NMR is a very powerful analytical technique, but it has always been limited to relatively large samples by its intrinsic low sensitivity. Higher magnetic fields increase the range of systems that can be analyzed by NMR. Cryoprobes, which have lower noise and higher Q factor than conventional room temperature probes, have also been effective in improving sensitivity. Even better sensitivity can be achieved by replacing the cryoprobe’s normal metal coil insert with resonators patterned from thin-film Y1Ba2Cu3O7-d, a superconductor that maintains its excellent RF properties even in the high field of an NMR magnet. The improved sensitivity can be best realized for 13C and small samples where RF loss in the sample itself does not dominate the resonator Q factor. These probes have been valuable for natural products and metabolomics applications [1]. A high Q factor has the advantage of improved sensitivity, but it also limits the possible bandwidth for reception and the minimum excitation pulse that can be produced. We have increased the Q factor of our 13C channel in both a 600 MHz microsample probe and a 900 MHz probe by designing the resonator to work without certain lossy metal elements that were previously needed to avoid interference with the 1H channel. At 600 MHz the matched Q factor has improved from 1300 to 4300 [2] and a similar Q factor has been reported in the 900 MHz probe. With the higher Q factors, we have run into both the detection and excitation limits on bandwidth. We will discuss how to overcome these limits and preserve the bandwidth needed for direct 13C detection while preserving most of the improved sensitivity of higher Q factors.