A Quickie for 2017?

[Dr. Toobz]

After a busy few years getting settled into clinical practice, I am looking to fire up the soldering station once again to build another Bottlehead project! I used to have a Quickie 1.0 wired up for headphone service, but sold it when moving about five years ago. Despite also having built a Crack in 2010, I more or less gave up on high impedance headphones, and a SEX 2.0 amp I built in 2009 serves as a speaker amp. I therefore may build another Quickie, with its clean-sounding battery supply, for use with Grado SR-325e headphones in my home office. I wonder about the following:

a. With Grado headphones, does the PJCSS make a large difference in volume or sound quality vs. the stock plate resistors? I recall also having played around with 150H chokes as loads, but found the sound a bit too warm and syrupy for headphone use.

b. If building a Quickie for headphone use, where have people been putting their headphone jacks? I have considered using the pre-existing holes for a set of input RCA jacks as a place to put a pair of stereo 1/4" jacks, one for input purposes, one for the headphone output.

I am planning to use these transformers for headphone duties vs. the Speco T7010s I used back in 2009: http://bottlehead.com/smf/index.php?topic=5829.msg84941#msg84941

Anybody else using the newest Quickie with Grados? I'm curious to hear if this is a good idea...

[mcandmar]

I highly recommend those transformers as they are better than the Specos in just about every way.  To the point the Specos are obsolete IMO.

PJCCS should indeed give you maximum gain, and the lowest distortion.  I have always run mine with plate chokes and have been tempted to try a constant current source and measure the performance difference. In fact i will put that on my new years todo list

[Dr. Toobz]

I liked the plate chokes best when using the Quickie as a line pre-amp, mostly because they were a cheap way to inject a bit of tubey, rich distortion if the volume was turned up high enough. (My Klipsch speakers are not what I would call warm or rich sounding!). With headphones, on the other hand, I found the chokes to be strangely non-linear, though I now suspect that I may have instead been hearing the impact of the Specos and their lumpy output curves.

[mcandmar]

Almost certainly you were hearing the limitations of the Specos as i would not describe mine as warm and tubey sounding at all, that is just not my cup of tea.  In comparison i find my S.E.X. amp a little more lush and midrange focused vs the Babybottle.  Its that delicate DHT tube sound that i love so much about it, and the fact it is a single gain stage.  Oddly it performs just as well with my HD800's as it does with my Grados, but i originally built it just for the Grados.

The frequency response charts i posted were run at pretty much full volume, and from memory with a 32ohm load it was ~.5% THD so it is not entirely a subjective option. You have me intrigued now about CCS plate loads, dangit.