DIYRE EQP5 Pultec EQ Kit

DIYRE EQP5.

My first foray into the world of 500 series modules is with the DIYRE EQP5 Passive EQ kit.  The build includes the vintage option using all stock components, except for the Warm Audio X731 op amp that I had layng around.

I was hoping for the CAPI 511 rack to become available as the foundation of my 500 series journey, but couldn’t wait for it to come back into stock. A promotional summer sale of the Fredenstein racks pushed me over the edge to move past waiting for the CAPI. I ended up with a Bento 8, after reading some positive reviews indicating that the power supply was improved over older models.

Fredenstein Bento 8.

Edit - 7/21/23 - I built GAR AM10 and OA10 op amps for the EQP5 to try a non-API flavor in the EQP5. These are Quad Eight and Neumann circuits respectively. The OA10 is described as the warmest of the GAR op amps, and I wonder if this means I can push the high shelf control up a little more without getting harsh. I haven’t compared these two op amps side by side yet, but will be an interesting exercise to see if my preconceived notions hold up.

GAR AM10 and OA10 op amps.

Running drums into the EQP5 with the EQ flat adds a subtle tonal change at unity gain with the OA10 installed. The level seemed to drop a few tenths of a dB with the Warm X731, so I was glad to have built the GAR op amps. The push-pull trick with the LF controls tightens up the kick drum without making it sound smaller. Being able to boost/cut 30Hz or 60Hz independently is a nice subtle detail. The HF boost at 10k gives sparkle to cymbals, but is subtle enough to avoid harshness.

For bass guitar, I wanted a little more control over the frequencies. I liked what the HF boost did on dreadnaught acoustic guitar recorded with my mid-heavy Beesneez BU87I C.

To be continued.