incl. mid/side matrix
Black front panel
Black body knobs, grey caps
Blue push button switches
Green shelving indicators
Potentiometers (center click @0dB)
12dB cut/boost range
External power supply unit included
Input: LUNDAHL LL1540 – they have a nice softening effect on the bass/lowmid frequency range. Signal looses some transient energy, but in a very pleasent way. If you aim for warm, smooth and „pillowish“ this helps a lot.
Output: CARNHILL VTB2281 – provides a very gentle rolloff towards bass and subs due to the interaction with the circuits output impedance. (see graph below). The good thing is that it´s perceived as more sparcle on top rather than less bass. Works great on mixes which seem a little too bass heavy.
Input and output Xformers are individualy switchable (hard relay bypass) from the frontpanel and insertion loss is compensated so there is no level change happening when switching the transformers in.
The transformers are placed inside the bypass loop but outside the mid/side matrix.
From +/-12dB to +/-6dB reduced cut/boost range provides more control around the 0dB position. Custom front panel with 6dB lettering.
12/6dB range switches
Output level controls
+/-10dB output gain knobs. 1/2dB steps. Placed directly after the EQ circuit but before the mid/side decoder so they control either left and right or mid & side level depending on if M/S is engaged.
It´s possible to combine the output level control with the transformer option or mid/side cue but not all 3 together due to limited space in the middlesection.
Front panel color
It’s possible to manufacture the face plate with a colored finish. Almost any RAL color is possible.
ELMA A4 series rotary switches instead of potentiometers, stuffed with precision metal film resistors (920 resistors for 30 switches) to squeeze out the last bit of precision. This is a custom build with a turn around time of 7-9 weeks.
There are 2 advantages compared to stepped potentiometers:
- Even higher precision and matching: Not only channel to channel, also even unit to unit. Recall the same setting on another HDE-250 and be sure it sounds 100% the same.
- Having control over stepsize: Stepped potentiometer come with a defined change in restance per step. Using switches, those resistance values per step can be determined by the actual resistors the rotary switch is stuffed with, so it is possible to precisely define every single step. This, for instance, allows for smaller gain steps around 0dB and become larger in the higher gain ranges or define custom frequency points.
Due to the different mechanical structure (frontpanel, circuitboard etc.) of the ELMA version it is not possible to upgrade/convert a potentiometer version to ELMA switches.
The output level control option is not available for the ELMA version since the switches are way larger than the potentiometers so there is less space in the center to fit the level control PCB in.
- 25 Watts external PSU
- Primary voltage 230 or 115V/AC
- Secondary voltage 24V/AC
Dimensions & weight
DC coupled, no coupling capacitors – servo regulated
- 1.8Hz – 414kHz (-3dB)
- 3.0Hz – 188kHz (-0.5dB)
Mid/Side matrix engaged
- 1.8Hz – 189kHz (-3dB)
- 3.0Hz – 81kHz (-0.5dB)
X-fomer option engaged (Input and output xformers)
- 7.0Hz – 106kHz (-3dB)
The HDE-250 features a global hard relay bypass. It takes the entire EQ out of the signal path when switched „off“
The band on/off switches act (electrically) like the cut/boost knob is set to 0dB when switched „off“
- Band 1: 15 – 820 Hz, shelf and bell
- Band 2: 15 – 820 Hz
- Band 3: 140 Hz – 8.2 kHz
- Band 4: 440 Hz – 25kHz
- Band 5: 440 Hz – 25kHz, shelf and bell
How & where?
If you´d like to purchase a HDE-250 please send me an email
- Base version: usually in stock
- Custom units: 2-3 weeks
- ELMA version: 8-9 weeks
Ordering a custom unit requires 50% deposit of estimated total and balance when the unit is finished.
Bankwire or Paypal accepted
|HDE-250 (Base version)||2190€|
|Stepped potentiometers (41 clicks)||+215€|
|6dB cut/boost range (incl. custom front panel)||0 €|
|12/6dB range switches (12dB-off-6dB or 10dB-off-5dB)||+195€|
|Custom front panel color||+95€|
|Custom knob/cap colors||0€|
|Custom push button colors||0€|
|Stainless steel handles||+25€|
|Output level controls||+185€|
|ELMA A4 series rotary switches instead of potentiometers||+3400€|
Prices excluding VAT and shipping. Effective 01/2020.
Orders from Germany or non business orders from inside the EU are subject to 16% German VAT
Germany: DHL 15 – 23€
European Union: DHL 49 – 65€
For shipping outside the EU we strongly recommend UPS or Fedex since the running time is more predictable.
North America: UPS around 165€ depending on exact location, running time usually 2-3days
South America: UPS or FedEx around 185€
Asia: please ask
Shipping costs vari a bit depending on total value and weight (xformer & ELMA option add extra weight)
Goods over 1000€ value and shipped outside the EU require ATLAS customs declaration so there will be a 1-2 days delay until we get the freight papers from customs and can ship the package.