SpeakerTalk

[buril2000]

Anyone ever tried this combination?
I am very interested in trying this amp on my 107/2, but they need quite a lot of power.
The PA7 is rated 200 wpc.

[Parts]

It depends on what you are paying for the amp and its condition ?

[buril2000]

The amp is in mint condition, and I will pay approx. 700$

[Parts]

Hello Buril,

The price is quite reasonable, it cost 1700 back in 89/90 did it not ?

I was sure I had a review of this but have been unable to find it, issue 54 of HiFi choice I think ?

In my experience the 107 needs current as well as power, I am not sure of the current capabilitys of the Nakamichi PA7.

I remember Denon 6600 mono block amps being described as good partners for the 107, only to come to the conclusion they had not enough control in the bass and detail retrieval was not the best, there was also the big Nad 218 amp which again had a lot of power but ultimately was lacking.

These had a similar output and spec to the PA7, but lacked current compared to amps like Krell, Classe and Musical Fidelity.

My own quest has been quite varied, and I would always recomend Bryston ST and SST models (the little 3B sst is superb) anything from Krell (the KAV250a is quite superb) and Classe audio CA range is good.

I also like Musical fidelity Nu-Vista, though these may produce excess hiss in certain circumstances.
And the early Musical Fidelity A370 and 470 were good with Kef 107 , also Meridian's 605 monoblock's with the 601 pre?dac which had the Kube circuit as one of the DSP settings, these were the british amps of choice when the Kef 107 was in its youth with the well heeled going for KSL/KSA 150 combos.

Of course the price of the Nac is quite reasonable, over here you can pick them up for as little as £550 if lucky, but you could always question if saving and holding out for a better power is worthwhile ?

What amp system are you using at the moment, and how hard do you drive the 107's ?

[buril2000]

Thank you for the good tips.
I used the meridian 605 monoblocks, but they turned out to be much too small. The fuses blew at moderate levels after a few minutes.

Now I have the Yamaha M-85 power amp combined with meridian (tuner, pre, CD).
The Yamaha amp is powerful and sounds great with the 107/2, but I need a little more bass control.

Pictures: http://avforum.no/minhifi/show.php/buril2000

[Parts]

Hi again,

The PA7 has protection circuits, which could easily trip as the Kef 107 flexes its bottom end, I've had this problem with the little Classe CA100, and a Technics SU-MA10 amp, particulary if you are using the Kube.

The PA7 is not full class a, and was designed by Nelson Pass, of Threshold?Stasis amplifier fame. From what I can gather it may be quite similar in performance to the latest Usher R 1.5 power amp.

Although good, these had the same sort of power as the Meridian 605, which was better reviewed.

I think at the price it may be worth giving a try, it may out perform the yamaha, or give a different aspect to the sound, ultimately though a better power amp will show more of what the K107 is capable of, and this is quite a capable speaker, it will easily show the short commings of a Krell KRC 3, and the differences in quality between say the Nu-vista 300 and Krell FPB 300, or the capabilities of a top end source.

I personaly would try and save for something like the Bryston or Krell or a Classe CA200, but would recomend caution with the bigger Krells (over 200w and including the KAV250), the dynamic range may burn out a bass driver or two, the Kef 107 may seem to need power but it is only a 150 watt speaker, and needs plenty of control , anything decent over 200w has the capability to burn a voice coil out, yet an underpowered amp or high power amp with no drive capability will also have the capability of clipping and taking out a tweeter.

[Parts]

Your right speaker seems a little close to the corner ?

[buril2000]

If the PA7 has sensitive protection circuits, it is probably not the amp for my 107/2.

Ok, if I understand this correctly, I should get a bigger amp, but not too big, because I will blow drivers?
I have found a "Hiraga Class A amplifier", and it costs about the same as the Nakamichi. The Hiraga has over 200 000 uf on each side. 20w class A.
Is this sufficient?

[buril2000]

[Parts]

The Hiraga looks like it may have superb bass control. I have just looked at the schematics but it's 20w power is not going to give you much to play with ?
I am positive this design is still going to clip, my Classe CA100 is a 100w amp which double output to 200w into four ohms, it is the smallest amp I have found to use with the 107, its protection is quite good, though will trip quite early at high levels of low bass. Its current capability is superb though.

Is there no way you can demo these two amps (the Nak and Hiraga) at home ?
Another second hand choice wich may be near the budget you are thinking of is the Meridian 557 ?

I think the quality available from both the Nak and Hiraga will be lacking both in quality and absolute control compared to anything like a krell KSA 150, or Musical Fidelity A370 but I am not sure what these would cost you second hand at your end.

I think I would choose the Nakamichi PA-7 , I do not believe the internet reviews of it being anywhere near as good as Krell or bryston, but the protection may not be a problem unless you use a lot of volume with low bass information, it may actualy be a good performer which keeps you more than happy until the next step comes along.

[buril2000]

I haven't heard the nakamichi and the hiraga side by side, but I have heard the hiraga on the infinity kappa 9.2i, and that's probably the best amp I have heard on these speakers. And they are known for being a tough load for any amp
But maybe 20w class A is not enough, no matter how "powerful" it is?
I have actually tried the meridian 557, and they seemed a little small, too
Maybe it's just easier to sell the 107/2's.....
No! Forget I said that!
What are the specs for the krell ksa150? And what kind of price do they usually demand for this?
Thank you for the good tips so far!

[centaurus]

okay,

will somebody lay this debate to rest. is nelson pass's statis technology basically a quad's current dumping? so, despite pass's reputation as an innovator (which is he still is regardless), he basically nicked current dumping from peter walker? it's just that english patents didn't hold up in america.

Robby

[Laemmle]

I ran my 107's (first series) with this exact amp!

Nothing bad about the reproduction, but was on an audiophile kick at the time and traded for mono Counterpoint amps...which led to other upgrades, to finally find bliss with McIntosh MC252.