Description

My system is based on the concept that one can assemble an otherwise unaffordable "super system" via DIY. Even if I was doing much better, I would probably still be embarrassed to spend big money on top-flight commercial components - especially after hearing the 500C.

At the inception of my first truly high end project, the International” Loesch preamp, I was informed in no uncertain terms by the guys on the Joelist that it was not only possible to build something that approached state-of-the-art commercial products but that it was an easily attainable goal to surpass them. In subsequent listening sessions at audio salons around NYC, I found this to be accurate. My preamp was definitely in the same league as commercial products costing up to $20K – several high dollar pre’s were actually a disappointment in comparison. Note that this really isn’t that amazing when you consider that DIY projects don’t have to meet the manufacturability, reliability and parts cost-points that commercial products do.

There are some very talented engineers and enthusiasts on several continents who continue to share their designs via the internet. My strategy has been to take proven DIY designs – i.e., well received by previous builders and build my own version. I have found value in waiting until the project has been built and subsequently rebuilt/modified by the designer and/or other well qualified enthusiasts. This comprises added R&D and helps to negate the "proud papa" syndrome. Once I settle on a design, I choose passive parts that I hope will tailor the component to my taste. Of course, every single experiment has not been a total success ;0)

Everything in my system is currently DIY except the tuner and CD player - which are also modified.

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Components Toggle details

    • DIY Stereo 211 on Two Chassis'
    The signal section is after Dennis McCotter's design from several years ago. Contrary to many, I like the 211 better than the 845 - understanding that a system optimized for 845 will usually sound bright with the 211. To me, the 211 has better hi-freq extension and tighter bass while retaining the 300B-like mindrange. I generally find the 845 too "brown" sounding.
    • DIY 211 signal chassis from front
    Front view
    • 211 PS Custom
    Here is a pic of the power supply after changing the rectifier sockets. A hammond cage will cover the toroid and rec tubes after it is painted. Features: Bendix (Northern Electric) 10H choke 4000V. The red cap is plastic in oil 3000V. The two smaller oil caps bypass the main HT cap bank and are the old PCB types - yikes! Notice the two power umbilicals. The 1150V umbilical is 10KV rated insulated wire covered by a 7KV rated non-conductive fiberglass shield and heat shrink. The connectors are overrated as well.
    • DIY 211 signal chassis underneath
    Signal circuit features: The small signal circuit is a copy of the SJS 417A to IT circuit - avoiding a coupling cap between the stages. The OPTs are James 10K. The 4 large resistors take the 12V AC for heating the 211 down to 10V - I mounted them on an aluminum plate for cooling. The power comes in via two unbilicals - one only has the 1150V HT; the other has everything else including the main ground. Oddly, there was a slight hum in my former residence but it is totally silent via 93dB effecient speakers in my current place.
    • DIY 211 PS chassis underneath
    The PS was designed in Duncan's PSU free software, which rocks. I was going for 1150V HT and 205V LT - I got 1154 and 207! Features: Seperate PS for LT and HT. The HT is Rectified by a 6CJ3 damper diode bridge. The LT has a CREE diode bridge. The white and grey caps are Unlytics. The heaters are 60kHZ AC lighting modules giving 10V of high frequency AC. Sounds as good as whatever is in front of it.
    • International Loesch Preamp after T. Loesch's Tocatta II
    This is my build of the A. Loesch design as modified by T. Loesch, with parts choices and exterior design by yours truly. Circuit features: Full featured preamp including MC RIAA. External regulated PS. Sowter volume control transformers configured as autoformers and switching via mercury relays.
    • new Lenco L59 Trans-fi Terminator
    I added a layer to my old L59 plinth and a Trans-Fi Terminator tonearm. After only a few hours it sounds excellent.
    • EAR USA 834P
    Here is my rebuild of the 834P using Mr T's mods. The idea was to upgrade the MM sound and get 4 phono inputs in one unit with relay switching of the transformers. Note the air caps (tuners) used for the RIAA eq - groovy!
    • Custom 834P Mr T
    Here's the guts. Good for me that I never got around to selling my EAR.
    • Fisher 500C
    My $47 thrift store find. The power tubes looked dead so I never powered it up until I did the PS mod. To my surprise, all the tubes are good and it sounds truly great pumping out the Sunday morning oldies on FM. I refin'd the cabinet and it is a passably cool piece of furniture. The speakers are Dynaco A-35's - currently going for ridiculous amounts on ebay. Wire = 89259 star quad built last century - knew it would come in handy some day.
    • 500C Restored on bench...
    ..After final cleaning and a few new knob brights. Since it was in a cabinet the face is still like new.

Comments 15

Showing all comments by mgreene.

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Owner
Hi Paul and Leadercrat,

Thanks for your excellent complements. Take heart - I am an electronics ignoramus! :) My system is a progression from minor stupidity to gross stupidity. In other words, you start off building something low voltage and undeadly and build up to the dangerous and exotic. I do admit to having a minor talent for making / fixing things - and I can follow directions. Other than being aware of the various elementary formulas (and where to look them up when I need to employ them) I remain fairly ignorant of electronic theory. Safety is the key – one hand in your pocket, etc. I really only studied electronic safety and soldering technique. Of course I learned to read schematics and the function of all the typical electronics parts, but that’s mainly it. Oh yes, I learned to humbly ask questions. I worried the life out of Thorsten Loesch and he was kind enough to oblige :)

My modern electronics journey began when I refurbished several old tube table radios in the early nineties - I fixed an old Telefunken shortwave from the thrift store just in time for the "golden age" of shortwave broadcasting in the mid to late nineties. All of that lead to tube receiver modification and so on. My first scratch project was a two tube line preamp around '97.

Supercat - as to cost, I have cleverly hidden that aspect of DIY even from myself :) But add up the cost of the parts you see and that is basically it. It depends on how good you are at finding parts and striking a deal to buy them. Take the knobs on the Loesch preamp – I got estimates of as much as $400 to machine those knobs. I ended up going to a huge CNC facility and struck up a friendly conversation with the owner (he turned out to be a minor stereo buff still using his TT) and got them for $70. In a nice way, he told me to never come back - i.e., never to expect him to stop his line for cheap one off job, at that kind of price again :) Getting the parts takes time and if you charge yourself for your time, your savings from DIY wont look so hot. But did I spend $20K of my time building the Loesch preamp? Hardly. And of course, at times hunting parts was fun too (think dusty warehouses and hamfests) ...and I honestly felt that it did sound better than a well known $20K preamp available at the time I built it. My cost goal for the preamp was less than $1,000 - and I am pretty sure I came in well under that.

Now to foist my DIY OPINION:

Make a preamp – the best you can afford – make it purdy - the Aikido circuit would be my choice. Modify an existing amp – the Chinese PP KT88 amps of various types can sound fabulous. A tube preamp with a SS amp can also be a great combo. Don’t attempt to build speakers unless it’s a kit. Why? Ever notice that most DIY’ers either build electronics OR speakers. You need a whole other set of tools, electronic and mechanical, to build speakers. After you price out all the drivers, XO and cabinets – you might find that a used pair of highly reviewed speakers are very close to your real cost and will not drive you insane trying to get that one last aspect of their performance right.

Kind regards

Mike

mgreene

Owner
System edited: In the new house. Finally got my 500C going and am setting up my listening room.

mgreene

Owner
Thanks fellers. Its actually easier than it looks - just takes time.

Yes, Jean - Piezos. Believe it or not I got another one since I posted the PIC - an X! The Loesch pre is fairly amazing - it sounded great with carbon pots from rat shack and even better with the XF volume controls.

No OZ, no speakers - I just "make eyes" at my purdy electronics. Of course I have several speakers, I have been reluctant to post on my current DIY speakers because they are not up to the level of the rest of the system due to one major fault - chesty bass. When I get it sorted I will make one of those groovy system pictures.

Mike

mgreene

Owner
System edited: Pics of my finally finished giant L59 added.

mgreene