mwhouston Posted June 17, 2016 Posted June 17, 2016 Checkout the step by step build of a BH top of the range HP amp. http://www.stereo.net.au/forums/index.php/topic/105788-bottlehead-crackatwoa-headphone-amp-build/ 1
awty Posted June 17, 2016 Posted June 17, 2016 This is the second of these Bottlehead headphone tube amps I have assembled for others. This one also has the speedball upgrade. The owner wanted a dark high gloss base and copper top plate. Only finished it a few days ago. I'm currently putting another one together for an SNA member. A thread has been started and I hope to update it as I finish major steps in the construction. Great job. Copper and wood are gorgeous together. How did you cut the slots?
davewantsmoore Posted June 18, 2016 Posted June 18, 2016 (edited) I made this 'synergy' horn That's excellent ... but why would you call it a "synergy" horn (as opposed to just a 'horn') EDIT: just noticed Zog got in first Edited June 18, 2016 by davewantsmoore 2
Nada Posted June 18, 2016 Posted June 18, 2016 To reduce higher-order-modulus (HOM) distortion. can you measure before and after the foam filter and graph the difference?
awty Posted June 18, 2016 Posted June 18, 2016 I don't even know what I'm looking at, Tony. Looks to be a Emont & Zealand room rumbler Mrk1 or Mrk2 .....maybe? Great work tony.
Guest Posted June 18, 2016 Posted June 18, 2016 5.5 (80Kg +) square meters of membrane traps for behind a set of speakers in front of a concrete wall, yet to be fitted with centre core and front panel
Guest Posted June 24, 2016 Posted June 24, 2016 Gathering materials for the membrane trap, may as well start measuring and cutting
mwhouston Posted June 24, 2016 Posted June 24, 2016 5.5 (80Kg +) square meters of membrane traps for behind a set of speakers in front of a concrete wall, yet to be fitted with centre core and front panel And the WAF?
Guest Posted June 24, 2016 Posted June 24, 2016 And the WAF? http://www.stereo.net.au/forums/index.php/topic/75988-a-battery-based-audiophile-story/page-50
Equaliser Posted June 26, 2016 Posted June 26, 2016 (edited) Got bored today so I slapped up a headphone amplifier using an enclosure from gavtron`s old 2 channel b22 amp I bought from him a moon ago, some spare pcbs and other parts. Carbon vinyl wrapped the case which is a hammond variant (number slips me). Had to pull apart the Valab/Teradak 50k stepped potentiometer that I had lying around which the turning tension was too tight (had to perform some surgery), not as smooth as my DACT CT2 but big improvement. The circuit is designed to the specifications around the opamps which are not rollable except the 797. Pure 99.999% occ silver stranded 26awg wiring for purest sound (subjective) for areas where crucial: inputs, outputs and the volume pot. Just needs some feet and my engraved business logo badge. Pictures: (yes the back panel is a bit rough as it was for another amp, I`ll find a plastic clip in cap for that hole) Sent from my LG-D855 using Tapatalk Edited June 26, 2016 by liteneasy 4
mwhouston Posted June 26, 2016 Posted June 26, 2016 Got bored today so I slapped up a headphone amplifier using an enclosure from gavtron`s old 2 channel b22 amp I bought from him a moon ago, some spare pcbs and other parts. Carbon vinyl wrapped the case which is a hammond variant (number slips me). Had to pull apart the Valab/Teradak 50k stepped potentiometer that I had lying around which the turning tension was too tight (had to perform some surgery), not as smooth as my DACT CT2 but big improvement. The circuit is designed to the specifications around the opamps which are not rollable except the 797. Pure 99.999% occ silver stranded 26awg witing for purest sound (subjective) for areas where crucial: inputs, outputs and the volume pot. Just needs some feet and my engraved business logo badge. Pictures: Sent from my LG-D855 using Tapatalk Image?
Equaliser Posted June 26, 2016 Posted June 26, 2016 Uploaded pictures. Sent from my LG-D855 using Tapatalk
Equaliser Posted June 28, 2016 Posted June 28, 2016 @@liteneasy Nice work! Your board or DIY kit? Board and pcb mount trafo is from Jims Audio, rest of the parts I had to source according to BOM and schematic. The design is based off Ray Samuel's XP-7 with a few modifications.
betocool Posted July 3, 2016 Posted July 3, 2016 Trying my luck with a Python based audio analyzer.... first steps. 3
mwhouston Posted July 5, 2016 Posted July 5, 2016 A Crackatowoa I assembled for an SNA member. Base has been glued, thus the band to hold it all together until glue dries. 4
Thebaconson Posted July 13, 2016 Posted July 13, 2016 Just thought I'd throw up some pictures of some new PC speakers I threw together using, Dayton AMT Mini-8 tweets, RS52 dome mid and RS225 8" woofer, in a sealed box. Bought the lot from parts-express in the US, very fast shipping was about 7 days to arrive. Cross over is a 18db 3-way, using Jantzen cross caps and coils, I added a 2.85db L-pad on the mid to keep it inline with the tweet and woofer. SpeakerBug is where they came from and they were more than happy to free of charge unwind some coils to get me exact values. Started off trying to paint them gloss black, but no matter how much I filled and sanded the joins, the gloss just brought them out, you could see it at certain angles, so I eventually gave in and went with carpet. Trust me to make a 5 sided box so I could sit it in a corner. Designed and etched the boards myself, little crowded but 150x150 was the largest sheets I had lying around. did the usual space coils 90degree apart and gave it all a good coating of hot glue, the crossover is mounted on its side on an acrylic plate screwed onto the back of the box, woofer section is a sealed section of its own and tweet/mid/crossover is a separate section. 6
zog Posted July 13, 2016 Posted July 13, 2016 Just thought I'd throw up some pictures of some new PC speakers I threw together using, Dayton AMT Mini-8 tweets, RS52 dome mid and RS225 8" woofer, in a sealed box. Bought the lot from parts-express in the US, very fast shipping was about 7 days to arrive. Cross over is a 18db 3-way, using Jantzen cross caps and coils, I added a 2.85db L-pad on the mid to keep it inline with the tweet and woofer. SpeakerBug is where they came from and they were more than happy to free of charge unwind some coils to get me exact values. Nice, good to hear P.E. shipping is quick as I'm awaiting some goodies from there as well. Was the crossover a published design for those drivers or did you develop it yourself? Have you done any measurements? Great work!
Guest Posted July 13, 2016 Posted July 13, 2016 DIY membrane traps almost ready for install on the rear wall of the Lounge. Will take a few before and after acoustic measurements for posterity
mwhouston Posted July 13, 2016 Posted July 13, 2016 I had never thought about unwinding chokes until a friend suggested it about a year ago. Most of the time I would design my Xover points around stock off the shelf chokes. But the old unwind trick means more accurate Xovers. The worse finish you can have on a speaker box is a piano or a gloss timber finish. Lots of nice reflection surfaces = bad. The best is a stippled or "woolly" finish like yours. Acoustically dead. That's why I paint all my boxes with a roller constantly going over and over the semi-dry surface to further tease out the paint. The speakers look good. Good work. What are the Xover points?
Thebaconson Posted July 14, 2016 Posted July 14, 2016 (edited) Nice, good to hear P.E. shipping is quick as I'm awaiting some goodies from there as well. Was the crossover a published design for those drivers or did you develop it yourself? Have you done any measurements? Great work! I had never thought about unwinding chokes until a friend suggested it about a year ago. Most of the time I would design my Xover points around stock off the shelf chokes. But the old unwind trick means more accurate Xovers. The worse finish you can have on a speaker box is a piano or a gloss timber finish. Lots of nice reflection surfaces = bad. The best is a stippled or "woolly" finish like yours. Acoustically dead. That's why I paint all my boxes with a roller constantly going over and over the semi-dry surface to further tease out the paint. The speakers look good. Good work. What are the Xover points? Long day yesterday, 12dB crossover sorry, points are 800,8000. I was going to go a 12dB but the cost of the additional coils was making the crossover cost more than the drivers. The crossover was of my own design and calculations, I plotted the box on BassBox Pro nothing too fancy. As far as measurments go, nothing to fancy, just my ears and a few friends ears. Not to concerned on its response, it's for the PC and yeah I think it sounds good, that's good enough for me with these. I got express shipping from PE as it was only a few dollars more than standard but yeah was surprisingly quick. Now that the PC speakers are out of the way, it's back to the graphic equaliser and the headphone amp projects. Equaliser has been sitting around gathering dust for a while now. Edited July 14, 2016 by Thebaconson 4
mwhouston Posted July 15, 2016 Posted July 15, 2016 Here is yet another of my "Mimic" phono stages. This is also for an SNA member who wanted two switchable inputs and the ability to switch between MM and MC thus the switches on the back. There is also a battery test point at the front. All the drilling is done and the preamp assembled now for the internals. 3
Recommended Posts