|Timbo in Oz 's How long have you had those ugly spheres Tim? 25 years! ???? System|
|IP Address: 188.8.131.52||Last Update: July 17, 2019 at 20:36:43|
|Amplifier:||Two Leak Stereo 20's rebuilt / MODIFIED. They passively bi-amp the spherical speakers.|
PP EL84 / 6BQ5 amps (Sovtek EL84M). One in pentode (20wpc)and one in triode mode. The originality types hate me.
Spare Stax DA80 45wpc pure class-A transistor amp. A 1980's Transistor classic, now updated with STAX reference type gain and driver stages.
|Preamplifier (or None if Integrated):||A four valve pre-amp, in a gutted Quad 22 box. Separate big regulated PSU, with '0-volt' reference ground plane. DC heaters. Ceramic sockets, heaps of new 'good' RCA's on back. DIN socket for tape monitor.|
RCA type Phono stage 12AX7 x 2 and passive RIAA. 1 x 12AT7 for line gain + 1 x 12AU7 for gain-less output buffer.
The RIAA stage has a steep <20 hz filter, plus AW's/VSE 50K ideas.
|Speakers:||Spherical concrete enclosures in off-white. SPHERES! Audiospheres made here in 1978!|
Foster (Japan) paper bowl-cone - papiermache backed 8 inch 38mm VC, and 35mm soft dome. 91db/w 35-13,000hz. No Lowpass in the passive crossover! Bought 'instead of' Quad 57's.
Rear surround pr are 'sphere model 2's for surround/ambience.
Soon to be replaced by QUAD 63s and 'DIY Swarm' sub array
|CD Player/DAC:||Rotel RCD 965BX with both Ltd Edition AND Discrete mods. A VDH brown I/C cable, ferrite clamps on power cable. First CD player I could bear when auditioning.|
|Turntable/Phono Stage:||Thorens TD150 [tweaked]/ SME 3009/STAX 2-pin head-shell/ SME FD200 fluid damper (STP)/ Denon 103D - rebuilt VdH - type 1 stylus and boron cantilever. Nagaoka Disk SE22 mineral loaded mat and GB clamp. Spindle extension for clamp. Nylok nuts on suspension bolts. |
|Other Source(s):||ANTENNA array:- 1. FM antenna is a 7 element Yagi for band II/2. VHF DTV antenna. Tuner is a rebuilt & modified simulcast valve rcvr. Wide-audio bw mono AM. Stereo SS MPX decoder by Studio 12 in Wales in the UK. PP amps are OFF.|
Tall DIY gal. steel mast. 3 mounting brackets
RADIO & TAPE
Tuner? It's a rebuilt Kenwood tube receiver (model W8) - with power amps off. Hi-Fi AM sound, plus an internal Studio 12 decoder for FM Stereo.
TAPE? Cassette deck is an upgraded Nakamichi B300. Long play tape is a Panasonic (Technics?) F55V with mods to the audio stages. 4 hrs SP and 8 on Long play.
|Speaker Cables/Interconnects:||Spkr Cable was Lucas, is now short 5ft lengths of Supra 1.6. Hardwired to xovers now on floor in separate boxes. |
Pre-power 4 long pcs of 'BRAND-REX LTD DIGITAL 1701248 20AWG SHIELDED TYPE 60degC (UL). Ha ha ha! ;-)
IC's are VdH102II and III and a VdH brown cable, plus various home made stuff based on DIY/tweaks ideas over two decades.
|Other (Power Conditioner, Racks etc.):||Main Rack is bolted to an exterior wall and is made from cream concrete, ie it is a big step what you climb up into houses on.|
Spkr stands, column and base are also of off-white concrete filled with sand and spiked (9 spikes per pair!)
Separate AC supply lines - 2 of. AC isolator TX type filters on pre amp and TT leads.
Surround processor is a Luxman tweaked and with pre out/amp in sockets added. It can thus feed the PP tube amps in the old 'Tuner' aka rcvr, and its 'own' centre and rear amps.
|Tweaks:||Careful Siting: of spkrs ('near field' at unequal distances to boundaries; and source eqpt / very careful TT set-up/ ferrite power cable clamps.|
Absolute Polarity switching / Hardwiring
/ external Xovers / Biamped / big 24' throw cushions against spkr column/stands.
All sources and the Pre are mounted (see stands)well away around the corner of the L-shaped room, the TT is positioned at a low pressure point for LF.
Micro careful TT set-up ie of the suspension, arm / cartridge.
SPKRS are now hardwired and the xovers are out in Jiffy boxes on the floor. There's an expensive 4PDT relay in each Xover to allow polarity switching, and the boxes are filled to the brim with oven dried sand.
System is bi-amped with the two baby Leak stereo amps.
Each spkr has a large throw cushion resting under it against the support columns.
The most recent tweak was to put first order filters on the inputs to the power amps. 175 hz on the tweeter amp and 5khz on the mid/bass amp. Highs got sweeter and more detailed, cymbals especially you can hear the little grommets ringing.
Speakers are at maximally unequal distances from the boundaries, virtually the Cardas sites ratios, and we sit nearly in the near field.
See room treatments and Surround below.
|Room Size (LxWxH):||L-shaped room 32 feet longest diagonal x 14 ft x 8 ft|
|Room Comments/Treatments:||Began in 1981 on the room! |
SEE SURROUND and ambience, below.
Most recent change Nov 2004 is new lower and low-backed, tropical Malay Straits style lounge suite.
[Feb 2004] tweak was 4 small 10 inch cushions in ceiling corners, now with a 5th absorber! ........ WOWWWWWWW!
Have 5 scrounger tweak panels. Mostly covered in Marimekko prints and Oriental printed decorator fabrics, all are set off the wall.
5 is a rear diffuser - made from two old louvred doors covered with a Belgian tapestry and stood off the wall by about 6 inches. Ceiling has acoustic tiles at the first reflection points.
Rear surround pr will be 'sphere model 2's for surround/ambience. I would really like to get a proper 'audio' surround processor with reverb control initial decay etc etc
Four ambient wedge shape mini 'fold back' style boxes to face up walls to be added, using FE103 FR drivers.
|Music Preferences and Comments:|
|Music Used (Genre/Selections):||Popular music IS important to me, but - NOT as much as |
Historically Informed Performance - romantic /classical baroque renaissance and earlier, is preferred. Choral music (church stuff) like Byrd, Purcell, Bach, Palestrina, the Gabrielis, etc etc.
Blues, R&B and Jazz, R&R from my youth. Some pop. Humour and spoken word. eg. George Carlin, and the GOON's (?).
Karajan's DG La Mer.
All three Kuijken brothers playing Haydn's flute trios (Vc Vn and Fl) on two Accent LP's.
Muddy 'Folk Singer'.
Most of Ry Cooders LP output.
the McGarrigle sisters.
CPE BACH and GP TELEMAN.
LBNL Mozart, of course, ;-).
|System Goals/Comments:||DSP room EQ when affordable. (maybe?)|
a 'New' rebuilt TD 150 and Mission 774 damped arm, new motor.
Address mid bass and bas extension issues?
Ambience surround. Am slowly working towards a 'low level / distributed ambience extraction system' using small full range drivers/boxes aimed up the walls. Now in train. Using s/h Luxman processor.
Deal with baffle dip step, mid bass and upper bass dips by going 2.5 way with a second matching sphere facing the floor, tweeterless. apply 6th order assist in the bass, 2nd order filter with gain.
Mount the Mission 774 arm I now have. On a second rebuilt and modded 150.
Improve and extend the room treatments.
|System Strengths:||Fast and revealing, all recordings sound very different from each other, yet still wonderful musically even where engineering is crap - passes the 'Audionote test'. |
Great depth, if there at all, some height. Scary fast on orchestral tuttis / transients.
Compressors can be easily heard working on pop and R&R.
The bass can be very clean and slammy.
My mother hated the 'spheres! My mother in-law too!
Very dynamic, you can count the voices in choirs.
|System Weaknesses:||the usual upper bass and mid bass power response dips, NB as measured with a Tandy Dig. SPLM mind, and I haven't tried warble tones yet. L-shaped room so TWO sets of dips|
Also affecting this area is - midbass driver is run as is, with only parallel RC for Z rise Eq and damping, there is NO low pass filter, and thus NO shelving bass boost EQ NO baffle dip compensation!
And of course, there is the floor dip as they are stand mounters.
|Video/HT System: Separate|
|Speakers (Center, Surrounds, Sub):|
|Other Interests/Hobbies/Occupation:||Reading, literature (&poetry), military history, history and philosophy of science, history of: technology, religion, 'systems' thinking.|
Bush-walking, gardening / landscaping, cooking, cycling, sex, woodwork, home-maintenance.