New "Moog" modules for 2023

Three new modules for 2023, see the "Moog eurorack modules" page for more details:

951 and 952 Keyboard Inferface modules.

These modules provide functionality that is present in Moog modular keyboards, and are primarily intended to provide easy performance adjustment of 901A/B oscillators. They can also be used with standard Behringer System 55 VCO modules.

Each module features:
-  “Scale” control: CV multiplier, from 0.94 to 1.06
-  “Range” control: adds or subtracts an offset to the CV ±150mV (approx 2 semitones)
-  Switchable exponential or LCR (“linear constant rate”) glide.

The 951 is an 8HP single channel module. The 952 is dual channel module, also in 8HP.

 

 

 

1125 Sample-Hold Controller

The Fitzgreyve 1125 is a 16HP Eurorack implementation of the Moog 1125 “Sample-Hold Controller “ accessory.

The original Moog design has been used, but with the following additions:

-          START and STOP input jacks, voltage triggered (V-TRIG).

-          External Sample-Hold input jack, bypassing internal voltage sources.

The panel layout is intended to capture some of the “look and feel” of the original, in a Eurorack format.

 1125 Video:

 

Not "Black Friday" Sale

 The "not black Friday" Sale.

I'm clearing out some of my older projects, so it's "buy the panel, get the PCB for FREE":

Until further notice, all of the panels below now come with a matching FREE PCB:

 

100m-ish Modules:

• 100m-ish VCO Driver  GBP 14.00 (3 in stock)
• 100m-ish Audio Delay GBP 15.00 (9 in stock)
• 100m-ish Ring Mod GBP 12.00 (1 in stock)
• 100m-ish Signal switch Aluminium panel GBP 16.00 (7 in stock)
• 100m-ish fixed HPF Aluminium panel GBP 12.00 (7 in stock) slide switches included
• 100m-ish fixed HPF Black FR4 panel GBP 6.00 (8 in stock)  slide switches NOT included (see below)
  

 

Other Modules:

• dAhDShR enhanced ADSR GBP 16.00 (7 in stock)
• Transient/ dAhDShR Expander Black Aluminium Panel GBP 10.00 (8 in stock)
  

 

Useful accessories:

• Slide switches for 100m-ish HPF GBP 2.00 for 2
• Programmed PIC chip for dAhDShR GBP 6.00

 

995A Reversible Attenuators

 

My latest module is a Eurorack implementation of the rare Moog 995A reversible attenuators, or “attenuverters” in modern terminology. This was suggested by a customer.

As far as I am aware, this was produced as a “special” for the Keith Emerson Moog Modular, and therefore only included in the recent "Emerson" reproductions.

The module uses my interpretation of the Moog op-amp based attenuverter circuit based on the  CP3A PCB.

912 Envelope Follower development

 

Debugging of the 912 envelope follower is proceeding. I found a couple of minor errors in my PCB design (missing tracks!) that are easily corrected.

Once adjusted using the published Moog procedure, it seems to work OK - mostly.

The one issue I need to resolve is that althought the control output is fine down to 1mV RMS input signal, it becomes unstable when there is no input signal present.

 

Below are a couple of oscilloscope traces of the "control output" (upper) when the input is a repeating 250Hz sine wave envelope (lower).

 

I believe there is an error in the published Moog Schematic - the CL-1 diode in the trigger generator is the wrong way round ? With the schematic, the diode simply provides a path from +12V to 0V via R9A (330 ohm) - R9A just gets hot!

I believe the diode needs to be reversed, this is supported by pictures of actual Moog 912 units, where the diode cathode is clearly connected to R9A.

Another 904C Filter coupler video

Couple of videos of the 904C Filter Coupler in action, this time one built by a customer:

 

 

Eurorack "Moog" Modular

Having started with "Moog" modules in eurorack just over a year ago, my planned two cases are now complete:

I orginally planned this as a Moog IIIC lookalike. I made the decision that the lower ("console") row would be normal eurorack height, not the reduced module height used in the original (5U high) Moog modular.

Key to modules: (B) Behringer, (F) Fitzgreyve, (A) AMSynths:

Top cabinet:
(B) 914, (F) 992, (B) 904A, (F) 904C, (B) 904B, (B) 904A with AMSynths daughter board, (B) 994, 2 x (F) 911+, 3 x (B) 902, (A) 993, (B) 911, (B) 911A, 2 x (B) 911.

Bottom cabinet, upper row:
(F) 901ABBB, (F) 901ABBC, (F) 901, (B) 921, (B) 995, (B) 960, (B) 962, 2HP Tune

Bottom cabinet, lower row:
2 x (F) CP3, (F) CP3A, (B) 923, (B) 961, (A) 924 mixer PCB with (F) panel.

The cases are recycled vintage mahogany. I've already got more modules than case space, so another case is being build. Not fitted, lying on top: (F) 991, spare (F) 901B, another (B) 921.

911+ Envelope Generator

 

The Behringer 911 Envelope generator is excellent value for money, but suffers from difficulty getting values at the extremes of control travel due to the use of budget potentiometers. This is particularly a problem at the low end of the T1,T2, T3 controls which leads to difficulty in setting short envelope times. The panel control values also do not generally match the actual envelope times.

This module is designed to address the above issues, add some additional functionality (looping modes, linear envelopes, "Punch", Time and Level modulation), while maintaining the Behringer System 55 “look and feel”.

The Fitzgreyve 911+ uses nothing resembling the original Moog circuit, being based on a PIC microcontroller. Single PCB, all through-hole components.

 

 

 

ADR envelope in LFO mode.