Installed lots of iron in my Quickie or how to spend $1,000 in a $100 kit

xcortes · 6649

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Offline xcortes

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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!
« Last Edit: February 13, 2011, 05:16:59 PM by xcortes »

Xavier Cortes


Online Paul Joppa

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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...

Paul Joppa


Offline mrarroyo

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INSANE! I love it. Please post a pic of the top side.



Offline Grainger49

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That's just crazy!  Awesome job shoe horning everything in there.



Offline ssssly

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wow, he's as crazy as me. I love it.






Offline xcortes

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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.

« Last Edit: May 09, 2011, 06:12:55 AM by xcortes »

Xavier Cortes


Online Paul Joppa

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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.

:^)

Paul Joppa


Offline xcortes

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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?


Xavier Cortes


Online Paul Joppa

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sure.

Paul Joppa


Offline xcortes

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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!

Xavier Cortes


Offline braubeat

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Reply #10 on: April 10, 2011, 01:21:44 PM
Hook up the input trannies as autoformers with a step up. Seems like that should work good.

Michael



Offline xcortes

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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.

Xavier Cortes


Offline xcortes

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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!



Xavier Cortes


Offline ironbut

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Killer stuff Xavier!
Glad to see that you're keeping extremism alive in your neck of the woods.

steve koto