Amp for Kef 104ab??

Wavod

Active Member
Hi. My friend has a pair of Kef 104ab speakers which he had paired with an old Nad 2 channel amp which has finally given up ( I think not powerful enough to drive the 104ab's). He doesn't want to break the bank & his budget is £200 - £300 max. I feel the nearer he can get to 100w per channel to drive the unforgiving Kef's the better. What do you think, and any suggestions either for a vintage amp or more recent? Thanks...........
 

Orobas

Well-known Member
Hi. My friend has a pair of Kef 104ab speakers which he had paired with an old Nad 2 channel amp which has finally given up ( I think not powerful enough to drive the 104ab's). He doesn't want to break the bank & his budget is £200 - £300 max. I feel the nearer he can get to 100w per channel to drive the unforgiving Kef's the better. What do you think, and any suggestions either for a vintage amp or more recent? Thanks...........
Welcome to the world of vintage speakers!

Let's have a look at the AB in a bit more detail...

is it easy to drive... Yes! it's 8ohm @96db (12.5w needed to reach this target)
what is its power requirements... 15-100w into 8ohm

what is this power requirement realistically..
This is where it gets interesting.. the 104AB was a 1976-1980 speaker.. the bulk of amps at this time were solid state, no electronics or processors of today and a lot were still competing with valve sound..

So what about the drivers.. old heavy iron magnets, heavy doped paper, bextrene.. these were slow dense materials as that is all they had at the time..

Right.. lets now fast forward to the 2000 onwards...

We have lightweight fast cones, plastics, rare earth magnets, superior electronics, resistors, caps and so forth with speakers... Our amps are microprocessor based.. use amp modules, they're lighter, use more modern components and just are far quicker.

This is where the problem lies.. How to put a New amp with an old speaker... It's much easier to put an old amp with a new speaker!

Nad's had good power delivery.. they were ahead of their time with their soft clipping function and even today.. Nad is a decent firm and well worth considering

What we need to do is pair an amp to the heavy slow speaker.. There are a number of amps that can do this out there.. even amps like my powerhouse Roksan can be got used for £300... will my amp work with the Kef.. oh yes.. is it the right amp... nope.... not by a long shot.. it is not voiced right.

You need a light airy amp with plenty of current for this Kef.. a half decent Marantz 5005 or a 6007(used) more than likely will be your best best on this.. @Ugg10 , @gibbsy are the kef guys here.. i do believe so do wait on them!

There is one other hurdle and that is an unknown for me.. that Passive Radiator.. getting that balanced... I always had issues with Linn Isobarik's getting them sounding right and it took me a good few amps trial and error before i gave up lmao!
 

gibbsy

Moderator
Obviously looking at the used market for an amp. Marantz has already been mentioned and there are several good units around. They will have around 45 watts into 8 ohms. I would also look at some Denon amps as they tend to be a bit more open than Marantz. Look for a PMA 720AE which will give you 50 watts into 8 ohms and 85 watts into 4 ohms, so a good power delivery.

An early Rega Elex or Elicit will also be a good match. It's finding them is the trouble. I've had a quick look on evil bay and found a Marantz PM-66SE KI. That may very well suit.

 

Wavod

Active Member
Thanks for your input & help guys 👍. He has decided to snap up the Marantz PM-66Se Ki mentioned above. I have personally had previous experience of Marantz amps and CD players in the 80's & 90's and they've always served me well in the past & I've always used Kef speakers due to living a 10 min drive in Maidstone previously from their HQ. Was always impressed with their products & customer service. Even now I live in Somerset I remain loyal when I get the upgrade bug 👍
 

Ugg10

Distinguished Member
If the Marantz drops through then I would suggest this, may be a bit more neutral than the Marantz but will keep good control of those speakers -

 

gibbsy

Moderator
If the Marantz drops through then I would suggest this, may be a bit more neutral than the Marantz but will keep good control of those speakers -

I saw that ad. Went to link in the early hours but it was showing as deal ended, so assumed it had gone. Buyer must have pulled out. Was certainly one to consider. The Marantz is now showing as ended.
 

Mark.Yudkin

Distinguished Member
Hi. My friend has a pair of Kef 104ab speakers which he had paired with an old Nad 2 channel amp which has finally given up ( I think not powerful enough to drive the 104ab's). He doesn't want to break the bank & his budget is £200 - £300 max. I feel the nearer he can get to 100w per channel to drive the unforgiving Kef's the better. What do you think, and any suggestions either for a vintage amp or more recent? Thanks...........
I still have the pair of Kef 104aB's I bought in 1980 in the office, driven by a Technics SA-GX180 I bought 25 years ago (source by a Yamaha CD-NT670 bought a week ago). In 1980 I purchased a Sansui AU-417 (now scrapped) to power them.

The KEFs are easy to drive, you don't need anything like 100W. I doubt I'm using even a small fraction of the 40W the Technics can do (volume control never gets past 9:30). The passive radiator has no effect on the amplifier requirements, and the speaker is a lot less sensitive to placement than the Quad, then Martin Logan, ESLs I migrated to.

The only issue I ever had was interference between the speakers and the CRT TV, meaning I needed to keep ca 30cm separation. Of course, this is not a problem with modern flatscreen TVs.

There are a number of new stereo amplifiers with 40W + in your price bracket, such as Denon, Marantz, Onkyo, Pioneer, Yamaha. And of course you've already looked into second-hand options.
 

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