Amplifier upgrade

[j.postema]

Hi all,

I've built my own pair of full-range electrostatic loudspeakes. I'm quite happy with them and they are big (door size) panels. Although stats can be difficult to drive my current aplifier seems to have no problems at all driving them. It is a Harman Kardon HK680 integrated amplifier. If I'm correct is has a positive review: (not sure if the source is reliable)

https://www.tnt-audio.com/ampli/hk680_e.html

As always - I'm wondering if there is room to improve things. I would think the living room where my audio system is intalled is the foremost important factor and I didn't do much about room treatment. As this is my third pair of DIY stats I think it would be quite difficult to make big improvements here. (although I have plans to build new panels).

I use a budget CD player (Marantz CD5001) and an old but fine turntable (Pioneer PLD12D with AT100e cartridge) I guess at the source there is room for improvement.

But how about the amplifier? When reading reviews I read a lot of subjective terms describing different amplifiers. At the other side there are people that tell each amplifier should sound (almost) equal as it just aplifies the signal - nothing more.

Then there is the factor of load - electrostats are well know for being a more diffult (capacitive) load compared to magnetic loudspeakers (resistive). And electrostats are well know for being (very) resolving. Would this mean there is room for improvement and would it be worth the effort to upgrade my HK680 amplifier?

Ideally I would select up to five to ten different amplifiers and compare them at home. But I guess this will be difficult - if not imposible. It would be difficult to bring them to an good audio store as well. I always prefer to test things by myself and alone.

So to summarize my question: do you think an amplifier upgrade can result in a clear audible improvement in my case? And what amplifiers would qualify for this? For instance, would a Quad 606 MKII qualify?

[DSJR]

My opinion and experiences only... The Quad 606mk2 onwards *to me,* is a true now lower cost safe-as-houses reference point, able to drive well over 200W per channel into a 4 ohm load and able to drive practically anything within reason, including electrostatics - all this without losing the music in my experience! The 606mk1 needs the larger supply caps at least (when new, the mk1 could sound grainy/dirty for the first hour or so, not the later ones I remember, which came on song practically after switch-on). Preamp choice will be important though. I think it's happy with a passive, but active preamps can often have more of a sonic influence than the power amp itself, so choose carefully is my recommendation. I seem to think a current Croft Micro 25 would be a great start myself.

Of course there are other power amps out there and some have ballistic bass while others have etched 'detailed' highs. Trying to find a nice balance all through while safe into a possibly tricky electrostatic load may well be a problem, especially if you made the speakers yourself. I'm sorry I can't help any more.

Depending on the efficiency of the speakers, I wonder how the neat Quad Vena II would do? Looks great in the flesh and 'feels' right as well imo... price isn't high either.

[Macca]

Can the HK680 be used as a power amplifier only?

[j.postema]

Can the HK680 be used as a power amplifier only?

Yes it has a switch to seperate pre - and power amplifier.

[Leeken]

I’m no prolific box swapper or listener of lots of different kit,but I got one of these recently and pound for pound brand new with a guarantee I think it’d be hard to get better https://www.lintone.co.uk/quad-elite-qsp-stereo-p-amp-black-special-offer

[Macca]

Yes it has a switch to seperate pre - and power amplifier.

I'd suggest getting a quality pre-amp then, and keep the HK as a power amp only.