RE: Determining the size of inter-stage coupling cap

SET Asylum

Single Ended Triodes (SETs), the ultimate tube lovers dream.

Posted by 91derlust (A) on January 22, 2017 at 18:59:29

In Reply to: Determining the size of inter-stage coupling cap posted by EricSan on January 22, 2017 at 18:24:42:

>>> also found Al's thread about replacing R10 with a choke that has the impact of changing R10 to 250k (http://www.audioasylum.com/cgi/vt.mpl?f=magnequest&m=11930). If I incorporate this change with a pair of nice NOS oil caps that measure 0.25uF, am I correct that this shifts the corner frequency to about 2.6Hz (and keeps phase shift below 26Hz)? <<<

Why does replacing R10 with a choke have the impact of changing R10 to 250k? Damping resistor? I thought a significant benefit of using grid chokes was a dramatic reduction in the grid-to-ground resistance.

Remember also that other things being held constant, adding a grid choke will induce a resonant peak in the bass; increasing the coupling C can help manage the peak.

It has been a while since I looked at grid chokes - I could be way off.

Also consider, it is debatable whether the benefit of reducing phase shift below ~100 Hz justifies the trade-offs, for example: passing sub-bass frequencies.

Cheers,
91.

"Confusion of goals and perfection of means seems to characterise our age." Albert Einstein

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Follow Ups Full Thread

Topic - Determining the size of inter-stage coupling cap - EricSan 18:24:42 01/22/17 (11)

RE: Determining the size of inter-stage coupling cap - Paul Joppa 14:51:49 01/23/17 (3)

RE: Determining the size of inter-stage coupling cap - EricSan 06:18:32 01/24/17 (2)

RE: Determining the size of inter-stage coupling cap - Paul Joppa 14:24:14 01/24/17 (1)

RE: Determining the size of inter-stage coupling cap - EricSan 10:05:52 01/25/17 (0)

RE: Determining the size of inter-stage coupling cap - EricSan 11:39:00 01/23/17 (0)

RE: Determining the size of inter-stage coupling cap - EricSan 05:01:50 01/23/17 (4)

RE: Determining the size of inter-stage coupling cap - Tre' 07:18:50 01/23/17 (3)

RE: Determining the size of inter-stage coupling cap - SteveBrown 08:44:35 01/23/17 (2)

RE: Determining the size of inter-stage coupling cap - Tre' 08:59:22 01/23/17 (1)

RE: Determining the size of inter-stage coupling cap - used-hifi 10:29:13 01/23/17 (0)

RE: Determining the size of inter-stage coupling cap - 91derlust 18:59:29 01/22/17 (0)

Follow Ups

RE: Determining the size of inter-stage coupling cap - 91derlust 18:59:29 01/22/17 (0)

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