In Reply to: RE: DHT 01a tube preamp posted by mwhouston on February 14, 2025 at 16:29:01:
"To limit output I put a series resistor of 330K to the output RCA with 100K to ground at the RCA"Your later comments regarding HF response and testing indicate that you don't understand how this all works together. Below is the frequency response of the 300K/100K combination driving your 175pF cable. And this doesn't account for the additional output impedance of the 01A anode or input capacitance of the amplifier. In addition to high frequency loss, phase (dotted line) is badly shifted.
Edits: 02/16/25
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Follow Ups
- Poor Design for a Preamp - Triode_Kingdom 09:51:58 02/16/25 (30)
- RE: Poor Design for a Preamp - FlaCharlie 12:17:02 02/16/25 (27)
- RE: Bartola - deafbykhorns 11:08:37 02/17/25 (3)
- I bet that works good - Tre' 13:34:15 02/17/25 (2)
- RE: I bet that works good - Triode_Kingdom 16:48:57 02/17/25 (1)
- Yup! nt - Tre' 17:15:13 02/17/25 (0)
- RE: Poor Design for a Preamp - Tre' 12:57:28 02/16/25 (22)
- RE: Poor Design for a Preamp - mwhouston 17:55:07 02/26/25 (5)
- RE: Poor Design for a Preamp - FlaCharlie 10:19:33 02/27/25 (2)
- RE: Poor Design for a Preamp - mwhouston 14:13:55 02/27/25 (1)
- Metal Tubes / Tube Sources - FlaCharlie 10:43:52 02/28/25 (0)
- Confusion - FlaCharlie 09:50:01 02/27/25 (1)
- RE: Confusion - mwhouston 14:08:29 02/27/25 (0)
- RE: Poor Design for a Preamp - FlaCharlie 14:34:32 02/16/25 (15)
- RE: Poor Design for a Preamp - Tre' 15:22:32 02/16/25 (14)
- RE: Poor Design for a Preamp - mwhouston 19:58:38 02/16/25 (13)
- Yes, with DHTs hum can be an issue - Tre' 20:29:51 02/16/25 (12)
- RE: Yes, with DHTs hum can be an issue - mwhouston 20:34:15 02/16/25 (11)
- RE: Yes, with DHTs hum can be an issue - Tre' 20:39:48 02/16/25 (10)
- RE: Yes, with DHTs hum can be an issue - mwhouston 03:48:34 02/26/25 (2)
- RE: Yes, with DHTs hum can be an issue - FlaCharlie 06:32:38 02/26/25 (1)
- RE: Yes, with DHTs hum can be an issue - mwhouston 13:32:24 02/26/25 (0)
- RE: Yes, with DHTs hum can be an issue - mwhouston 20:51:24 02/16/25 (6)
- RE: Yes, with DHTs hum can be an issue - Tre' 21:37:40 02/16/25 (5)
- RE: Yes, with DHTs hum can be an issue - FlaCharlie 07:45:40 02/17/25 (4)
- RE: Yes, with DHTs hum can be an issue - mwhouston 16:42:17 02/19/25 (0)
- Those are all good ideas but... - Tre' 09:06:57 02/17/25 (2)
- RE: Those are all good ideas but... - mwhouston 13:50:02 02/20/25 (1)
- "I tried for months but to no avail." - Tre' 18:16:22 02/20/25 (0)
- RE: Poor Design for a Preamp - FlaCharlie 11:42:34 02/16/25 (1)
- RE: Poor Design for a Preamp - Tre' 13:18:33 02/16/25 (0)