Helsinki DIY 2011
It was a rather small scale event on a sunny spring Sunday and in a pleasent environment - an old mension of Rastila from the early 19th century.
Not as popular as the pet show held simultaneously elsewhere in the city; empty seats were looming large - at least when I popped in.
Echoey rooms made the circumstances far from ideal for serious listening but the "stimmung" was good. It's the gear that steels the main attention here. And a lot of respect goes to the sincerity of the DIY hobbyists who brought their stuff there. These are people who in their own way want to study concepts not available on commercial markets, and people who invest in true knowledge rather than in surfaces.
The event consisted of five rooms equallying to five setups. The core of the first room was a 4" Jordan JX92 based single unit speaker.
To smooth irregularities caused by the round design-enclosure, the presenter had developed a special filter section housed in a big wooden box reminding me of a box where wood for sauna are kept.
The source was a computer hooked to a b-DAC, and amplification was provided by a Harman-Kardon integrated. The Behringer active crossover was for filtering the subs, which apparently were not needed in the smallish room. Quite listenable sound, if not quite reaching the moon.
Cigar and other wooden boxes are something that DIY hobbyists all over the world fancy. This wooden box is from IKEA, and houses a DIY USB DAC.
The famous Philips AD9710 drivers were mounted in dimensionally challenged OB baffles. Given that a criterion for these speakers was minimum time needed for building them, the sound was not bad at all. The dry and somewhat forward yet smooth character of the sound of these vintage drivers is always appealing.
The speakers were driven by 2-3 watts of a ECL82 SE Mullard clone. Modified.
The system by Hannes H. trusted on an active 3-way speaker with an anonymous woofer, SEAS midranger and a Bohlender&Graebener ribbon tweeter. The speaker was fed via Behringer crossover by 6 channel Rotel power amp, and Primare P30 pre. An atypical sound: atypical to commercial speakers, but not in this context. Nice.
The next system made use of massive OB baffles designed by Kimmo Manner. An open, well-thought sound in a challenging listening environment.
... featuring a Supravox midrange driver and a Fostex FT96 tweeter. The midrange unit starts to roll off naturally around 300Hz, the roll off was speeded up with adequate filtering to match its response with the 12" Supravox woofer.
The speaker was fed by Ayon Spirit II as a power amp, a phonostage with a pot was functioning as a preamp. The analogue source was Linn Sondek LP12, and digitally music was sourced from a laptop and E-MU 0404 USB DAC.
JSL demoed a simple and straight system a with 2,5-way speakers in a sealed box, a single-end pre and power mono blocks. The speakers are configured as D'Apollito with 6dB crossover slopes. Two Vifa P17WG mid/bass units and one Seas DXT tweeter.
Inside the the preamp there's a 24bit/192kHz DAC and a phonostage. The mono blocks are single-ended Class A, zero feedback designs delivering 5-10 watts of useful power.
Some miscs. This is an interesting PP (PCL84/ECC83) tube amp by Raimo Jokinen, in that its left channel is a phase-inverting (out of phase) design, and the right channel is an ultralinear PP. The amp enables listening one channel at the time in order to facilitate comparisons. In a stereo listening - I was told - there was no way of telling the difference but in a mono listening the difference was recognizable, in favour of the left channel.
By the same designer: 7W from two ECL82's.
An old Finnish hifi-speaker by Salora.
