@yowser I've worked with the V-Caps a lot. The Copper foil series is audibly superior (and measure better as well). Given how you're going about this the cost differential seems irrelevant. I do feel compelled to point out however that as coupling caps the copper foil caps are better than the ODAM parts (which are quite good). You might want to rethink this.
Preamp power supply capacitor upgrade
I recently purchased a used Backert Labs Rhumba Extreme 1.3 preamplifier. Although it sounds excellent, I’m on a quest to get it to sound as close to the Backert Labs Rhythm as I can on the cheap. I’ve already sent it back for the 1.4 circuit upgrade and I upgraded the coupling caps to V-Cap ODAM’s. I’ve also upgraded the tubes to Amperex 7316’s from several recommendations here. For reference, my amplifier is Coincident Frankenstein 300B MkII and speakers are Reference 3A Reflectors.
The Rhythm power supply uses four 0.33uf V-Cap CuTF caps which gets rather costly at $218 each. However, the TFTF caps are discounted at $104 each.
My question is, since these would be used in the power supply, would the price differential justify going with the CuTF vs the TFTF?
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@atmasphere Thanks for chiming in! I did consider the CuTF's for the coupling caps but they are not available in 2.7uf. I wanted to retain the specification of the existing circuit. |
@erik_squires I understand what you're saying and is partially why I posed the question. Below is Backert Labs justification for the V-Caps in the power supply: "At Backert Labs, all of our preamplifiers use the new GreenForce™ power supply. Because GreenForce is totally unlike previous power supplies, Bob Backert was granted a patent on GreenForce in 2013. For those who are familiar with electronics, an example of the surprising quality of GreenForce is that the capacitors used to power our Rhumba preamp total less than 1 uF (one microfarad). Most power supplies for a similar preamp would use hundreds, or 1000’s of microfarads. Because so little capacitance is needed, GreenForce is the only power supply in the world that can run a stereo component entirely on PTFE capacitors such as V-Cap™ capacitors, which we feel are the finest type of capacitor for a power supply available today." And another excerpt: "The heart of any power supply is its capacitors. Similar to batteries, capacitors provide the power for your equipment to operate. The GreenForce power supply employed in all preamps by Backert Labs is unique, in that it allows the use of extremely high quality capacitors to run the power supply. In our Rhumba and Rhumba Extreme models, the GreenForce power supply uses very high quality polypropylene capacitors for extremely linear and nimble response. In our Rhythm models, the GreenForce power supply uses the costly V-Caps™ copper/PTFE capacitors. Online capacitor comparisons such as The Great Capacitor Shoot-Out tend to rank V-Caps in first place (and that is with the tin version of V-Caps, rather than the upgraded copper version that we employ). The Rhythm 1.3 preamplifier is the only audio component in the world with an all-V-Caps or all-PTFE power supply. The results: Incredibly fast transients. Tight, accurate bass with visceral texture and punch. Extremely accurate timing. Incredibly fast dynamic changes — dynamics that really tell the story of what is on your source material." |
I just went over to DIYaudio to read about this power supply and the patent. I can't say I would not absolutely use a great big cap right around the outputs and solve all my problems!! 🤣 So, I'm stepping back from this discussion as I'm not only not familiar with the thinking behind it but also have a number of questions that I don't have time for. |
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