EH - Attack Equalizer ( Knockout , KO , EQ )

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
gigelmargel
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Post by gigelmargel »

DiscoFreq wrote: I test everything on bass, the treble pot gives more attack (and fret noise).

Maybe the cutoff frequency in your clone is too high?

IIRC, the Polish attack equalizers have cutoff frequencies at 300Hz for bass (LP) and 3000Hz for treble (HP).
Thx for your answer DiscoFreq!
I made my clone using this schematic: https://i181.photobucket.com/albums/x12/ ... TACKEQ.jpg.
The Polish versions sound better than the EHXs in your opinion?

After I finished (and tested it) I doubled the values of C11-C13 and C15-C17 to halve the cutoff frequency for treble and it sounds a little better (so, now this frequency is around 3KHz as you said).
What I must to do to raise the bass cutoff frequency? I must to multiply by 4 the values of the caps C2-C4 and C7-C9?
Now I want to lower R4 from 680K to 470K because it seems to me that the dry signal is too low.

Best regards!

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DiscoFreq
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Post by DiscoFreq »

I liked them all, but I never tested them side by side, I bought the Polish models a few years before the EHX pedals.

I can't help you with the technical questions, I still have to find some time to learn about that ;)
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gigelmargel
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Post by gigelmargel »

DiscoFreq wrote:I liked them all, but I never tested them side by side, I bought the Polish models a few years before the EHX pedals.

I can't help you with the technical questions, I still have to find some time to learn about that ;)
OK...thx a lot anyway!

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Post by joeshmoe »

I stumbled on this forum when I suddenly remembered and Goog'd the f'ing name of this crappy, tweegy-looking EH pedal I bought and used in the early 70's with my P-bass when I was looking for something to try to emulate Squire's Rick when my band did Yes copies. For the life of me, I could not remember the name - I kept thinking it was called an Octave Equalizer and kept hitiing dead ends looking for it. I was looking through some old boxes in the basement, and I found a couple of the other EH plugin-type boxesI had forgotten about - a Screaming bird with no bottom cover and a Muff with more than a little corrosion on it and a broken solder connection, and I immediately remembered the name of the AE.
Anyway, this pedal fit the bill (to the extreme), to the point where I had people yelling at me to "tone down that horrible clicking noise". What it did, the way I used it (remember, this was the early seventies), was it exaggerated the bottom and top ends, and was able to do so in a way that it appeared to knock out almost all the mids. I remember also being able to set it so that it knocked out just about everything but the clicking of fret and pick noise on the RotoSounds I had on the Precision. The thing I really liked about it was that it was able to give the bass a really pillowy, muffled bottom, and of course a rather nasty treble edge at the same time, or go to one or the other extreme. It did give me a little grief on certain parts of the neck though, so it required, unfortunately, a somewhat narrow tonal "range" I had to settle for in order to keep from dropping out on certain notes. Probably nothing that any number of decent pedals couldn't do today, but back then it was a big deal to me, and quite frankly, if I ever dig it up, I'd probably use it ina heartbeat. It was what it was, but I don't think many musicians back then were able to find much good use for it.

dimych
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Post by dimych »

About Tesla Vrable Attack Equalizer: It seems like ironman28 got rebuilded device in old enclousure. Used soviet opamps К140УД2А, pots are soviet СП3-4, resistors and caps are soviet too, only one Tesla cap i noticed. Here is gutshots of my device.
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As you can see all parts are old Tesla made.

andregarcia57
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Post by andregarcia57 »

someone has layout?

mateuszkaczmarczyk
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Post by mateuszkaczmarczyk »

DiscoFreq wrote:I don't have the EH Attack EQ, but I do have the 3 Polish Attack EQ's by PUE, Kod and Koda, I suppose they're copies (the knobs have the same functions), but I'm not sure :)
Are any of those buffered? The polish ones. It's tough to find any info about them.

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