These are the same OPTs, all designed by Menno.
I remember sitting at a cafeteria table at AES in NYNY fall 1999 and hearing Menno and Bill Perkins, both brilliant transformer designers discussing th epros & cons and the technical stuff wrt toroid (Menno) and C-Core (Bill) OPTs. Quickly went over my hea dby iremained glued to what they were saying, and it was fascinating.
dave
This one has been plauging me since Oct last year, but now I have finally started to get things together.
A small 12B4-SE with a HV DC/DC SMPS, intended to run on a 12V lead battery.
I have mislaid the phonosockets ... again!
Transformers are cheap Chinese and the box is some kind of "wooden box" from H&M HOME.
A small 12B4-SE with a HV DC/DC SMPS, intended to run on a 12V lead battery.
I have mislaid the phonosockets ... again!
Transformers are cheap Chinese and the box is some kind of "wooden box" from H&M HOME.
Attachments
I remember having a chat with Ward de Ceuninck during a lunchbreak at work, (he is one of the two guys behind Monolith Magnetics) and I know exactly how you felt. He is good at explaining things but it quickly went from uhuh, sounds alright, uhuh... into physics that are beyond my knowledge and which might as well be black magic and witchcraft. Too bad his products are way out of my financial comfort zone because they sure look good
all tube graphic EQ
Unexpected arrival of shipping from US during lockdown of remaining parts necessary to finish this all tube graphics EQ by Rickard Berglund, then again extended quarantine until May 15 so perfect for give a finish to this project.
On page 930 #9296 of this thread the wooden board and other info, here the final build, big task has been find a way to avoid to much cable connections, so I made this kind of "guitar string" for connect the all 10 modules, this workout very well avoiding bundles of wires and unwanted oscillations.
I just tested musically and sound and work very very well, no oscillation whatsoever and even the little hum on the wooden board test is gone, max vol on amp and no noise at all.
I still need nice knobs and somehow some print for the front panel.
I will test now the EQ with generator, scope and Rew for see the real performance.....all the best
Unexpected arrival of shipping from US during lockdown of remaining parts necessary to finish this all tube graphics EQ by Rickard Berglund, then again extended quarantine until May 15 so perfect for give a finish to this project.
On page 930 #9296 of this thread the wooden board and other info, here the final build, big task has been find a way to avoid to much cable connections, so I made this kind of "guitar string" for connect the all 10 modules, this workout very well avoiding bundles of wires and unwanted oscillations.
I just tested musically and sound and work very very well, no oscillation whatsoever and even the little hum on the wooden board test is gone, max vol on amp and no noise at all.
I still need nice knobs and somehow some print for the front panel.
I will test now the EQ with generator, scope and Rew for see the real performance.....all the best
Attachments
I am looking for that nice Mains On/Off switch with back light. Have browsed the internet but could not find that particular one. Where did you purchase it if I may ask?
This is my first go at an OTL headphone amp. It's based on the ubiquitous 6AS7 cathode follower topology, and I must admit, I looked at Pete Millett's Wheatfield HA-2 schematic more than once.
I built the amp specifically for my Sennheiser HD6XX, and there's no detectable hum or hiss. The soundstage is spectacular.
The front end is a 6EJ7/EF184 triode strapped with an active load provided by a 6C4 in a mu-follower configuration. I set the negative feedback by ear, and it turned out to be around -10dB.
I built the amp specifically for my Sennheiser HD6XX, and there's no detectable hum or hiss. The soundstage is spectacular.
The front end is a 6EJ7/EF184 triode strapped with an active load provided by a 6C4 in a mu-follower configuration. I set the negative feedback by ear, and it turned out to be around -10dB.
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No problem
It's this one:
19mm Metal Waterproof 12V LED Power Symbol 5Pin ON-OFF Car Push Button Switch | eBay
Yes you right lot of work but paid off, thanks for your comment...all the best
Glossmaster, these are nice amplifiers, but promoting them here in the Photo Gallery is a violation of forum rules and they will be removed.
You may repost in a thread in vendors or arrange for your own forum if you like.
Thanks Kevin for the reminder and the compliment. I should have left out the link to my web page.
My new pre amplifier.
Active load on the gain stage and solid state current sink on the cathode follower.
Power to the supply and the two auxiliary outputs (one push button start for pre and two mono blocks) is via soft start and DC blocker.
Active load on the gain stage and solid state current sink on the cathode follower.
Power to the supply and the two auxiliary outputs (one push button start for pre and two mono blocks) is via soft start and DC blocker.
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