“God is in the detail” – Ludwig Mies van der Rohe (et al)
Sometimes it’s necessary to re-examine the little things, the forgotten details. Try to dig out the last 10% improvement.
Consider amplifier and loudspeaker connectors.
We know that music signals are alternating current, AC not DC – swinging positive/negative. We know also that “current in a conductor resides at the surface at high frequency” (Prof. Malcolm Hawksford,
HFNRR Aug 1985): Continue reading
It’s been over 2 years since I purchased a
Lounge Audio LCR phono preamp (US$300).
I was keen to investigate LCR phono EQ and possibly incorporate LCR EQ into my own
Phi-42 vacuum tube DIY phono stage.
I shipped my Lounge LCR (MkI) back to Lounge Audio (Robert Morin) in California, for upgrading to LCR Gold specification (plus some extras).
The results are outstanding.
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).
Pt I, next, the Amplifier boards are removed for modifications:
Reduce input gain by 50-60%, to suit higher output from modern digital sources (Roe MK2 and Takman REY metal film resistors, change values to increase feedback, output stage).
Replace electrolytic capacitors (Elna Silmic II).
Renew transistors (3 per channel, BC550).
The Quad 33 preamplifier is 50 years old, now.
It was introduced by Quad Electroacoustics in 1967 (to partner the 303 power amp) and 120,000 units were reportedly manufactured over 15 years.
The Quad 33/303 was Quad’s first Solid State consumer preamp/power-amp set.
My Quad 33 is serial no.6184, which means probably late 60s-early 70s manufacture.
Diego Nardi published his φ42 (Phi 42) Phono Preamp in Sound Practices magazine, issue 14.
This is an all-tube (valve) circuit, designed without (global) negative feedback.