Success at last!!
Over the last few days I have been building and subsequently troubleshooting my newest preamp design. I
and
and suddenly
when I realized I wired the pins backwards!
Anyways...enough about me! What about the preamp?
I wanted to build a simple preamp that could either be built as a kit or assembled in a day or so with pretty cheap parts but would provide a level of performance way out of its pricing league.
The design is a single polarity common cathode with humbucking feedback to eliminate noise. All resistors are 1% metals and the signal caps are Jantzen Z-standard and cross-caps (right at a buck a piece). Total parts cost was $150, with shipping involved $175 or so.
The tube is a 6j6 which is a common cathode dual triode in a miniature 7 pin bottle. Here is one next to a 12ax7:
The chassis is a Hammond job, as is the tranny and choke (if these were sold the PSU would be changed to a CRC filter with comparable ripple and voltage for cost savings).
Selector switch is from TCJ and the pot is an ALPS blue.
The heaters are odd as they are exposed and glow all the way up the side of the tubes:
And finally, the insides:
How does it sound?
Like a lot more than $200, but not like $1000 thats for sure. I would put it on the warm side like the candela or VTL deluxe that I own. I have only listened to a few songs so I don't have detailed impressions, but I listened to some of my usual test songs and I have a pretty good idea of what it will sound like over time.
Highs are smooth and sort of laid back, but accurate. Bass is much the same...at first I thought it was thin but then I realized it was more warm and accurate sounding. Mids are warm. Detail is good but not heart-stopping, it certainly would not replace my Aikido but at less than half the price I did not expect it to either. Soundstage is wide but not particularly deep, it has some depth but it does not project forward like the aikido can.
Overall I am pretty happy. I have some Westinghouse tubes coming and a lot of the Russian version coming as well.
