Klangfilm KL-RZ062 EQ's

[Murdock]

I couldn't find any talk about these interesting EQ's on here.
There is a documentation online. Specs, filter curve, make up and filter schematic are in there. But sadly the filter capacitor and resistor values are not given...

http://www.klangfilm.org/data/documentations/electronics/equalizers/kl-rz062/

(at the bottom is a PDF with most of the pages)

Does anyone have one?
What about the in- and output transformers and choke? Anyone know what specs these  could have?
Input transformer secondary wiring looks weird. Is it a 1:1 transformer?`

 

[rock soderstrom]

Thanks for that interesting document. I guess a replika of this device will be not cheap (expensive iron and switches).  The trademark "Klangfilm" means crazy prices for original devices, on ebay the guys from asia pay absurd money for that stuff!  ;D

 

[Murdock]

Yeah, I also noticed this.
Alot of sellers even use that trademark just to get more attention and higher price, even if the item doesn't have anything to do with Klangfilm  :

I can see that the switches would be a problem. But one could use 24 position switches with less boost and cut. Also the mid bands could be five 1dB steps instead of six 0,8dB steps... That would also bring the total positions down.

What about the iron? As I can see there are "only" two transformers and two inductors/chokes. And probably nothing fancy as the Pultec iron for example. But I'm not knowledgeable enough to calculate the specs of the iron....

It seems that the input transformer is loaded with a 40k resistor. Input impedance is stated as 2.5k ohms.
Would that imply a ratio of 1:4?
40k/2.5k=16 z ratio
√16= 4 turns ratio

?

 

[5v333]

Interesting unit. Have to stare at it for a couple of nights.

I think the input tx is a 1:4 as 40k at the sec looks like 2.5k at the pri with that ratio.

 

[Murdock]

I've merged the two pages of the make up amp schematic to make it easier to follow.

https://drive.google.com/file/d/1K4OLON6ytmgWFsn_GH_1os9a2-JZAodH/view?usp=sharing

 

[salomonander]

...i know some old guys here in germany that rave about these. but they also say its impossible to clone due to the iron. supposedly they are not possible to reproduce like most of the old tab/telefunken iron. im just repeating what they have told me

 

[5v333]

See if i get some of it right...

It looks like there are two different modules 062a and 062b.
Difference is found in the middle switch.
In one of the variants youll find a bell filter with 4 different frequencies. Db steps and freq selection is done with the same rotary switch.
The other variant looks like it has a tilt filter in the middle. Tilt and shelfs! That sounds very cool to me!

The output tube is a 12at7. Datasheet says plate R 10k - 15k.
Load on the secondary of the transformer is speced as 200r. And the output Z is speced 25r in the schematics.
10k-15k:200r has an impedance ratio of about 7.

With that, 25r looks like 1225r on the primary. Which is a factor of 10 below opencircut plate resistance. As in 20dbs NF. Does it sound reasonable?

I also think the output triode is biased at 8ma and about 3.5Vg-k.

The transformers looks like they are potted/shielded.

I havnt done anything with pentodes yet but i would say the ef804 is triode connected and with some sort of NF aswell. Unbypassed cathode so prob quite low gain.

The filters are passive (oh yeah that we like)
Maximum boost is 12db in the treb/bass and 4db in the middle.Maybe that is also the total loss of amplitude in the filters. Maybe just 1-2db more.

 

[gyraf]

*like*

 

[Murdock]

See if i get some of it right...

It looks like there are two different modules 062a and 062b.
Difference is found in the middle switch.
In one of the variants youll find a bell filter with 4 different frequencies. Db steps and freq selection is done with the same rotary switch.
The other variant looks like it has a tilt filter in the middle. Tilt and shelfs! That sounds very cool to me!

The output tube is a 12at7. Datasheet says plate R 10k - 15k.
Load on the secondary of the transformer is speced as 200r. And the output Z is speced 25r in the schematics.
10k-15k:200r has an impedance ratio of about 7.

With that, 25r looks like 1225r on the primary. Which is a factor of 10 below opencircut plate resistance. As in 20dbs NF. Does it sound reasonable?

I also think the output triode is biased at 8ma and about 3.5Vg-k.

The transformers looks like they are potted/shielded.

I havnt done anything with pentodes yet but i would say the ef804 is triode connected and with some sort of NF aswell. Unbypassed cathode so prob quite low gain.

The filters are passive (oh yeah that we like)
Maximum boost is 12db in the treb/bass and 4db in the middle.Maybe that is also the total loss of amplitude in the filters. Maybe just 1-2db more.

Yes, I also really like the look of the "a" version filter. You can come up with some really interesting curves in conjunction with the high and low filters.
No wonder people call them the german Pultecs  ;D

The "a" version also don't need any inductors 
Would still be interesting to know the value of the one in the "b" version.  :

I think one could use 1:4 (600:10k) and 5:1 (15k:600) transformers. As 600 Ohm is the facto standart now...
Lundahl has the LL1922 which seems perfect for the input. It's 1:4 and they recommend a load of 47k.
Output transformer should be easy  to source.


If my calculation is right, there is about 292V just before  the anode choke.
What do you  think is the plate voltage of the ECC81? If 250V than the choke would need about 5k DC resistance which seems reasonabe.
10-15k plate resistance would mean that a 150-200H choke would be enough, right?


I already emailed a few people here in Germany if they have maybe the values of the filter parts but till now, nothing...
But there is one guy who thinks he has the values but he has to "unbury and setup" his old computer. So this could take maybe a while. But it's a lead and he once repaired some of these EQ's. So we'll see.

 

[5v333]

i was just ignoring the choke... mostly because i havnt dealt with thoose either...

checking some more.

the datasheet for the eq says that B+ is 300V and consumtion is 8mA.

the first ecc81/12at7 only consumes about 1ma if i have made the maths right. i think the effective dc anode resistance is the anode resistor in paralell with the local feedback resistor. so not 100k but more like 77k

the ef804 i think is set to 0,5mA. couldnt find any curve sheets for triode connection but some charts gives me an idea that that circuit consumes 0,5mA.

that would leave the last triode with a consumtion of 6,5mA. and about 2.7Vg-k.
at that point their should be about 55V voltage loss from 300V.
55V / 6.5mA = 8461R

there is an series 1k resistor before the choke aswell so 7.5k might be more like it plus maybe some series resistance in the psu... so 5k might be just great.
if my assumptions are right that is.

 

[Murdock]

OK, got an answer from the last gentleman. Sadly he also doesn't have the values  :'(
Would it be possible to calculate the values with the filter curves and info we have?
On one of the filter schematics are a few values hand-written.

Or someone knows someone with a unit and could check the values on the components.

 

[5v333]

thers a pair for sale on e***y right now. not very cheap.
perhaps the seller has got documents.
or if theres any old studio that had them back in the days.

 

[[silent:arts]]

I put my 062b out of the drawer to do some (in circuit) measuring for you guys  8)

Input transformer Ü1:

 

[[silent:arts]]

Output transformer Ü2:

 

[[silent:arts]]

Choke Dr1:

 

[[silent:arts]]

Sorry, no chance to measure the inductor without desoldering some parts.

 

[Murdock]

Wow, you got one 
Thanks alot for the pictures and measurements!!

The choke is odd. Only 8H and then 11k DC resistance? 

Is it possible for you to see the capacitor and resistors values on the switches?  : ;D

 

[5v333]

cool! if i understand it from your measurments with the transformers, it looks like theres a very low source imipedance and a very high load impedance. the ot shows a 10:1 ratio but with source Z of 12K and load Z of 200 that ratio would prob be lower.

thanks for taking the time!

in the hi/lo filter tank r1 r2 r3 r4 are fundementals

in the LC precence tank r21 r22 r23 are fundementals. if one of the four eq caps are measured we can prob work out the the inductor, but we need to know which of the caps it is.

 

[[silent:arts]]

cool! if i understand it from your measurments with the transformers, it looks like theres a very low source imipedance and a very high load impedance.

yes. Zout = 15Ω, Zin = 100KΩ

in the hi/lo filter tank r1 r2 r3 r4 are fundementals

R1 = 200K, R2 = 300K, R3 = 300K, R4 = 100K

in the LC precence tank r21 r22 r23 are fundementals. if one of the four eq caps are measured we can prob work out the the inductor, but we need to know which of the caps it is.

There is no access to R21 to R23. It is a 3D build, even hard to do a photo of it.
R21 to 23 are the resistors in the middle of everything:

 

[[silent:arts]]

I won't do further research since I already broke R3 while poking around.
The unit is in original fragil condition and needs a complete refurbishment.
I don't have the time right now for doing it, but breaking undocumented things now and refurbish it later won't work well, so I will put it back in the drawer for now.

Attached the readable values of the presence part: