I managed to pick up one of the retro styled Yamaha A-S1000 integrated amps at a good price off eBay. I first spotted these in the windows of Practical HiFi and Sevenoaks and was taken back by the build quality and looks for the price. Furthermore I wanted an amp with tone controls and an headphone output. Yes... you read right... 'Tone controls'. Even in my narrow music tastes of Berlin School, Electronic and Ambient etc there is a wide range of mixes in that some sound lean and others the opposite; so I thought tone controls could be useful. Also the Radio seems to vary widely especially between daytime and night-time shows. Most daytime shows on Radio 2 sound more compressed and lacklustre compared to later shows at night so another reason for trying tone controls out.

YSA Symphonies Plus

The Symphonies Plus Vacuum Tube Pre-amp is made and sold by YS audio as a level 2 product for around £490 + duty and taxes in the UK.  It was originally cheaper at just over £200 but they seem to have increased the price late 2009. YSA have a scale of 1 to 4 for their products and they sell a number of pre-amps and power amps at various levels of internal parts quality and upgrades.

This pre can be upgraded to level 4 by some mods and tweaks recommended by the original designer. It needs some changes to get the very best out of it and in some set-up's without a few critical mods it could sound mis-matched. It uses 3 x Ecc83 (12AX7) tubes with global feedback in the circuit. Sound of the unit before any upgrades or mods is fast, dynamic with bite and edge without being overly sharp, not at all fat, slow, coloured and mushy like some other tube amps can be. Construction quality as standard is excellent with a full non magnetic anodised black metal chassis, thick brushed aluminium face plate, anodised aluminium knobs, C core mains transformer, regulated power supply, tube rectifier, circuit screening and tube dampers etc. Dale resistors are also used throughout the circuit.

Lightspeed Passive

If you search the diyaudio.com forum you will come across a passive attenuator design by a guy called George Stantscheff. What makes his design unique is that the audio does not pass through any contact points in the form of a "wiper" as with a pot or a stepped attenuator. The main component in the Light-speed Attenuator are Silonex NSL-32SR2 Opto-couplers.

Sound

Sound is very surprising for a passive and not what I expected when I borrowed a DIY one off Dave H down the road from me. Most passives sound detailed but thin, weak, small and lacking dynamics. This passive is quite the opposite having a very wide sound stage, really deep bass and a natural textured sound. This is by far the best passive pre-amp I have ever heard even compared to TVC / AVC units. In a system with sensitive speakers it works amazingly well. However with difficult loads such as a power amp needing an active pre-amp with voltage gain like my Nelson Pass F5 or the F3, or using speakers under 90+ db then it is not as great. It still has the same wide sound, deep bass, detail and naturalness, but it sounds 2D with no projection. It just lacks that edge and bite of an active stage.