Post your completed projects

After six months of ground loops, bad solder joints, and some bad ideas. My “Dog’s Breakfast” Series 2 Bose EQ is complete. No buzz, and hiss only when you crank the SGCD/Preamp and M700’s to 100 (no music). At normal listening levels, you only hear the music.

DHS who has an EBay service that will modify any Series Bose EQ was the “inspiration” for the mess I created. I took his Audiophile Modifications a few steps further adding a Toroidal Transformer (guess where I got that idea from - and it was a huge improvement in SQ over the crappy 50 year old one that was in there). After the transformer, I added an industrial grade full wave rectifier module followed by three KEMET super low ESR power supply capacitors for the 3 voltages that feed the Bose EQ circuits. All signal capacitors are SoniCraft ordered from their website (see DHS’s eBay Audiophile version). All other Aluminum Electrolytic’s are Made in the U.S.A. Vishay’s from Mouser. All resistors are Vishay 1% metal film 1W - 3W. For the transistor bypass caps, I removed the ceramics and installed WIMA’s. For the final wiring of the audio paths, I chopped up a 1.5m RCA cable and used it to interconnect between the Bose EQ and the Chinese “Black Bear” adapter boards. I replaced the cheap crap with OPA 2134’s, WIMA bypass caps and Vishay Aluminum Electrolytics. Left the “1% metal film” resistors intact cause that’s just too much work with little return. I’ll just assume they are what stated on their eBay website. The PCB quality is actually pretty good considering it’s Chinese.

Ordered some sample OPA627’s and Brown Dog adapters (work great) to try out some op amp “rolling”. No harm when the parts are free.

If ever put this awesome sounding mess into a chassis, I might actually finish designing and getting fabricated a full circuit board. That was my original intent before getting this Series 2 box from eBay and getting into some nasty Rabbit holes.

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Oh man that’s awesome! Congrats on getting the build working well :grin:

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Thanks Schroedster. Looks like Shit but sounds awesome. Thought I’d revive this Thread started by the Guy who designed my Amps. The Bose box breaks the fully balanced chain. The 6dB gain along with the noise immunity that XLR’s offer made a difference. I literally have AudioQuest Red River cable/interconnects on the entire audio chain. This includes the out and in points at the Bose EQ PCB.

Haha maybe I’m just used to seeing projects in various states cause it doesn’t look bad to me at all :stuck_out_tongue:

I’ll have to pester our engineers to start posting some pictures. Many of them have their own personal projects that they work on at home.

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I’m in the WiFi game now (“Wireless Network Engineer”) but my past life both in Ottawa, Canada in in New Jersey years ago was as a bench tech. I used to SMT prototype A LOT. This includes hand placing/soldering 0402, 0603, 0805 (easy), and 1216 (easy peasy) SMT components. Honestly, I HATE soldering and farting with through hole components (but you don’t need a microscope - unlike a lot of SMT work).

Using PCB Artist I’ve already schematic captured the “Dog’s Breakfast” into all SMT (except the SoniCaps, and all the other throughole capacitors) which I’ll relocate onto the new PCB (way way into the future $$$$).

If you look at my seldom used Twitter account, my tagline is “WiFi pays for my HiFi”

Since graduating Community College so so many years ago, I’ve been stuck in the world of RF production and engineering. But the last several years got me into WiFi Network Engineering (on the RF side of course) cause I needed the money…no joke.

I always wanted to work in audio professionally as an Eng.Tech and years ago while unemployed in Canada (Eh!), I’d applied to Sonos, Bose, Apple, and so many other name brand (consumer ugh!) firms, but nothing. So the last year or so in order to keep up my rusty chops, I’ve been doing a lot of “little” audio projects at home. No Oscilliscope/Spectrum Analyzer/VNA, and no Variac. Not the correct way to do things and I’ve let the smoke out of a few components. Just a two DMM’s (and old Fluke and new Agilent that I won at a Keysight event) and very little common sense. :joy:

Thanks for the compliment !

Joe

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Sounds like you’re pretty darn well versed when it comes to soldering and doing board layout!

Maybe you’ll have to make your way out to Colorado someday :wink: Not only are we here, but there’s also Boulder Amplifiers, Avalon, Ayre, YG Acoustic, and Grand Prix Audio to name the big ones. Somehow Colorado turned into a haven for hifi :grin:

I’ve learned SMT prototyping the hard way (solder paste applied manually works awesome but you need to electronically clean so that any solder balls lift out to the top of the tank). I was happy the other day when I soldered qty. 4 8pin SOIC opamps by hand with my trusty Metcal fine tip iron (I hate the big Wellar’s). No solder shorts, on straight, and no microscope ! Not bad for almost 50…LOL

I plan to take tour of PS Audio this Summer (maybe earlier) with my Wife who’s never been to Colorado. I notice that about CO. With Rocky Mountain Fest, and all the audio companies out there. I’ll be honest, Paul’s video’s was what turned on on to you Folks early last year. That and I remember the PS Audio ad’s in the Stereo mag’s as a kid growing up Canada.

Well versed but ain’t gettin’ any younger ! Here’s a blast from my past (Nov. 1994). My first Tower Speaker. Just graduated with my Elec. Eng. Tech. degree and built these at home (my Mom was not impressed with the mess in her basement but she like the end result). I didin’t know you have add an L-Pad between the mids and tweet’s.

Designing, Building, and Testing Your Own Speaker System with Projects by David B. Weems was my Bible for building these (yes, L-Pads are mentioned but I skimmed over that chapter…LOL). Sounded good to me but I’ll admit the mids’ & high’s were peaky. Bass output would have benefited form installing fixed L-Pad’s on the mid’s and high. All 3rd Order Butterworth filters. I really didn’t know WTF I was doing. Borrowed idea’s from Paradigm & PSB. Not these sounded anywhere near as good as a PSB Stratus Gold or Paradigm Reference Studio Speaker of that time. Couldn’t afford either anyway.

I took these photo’s with me up to Ottawa for a job interview for an RF Bench Tech. (my 1st gig - left home ASAP) and got the job because my future Boss was also an Audiophile !

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Summer is the perfect time to visit CO! Doesn’t get much nicer around these parts (unless you like to ski, that is)

Looking forward to you and your wife making it out here :grin:

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I was doing some light back yard cleanup work today and decided to make my outdoor sound setup completely wireless. It supports WiFi 2.4Ghz and Bluetooth aptX HD. The only piece I purchased was the inverter and it’s probably 20 years old and a BT adaptor. Less than $50 all told. Roon endpoint, Spotify and Tidal works a treat and plays ‘the cops are going to be called’ loud

My then girlfriend, and after 5 years soon to be wife, donated the Apple AirPortExpress and a former tenant left the guitar amp. I’ve used it on 120V for a long time but had an old LiFePo 12V (a couple actually) with Anderson connectors for motorcycles in the years past. Light and powerful and tolerate of massive abuse. One 4S2P and one 4S, the latter drove it for 2 hours before I decided it was enough testing.

I think it weighs about 18lbs

I put a back door (hinge and clasp) on it with some damping material. I prefer the bass with the back closed vs. baffle less. I’ve got an old RS passive mic that stores inside too for those adhoc party speaches

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Nice work Brett66 but if your WiFi stuff can support 5GHz. use it instead of the dreaded overcrowded 2.4GHz. Now if your neighbours live an acre away from then 2.4GHz is actually better as it will propagate the RF further and you shouldn’t have any interference issues.

“Trust me”. I’m an RF Guy stuck working in IT. I used to be a real RF Guy. Now I’m just a fake one.

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Thanks, used it today for a couple hours loading up two trucks full of well seasoned avocado wood, hauling and stacking. Played some Dr. John in memoriam.

I’m a fake RF guy too. It’s an old Apple AirportExpress that only support 2.4. I’ve scanned and use the least used channel in the area so it’s not an issue.

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In memoriam? Dr. John died? Dang…

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And here we go again. Much simpler modifications. It’s for the Center Channel 901. The crappy transformer, the three Power Supply Capacitors (top left), and the AC Filter/Neon lamp will be removed. Clean DC Power will come from the “Dog’s Breakfast” EQ. LED to replace the Neon bulb. Surface Mount Vishay 1% Thin Film 0603 Resistors, KEMET Yellow Tantalum’s for the various DC feeds. The SMT equivalent of Transistors will go on the underside of the PCB. For temporary, I ordered an Active Volume Control stuffed PCB. Future plan is to add a remote Volume control with digital display from eBay. By going SMT, I free up a Ton of space. Soldering 0603 package components without a microscope and my Wife’s Eyebrow Tweezer’s wasn’t easy and I’m not getting any younger :slightly_frowning_face:

Configured as a True balanced setup single channel. Should be complete before the weekend. Forgot to order a few parts from Mouser. Shipping was 3x the price of the components & I did I this twice :face_with_symbols_over_mouth

To save a few bucks, I had some Solen Caps which I stacked as 5uF. The tiny 15nF Solen Caps are put in the Bass Circuits only but the big single 5uF’s are for the output only
:

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Not sure how I missed this but that is pretty bad ass!

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I have no life…LOL.

Thanks Jeff. The EQ is the Secret Sauce that turns these Turds into Treasures. “Components Matter”

I finally got it working this morning. Had solder shorts on two Surface Mount transistor’s (I told you Guys this wasn’t easy). The sound is OK but my Dog’ Breakfast Bose Series 2 EQ hasn’t better Bass extension and midrange. It my be the cheap Solen’s I put on the output stage. The lack of big beefy Toroidal ike I have the Dog’ Breakfast may be another reason. Anyway, it’s good enough to run my Center Channel 901, so I pleased with the results.

Gonna leave it in single ended Stereo Mode for the Weekend and convert it to dual mono XLR terminated Balanced next week.

Were getting there. Ain’t a Dog’s Breakfast anymore. Still have the active center channel volume control to finish. Once that’s working, then I’ll remove the transformer (covered in copper tap) and remove the two silver and one black capacitors. The 3 DC voltages will be tapped off the three big black KEMET capacitors on the left of the box (next to the little volume control PCB).

The two channel true balanced L & R channel is up and running again. The only time I hear any noise is when the SGCD/Preamp is set to 100 and it’s so low, you never hear the noise when playing at normal or apartment level volume. Final pics hopefully by the weekend.

Center Channel volume is Passive (for now). Had a nasty GND loop even though I’d star GND’d everything to one point. Still have a slight bit of hum on The right side is quiet. Blue LED’s intensity matched the power buttons of my PSA gear. :slightly_smiling_face:

A very good neighbor brought their wine barrel cooler over for an event we hosted in August. I just had to make my own. Complete with motion/light activated lighting curtosy of a $3 mushroom light from Ikea

Everything else came from my supply of hardware and lumber

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Wonderfully fun!