Sunday, March 12, 2017

Main system update

There are only minor changes in the main system. As you can see, I have new open baffle speakers. These are inspired by NOLA speakers, formerly ALON by Mr. Marchisotto, ex Dahlquist speaker designer. They are based on four Dayton reference series midwoofers per side, RS125 on open baffle, and planar HiVi tweeter. I preferred one tweeter to short array, as it is already vertically quite directional, being quite big. As before, this open baffle is crossed actively at 160 Hz up. Woofers are open baffle 2x15" as before. All biamped.
New NOLA like speakers have significantly simpler passive crossover, as these are only upper pass for midbass (4th order) and lower pass for tweeter (2nd order), crossed at 3k Hz. They sound more coherent and very musical.

Once NOLA finished, it gave me an opportunity to redesign previous open baffle speakers. They are still work in progress, righ now on the floor in the middle. I replaced Fostex FF125K fullrange with FaitalPro 5FE120, which simplifies the crossover, as Faital has almost no breakups. Baffle was redesigned too, to allow more directivity. Ideally, these should be using 4way digital crossover, but I am not there yet.

One last update is amplifier. I was using various chip amp circuits, LM1875 was updated with LM3886, inverted with buffer sounded little cleaner and more dynamic. Recently, I purchased DartZeel clone from ebay, and I am testing it now. Sounds very musical, in spite of measuring badly, its no global negative feedback amp with quite unique features. Lack of global feedback make this amp perform ever more dynamic and musical. Generally too much negative feedback is considered bad, resulting in boring fatiguing sound. This one is opposite, very musical.

Most recently I got SANYO Plus P55 mosfet amp of ebay, and will be testing it in the main system, after its adjusted and cleaned. Once you have Sanyo Plus tuner and preamp, you must have amp too.

Sunday, March 13, 2016

System 2

System two consists of yet another SONY tuner ST-S555ES, then Cambridge Audio Azur CD player 640C, Phillips DCC digital tape player, Pioneer RT-707 reel to reel player with type II dolby and diy turntable based on TESLA 1100 arm and AKAI direct drive table. Phono preamp is either SPARTA or Actidamp MkII. Cartridges include Benz Micro ACE, Audio Technica ATOC9, AT ML440a microline, Ortofon Red, AT92E, Signet and many others.
Signal selector is diy, preamp is JC-2 in old Parasound preamp box, Behringer Ultra Curve 31 band digital equalizer, and two LM1875 chip amplifiers, one in transconductance config to power mid/tweet section, one stock to power woofers. Active crossover ~160 Hz for woofer section. Like first system, this one is biamplied too.
Speakers are diy, based on HiVi ribbon tweeter, Dayton 2" soft dome, two Dayton 6" midbass in isobaric clamp, and 15" Jamo as woofers in closed boxes.   

Tuesday, March 8, 2016

I am back!

Hi friends,

it's been a while....I have not posted anything on my blog in two years. It does not mean I stopped listening to music or building speakers and amplifiers. I was on sabbatical. Well, I used to work for small biotech company, which was acquired by large biotech company (swallowed, forcefully bought, insert your own...), and as it often happens, things change. Some people were let go, some were kept. I was offered to relocate into neighboring state, or take severance. I opted for severance. I got rid of most of my furniture, and gave away a lots of my audio stuff, kept just the best and moved my stuff into friends one-bedroom basement. Then I went on tour around the Australia and New Zealand. On the way back I stopped in Singapore and Dubai, and went for few month to good old Europe to visit relatives. Then I visited Banff in Canada. All together about nine months. Since then, I found another job in small  biotech company and moved to 2 bedroom apartment in Germantown. I consolidated my two main systems into living room, so now I have two systems intertwined in one room. Here is how it looks.
System one...

My audio system currently consists of Jungson HDCD player Moon Harbor, SONY ST-555ES tuner, Onkyo 2700 cassette player, Technics DCC deck, Technics SL1200 turntable, Onkyo 306RS riaa preamp (only for turntable), diy signal selector, modified 6H6P tube preamp, Behringer UltraCurve 31 digital equalizer, LM1875 transconductance amp, 160 Hz active crossover for subwoofer, and 100 watt amp for woofers. Speakers are diy, all open baffle, tweeter is B&G neo3 with back plate removed, upper mid is Fostex FF125K, lower midbass is 6" Pioneer, woofers are two 15" Jamo per channel in dipole configuration. Sounds ok for now.
Maybe future project will be mini dsp 2x8 with four channel amplification. Who knows.