Bottlehead Forum
Bottlehead Kits => Legacy Kit Products => Quickie => Topic started by: xcortes on February 13, 2011, 05:08:25 PM
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I have a pair of Magnequest Peerless TL-404 wich is a fantastic autoformer designed for headphones. This is the same that Doc has in his big headphone amp. Such pair is earmarked for a WE 437A headphone amp.
But last week I crossed paths with another pair. And I couldn't help getting it. So tonight I instaled it in my Quickie along with lots of other changes:
1. Changed the selector switch to a 3 pole one to switch grounds, because of 2,
2. Installed 10k:10K MQ B7 Ni input transformers,
3. Replaced the pot with a 10K Penny and Giles pot,
4. Installed a switch to select 50 ohm or 200 ohm taps on the autoformer,
6. Of course added a headphone connector.
The Quickie already had the PJCCS and Auricaps. I'm using Mullard tubes. The sound is heavenly from the 50 ohm taps on my Sony MDR-R10s. I will need to do a head to head comparison with my (also hot rodded) Sex.
Coooool kit!
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I love it - Xavier, you're an animal!
One of the great features of the quickie is there's no power transformer to induce hum into the iron parts heh heh...
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INSANE! I love it. Please post a pic of the top side.
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That's just crazy! Awesome job shoe horning everything in there.
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wow, he's as crazy as me. I love it.
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This baby sounds amazingly good! I've been experimenting with cassettes recording my tapes from the Tape Project and others on a nice Nak deck. Playing them on this nice Walkman through the Quickie is a fantastic experience. This is portable hi-fi and no BS!
Only problem is the Walkman only outputs 0.25v. I'm thinking of adding another Quickie in there (sharing the batteries) to add gain. The extra switch is the 50 ohm 200 ohm selector and you can see I rewired the inputs so that now they are right and left instead of front or back. No need to have cables all over the amp this way.
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See if you can find a couple 1U5WA types. They can be triode-wired for a gain of around 10, and are supposed to be low-microphonic types. Can't drive an interconnect or a headphone, but can easily drive a 100K volume control. Add a third D cell for both of them - each draws half the filament current of a 1S4, so the batteries will have the same lifetime. Plate load 18K, no cathode bias needed.
:^)
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Cool idea. Do you think I could use the 10k pots before and then a coupling cap and a 100k grid resistor on the 3S4?
Even better, how about a pair of RGC 16 grid chokes to squeeze more MQ iron in the operation?
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sure.
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Before doing more mods I took a pen and marked what every switch is for. And not happy with that identified the sockets, jacks, etc. I think I like it. I will do that to the rest of the BH gear!
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Hook up the input trannies as autoformers with a step up. Seems like that should work good.
Michael
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I purchased, and had serviced by ESL labs, a WM-D6C Walkman which is outstanding. But the output is only 0.25 v. Not enough to use it with my Quickie with headphones. So with PJ help I added a second gain stage. Basically a second Quickie sharing batteries. It has it's own PJCCS board. Instead of grid resistors in the second stage I used Magnequest grid chokes (this baby has now more MQ iron than you thought you could squeeze in this small box. I think I need to experiment with the size of the couping and output/parefeed caps size but sounds very nice at first fire.
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The amp is now at the office with it's new mates, a set of HD-600 headphones. I'm playing several cassettes recorded over the weekend. I decided to give Dolby (C) another chance and on this deck it works very well. No breathing effect or anything and no tape hiss.
The "integrated" Quickie (I guess that's what it is since it's an amp with a preamp in the same box) is clean, fast and detailed. I guess running everything from batteries helps a lot. It's very quiet too. No issues with microphonics because I'm using headphones.
The only problem I'm detecting with cassettes is some dropouts. Minor but still there. But you can listen to this sh*t for hours without any fatigue. I would put this little cassette system against any CD player anytime!
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Killer stuff Xavier!
Glad to see that you're keeping extremism alive in your neck of the woods.