The Altai B005HE parametric equaliser.
My 2021 exciting ebay Covid lockdown purchase, a splendid item enhanced by a noteworthy half-price refund from a noble fellow. From faulty to fixed, a combination of six miscellaneous defects, a few dodgy solder joints, an inductor rattling around inside and a long-suffering blown-up op-amp victim. I also increased the smoothing capacitors of the internal bi-polar supply, from 470uF to 1000uF.
The undocumented ultra-rare seven band parametric EQ was originally intended to cling on beneath a vehicle's dashboard to boost mobile beats. I am sure it is 'Bee, zero, zero, 5, H, E', and not 'Bee, Oh, Oh, 5, H, E'. I'll call it 'The Booshe'. Actually Altai made it as clear as mud by giving it two model numbers, so it's the B005HE (PS150E), maybe it's a rebranded replica of the latter.
This obscurity runs on 12 volts DC at 180mA, and has a black, red and orange triad of wires emanating from the rear. Positive, negative, and the orange is to turn on the equaliser by receiving 12 volts from the car stereo's 'Remote' trigger wire, I'll simply connect the orange to the red. This EQ is a radically minimalist super space-saving solution to tweaking a retro stage piano.
This obscurity runs on 12 volts DC at 180mA, and has a black, red and orange triad of wires emanating from the rear. Positive, negative, and the orange is to turn on the equaliser by receiving 12 volts from the car stereo's 'Remote' trigger wire, I'll simply connect the orange to the red. This EQ is a radically minimalist super space-saving solution to tweaking a retro stage piano.
I replaced the unruly supply wires with a 2.1mm DC socket and a slide-switch, resin filled into the aluminium can of a big-old hollowed-out capacitor, what else?! There's no room at the back of The Booshe to tastefully attach a socket or switch as it is a very compact 'half DIN size??', or 177mm wide x 155mm x 25mm.
It is a true stereo LINE level device in a higher audio eschelon than the faux stereo Altai G020A on the previous page. There are two separate stereo inputs, either CD or LINE (both LINE level), selectable on the front panel, with input level adjustment trim-pots located on the top panel, and two separate stereo LINE outputs (front and rear) which can sound simultaneously or individually using the fader control.
The seven bands each discreetly conceal a four position switch secreted atop of The Booshe to select a specific frequency to be controlled by the seven front panel knobs - f1 to f7. It's tenuously trying to be a 28 band EQ and it clearly takes delight in deception.
One must brandish a suitable screwdriver-style implement, (plastic or wood is sensible) to operate the frequency switches and the forementioned input level pots.
One must brandish a suitable screwdriver-style implement, (plastic or wood is sensible) to operate the frequency switches and the forementioned input level pots.
Thankfully there are no nasty miniaturised surface mount devices to be seen inside, the eighth watt resistors are the smallest components and the dual-gang pots are futuristically small. Mainly polystyrene and ceramic capacitors tune the frequencies which are steered into seven TL072CN two-channel op-amps and then funneled into another two TL072CN chips that form the four LINE outputs.
To determine the blown output op-amp I traced backwards from the output RCAs, realised a lack of output on an op amp, fitted two 8 pin IC holders and swapped the chips for a matching pair of TL072CPs I had, which finally fixed the boisterous buzzing.
As the eighth watt resistor was popular in the 90s, the tiny variable pots are not very 80s and both the chips and electrolytics have 94 on their date code, I deduce that The Booshe was made in 1994 AD.
As the eighth watt resistor was popular in the 90s, the tiny variable pots are not very 80s and both the chips and electrolytics have 94 on their date code, I deduce that The Booshe was made in 1994 AD.
The Booshe is masquerading as a parametric EQ but I'm catatonically confused and maybe misled, should we not have band width controls, the elusive 'Q' control? The front panel does not resemble a typical graphic EQ, but the seven fiddly band controls are just rotary instead of straight slide pots - with only minimum, centre notch and maximum position markings.
My initial musing and naive assumption was that as I increase the seven frequency level controls, the frequency gain is amplified and the width of the frequency band simultaneously widens. Having connected my Kurzweil SP2X, the semi-vapid stage piano, I attempted to clear the waters. With tactile tweaking using my new whittled wooden lolly-stick (as a slipped screwdriver could create a soul-destroying surface scratch), I successfully brightened and honed the SP2X sound.
It seems to be more graphic EQ than parametric EQ, but I'd never experienced a real parametric EQ before. However, when each of the frequency pots was cranked up to maximum I revealed an imposing brain resonating tone, which was odd to my ear. I propose that maybe something vague and unique is occurring within this baffling box, but it'll just be discombobulation. I've since obtained a real parametric EQ, the Alpine 3401 showcased on the next page. This Altai EQ is definitely not parametric in any way. Trading Standards may be interested in this mis-labelled misleader.
Other than painting the grooves in the knobs white so I can finally see which way they point, sourcing a sparkling set of new hex screws for the front panel and affixing four adhesive feet, there's not much else to say other than this baloney-spouting Booshe device offers perpetual parametric perplexity, it deceives and temporarily left me floundering in uncertainty.
It seems to be more graphic EQ than parametric EQ, but I'd never experienced a real parametric EQ before. However, when each of the frequency pots was cranked up to maximum I revealed an imposing brain resonating tone, which was odd to my ear. I propose that maybe something vague and unique is occurring within this baffling box, but it'll just be discombobulation. I've since obtained a real parametric EQ, the Alpine 3401 showcased on the next page. This Altai EQ is definitely not parametric in any way. Trading Standards may be interested in this mis-labelled misleader.
Other than painting the grooves in the knobs white so I can finally see which way they point, sourcing a sparkling set of new hex screws for the front panel and affixing four adhesive feet, there's not much else to say other than this baloney-spouting Booshe device offers perpetual parametric perplexity, it deceives and temporarily left me floundering in uncertainty.
Miniaturised on the outside but not on the inside, it is appealingly compact, undoubtedly useful and well worth the £13.10 outlay, even if only to keep my tinkering skills satisfied. The masked-up, muzzled and muted monologue in my head says that the parametric-ness is not happening here, the parametrical claim on the front panel leaves me unconvinced, I have been fooled by fake news. This intriguing item is just an immensely awkward equaliser, however I found the perfect partner for The Booshe, the Yamaha P50m piano module. It's good to give the P50m module a musical airing through this crystal-clear clean-audio buzz-free beauty.
I wrote to the only available hope of clarity - Electrovision Ltd. It appears that any information pertaining to archaic Altai apparatus has been resigned to the recycle bin, so again I've done my duty and informed the world in my whimsical way.
I wrote to the only available hope of clarity - Electrovision Ltd. It appears that any information pertaining to archaic Altai apparatus has been resigned to the recycle bin, so again I've done my duty and informed the world in my whimsical way.