1. The preamp's output impedance is determined by the nature of the circuitry.
2. V-Cap TFTFs (teflon-film, tin foil) are fine-sounding caps and arguably as good-sounding as money can buy, and so are SoniCap Platinums (which also are made with teflon film, in this case a proprietary teflon-alloy) and which also are arguably as good-sounding as money can buy. SCPs are significantly less expensive.
3. I understand the CardasGR uses 'propylene and teflon film.
4. The high-pass filter established by your output couplers and amp input impedance is about 7 Hertz, rather high WITHOUT an output-load resistor in the preamp, and I'd be very suprised if there isn't one. (If there is one, the filter point goes UP.) If you intend to keep this amp and if you'd like to have more-solid-sounding bass, I'd move that filter down at least an octave by about-doubling the value of the caps. I believe I'd build a composite cap and start with a MultiCap RTX ('styrene) of 3/200 ($42), a 1/600 Cardas GR, and then a 0.1/600 SoniCap Platinum ($29). Another combination that has potential and is less expensive would be a large SoniCap-1, say a 6.8/200 for $14, with as large a Cargas GR as you choose to afford, say a 0.47 for $30, in parallel. This gains even higher-quality bass via a lower filter point--in this case just over 2Hz ignoring the preamp's output-gounding resistor.
5. I mount caps with 3M double-sided plasic-foam tape. Here's a pic...
...of the couplers in my ASL 'Canes, showing a pair of CGRs 'taped' together and also to the ceiling of the amp.
6. Caps break-in just as about-all other 'passive' devices; I recommend AT LEAST 50 hours of high-level music for the 'propylenes, 100 hours for 'styrenes, and 500 hours for teflon caps, before you listen critically.
BTW I do put my money where my mouth is; I used SoniCap Platinums in the 1st coupling position and Cardas GRs in the 2nd in these Hurricanes, in spite of having to buy 4 SCPs and 16 CGRs!
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2. V-Cap TFTFs (teflon-film, tin foil) are fine-sounding caps and arguably as good-sounding as money can buy, and so are SoniCap Platinums (which also are made with teflon film, in this case a proprietary teflon-alloy) and which also are arguably as good-sounding as money can buy. SCPs are significantly less expensive.
3. I understand the CardasGR uses 'propylene and teflon film.
4. The high-pass filter established by your output couplers and amp input impedance is about 7 Hertz, rather high WITHOUT an output-load resistor in the preamp, and I'd be very suprised if there isn't one. (If there is one, the filter point goes UP.) If you intend to keep this amp and if you'd like to have more-solid-sounding bass, I'd move that filter down at least an octave by about-doubling the value of the caps. I believe I'd build a composite cap and start with a MultiCap RTX ('styrene) of 3/200 ($42), a 1/600 Cardas GR, and then a 0.1/600 SoniCap Platinum ($29). Another combination that has potential and is less expensive would be a large SoniCap-1, say a 6.8/200 for $14, with as large a Cargas GR as you choose to afford, say a 0.47 for $30, in parallel. This gains even higher-quality bass via a lower filter point--in this case just over 2Hz ignoring the preamp's output-gounding resistor.
5. I mount caps with 3M double-sided plasic-foam tape. Here's a pic...
...of the couplers in my ASL 'Canes, showing a pair of CGRs 'taped' together and also to the ceiling of the amp.
6. Caps break-in just as about-all other 'passive' devices; I recommend AT LEAST 50 hours of high-level music for the 'propylenes, 100 hours for 'styrenes, and 500 hours for teflon caps, before you listen critically.
BTW I do put my money where my mouth is; I used SoniCap Platinums in the 1st coupling position and Cardas GRs in the 2nd in these Hurricanes, in spite of having to buy 4 SCPs and 16 CGRs!
.