Photos of LDA builds

Prototypes

Prototype #1

This is the first, 200 Watt / 4 ohms prototype, which was made utilizing the transformer and heatsink of a defective Onkyo TX-SV525R amplifier. The first PCB version, LDA192, is in it, plus you can see the power supply with the solid state relay as well as the APBM protection circuit in a separate photo.

 

 

 

Prototype #2

A 2x110 Watt / 6 ohms prototype, which was made utilizing the transformer, power supply, and heatsink of a defective Onkyo TX-DS656 amplifier. This is still built on the LDA192 PCB, but it contains the modifications deemed appropriate according to the experimentation and measurements. The later LDA162 PCB has these modifications. It contains a temperature controlled fan and a protection circuit with mechanical relays.

 

 

Prototype #3

A 2x70 Watt / 8 ohms or 4 ohms prototype, which was built on the LDA162 PCB in the chassis of a defective Yamaha HTR-6230 amplifier, utilizing its transformer, power supply, heatsink, and protection relay.

 

Prototype #4

A 2x100 Watt / 6 ohms prototype, which was made utilizing the transformer and heatsink of a defective Onkyo TX-SV545 amplifier. It contains the LDA162 PCB, plus you can see the PS1S power supply and the SPRS turn-on thump muting circuit.

 

 

Prototype #5

In place of the LDA192 PCB of the first prototype, the newer LDA172 PCB was populated and installed, other things remained the same.

 

Prototype #6

The #5 prototype felt lonely being the only mono prototype, so I made another similar, 200-Watt one with the newest amplifier PCB, the LDA17. There is only a slight difference to the LDA172 PCB, but I deemed right to test it, too, before I offer it to other people. Test results are the same as with the LDA172.

 

 

 

Builds by other persons

József, Tápióbicske

József is the first person, who sent photos and comments after successfully building the LDA amplifier from the LDA172mc kit. He built the amplifier to lower than maximum power with lower supply voltage, and used the SPRS turn-on thump muting circuit. He designed and built his own power supply.

He commented on the result as follows: "Az élesztés a leírásod alapján nagyon egyszerű, könnyű beállítani. És ami a legfontosabb: nagyon jó a hangja... Ami nagyon tetszik az erősítődben: késő este, ultra kis hangerőn hallgatva is van mélye, még van benne dinamika is, de nagyobb hangerőn sem kezd el kiabálni. Szóval egy igen jól sikerült termék. Volt már néhány gyári erősítőm, de mind a kukában végezte. Mondjuk nem a high end kategóriából voltak, de jó nevű gyártóktól származtak pl.: Marantz. "

 

 

 

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