SL-2520 - Two versions of the SL-2520 were designed as replacement opamps for vintage console restoration. The vintage or “red dot” version is built to match the Huntington and Melville NY opamps from the 70’s. The clean, or “blue dot” version, is made to sound like the newer 2520 opamps.

The original intent for making two versions was to use the colored vintage opamps, in console mic pres, and the cleaner versions in the summing amps of vintage consoles.

Since then, many SL-2520’s have found their way into numerous DIY projects, EQ’s and even newer Legacy consoles. A great number of SL-2520’s are in use everyday in major market studio consoles including Nashville and New York.

Some customers have mixed 2 clean channels and 2 colored channels in multiple channel mic-pre’s to take advantage of different sonic characteristics within the same circuitry of a mic pre.

Upgrades - The SL-2520’s utilize the same circuit as the highly desirable vintage opamps from the 70’s but with modern components. (The original transistors are no longer manufactured) Modern transistors are generally quieter and faster than their vintage counterparts.

Through exhaustive lab and listening tests, I was able to match the distortion characteristics of the vintage and modern opamps to achieve a sound that has been deemed “indistinguishable” from the originals by vintage console owners.

“I chose Scott's amplifiers for our API console because they are indistinguishable from the vintage originals. I also like the fact that they are not potted, and will dissipate heat more efficiently. Scott provides our replacement amps quickly and at a good price.

Richard McLaurin

Sl-2520’s are purposely unpotted for better heat dissipation and to allow repairs if ever needed.


Quantity Per Op Amp Total Savings
10 $55 $550 $150
8 $57.50 $460 $100
6 $60 $360 $60
4 $62.50 $250 $30
2 $65 $130 $10
1 $70 $70 we encourage
you to buy in pairs