Cathodyne VS LTP

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Cathodyne VS LTP

Posted by Triode_Kingdom (A) on April 30, 2021 at 14:07:58

My current amp project is poised to use an EF86 driving a 6C4 cathodyne (1/2 12AU7). I've been comparing the 6C4 in this mode to a 6J6 as a long tail pair, and the results in SPICE have been surprising. The 6J6 is pretty clean regarding distortion, even when the outputs are pushed to 60V p-p (the approximate level needed to achieve full output from the 5881s). The spectrum looks pretty typical, with 2nd and 3rd harmonics fairly similar and higher frequency energy decaying quickly. The 6C4 cathodyne, on the other hand, doesn't fare so well. The 2nd and 3rd are pretty well controlled, but there's a lot of energy popping up at the 4th, 5th and 6th. Even the 7th looks as though it might be audible. I don't rely on SPICE as a primary tool for distortion analysis, but I hadn't expected to see anything like this. I'm just wondering if anyone here has experience with the 6J6 as a LTP, and what your impressions (or measurements) have been. It would be easy to change the topology at this point, and the additional gain afforded by the LTP compared to the cathodyne would come in handy.

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Topic - Cathodyne VS LTP - Triode_Kingdom 14:07:58 04/30/21 (16)

RE: Cathodyne VS LTP - PakProtector 05:09:58 05/01/21 (15)

RE: Cathodyne VS LTP - Triode_Kingdom 06:46:04 05/01/21 (14)

RE: Cathodyne VS LTP - kyle 09:46:43 05/03/21 (5)

Thanks, I'll keep it in mind! (nt) - Triode_Kingdom 12:41:06 05/03/21 (4)

Increasing Gain in Respectable Transconductance 7 Pin Mini Types - Eli Duttman 02:12:57 05/04/21 (3)

Distortion RE: Increasing Gain in Respectable Transconductance 7 Pin Mini Types - Paul Joppa 07:47:35 05/04/21 (1)

HK Ratings - Triode_Kingdom 08:43:25 05/04/21 (0)

RE: Increasing Gain in Respectable Transconductance 7 Pin Mini Types - PakProtector 03:13:43 05/04/21 (0)

RE: Cathodyne VS LTP - Eli Duttman 16:28:47 05/01/21 (7)

RE: Cathodyne VS LTP - Triode_Kingdom 20:22:10 05/01/21 (6)

RE: Cathodyne VS LTP - rage 11:52:04 05/05/21 (2)

Choke in the Tail - Triode_Kingdom 23:35:44 05/05/21 (1)

RE: Choke in the Tail - rage 06:55:38 05/06/21 (0)

Decision - Triode_Kingdom 23:51:27 05/01/21 (0)

RE: Cathodyne VS LTP - Eli Duttman 23:35:54 05/01/21 (1)

RE: Cathodyne VS LTP - PakProtector 05:47:03 05/03/21 (0)

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