Personal Preamp Evolution.

Yamaha C-80, Yamaha C-2, Sumo Athena, Blue Circle BC3, Blue Circle BC3000, Hovland HP100 and Antique Sound Lab TwinHead.
Dynaco Pat4, SAE P202, Forte F44(early model), Threshold FET ten/hl, Threshold FET nine/e, Forte F44(later model). Time frame: 37 years.
Dynaco kit, Mark Levinson ML 2, Audible Illusions, Melos, Classe DR 5, Klyne 7 series, Lector, PS Audio PCA, PS Audio GCP 200, now using the variable output stage of Raysonic 168 CD player.
Bryston B-60 (used thru pre-outs)>Air Tight ATC-1>Edge Sig 1>Supratek Syrah>Herron VTSP-1A>Deja Vu Audio Custom Preamp.
Krell KAV250, McIntosh C712, Rogue Magnum 99, Audio Research LS3b, CJ PV10a, Belles GR8, McIntosh C712 (#2), Classe CP50, BAT VK3i, Cary SLP-98, McIntosh C42. I also currently own a Kora Crescendo. My time frame is 10 years.

Rotel RC 1070 > Rogue 66 > Music Angel Marantz 7 clone
ARC Sp-9 II, Krell KBL , CJ prem 14, 16ls, Art, all CJ mk 1's,
First Sound Pres Dlx mk.2, EAR 912, Messenger full function w/
solid state power supply. 20 years with 3-4 year period owning a Tenor 75 integrated.
Marantz 3200,Hafler DH 101,Audio Research SP 7,Audio Research LS 15,Morrison ELAD,Cary 98L,Edge SL 1,Modwright 9.0SE,Supratek Syrah,Aesthetix Calypso,Audio Horizons TP 2.0,
REF 3,Jeff Rowland Capri.My reference piece remains the Audio Horizons,pound for pound it's simply the best.This opinion is based solely on use in my system and is not an absolute.
1) Pre-amp stage of an Arcam Alpha 7R integrated

2) Musical Fidelity A308

3) BAT VK-31SE

-looking at that list, those are 2 very large steps
First, Kenwood KC-106 From 1987-1997
Then system broke down, and got a crappy receiver.
2. Kenwood KC-206 with remote from Nov.1997-March 1999.
3. Kenwood Basic C-2 From march 1999-July 1999
4. Yamaha CX-1000 Multi-voltage July 1999-July 2003
5. Adcom GTP-600 (10 steps back in sound and control
quality). Sept.2003-Jan.2005
6. Pioneer Elite C-91 Jan. 2005-present
1) Onkyo 304 RS
2) Audio Research LS3
3) Krell Krc 3
4) Eastern Electric Minimax
5) deHavilland UltraVerve
David Hafler DH-101
Lazarus tube pre amp
Klyne 6lx3p
PSE hl-1
Span of 22 years.
Rogue 66
Rogue 99 Magnum
Audible Illusions 3a
EAR 864P
Cat Ultimate v1
Hovland HP100
Yamaha Surround pre?
NAD 1600 pre/tuner
Superphon Rev II
Audio Research LS1
Audire Diffet
C-J PV10a
Musical Fidelity A3cr
C-J premier 17ls s1
Audio Research LS 17
C-J premier 17ls s2

What a sickness this hobby is.
Audible Illusion Modulus 2D
Audio Research LS2B
Audio Research LS15
Sonic Frontiers Line 3
Sonic Frontiers Line 3SE
Sonic Frontiers Line 3SE+
Einstein pre amp
Evolution implies progress, which I'm not sure is the case. Returning to some vintage roots finding some surprises. Here's the sequence (since 1968), with some overlap

McIntosh C20 (20 years)
Audible Illusions Modulus 3 (10 years)
Creek OBH-10 passive (8 years to date)
Wright WPL-10v (6 months)
Audible Illusions Modulus 3a (3 years to date)
Conrad-Johnson 17LS (1 year)
Hovland HP100 (1 yr)
Mapletree Audio Ultra4 (1 yr)
Promitheus TVP (1 yr)

Notice the trend. At this rate, I'll be trying a new one every 3 months!
Quad 33, Dayton-Wright SPA modified, Precision Fidelity C-7, Classé DR-7, BAT VK-3i, BAT VK-51SE. Then I eliminated the preamp completely buy using the preamp section in the Audio Aero Capitole and Prestige CD players.
Hafler DH101(1977), Musical Concepts modded DH101(1979), Musical Concepts main board added(1980), Hegeman Hapi 2(1981), Audible Illusions 2d(1982),Audio Research SP-9(1986),sold everything 1988(kids), Rotel RSP(?) home theater(2002), Odyssey Tempest(2004),Audio Horizons TP2.0n(2006)

HH Scott integrated (~1965)
Kenwood integrated (~1976)
Sherwood receiver (~1981)
NAD 1020B
B&K xxx5
Audio Research sp9mkii
Sonic Frontiers SFL1-SE
Air Tight ATM1 (amp w/attenuators)
Spectral DMC20mk2
Cary SLP2002
CAT SL1mkiii
Joule Electra LA150
Joule Electra LA100mkiii
Atma-Sphere MP-3
Herron VTSP1-166a
Dodd Battery Powered

This makes me feel old! Cheers,
Sbank-how do you like the dodd vs the atmasphere mp3 you had???
Fisher Integrated
Harman Kardon Integrated
Threshold FET 9
Audio Research SP14
Placette Linestage
Joule LA100 Mk3/OPS Mk3

Still have the Placette and Joule to enjoy
Bryston BP .4
Morrison ELAD
Plinius CD LAD
Jolida Envoy
Forgot one:

HH Scott integrated (~1965)
Kenwood integrated (~1976)
Sherwood receiver (~1981)
NAD 1020B
B&K xxx5
Audio Research sp9mkii
Sonic Frontiers SFL1-SE
Air Tight ATM1 (amp w/attenuators)
Spectral DMC20mk2
Cary SLP2002
CAT SL1mkiii
Joule Electra LA150
Joule Electra LA100mkiii
Atma-Sphere MP-3
Herron VTSP1-166a
Dodd Battery Powered

This still makes me feel old! Cheers,
1) +/- 1983 a Kenwood Receiver>

2) 1985 Hafler DH 101>

3) 1986 picked up a second Hafler DH 101>

4) In 1990, sold everything to finance a move >

5) Went without any "real" audio between 1991 and 1993>

6) 1994 picked up a Luxman Mosfet Receiver>

7) 1998 got a B&K ST - "Crap" >

8) ASAP in '98, I got rid of the B&K and picked out a Bryston 3B-ST>

9) Beginning in 2000, and over the next year or so, I toyed with a Sim Audio I-5 and Bel Canto Evo but ended up living with my back-up Luxman when I had to move once again >

9.1) 2001 - I started reviewing for, so there were many many amps going through my house, so from this point forward the listed amps are only those I purchased and owned for at least (12)months, except the Nuforce which were upgrades until the SE V2 unit, which I purchased a whole new chassis....>

10) 2003 - Antique Sound Labs (?) >

11) 2004 - Edge G-3>

12) 2000 & 2006 - reviewing several amps, some stayed months, some weeks...then...>

13) 2006 came the Nuforce 8.0>

13) 2006.5 Nuforce 9.0>

14) 2007 Nuforce 9.0 SE>

15) 2007.5 Nuforce 9.0 SE V2.....

So, with the SE V2, I really began to settled down. I was a bit antsey with the "SE" only version, but with the V2, Nuforce really hit out of the park for me...

Span of time: 25 years! Yikes.

Jan- Jas Array 1.1 tube
Feb- Supratek Chardonnay
Mar- Granite Audio 770
Jun- Dodd battery pre
Sep- Isabella (Red Wine Audio) with Isabellina NOS DAC

2009 - non
2010 - ???
Kenwood 700c (1977). Kenwood 700c restored (2006). It's been a hell of a ride.
McIntosh MA 5100 integrated in the seventies. Sold everything and was out of the hobby for more than a decade.
Creek integrated around '91. Arcam Alpha 9 integrated in the late '90s.
Conrad Johnson PV14, then upgraded to Series 2.
CJ Premier 17LS, then upgraded to Series 2.
Modwright SWL 9.0SE, then upgraded to Sig.
Modwright LS 36.5 at present.
My first preamp was an integrated with pre out/ main in jumpers that I used as a preamp. My first dedicated pre was an APT Holman which was great in it's day. That was replaced with a PS Audio 6.2 which was active or passive. That was replaced by a McIntosh C15 which was recently replaced by a McCormack RLD 1 which is the best pre I've owned to date by far.
1. Musical Fidelity X-Pre/X-PSU/X-LPS

2. Aragon 24K with IPS

3. (Present) Audio Research LS-2 (tube: Philips E288CC) with Sphinx Phono pre

And I have a PS Audio 5.6 pre for use in my second system.
Used a KenWood KA-6100 integrated as a pre after a little snip-snip, solder-solder. If I knew than what Iknow now, I'd have installed pre-out RCAs and done the same for main in.
Replaced that with a NAD1700 about '86 or so, than junked that out for a nice integrated, a PSAudio GCC250.
I don't change equipment that often, to have a 'history'.
Dyna PAT-4
Harman Kardon Citation 11
Crown IC-150
ARC SP-3a1
ARC LS-15 (plus PH3-SE)
Upgraded ARC SP-3a-1 to SP-3c
Pioneer SA-9100 integrated
Audio Research SP 9 Mk III
CAT SL-1 Ultimate
First Sound Presence Deluxe Mk II 4.0
only those that i can remember...

supratek chardonnay, supratek Cabernet

solid state : Metaxas reference, Electrocompaniet EC 4.7,
Viola Cadenza

Passive: Cello Etude, Bent audio Noh TVC, promitheus ref4 TVC, lightspeed attenuator, Bent audio unit autoformer

special price for the VIOLA Cadenza in S.S
Supratek Cabernet in Tubes
Bent Audio preamp
Quad 22, Meridian 101B, Verdier Control B, TRON Meteor

The TRON is streets aheadof anything else I've heard.

1. Luxman - full featured one w/pretty rosewood case
2. Acoustat TNP
3. Dyna PAS 3
4. Dyna PAS 2
5. Music Reference RM5 mkII
6. Hegeman Hapi 2
7. Superphon Rev Basic DM

Many years spent with tube amp w/volume control and passive switch box and also tube & SS int. amps
I started out with a Kenwood receiver in 1973, then as I became aware of high-end audio I bought a CJ PV-5 in 1986 which I still use although its heavily modded (new caps, new power supply). Hitting the Easy Button NOW!--Mrmitch