Re: Klangfilm KL-RZ062 EQ's
« Reply #20 on: November 18, 2018, 12:50:34 PM »

@volker

👍 big like


5v333

Re: Klangfilm KL-RZ062 EQ's
« Reply #21 on: November 19, 2018, 10:27:44 AM »
your contribution is honored!
to bad about the broken resistor.

F = 1/(2π(√LC))

1.4K = 2000pF + 6.46H
2K = 1300pF + 4.8H
2.8K = 900pF + 3.58H
4K = 500pF + 3.16H


5v333

Re: Klangfilm KL-RZ062 EQ's
« Reply #22 on: November 19, 2018, 10:32:52 AM »
the hi/low tank has a loss of 19dbs when flat.

Murdock

Re: Klangfilm KL-RZ062 EQ's
« Reply #23 on: December 05, 2018, 05:40:47 PM »
https://www.ebay.de/itm/KI-RZ-062b-KLANGFILM-Universal-Equalizer-Universal-Entzerrer-KI-RZ-062b-RARE/192747834827?hash=item2ce0aa8dcb:g:hEsAAOSwmOBcBvdr:rk:1:pf:0

anybody with too much cash and willing  to sacrifice these modules to the great god of the diy?  ::)

At least I can see some values on the picture. I will try to assign them to the schematics

Re: Klangfilm KL-RZ062 EQ's
« Reply #24 on: December 12, 2018, 07:35:06 AM »
https://www.ebay.de/itm/KI-RZ-062b-KLANGFILM-Universal-Equalizer-Universal-Entzerrer-KI-RZ-062b-RARE/192747834827?hash=item2ce0aa8dcb:g:hEsAAOSwmOBcBvdr:rk:1:pf:0

anybody with too much cash and willing  to sacrifice these modules to the great god of the diy?  ::)

At least I can see some values on the picture. I will try to assign them to the schematics

3000€  and 2days, 9 hours left! Will it go over 5000€?  :D

Update: The winning bid was EUR 4.856,00!  :o
« Last Edit: December 15, 2018, 08:18:38 AM by rock soderstrom »

Murdock

Re: Klangfilm KL-RZ062 EQ's
« Reply #25 on: December 15, 2018, 08:54:31 AM »
3000€  and 2days, 9 hours left! Will it go over 5000€?  :D

Update: The winning bid was EUR 4.856,00!  :o


Almost! Also thought it would hit the 5000€...
Did you buy it?  ::)

Re: Klangfilm KL-RZ062 EQ's
« Reply #26 on: December 15, 2018, 12:37:50 PM »

5v333

Re: Klangfilm KL-RZ062 EQ's
« Reply #27 on: December 24, 2018, 09:16:29 PM »
ive been trying get my head around the hi/lo shelf today.
even though it seems very simple, i find some of it quite difficult and has made me dive into RDH4 to get more insight in old "simple" RC networks.

attached is a sketch on how the cut and boost operation looks like.

when ever a cut or a boost is used, one resistor and one capacitor is added for that amount of boost/cut.


5v333

Re: Klangfilm KL-RZ062 EQ's
« Reply #28 on: December 25, 2018, 08:39:56 PM »
this is how i think the bass boost works.

a resistor is added to the lower resistor (R4) in the main voltage divider. when doing so, the voltage divider gets a lower negative ratio - 2db less for every boost.
all frequencys are boosted.
then we add a shunt capacitor to roll off high frequencies from the newly set amplitude.
the rolloff will stop at the initial gain level.
so we are not adding bass but adding level and then filtering out highs.

for 2db boost i calculated an extra resistance to the R4 of about 31K.
looking at the curves in the datasheet, it looks like theres a little bit more gain than 2db so 31K becomes alittle bigger.
i noticed that all R´s and C´s are not in values we are known to today so my guess is that we are looking for a 35K resistor.

i havnt found any definitive method for this but RDH4 says that if we know the gain of the boost and we know at what freq half of boost is then we can use:
C = Halfgain ratio / (2 x π x Fhalf x R )

we can use the curves in the datasheet.

Half gain ratio of 2db is 1.122
freq at half of 2db boost is at 70hz
R is what ever the C sees i think. 35K//900K = 33.7K

1.122 / (2 x π x 70 x 33.7K) = 75.6nF

again we are talking about older values. dodnt know what could been choosen but perhaps 80nF was more common then booth 75nF and 82nF...

i tried this 2db boost setup on my breadboard with about 35K on a pot and 80nF and it was about right. 100nF was abit too high and 47nF was too low.

but it is rather speculative isnt it?!

5v333

Re: Klangfilm KL-RZ062 EQ's
« Reply #29 on: December 26, 2018, 11:09:58 AM »
i just made a breadboard setup for 12db boost.
in the datasheet the curves show a boost of about 11db at 40hz. i got about 10db with 500K+8nF.
so perhaps 600K or 7nF is better.

so the values seems about right and will work. however, there can be tiny differencies with the real deal.

lets proceed.


Murdock

Re: Klangfilm KL-RZ062 EQ's
« Reply #30 on: January 22, 2019, 06:48:18 AM »
Wow, great progress!
Thanks for sharing!

Do you know what the gain is from the make up amp?

Would it be possible to use, for example, the Pultec filter with this make up amplifier?

Or are these completely different filter circuits?

5v333

Re: Klangfilm KL-RZ062 EQ's
« Reply #31 on: January 24, 2019, 11:24:32 AM »
I have to get confimation from somebody else from the forum but i guess it is set by Rfeedback and Rcathode(of the first triode).
100K/4K = 25 (28dB)
if the OT is 8:1 then the gain including the OT is 25/8 = 3.125 (10dB)

Ive been very busy and stressed this month so i have not been able to proceed. But ill have some more look at the hi/lo filters further on.

i did work out one value for the hi boost but have not had the time to test it on breadboard.
i think the handwritten values in the schems are not original values but a plan on doing 0.5dB steps.


 

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