This is a Nelson Pass designed ACA (Amp Camp Amp) that I built with a massive analog power supply. (The typical SMPS brick power supply supplied with the kit you can buy is a joke.). If you are a builder this is a great platform for building any of the Pass First Watt amps. All you have to do is bolt the power transistors to the massive single heat sink and mount the two amplifier boards. The power transformer is an Antek AS-4220 - 400VA 20V TRANSFORMER. Each filter board is 40,000 mfd of audio grade capacitors. As it stands it is an ACA with a lot of grunt and transparency thanks to the oversized analog power supply. It runs HOT. THIS IS NORMAL for a class A biased amplifier. The heat sink gets up to about 50C when it is fully warmed up which is where it should be. NO BOTTOM PLATE. Includes power cord. On Aug-31-23 at 08:37:55 PDT, seller added the following information: I also have a First Watt F5 clone for sale here on eBay.

Nelson Pass: This is a wonderful creation of Class A assemblage . So good. So real. No blemishes. Showroom look and sound. No longer produced. Internals are. JUMPERS included for RCA connections, over co- existing XLR (R) and (L) plug-in connectors. 10/10. Showroom. Pass Labs protectors in shipping box are excellent . Black with silver faceplate, LED blue.

Nelson Pass First Watt F4 25W Class A Amplifier, built inside NAD 208 case. Smooth detailed sound not for low efficiency speakers. Like everything else from First Watt the F4 is a unique amplifier. It has no feedback and no voltage gain, only current gain, it will deliver up to 25 watts into 8 ohms and 50 watts into 4 ohms. It is built as dual-mono circuit boards, powered by a 500w toroidal transformer and filtered with 86000uf per channel. It has a soft starter with thermal protection, speaker protection, rhodium plated RCA and banana sockets, input and output wires are silver plated OFC. The combination of a simple Class A circuit operated without feedback and the good objective performance gives us a superb sounding amplifier. The low distortion, bandwidth extension, and high damping results in midrange clarity, treble detail, and control on the bottom end. While these are available from most good solid state amplifiers, the F4 also brings depth, imaging, midrange warmth and top-end sweetness.

NELSON PASS FIRST WATT F4POWER AMPLIFIER The First Watt F4 is a classic Nelson Pass/First Watt design with JFET inputs and MOS-FET outputs. However, as with the other FW amps there is a twist here, namely that the F4 has no voltage gain. That means it’s essentially a buffer than can provide a full 25W class A output. its low or no gain so needs a preamp with a decent output Track Page Views WithAuctivas Counter

Nelson Pass First Watt F5 Power Amplifier.. 2nd owner, comes in good condition.