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$77.00AUD inc GST for Australian Customers
(Approx $53.08USD outside Australia)

Product Information
Stock Level0

JLM25HVFET opamp is a modern take on the 2520 but with several improvements and changes including a high impedance FET input stage.

This opamp is made to be used in circuits where the DI input is after the input transformer directly feeding the +in of the opamp.

It allows the normal 100k or less resistor from the opamp +input to 0v to be changed to 1Meg or higher to give a fantastic high impedance DI input without opamp DC offset problems.

  • FET input instead of normal Bipolar.
  • Voltage range of +/-12v to +/-25v.
  • Improved constant current source.
  • Improved thermal layout for least DC offset on output.
  • Improved output transistor thermal bias current control.
  • Opamp is open unpotted design for servicing and repairs.

We test the JLM25HVFET at +/-25v into a 50ohm load at extreme overload.

Works perfectly on our BA BAD BAN PCB's or any normal 25** type mic pre & EQ PCB. Doesn't work in API2500 comp.

Test results for JLM25HV/FET against vintage API 2520 in BA kit


Frequency response (from 40 Hz to 15 kHz), dB:+0.10, -0.56+0.10, -0.56+0.10, -0.56
Noise level, dB (A):-108.6-108.3-108.6
Dynamic range, dB (A):108.5108.4108.4
THD, %:0.00210.00230.0024
IMD + Noise, %:0.0220.0240.024
DC offset at opamp output pin+/-25mV+/-20mV+/-50mV
Min to Max +/-power rails+/-12v to +/-20v+/-12v to +/-25v+/-12v to +/-25v


Frequency response in BA kit

Spectrum graph


Noise level in BA kit @ 10dB of gain

Spectrum graph

Basically noise floor of computer testing setup except for 50Hz peak due to open BA PCB kit on bench with no case.

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