East Uni-Pre adjustments questions

[p12bassnut]

I am looking for a simplified explanation of the Bass/Treble EQ circuit adjustments available on this preamp.
Set Treble Control Freq.
Set Bass Control Upper Freq.
Set Bass Control Lower Freq.

These are the 3 frequency adjustments on the circuit board. (accessed from inside)

Is the Bass boost/cut a sort of parametric ? Why is there a lower AND upper bass freq adjustment?
How does one adjust these in relation the each other?
Also, Is it CW or CCW for the lower end of each frequency range ?

I am just trying to understand how this preamp works and get the maximum amount of flexibility in my situation.

 

[Killing Floor]

Hey. Search the John East Preamp Club in TB. Better luck.

I only have the 3 bands with bass, treble and parametric mid.

The John East preamp club

 

[Mr. Jiggy Fly]

Are you referring to the Skjold/East Deluxe preamp? I can explain that for you. But the newer East UNI preamps are different and, I believe, feature parametric freq selection points as you cited above.

The Skjold East pre is quite different and features a treble boost, sweepable midrange freq. selection, and a passive tone. Mine also uses a four way selector rather than traditional blend control.

I am looking for a simplified explanation of the Bass/Treble EQ circuit adjustments available on this preamp.
Set Treble Control Freq.
Set Bass Control Upper Freq.
Set Bass Control Lower Freq.

These are the 3 frequency adjustments on the circuit board. (accessed from inside)

Is the Bass boost/cut a sort of parametric ? Why is there a lower AND upper bass freq adjustment?
How does one adjust these in relation the each other?
Also, Is it CW or CCW for the lower end of each frequency range ?

I am just trying to understand how this preamp works and get the maximum amount of flexibility in my situation.

 

[p12bassnut]

Yes it is in a Skjold.
Here is a picture of the 3 adjustments available.
Treble Control Freq.
Bass Control Upper Freq.
Bass Control Lower Freq.
Any clarification on this would be appreciated.

 

[p12bassnut]

Bump

 

[Jared Lash]

I don't know if you're still looking for an answer here but essentially the lower and upper bass settings control how much of the bass frequencies are boosted when turning up the bass knob.

The lower setting (on the Uni pre at least, don't know if it's different for the Skjold version) goes from 20-80 Hz and the upper setting goes from 40-200 Hz.

So at the widest (lower setting at 20 Hz, upper setting at 200 Hz) when you turn up the bass knob it increases all of the frequencies between 20-200 Hz. At the narrowest (lower knob at 40 Hz, Upper knob at 40 Hz) you would just get a narrow bass boost right at 40 Hz.

I haven't scoped it but it sounds to me like there's still a peak at whatever the middle of the setting is and it rolls off towards the lower and higher bass settings. My ears may be fooling me, but if this is the case it's not an equal boost across all the selected bass frequencies but more the range or window that is affected.

But the bottom line is that it only matters what sounds good to you. The factory settings are (I believe) 20 Hz and 60 Hz so you might start there. Put the lower control at the lowest point and the upper control one a little bit up from the lowest setting and adjust from there.

The treble control is shelving so it boosts all the frequencies above the frequency you set it at. The range is 1kHz to 7.5 kHz. Start with it in the middle (factory setting is 4 kHz) and adjust based on whether you want your treble boost to start higher or lower.

Personally I feel like shelving at 2kHz or lower is overkill but YMMV.

And of course you can always try to contact Pete Skjold. Since it's one of his basses I bet he'd help you with preamp adjustments/advice.

 

[p12bassnut]

Thank you for the info. It does help me understand how the preamp works and what I'm actually adjusting.

 

[VSR]

Is somebody so kind to help me with the following?

On a East UK Uni-Pre Onboard Preamp where are the factory settings for each knob? (at what time on the internal white knobs the arrow is pointing?)

According to the manual the factory default settings are as follows:

• Flat Response / Pre-Shaper - set to Flat Response.

• Bass Control: Boost & Cut / Boost Only - set to Boost & Cut.

• Bass Control: Lower Window Frequency - 20Hz.

• Bass Control: Higher Window Frequency - 60Hz.

• Treble Control: Shelf Frequency - 4kHz.