Midlife crisis?

Comnoz

New Member
Some people go for cars, others for girls.
Me, I have a great wife, so I built an insane stereo system for my shop. Nothing high dollar here. Just many years of accumulation.
Here we go with show and tell.
Here is the main amp and speakers that is in my avitar
Big tube amp (1).jpg
Now back to the source.
It is a dual motherboard industrial pc. One board is devoted to J River and the other is devoted to VinylStudio. The PC renders it's music from an 8 Tb server that is tucked away where I can't hear it.
There is a scratch built tube DAC on top of the PC.
For A to D I use an ADL- GT40
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Next is the turntable I built a few years back. The table and all the main parts are milled from glass re-enforced virgin Teflon.
It mounts a Grace arm and the drive motor is salvaged from an old tape machine. The box to the right of the GT40 is the motor speed control.
Vacuum is applied through the spindle from a pump that is in a little doghouse outside the building.
There is a prox sensor for arm position and a vacuum over hydraulic tonearm lifter.
The little blue button below the deck is a motion sensor. When I get my hand within an inch it will raise or lower the tonearm.
I use either a Shure v15/IV or a Empire 2000/3 cartridge
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A Pioneer DVD player handles the digital media.
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Next comes the preamp. It uses 4-6H1N tubes and an autotransformer volume control.
It uses a vacuum florescent level meter from an old Russian tape deck.
The remote power supply uses a 6X4 rectifier and a tube pass element.
It is built in an old sweep generator housing.
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I use a BBE 482I for a dynamic tone control when needed and use a reworked BSS active crossover to separate the sub channel from the main channels.
P1020701.JPG Next post I will go to the main amp.
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Now for the amp.
220 volts comes in to a 5.25 KVA balanced toroid for clean 110 and 220 volt supplies.
The B+ is supplied by a pair of 2 KVA transformers salvaged from induction heating furnaces.
A pair of 872a mercury vapor tubes handle the rectification for a capacitor input supply. After filtering with a 100 lb. choke there are 12 -10.000 mfd caps [sourced from a windpower generator] charged to 2300 volts for a nice stiff supply. This capacitor bank is charged with a small transformer and solid state rectifiers during the warm-up sequence before the large transformers are powered up.
The dark glass provides UV protection.
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The B+ is supplied through another 50 lb anode choke to a pair of GU46 pentodes for a subwoofer channel.
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And two more 50 lb anode chokes supply four 4-400's for the main channels.
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Another chassis supplies the filament, bias, and screen voltages along with supplies for the driver tubes and their FET followers.
Also in this chassis is the timing relays needed to bring all this to life. There are two large motor driven variacs that slowly bring the filament voltages up -first to half voltage for standby and then the second unit ramps things up to full voltage when out of standby.
A small 750 volt supply powers 2 strings of gas reference tubes to supply reference to the large IGBT's used for pass elements in the voltage regulators. 600 volts is supplied to the 4-400 screens, 500 volts to the triode connected 6BG6 driver tubes and 400 and 250 to the 6sl7 input and 6sn7 phase inverters.
Plus and minus 400 and 150 are also supplied to the follower fets for the inverter and driver tubes.
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Then there is the upper supply unit that supplies screen, bias and drive for the subwoofer amp.
It uses a string of gas regulator tubes for screen regulation.
The digital readout is the rack temperature. It controls several stages of cooling fans to keep the case temp reasonable.
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Next post -speakers
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Now for the speakers.
I have two 18 inch JBL drivers in old Earth cabs for mid base.
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Two 48 inch BG ribbons topped by two Infinity Emit tweeters for each channel.
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Then there are 6 -10 inch infinity subwoofers -two per cabinet -hidden in selected locations around the shop along with the 21 inch Bayma sub that is mounted in a 72 gallon barrel and hanging from the rafters.
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The system has been in daily use for over a year now with only a few hiccups, a couple minor fet explosions and one ball of fire when I connected the sub amp feedback up backwards.
It's amazing what a little high voltage oscillation will do to an output transformer. :yikes:
 
I forgot to mention.
Including the chokes and variacs there are 36 iron cored transformers, 11 cooling fans plus staged temperature controls and a few large 10 guage air core crossover chokes that bring the weight up to somewhere close to 2500 lbs. -not counting the speakers.
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It is the best I have had -and I've had quite a few -including some that cost a lot more than this build
[of course labor doesn't count].
I'm just laughing in amazement. That is in another dimension.. meaning another world. Hearing that is on the fantasy list of something I'd like to experience... right up there with flying an F-16, or riding the Shuttle into space. It is the final word in unique, one of a kind...words completely fail to address the amazement at what you've built... Mid life crisis, a sports car and women, not a chance when one can build something that awesome. Thank you very much for sharing pictures and the description. Do the neighbors know..... awe, stupid question, how could they not know.
 
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