David McGown wrote:
THROW THE LEAKY CAPS AWAY!!!!
The Jensen caps are notorious for failing. Based on your original post, the caps are likely 20 years old. The Jensen oil caps have end seals that are cardboard, either rubberized or oil impregnated as I recall. The have a rolled mechanical "seal" at the casing. Unlike Vitamin Q, Russian PIOs etc., they are not hermetically sealed. Therefore, they lent are subject to drying out over time and becoming electrically leaky. Since they are prone to failure, why even bother testing them for reuse. The output tube cost more than a decent quality replacement film cap. Try the CDE 942C caps in the higher voltage ratings (1000V). If you want to keep with an oil cap, then use a Russian PIO that is hermetically sealed and will not dry out.
David
Yes, I will throw away the Jensen caps.
For now, this amp will be powering your bass horns between 100-450Hz. So, I need caps that are excellent in midrange. HF characteristics should not matter as the amp never sees high frequencies. I have power and output transformers for a 300B amp. When 300B is done, I might use it for bass horns and relegate Superamp for powering your JBL LE5-2 midrange horn between 450-2200Hz.
Russian PIOs are very cheap on EBay. Found this review of Audiocap Theta interesting. Might try them out.
Quote:
AudioCap Theta is constructed with polypropylene film and tin foil with gold-plated OFHC leads, and it is very reasonably priced compared to AudioCap PCU, which is polypropylene film and Copper foil and priced accordingly. I have read AudioCap Thetas being described as lean and clinical in the past, and that's exactly how they sounded in the beginning. However, after proper break-in, these things became extraordinarily rich and warm in tone, without any wooly, syrupy sloppiness. AudioCap Thetas definitely had another notch of detail and resolution in the mid-midrange compared to even the best metallized polypropylene caps, resulting in sumptuously textured and detailed voices; however, the upper-midrange and treble also retained this rich smoothness, which in fact made them sound a touch less open and sparkling compared to metalized poly caps like WIMA.