Italy - APP discrete op amps

APP - Abbate Pier Paolo



Our products:


Discrete operational amplifiers (DOA):


APP2050 (ver.2.0)

This op amps was designed for being used in preamplifier stage thanks its ultra low voltage noise.
I started for fun from the original jt-990 schematic, but all 990's stages are been improved by me in APP2050, so APP2050 could be considered an inedit circuit.

APP2050 has a frequency compensation circuit, totally different from that used in jt-990, for having great stability with capacitive loads (until 100nF) at unity gain, but with high slew rate and big gain. For less distortion, thanks to this circuit, the APP2050 can drive directly the output transformer without the LR network required with 990 (the jensen transformers jt-oli-3).

APP2050 has ultra low voltage input noise for 1:1 or 1:2 input transformers or trasformerless solutions.
Moreover APP2050 can run in effective class A operation.

web page:APP eng APP2050

- ultra low noise - 0.8V/rt Hz
- runs on class A up to 22dBu on 600ohm.
- unity gain stable on capacitive loads (up to 100nF)
- high slew rate 30V/uS
- quiescent current: +/- 38mA
- very high gain: 130 db max at low frequency.
- potted with special low thermal resistance resin.

NOTE: je-990 footprint with solderable 0.7 or 1.0 mm pins diameter.

price: 40 USD (launch price), selling on Ebay on request (I have 51/51 100% positive feedbacks).
Note: all prices are without shipping cost and VAT.


Power modules:

APPSI1022
mosfet power amplifier module.
- audiophile topology.
- max power : 100W on 8 Ohm, 180W on 4 ohm, 250W on 2 ohm.
- run on class AB.
Note: very trasparent and accurate sound.


contact us for more informations.



Company address:
Leonardo Da Vinci st. 111, 90145, Palermo, Italy, E.U.
e-mail:ppabbate@tele2.it contact: Pier Paolo.
internet site: APP studio engineering. (new site caming soon)