The current thread on CD player history made me think that one on each of the other main system components would be interesting, so this one is for amplifiers (as in amps used for hifi music systems, as opposed to any solely for other interests (such as guitar amps).
It would add interest if people were to include related detail, from reason for change to impressions of them to overall preference etc.
To kick off, this is my amplifier history:
Sinclair Project 60 modular amp, comprising the preamp module, a pair of Z30 power amp modules and PZ5 power supply. This was 1968-69. I built them into the plinth I made for my record deck. Impression? Well it got my first hifi system up and running, the system sounding better to me than anyone else’s music players of any sort that I heard.
Project 60 Mk 2 Next, I think late 1971, came a rebuild of the Project 60, putting it into its own box due to arrival of a new and much better record deck. I upgraded the Z30s to Z50s at the same time, raising power from 30 to 50W, hoping that would mean less frequent blowing of output transistors. Case was hand folded aluminium sheet, painted black.
Project 60 Mk 3 A year or so later I rebuilt the Sinclair amp again, this time changing to bridged Z50s, and a beefed up power supply with massive transformer and regulated electronics, in a separate box on the floor several feet away.
Radford HD250 integrated amp: 50W, with separate gain controls on channel inputs, tone control cancel button (which I normally left in cancel position). I don’t remember exactly when this was, probably 1976. It seemed to bring better clarity and control of the speakers.
Elektor magazine moving coil preamp (head amp) - DIY build, housed in an old shortcake biscuit tin (the steel providing better electromagnetic shielding than aluminium), The circuit was published in April 1978, so this would have been later that year. I was pleasantly surprised how effective it was, and of course it opened up the world of moving coil cartridges.
Musical Fidelity The Preamp 2a + MF P170 power amp replaced both the Radford and the Elektor head amp in about 1992. I’d heard MF amplification when I had auditioned and bought my firsr CD player in 1989, and with a recent speaker change this popping up for sale secondhand made sense to buy.
Tag McLaren P10 preamp: A fault with my Musical Fidelity preamp, with the MC input going oscillation on one channel while playing music loud took out the bass driver of one of my speakers, leading to lack of trust in it, led to this purchase. This would have been around 2006 or 2007.
Musical Fidelity P270 power amp bought around 2008 or 2009 - simply because I saw it on eBay at price I couldn’t resist! Replaced the P170: the same, but just more capable.
In 2015, by then streaming only, a change to source led to me feeding power amp direct from DAC, taking away the need for a preamp, so no longer in the system
Bryston 4Bsst2 power amp. I’d been aware of Bryston, and their reputation for being ideal amps for control of difficult speakers, highly respected with IMF transmission lines, and used by PMC for their speakers. Saw this for sale on eBay at an excellent price - though from Canada - converted to UK voltage by Bryson on the way to me, early 2016. Absolutely not disappointed - very capable, neutral sounding amp.
Bryston 9Bst 5-channel power amp. On eBay at a low starting price with no other bidders due (I guess) to a spelling mistake, a too good to miss cheap purchase gave me an opportunity to try tri-amping. This was maybe 2018, give or take a year. I took out one of the power amp modules, using the four remaining for mid and treble on the two channels, the 4B on bass. Compared active crossovers by ATC (EC23, analogue) and Behringer (modified DCX2496, digital), and settled on the Behringer. This amp and active XO currently out of use following my change of speakers in October 2022.
Future? Possibly up the Bryston 4B to 7B for more headroom (they’re about twice the power) - the 4B’s 500W peak capability into my 4 ohm speakers momentarily clips peaks if I play very loud, and also people say the 7B is the perfect match, being the same as 4B just more so… Of course I could try active again, though with the difficult manhandling of present speakers it is a quite a big job to convert. And there are other amps I could try (Naim? Chord?)… But whether I will ever do anything further is something I do not know - I am very content as is, and no longer working means resources are finite.
Edit July 2023:
Musical Fidelity A370. As 2023 started, this power amp had not been in my mind for years. I had long lusted after this amp from first discovering/buying MF amps over 30 years ago, eventually all but forgotten. Then lo and behold one popped up unexpectedly in excellent condition at a good price and presented itself before me, tempting me …and the future changed in an instant. The sound … simply great. It is Class A, 185WRMS with peak capability of 50 amps - effortless is a word that has been used to describe it, and I don’t disagree. More in a post I made just after buying: