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Author Topic: preamp as headphone amp  (Read 4534 times)

Offline steveidosound

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preamp as headphone amp
« on: September 29, 2009, 11:21:50 AM »
This is primarily directed toward one of our members who is way into headphones. (you know who you are Steve)
Anyway, I just re-discovered one of my old pieces of equipment lying around. it is an Apt / Holman Preamplifier (that is it's name and model) from the 70s.
I am using it with my Thorens / Grado  and fairly cheap AKG phones right now because my little Bellari  half tube unit broke - but they fixed it for free - but that's another story. Anyway, the Apt is a wonderful relic of what now seems to be a bygone era. A full featured actual preamp in the old sense with a phono stage. They took great care with the design of the phono preamp section and the headphone drive amp. It shows. I am going back and listening to older albums I know and love and hearing more detail than I have ever heard from some of them emerging from a very low (for vinyl) noise floor with plenty of gain and weight behind the sound. It almost begins to sound "master tape-ish" at times!
I swapped the Bellari back in to the same setup when I got it back. I have always thought it sounded good but it was pretty weak by comparison.
Just wanted to report my fun headphone experience. I briefly considered what it would take to modify the phono 2 input to an IEC or NAB switchable tape head preamp. Does not look easy to do as it is really one phono stage with some modifications for 1 vs. 2 and switching. 
Steve Williams

you don't want to know what equipment I listen to...

Offline ironbut

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Re: preamp as headphone amp
« Reply #1 on: September 29, 2009, 05:55:53 PM »
Hey, hey,
I remember the Apt/Holman! I'm still a fan of full function preamps (I have a CAT Ultimate that has a really nice high gain phono stage).
There were a few preamps with good headphone outputs but unfortunately the newer ones are lucky to have any headphone outs. A couple of really top notch preamp/headphone amps were the Melos and Sonic Frontiers unit's. The Melos units aren't the most reliable but when their working, they're one of the best for driving Grados. The Sonic Frontiers top models outsourced the headphone amp design and really only shared the power supply with the preamp functions.

I recall that a few members here had some preamps with built in tape head inputs (HK Citations). I don't think that any of them ever checked back in to tell us how the sound was.
steve koto
 Sony scd 777es(R. Kern mods)> Vpi Aires>Dynavector XX-2mkll>Bent mu>CAT ultimate>CJ premeir 140>Magnepan 1.6qr(Jensen xover)Headphone Eddie Current Zana Deux>AT ad2000,HD800 ,Metric Halo ULN-2 (battery powered),
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Offline Ki Choi

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Re: preamp as headphone amp
« Reply #2 on: September 29, 2009, 11:53:40 PM »
Actually all Sonic Frontiers Line 1, 2, and 3 had the same Headroom headphone amp module built into the preamps.  I had Line 3 for a while and still use Line 1 with the difficult-to-drive Sennheiser HD-600 with good result.
Ki Choi

Offline ironbut

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Re: preamp as headphone amp
« Reply #3 on: September 30, 2009, 01:03:36 AM »
I was sorry to see such a nice line of gear go. I have several friends with SF gear still and their DACs are the subject of some really decent sounding mods (they're actually getting a little hard to find because of that). Great value and high quality parts and build.
steve koto
 Sony scd 777es(R. Kern mods)> Vpi Aires>Dynavector XX-2mkll>Bent mu>CAT ultimate>CJ premeir 140>Magnepan 1.6qr(Jensen xover)Headphone Eddie Current Zana Deux>AT ad2000,HD800 ,Metric Halo ULN-2 (battery powered),
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Offline xcortes

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Re: preamp as headphone amp
« Reply #4 on: September 30, 2009, 09:13:26 AM »
I had a Fisher 400 receiver for a while. Although I didn't do comparisons with other gear in the same setup I did try with success  it's tape preamp and liked it's sound. It also sounded very well with my Sennheiser 600s through it's headphone output. No IEC eq though.
Xavier Cortes