I found a water jet mfg that gave me a quote to do some work last year. They were very reasonable.
Ray Fakhteh (ray@acwaterjet.com)
AC Waterjet
123 Crockford Blvd.
Toronto, Ontario,. M1R 3B7
Tel: 416-438-0111 416-438-0118 Fax: 416-352-1998
YOU NAME IT, WE CUT IT! ISO 9001-2015 CERTIFIED
rod@acwaterjet.com AC Waterjet | You Name It, We Cut It!
Ray Fakhteh (ray@acwaterjet.com)
AC Waterjet
123 Crockford Blvd.
Toronto, Ontario,. M1R 3B7
Tel: 416-438-0111 416-438-0118 Fax: 416-352-1998
YOU NAME IT, WE CUT IT! ISO 9001-2015 CERTIFIED
rod@acwaterjet.com AC Waterjet | You Name It, We Cut It!
Thanks twitchie. Amps are bit of a lift. 7 transformers and 4 chokes each channel. Have not weighed them, but not an easy lift. So I don't think they'll be coming out to Dave's.
Thanks Rick. The $ did add up with bulk foil resistors and some Blackgates in there. But nothing compared to commercial stuff from Italy or Japan. Most of the transformers came from surplus which helped a bunch.
Glad to see you found a waterjet company. They are really reasonable and can cut anything up to 3 inches thick. The waterjet had dual heads so they cut both the amps with one pass. I just laid it out so one could just be flipped over to be a mirror image of the other channel. I think the cost was $120 for both with them supplying the metal. That wouldn't buy a front panel for a DAC at Front Panel Express. Downside to waterjet is no engraving, and the finish on supplied aluminum was just rough sheet material with scratches. I ran a sander over them to create the finish. Looks fine.
Glad to see you found a waterjet company. They are really reasonable and can cut anything up to 3 inches thick. The waterjet had dual heads so they cut both the amps with one pass. I just laid it out so one could just be flipped over to be a mirror image of the other channel. I think the cost was $120 for both with them supplying the metal. That wouldn't buy a front panel for a DAC at Front Panel Express. Downside to waterjet is no engraving, and the finish on supplied aluminum was just rough sheet material with scratches. I ran a sander over them to create the finish. Looks fine.
verrry interesting, bulk foil resistors and some Blackgates in a tube amp design, oh boy 
and I thought I was stretching it using thin film Vishay MBA0204 & MBB0207 on the Hafler DH-220C design. You and Dave must have attended the same design school that I could not afford to attend As long as you are happy I am too. 
and I thought I was stretching it using thin film Vishay MBA0204 & MBB0207 on the Hafler DH-220C design. You and Dave must have attended the same design school that I could not afford to attend As long as you are happy I am too. I am not sure what newer model you refer too, XL?, I'd have to look again at that one.
Yeah Bob Cordell included the whole kit a caboodle, complementary dual jfets from linear system lsk489/lsj689, cascoded into current mirrors, 2-T push-pull VAS, buffered to the laterals, with a DC servo control, so no feedback cap required, low Z feedback network, the board is stuffed. We even designed a special output board too. We like how it all turned out, getting ready for release once we can secure those jfets, California is in lock down.
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I don't mean isolation transformer. I mean what I am doing while I'm locked away from the world trying to avoid the pandemic.
Very slowly I am finally getting speaker cabinets built. I'll post pics in a few weeks of the finished product. I am building my take on the Lampizator P17. Basically an 18" pro driver in a large open backed box for the bass, and a 10" Coral coax full range in a small open baffle for everything above 120hz. The small open baffle is 12x13". By sitting on top of the big box I avoid the big baffle problems and it can be moved to be perfectly time aligned with the bass.
The baffles are 1.5" thick black walnut to match the rest of the system. Boxes are finished and baffles were done by a pro butcher block builder. Should get delivery of baffles next week. Then assembly, finishing followed by audio nirvana.
pics of work in progress
Walter,
Excellent!! You are finally working on the speaker chassis
Regards,
Finished speakers ... at last!
Finished and playing.
My take on the Lampizator P17 concept finally plays. It sounds great.
I always wanted to try open baffle. Assembled the parts over past few years but never got around to the actual build.
These are three way open baffle. Below 120 Hz is handled by 18" pro drivers (Peavey Black Widow in U shaped OB. Everything above 120 is handled by vintage 10" Coral coax drives with alnico magnets. My innovation was to mount the Corals in their own 12" baffle that sits on the bass box. This gives small baffle width and the ability to move them front to back to align timing of the Corals with the sub woofer.
First order crossover uses Solen caps and Solen Hepta Litz inductors.
The front baffle is 1.5" Walnut butcher block. It was finished with 5 coats of Tung oil and lots of sanding. It is pretty nice to the touch. The bass cabs are made of Russian birch ply mated with MDF to make 1" thick walls and 1.5" base. These things are heavy, so they are on wheels.
Very happy with first audition. I had a good idea of the sound as I had listened to the driver with cardboard baffles for far too long. In the new cabinets the big change is the bass. It is effortless and pretty massive. They play down to 40Hz which is not bad for OB with OTL amps and passive crossovers. if anything I suspect I'll need room treatment to tame the bass.
Finished and playing.
My take on the Lampizator P17 concept finally plays. It sounds great.
I always wanted to try open baffle. Assembled the parts over past few years but never got around to the actual build.
These are three way open baffle. Below 120 Hz is handled by 18" pro drivers (Peavey Black Widow in U shaped OB. Everything above 120 is handled by vintage 10" Coral coax drives with alnico magnets. My innovation was to mount the Corals in their own 12" baffle that sits on the bass box. This gives small baffle width and the ability to move them front to back to align timing of the Corals with the sub woofer.
First order crossover uses Solen caps and Solen Hepta Litz inductors.
The front baffle is 1.5" Walnut butcher block. It was finished with 5 coats of Tung oil and lots of sanding. It is pretty nice to the touch. The bass cabs are made of Russian birch ply mated with MDF to make 1" thick walls and 1.5" base. These things are heavy, so they are on wheels.
Very happy with first audition. I had a good idea of the sound as I had listened to the driver with cardboard baffles for far too long. In the new cabinets the big change is the bass. It is effortless and pretty massive. They play down to 40Hz which is not bad for OB with OTL amps and passive crossovers. if anything I suspect I'll need room treatment to tame the bass.
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Intriguing how good the sound is when the box is removed or just with the back open. In 1968, I took the back off some very lovely Bozaks and haven't thought of enclosing the sound ever since, subs and upper-tweeters excepted.
I don't really know why I find the enlarged ambience such an enhancement for music. The stereo localization is as good as ever. Sure different sound when you go to the Martin Logan room at an audio fair.
B.
I don't really know why I find the enlarged ambience such an enhancement for music. The stereo localization is as good as ever. Sure different sound when you go to the Martin Logan room at an audio fair.
B.
Agreed. There really is a congested box sound. Open baffle is .... open. Sound stage is very precise and well behind the speakers. In my case a bit behind the stone wall of the fireplace. That takes some mental adjustment at first. Very much 3D and effortless. No question there are great box speakers.
I think open baffle are a good choice for DIY as they are easy to get a reasonably good sound, whereas box speakers require a lot more talent.
My final project will be room treatment. Will need to wait for after isolation.
I think open baffle are a good choice for DIY as they are easy to get a reasonably good sound, whereas box speakers require a lot more talent.
My final project will be room treatment. Will need to wait for after isolation.
I am thinking 2 years from now when we all have a proven vaccine in our arms. It will be sweet. Otherwise a bunch of white haired guys like me need to stay at home and build stuff to show off when it won't result in one of us reaching an early expiration date.