Finished Preamp MODS

[drlowmu]

I bought this dual mono phono preamp new in 1981. It is called a NEXUS / Bravura Preamplifier. It was built by an EE and two musicians, primarily John Tuttle and Robert W. Fulton. It is solid state, integrated circuits. Like my tube SE amplifier, it has no coupling caps in it !! It's performance has always been superior, so I have kept it, and used it, for the past four decades, with little desire to change to something else.

I just yesterday applied mods I have learned, in the last 15 years, to this phono preamp. The three pictures will tell the tale. Its surprisingly better, primarily now more dynamic, and it plays better timbre of instruments.

I have been collecting LPs since 1962, have perhaps 12,000, so this becomes an important piece of equipment. I adore hearing analogue play back !!







Thanks for looking. This has been interesting DIY mod to do and hear.

drlowmu

 

[Dr.Gary]

I bought this dual mono phono preamp new in 1981. It is called a NEXUS / Bravura Preamplifier. It was built by an EE and two musicians, primarily John Tuttle and Robert W. Fulton. It is solid state, integrated circuits. Like my tube SE amplifier, it has no coupling caps in it !! It's performance has always been superior, so I have kept it, and used it, for the past four decades, with little desire to change to something else.

I just yesterday applied mods I have learned, in the last 15 years, to this phono preamp. The three pictures will tell the tale. Its surprisingly better, primarily now more dynamic, and it plays better timbre of instruments.

I have been collecting LPs since 1962, have perhaps 12,000, so this becomes an important piece of equipment. I adore hearing analogue play back !!



View attachment 56475View attachment 56476View attachment 56474



Thanks for looking. This has been interesting DIY mod to do and hear.

drlowmu

View attachment 56477

In another thread you stated "In mid to late 2021, I happened to A-B my Bravura, against a 12AX7 Trevor Lees Cascode Phono Preamp. On my reference baritone male voice, for the first time in 40 years, the baritone's voice sounded like a real human being, and not fake in any way. Nicely, another good audio friend, GAVE me that same Trevor Lees preamp, to use for as long as I wanted. The Trevor Lees preamp, built in a DYNA PAS-3 chassis, can be easily duped and upgraded by me. I actually have designed a different tube phone / line stage unit, and my intent in mid 2022 is to build an all-out tube preamp, using most of the design techniques applied to this 6005 amp build, highlighted in this thread. Yes, I loved the Bravura, and I was cheap, so I never tried to replace it. That one A-B of the baritone's voice, has caused me to park the solid state Bravura unit on my shelf, and I will never use it again."

Putting your once-beloved Bravura preamp on the shelf and vowing to never use it again is like permanently garaging a Ferrari because it needs a new set of tires. The power supply capacitors in your Bravura are forty years old and don't come close to the level of performance that current-technology low-impedance, low-ESR, high-frequency electrolytic capacitors are able to provide. Unfortunately, replacing the twelve original electrolytics in the Bravura is a daunting and challenging task that requires the total removal and subsequent re-installation of the star-ground wiring on the underside of the Bravura circuit board. Nonetheless, in my opinion, the sonic result is well worth the effort.