In Reply to: You may have missed it... posted by Charles Hansen on August 21, 2003 at 19:45:04:
Went over to John's last weekend, and we took a look at some of those measurements (and measured my Purist Colossus IC)The question of whether John's measurement rig is flawed has been beaten to death, but here's what I saw:
We exchanged 4 or 5 different kinds of cable, all RCA terminated, and each cable exhibited 2 things:
1) A different pattern of harmonics of the original signal that was perfectly repeatable; we could exchange the cables back and forth and always get the same spectrum for a given cable. Some of the spectra included significant amounts of 8th - 10th harmonics.
2) A different pattern of noise (i.e. signals at frequencies unrelated to the original) that was also repeatable. Obviously, the shielding ability of the cables is different.
The repeatability of the tests makes me believe that the harmonic spectrum is not due to connector issues on the test setup, as was suggested in an earlier post, although I suppose you could always argue that the complex comination of distortion analyzer, RCA adapters and spectrum analyzer creates the signature, rather than just the cable. Sounds like what happens in a real audio system to me...
John's test set up is actually quite straight forward, and not all that hard to duplicate, so I'm mystified by the fact that so many people have foamed at the mouth about it, but none have tried it.
It's also interesting that nobody has been able to explain the results, prefering to shoot the messenger.
Peter
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- And now I've seen them as well.... - Commuteman 09:47:10 08/22/03 (45)
- Re: And now I've seen them as well.... - jneutron 09:58:50 08/22/03 (44)
- Hey, we're agreeing! - Commuteman 10:12:15 08/22/03 (43)
- Hee hee..we're jumpin thread to thread.. - jneutron 10:28:00 08/22/03 (42)
- So maybe I can help the communication - Commuteman 11:20:15 08/22/03 (41)
- Re: So maybe I can help the communication - john curl 15:30:28 08/22/03 (40)
- Seebeck/peltier... - jneutron 19:24:11 08/22/03 (36)
- Re: Seebeck/peltier... - john curl 23:21:43 08/22/03 (35)
- Re: Seebeck/peltier... - jneutron 04:53:47 08/23/03 (34)
- Re: Seebeck/peltier... - john curl 08:22:30 08/23/03 (33)
- Re: Seebeck/peltier... - jneutron 09:01:31 08/23/03 (32)
- Re: Seebeck/peltier... - john curl 09:54:43 08/23/03 (31)
- Ah...deflection of any technical conversation..typical, John - jneutron 10:22:54 08/23/03 (30)
- Re: Ah...deflection of any technical conversation..typical, John - john curl 13:06:57 08/23/03 (29)
- Re: Ah...deflection of any technical conversation..typical, John - jneutron 16:29:53 08/23/03 (28)
- Ok, so can you explain how these thermal effects might manifest themselves? - Commuteman 17:29:51 08/23/03 (27)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - jneutron 12:54:34 08/24/03 (26)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - john curl 15:37:42 08/24/03 (25)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - jneutron 07:59:53 08/25/03 (24)
- Can you stop arguing with JC and describe what you think might be happening? - Commuteman 09:09:25 08/25/03 (8)
- Who's arguing? I'm being bashed for trying to explain. - jneutron 11:21:13 08/25/03 (7)
- Are you sure you can use this Seebeck/Peltier cause and effect model? - Commuteman 12:18:56 08/25/03 (6)
- I forgot to add.. - jneutron 17:20:41 08/25/03 (0)
- I'll stick to this thread. - jneutron 12:31:19 08/25/03 (4)
- Can we get to some ballpark numbers to see if it's significant? - Commuteman 13:41:47 08/25/03 (3)
- You're killin me... - jneutron 15:56:18 08/25/03 (2)
- I think we're using the same numbers.. - Commuteman 17:28:12 08/25/03 (1)
- AHA!!!!! So that's where the error is... - jneutron 17:46:53 08/25/03 (0)
- Re: Ok, so can you explain how these thermal effects might manifest themselves? - john curl 08:50:17 08/25/03 (14)
- JC..you really have to read the posts.... - jneutron 10:29:16 08/25/03 (13)
- Re: JC..you really have to read the posts.... - john curl 13:36:44 08/25/03 (10)
- Hi John - jneutron 15:21:15 08/25/03 (9)
- Re: Hi John - john curl 16:47:15 08/25/03 (8)
- Re: Hi John - jneutron 17:04:43 08/25/03 (7)
- Re: Hi John - john curl 20:16:24 08/25/03 (6)
- Re: Hi John - jneutron 21:34:29 08/25/03 (5)
- And BTW..You never did say who Dr. Van den Hul was.. - jneutron 21:48:10 08/25/03 (4)
- Everyone is entitled to their opinion.... - Charles Hansen 22:03:03 08/25/03 (3)
- Hmmm. - jneutron 05:41:31 08/26/03 (0)
- Hellllooo Charles... - jneutron 03:45:13 08/26/03 (1)
- OH, and Charles..... - jneutron 04:55:27 08/26/03 (0)
- Peltier effects are reversible with current direction - Commuteman 11:43:41 08/25/03 (1)
- AHA..gotcha - jneutron 11:58:44 08/25/03 (0)
- Yep, my oscillator is now the problem - Commuteman 16:31:13 08/22/03 (2)
- Re: Yep, my oscillator is now the problem - Dan Banquer 05:29:28 08/23/03 (1)
- Thanks - Commuteman 09:59:43 08/23/03 (0)