I wanted both a valve and a solid state phono amplifer for my vinyl set up so I asked forum member Alan (firebottle) if he’d build me one of his FIREBOTTLE preamp designs. I’ve had the amp for a couple of weeks now and this is just a short review. I'm currently waiting for my modified Cambridge 640 to return from Arkless and hope to do a more in depth comparison at a later date. Both units come in at a similar price.
SOURCE: Lenco L70 & Alphason Opal tonearm (A&R P77 with Jico SAS 1)
AMPLIFICATION: Harman Kardon A402 (PRE) into Quad II valve amplifiers
SPEAKERS: EMI 319
First thing to note, the amp is housed in a very stylish enclosure. It looks professional and its solidly built. I particularly liked the way the chassis splits into two halves making access to the innards quick and easy. You need only remove the top two screws on the front and back panels to remove the lid. Looking inside the build quality is excellent, the wiring neat and tidy. It reminds me of a Croft in its simplicity. Alan replaced the standard 47K resistor with a 100K so I could play around with both resistance and capacitance loading. He also fitted internal wire tails on the phono inputs. The amp uses Mullard valves. The line up is 2 x PCF80 (8A8) Triode/pentode. PCC189 (7ES8) double triode.
Warm up is essential, there’s a dramatic improvement over the first half hour and beyond - in particular, imaging becomes more focused after extended use. Straight off the bat it surpasses all of my previous amps including the stock Cambridge 640. There’s shed loads of gain from this amp in my system and it goes loud effortlessly. The presentation is much more 'up front' across the left and right channels with greater transparency. This has been a problem I've found with previous 'entry level' phono amps which are just too muted in this area, but with the firebottle the balance between the centre, left and right channels, and all the nuances in between, is excellent.
For the purpose of this review I was using 160K/91pf loading which seems to give the flattest response on my spectrum analyzer. The treble is clear and smooth, but not overwhelming. Most notable, however, was the bass response, I was pleasantly surprised at how rich and deep it was. I’ve been listening to a lot of dance orientated music recently and, in particular, Faithless - New Arrivals, was a joy to spin.
The overall sound stage is big and spacious, the excellent mid range is key to the firebottle, it's uncongested and smooth. Andy Sheppard's 'Java Jive' was particularly impressive with powerful imaging and realistic instrumentation. This will make an interesting comparison with the Arkless Cambridge - from memory when I had the Arkless loaner unit in my system for a couple of days the centre channel soundstage dramatically shrunk due to the amps ruthless transparency and precision. It'll be interesting to discover how the two compare.
Overall I'm well pleased with this amp, I can't think you'd find a better value valve phono pre for the money. I'll update further when the modified Cambridge arrives.