Mpp - Page 709

Joachim Gerhard · 02:50 PM

In my system i handle rumble in a different way. My main panels are rolled off under 80Hz with a line filter of 6dB octave. They are down -15dB at 20Hz and -21dB at 10Hz.
Then i have an active sub that is Mono. The sub has a subsonic filter ( 18dB ) under 18Hz and some other tricks. Excess Cone movement is nill.
That may be one answer why i do not suffer "Soundstage Shrinkage ".

Salas · 26th August 2012, 02:48 PM

Quote:

Originally Posted by RCruz

How did you do this sim ?

I invoked AC analysis, deleted an input cap that was there, energized small signal AC, and boom.

Salas · 26th August 2012, 02:49 PM

Quote:

Originally Posted by Joachim Gerhard

In my system i handle ruble in a different way. My main panels are rolled off under 80Hz with a line filter of 6dB octave. They are down -15dB at 20Hz and -21dB at 20Hz.
Then i have an active sub that is Mono. The sub has a subsonic filter ( 18dB ) under 18Hz and some other tricks. Excess Cone movement is nill.
That may be one answer why i do not suffer "Soundstage Shrinkage ".

Quite possible indeed. That is why you could not know what they were talking about.

Joachim Gerhard · 26th August 2012, 02:51 PM

Have edited my post : "rumble" and -15dB at 20Hz, - 21dB at 10Hz

RCruz · 26th August 2012, 02:57 PM

Quote:

Originally Posted by Joachim Gerhard

Ricardo, the "natural" input impedance of the Paradise is around 10kOhm.
Say you need 2.3kOhm loading of the transformer ( Sowter 8055 ) you need a loading resistor of ca. 3kOhm. It appears in parallel to the "natural" input impedance.

Using a 1:10 sut I would load the cart with only 10000 / 10 square = 100
The tuscany "likes" 470r.... anyway it is good to know.

Joachim Gerhard · 26th August 2012, 02:59 PM

Transformer loading is different from resistor loading. To reach 470 Ohm you would need an enormous secondary impedance and that may not damp the transformer optimally.

RCruz · 26th August 2012, 03:01 PM

For the Tuscany I built a jfet input stage with a 47kr ohm resistor. The 1:10 sut pulls it down to 470r... It works very well indeed.

Joachim Gerhard · 26th August 2012, 03:02 PM

Here you can find information about the Sowter that i use sometimes. It is a good one besides Lundahl and Jensen. I have personally no experience with Cinemag and Haufe.
I tried Pikatron in the old times.

Joachim Gerhard · 26th August 2012, 03:02 PM

Sowter Type 8055

Joachim Gerhard · 26th August 2012, 03:04 PM

You may get a super sonic overshot when you load the transformer light that can sound very attractive.

26th August 2012, 02:47 PM	#7081
Joachim Gerhard diyAudio Member Join Date: Mar 2009	In my system i handle rumble in a different way. My main panels are rolled off under 80Hz with a line filter of 6dB octave. They are down -15dB at 20Hz and -21dB at 10Hz. Then i have an active sub that is Mono. The sub has a subsonic filter ( 18dB ) under 18Hz and some other tricks. Excess Cone movement is nill. That may be one answer why i do not suffer "Soundstage Shrinkage ". Last edited by Joachim Gerhard; 26th August 2012 at 02:50 PM.

26th August 2012, 03:01 PM	#7087
RCruz diyAudio Member Join Date: Sep 2006 Location: Saxon Blog Entries: 1	For the Tuscany I built a jfet input stage with a 47kr ohm resistor. The 1:10 sut pulls it down to 470r... It works very well indeed. __________________ RC

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26th August 2012, 02:51 PM	#7084
Joachim Gerhard diyAudio Member Join Date: Mar 2009	Have edited my post : "rumble" and -15dB at 20Hz, - 21dB at 10Hz

26th August 2012, 02:59 PM	#7086
Joachim Gerhard diyAudio Member Join Date: Mar 2009	Transformer loading is different from resistor loading. To reach 470 Ohm you would need an enormous secondary impedance and that may not damp the transformer optimally.

26th August 2012, 03:02 PM	#7088
Joachim Gerhard diyAudio Member Join Date: Mar 2009	Here you can find information about the Sowter that i use sometimes. It is a good one besides Lundahl and Jensen. I have personally no experience with Cinemag and Haufe. I tried Pikatron in the old times.

26th August 2012, 03:02 PM	#7089
Joachim Gerhard diyAudio Member Join Date: Mar 2009	Sowter Type 8055

26th August 2012, 03:04 PM	#7090
Joachim Gerhard diyAudio Member Join Date: Mar 2009	You may get a super sonic overshot when you load the transformer light that can sound very attractive.