The VP312 is an almost exact replica of the vintage API 312 circuit designed for 500 series or 51x Alliance racks. Input and output transformers are Ed Anderson’s replicas of the vintage API iron. The PCB incorporates the standard 2520 opamp footprint.
The VP312DI is basically the same preamp as the VP312, but with a bunch of built in DI options. These include pre or post input transformer modes, and a high-pass filter. Users can chose between many passive or active DI “plug-ins.” Unlike the VP312, this PCB cannot be cut down to fit four in a 1RU chassis.
- 500 series/51x compatible
- Can be adapted to fit four in a 1RU rack case
- Blank or finished faceplate and mounting bracket included
- Bourns gain pot
- Output trim
- API-style knobs with colored inserts
- 51x version takes advantage of +/-24v power rails
- Numerous DIY or prebuilt opamp choices
Price: VP312: $205.15-209.92 (+opamps)
Classic Audio Products offers two versions of this kit, one for 500-series racks ($208.27), and one for the DIY 51x racks ($213.12). One can also opt for a blank faceplate, which knocks $11.13 off of the price. Also, there is a 1% discount for ordering two or more channels. Finally, the opamp offerings vary in price from $17.31 for the Gar1731 bundle (gotta love a company that literally matches the price to the product) to $65 for the SL-250 Red/Blue Dots.
Adjusted Price: $293.65/channel (6 channels)
Since there are so many opamp and racking options, it’s impossible to calculate a really representative adjusted price, so let’s look at a one possible scenario. Buying two or more VP312 kits ($205.15 each) with the Gar2520 opamp bundle ($17.50 each), makes each channel $222.65. Add to this $71/channel of the API lunchbox, and you’ve got an adjusted price of $293.65/channel.
For more information visit Classic Audio Products, Inc.