of the benefit of bypassing.

That's why they are so physically large for the uF.