Amplifiers on the bench

After purchasing a (Tonghui) dB-Millivolt meter, I am able to more easily (and more accurately) undertake frequency response measurements of my Preamp and Power amp.

This enables me to directly read relative dB signal voltage output from my amplifier (or preamp) without laborious 20Log Vout/Vin calculations. (Thanks to advice from my pal Clarry.)

I will check out my recently built WOT Preamp and my usual 2A3 Push-pull amplifier. Continue reading

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WOT tube line-stage redux

A Line-stage With Output Transformer (WOT) was built back in 1998, a single 5687 tube per channel with output transformer (OPT).

However I failed to get rid of noise (EM pick-up and attenuator switching noise).  I lacked the expertise to optimise Grounding and to shield and/or orientate the output transformers (OPTs) properly.

Now, I have been fortunate to acquire a pair of Tango NP-126 Line Output transformers. So, I must re-visit the WOT Line-stage. Continue reading

LONDON DECCA cartridge

Since Feb 2018, I have been enjoying a London Decca ‘Super Gold’ cartridge.

This is a Moving Iron/Variable Reluctance type cartridge – with Moving Magnet level of high output – 5mV.

After a few decades of listening to high-end Moving Coil cartridges, the sound of the London Decca is a revelation. A different sound presentation. No need for A/B comparisons, the London Decca delivers exhilarating energy and power. It sounds more like ‘live’ music to me. Continue reading

REGA Planar 3 restoration

The iconic Rega Planar 3 turntable has been around since introduction in 1977.  The most recent editions are the P3 or RP3.

Thus, there are 30 to 40 year old Rega Planar turntables now in need of restoration.

This Planar 3 is from early-1980s, fitted with a Linn LV-V tonearm (and an un-branded Japanese moving magnet cartridge).

Continue reading

The WAND tonearm

The Wand tonearm was designed by Simon Brown (Design Build Listen Ltd) in Dunedin, New Zealand and was introduced in 2011.

This is a uni-pivot tonearm using Simon Brown’s own ‘defined contact’ uni-pivot implementation, a unique large diameter carbon fibre arm tube and stainless steel metalwork.

This model, The Wand Classic, is a ‘no-frills’ entry-level model with attractive pricing. Continue reading

The case for MM and MI cartridges

Moving Coil cartridge design has not changed fundamentally for 30+ years.

The traditional design of almost all MC cartridges, consists of a stylus on the end of a long cantilever, with a ‘moving coil’ attached to the inner end.

This whole assembly ‘sits’ onto a soft, resilient ”suspension’ or damper’ material and held in place by a rear tension wire. Continue reading