Last spring, I boxed up the stereo and put it in storage for the duration of the lounge remodel. When I unboxed it and powered up the system, my trusty Conrad Johnson PV1 preamp failed. After considering its age, accumulated problems, and the technical evolution occurring since I had bought it in 1980, I elected to replace rather than to repair.
- Richard Schram & John Curl Discuss Amplifiers at YouTube
What Happened to the PV1
Some years ago (1996) it began to make an occasional audible pop. I traced this down to the HV power supply. Rather than repair the existing supply, I found a HV regulator board from Welborne Labs, ordered one making the proper B+ voltage, and installed it in the CJ. The change actually included 2 boards, one for the filament supply and a second for the B+. The amplifier used two different B+ voltages so I made a little daughter board to derive the second voltage.
I was not careful about the sizing of a couple of resistors and undersized them for power dissipation. Over the years, they toasted and finally failed. Also, Welborne Labs had gone out of business and preamp voltage regulator boards were no longer available.
At the time I did this, I didn’t record the voltages produced by the original regulator. So when the home-brew regulator failed, I didn’t have the voltages in hand to design a replacement. Unfortunately, there was no service manual to be had and CJ had gotten seriously expensive since the beginnings of the high end in the 1970s.
Also, the PV1 had too few inputs to support an FM tuner, digital audio, TV audio and the other things it was going. And the input jack spacing was too narrow to use with modern RCA connectors.
Buy a modern preamp. But which one? I had Cambridge Audio DAC, FM tuner, and DVD player and liked the voicing and pricing of these products. Cambridge Audio is entry level high end gear well designed in London and contract manufactured in the mystic east.
But I remembered seeing many mentions of Parasound amplifiers in Absolute Sound over the years so I checked to see what the buzz was around current equipment. Both Absolute Sound and Stereophile listed the Parasound P5 as recommended equipment with kind words for the voicing and imaging of the product. It was the same price as the Cambridge Audio Azur 851. I literally flipped a coin and ordered the P5 from Audio Advisor.
The P5 arrived quickly, I set it up, and listened for a bit. I like the sound but hadn’t put any effort into speaker placement. About a week ago I rearranged the lounge to make entry to the kitchen easier. While I was at it, I moved the speakers to new positions flanking my audio cabinet but well into the room. The change in sound was amazing. The Dhalquist DQ-10s were now far enough from the back wall to image properly. The sound in the new position was coherent, the bass deep, and multiple layers of depth. Just beautiful.
My current system has the following major components
- 2009 Mac Mini running iTunes or Plex to play the little bit of FLAC I have
- Apple TV 4 with Plex and Tablo TV
- Apple TV 3 for music with the Telly off
- Apple Airport Express router
- Netgear 8 port Ethernet switch
- Panasonic ST42 plasma TV
- Parasound P5
- Cambridge Audio Azur 8851 BluRay player
- Cambridge Audio Azur FM tuner
- Cambridge Audio DACmagic DAC
- GAS Ampzilla
- Dhalquist DQ-10
- Cardas PB&J interconnects
- Nordost speaker cable
- Belafonte Live at Carnegie Hall
- Jazz at the Pawnshop
- Neil Young tracks from Weld, Harvest Moon, etc
- CSNY tracks from several of their records
- Tom Paxton
- Tom Rush
- kd lang Hymns of the 49th Parallel
- Cowboy Junkies The Trinity Session
- Cowboy Junkies Trinity Revisited
- D-Stringz by Stanely Clarke and company
- Buddy Guy Born to Play Guitar
Why the New Networking Bits
Since I first put this system together, I’ve added an Airport Express router and a basic layer 2 Ethernet switch. Originally, just a switch was in the rack. And WiFi in the lounge was spotty. The Airport Express serves the following functions
- Extends the 2.4 and 5 GHz WiFI networks in the lounge
- Starts a new collision domain spanning only the audio and video racks
The new collision domain makes both the lounge area network and the study area network calmer and more stable.
The Parasound Video
After doing this bit of rearranging and adding Cardas PB&J interconnects for the DVD player, DAC, and power amp (GAS Ampzilla) I did a YouTube search that located the interview video with Richard and John Curl, audio design consultant extraordinary. Richard talked about the company history and business practices and John talked about his fully differential complementary symmetry amplifier designs. And he mentioned his power amps that he designed for the Grateful Dead’s Wall of Sound touring rig. Cousin Bill had heard the Dead’s sound at a live concert here in VB during his mis-spent youth and found the video interesting. I expect I’ve just put a dent in Cousin BIll’s toy budget.