[sdiy] Phasing circuit

[patchell]

Magnus Danielson wrote:

>
> >     They also show the pole locations for the stages:
> >
> >     Side A:
> >         5.41Hz
> >         41.1Hz
> >     167Hz
> >     671Hz
> >     2694Hz
> >     11977Hz
> >
> >     Side B:
> >     18.8Hz
> >     83.5Hz
> >     355Hz
> >     1344Hz
> >     5472Hz
> >     41552Hz
> >
> >     Hopefully I didn't get any typos in there.
>
> Does it explain in any way how those numbers where calculated or generated?
> Is there any references to other articles?
>
> (actually, when I asked about references I really meant, what does that EN
> reference, but I agree knowing which EN is also good)

References:

[1] Harald Bode, "Solid State Frequency Spectrum Shifter", AES Preprint 395, Oct
1965
[2] Harald Bode and Robert Moog, "A High Accuracy Frequency Sifter for
Professional Audio applications", J. Aud. Eng. Soc., Vol 20, No. 6, July/Aug 1972,
pp 453-458

[3] haral Bode, "Apparatus for producing Special Audio Effects Utilizing Phase
Shift Techniques", US Patent 3800088 , March 26, 1974 (filed Aug 28, 1972)

[4] B. Hutchins, Musical Engineers Handbook, (1975) Chapter 6a
[5] B Hutchins, "Phase Shift Networks and Applications", EN#59 (2) Nov. 1975
[6] reference [2] page 455
[7] Data and Applictions Literature on AD533 multipliers and related products.
Analog Devices.
[8] Norlin Music (Moog); Bode Sound Company, N Tonawanda, NY 14120; 360 Systems
Los Angeles

    I could not find any information in the article about how they came up with
those numbers (however, I could have missed something).

    There was an article in either EDN or Electronic Design (I am not sure which
one), that had a BASIC program for calculating out the pole locations for a 90
degree phase network to any desired accuracy, I think...it would have been over 20
years ago...found it..."90-degree phase-difference networks are simply designed
with a program in BASIC.", Electronic Design, September 13, 1976...gee, nearly 30
years ago, my how time flies...but here is the part that sucks...I don't seem to
have the page that has the basic listing on it.  Does Electronic design have an
online archive?

>
>
> >     The article for the frequency shifter starts on page 5 of EN #83
> > pretty cool article.
>
> Me and EN#83 is dislocated in space and/or time.
>
> Beam me up Jim! ;O)
>
> Cheers,
> Magnus

--
 -Jim
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