Rose RV23 Preamp

This preamp dates from the early 90s when it had a reputation for great sound quality. It stands the passage of time well and still sounds very decent. It had had various mods and servicing over the years, including main electrolytic capacitors, valve sockets etc.Someone had also replaced the ribbon connector with some Cat cabling.It is a hybrid valve /solid state design, with transistors used for the phono stage and valves for the line stage.

My work was to upgrade the coupling capacitors, and add a choke power supply by adding a choke and additional smoothing capacitor. Once this work was complete it transpired the original main smoothing capacitor was pretty spent, so that was replaced too.That took a while to find as it broke down after around 2 hours use, but was fine up until then.

The result was very worthwhile, performance has been lifted to a very pleasing level. The pre operates with a much quieter background, displays subtleties better and is more dynamic to boot.

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WAD Pre2 /PSU 2 For sale

I’m selling these on behalf of a client who’s upgraded to my KT150 amps and preamp. These have been converted to cathode follower design as an improvement over the original hummy WAD design. These have been converted to cathode follower design as an improvement over the original hummy WAD design. The build contains every possible upgrade including: Tocos carbon pot in shunt mode with Vishay naked foil resistors, Vishay naked foil grid resistors, Jupiter beeswax signal caps. The power supply has an upgraded 30 Henry choke, Schottky heater diodes, and Hexfred HT diodes.*The valve is an ECC88 gold pin Mullard. Excellent sounding line pre in daily use. Front panels in good condition, some scratches on sides of black chassis.

AD Audio Announces New Amplifier and Preamplifier

AD Audio is pleased to announce a licensing agreement with Oddwatt Audio to build their amplifiers and preamplifiers. The first two products are the Cannonball KT150 Monoblocks and the Satchmo preamplifier.

For full details visit the AD Audio Sales Site here

Audiolab 8000a. 

The venerable 8000a can be split into pre and power amps relatively easily. Sockets are already provided, so it’s a case of removing two buffer resistors to remove the internal link between pre and power amps and adding two input caps to block any DC going to the power amps. It is also relatively easy to plumb in a relay in parallel with. The main delay circuit to add an 8sec mute to the pre out. Finding a relay that fitted the circuit board proved impossible, so I had to plumb in a larger relay. You also have to install the power for the relay from the main delay circuit.

The photos show the finished article with the white blocking caps and relay visible in the topside photo and power supply cable underneath.