Alchemist Kraken APD6

[southall-1998]

Any owners of this old wee beast on here?

I've got an early MK1 model in my collection. The style is not to everyone's taste, but I find them interesting. The best word to describe it is ''quirky''.

Is this amp made to be left switched on at all times?

S.

[hifi_dave]

Having stocked their products for a short while, I would suggest you only switch it on when you are in the room.

[Ali Tait]

Given this one's age, if it were unreliable, it would have self destructed many years ago. I replaced the PS caps in this, looks very well built to me, and with high quality components.

I believe Dave (Jollyfix) has one Shane.

[struth]

I wouldnt leave it on when not in use. its class a, i think and if the energy is not going out the speakers it will get pretty hot. an idle temp of 5p/60 degrees is normal ....

[southall-1998]

Indeed, this amp runs hot. Just like the Sugden A21a!

The old hifi reviews on the Kraken looks interesting.

S.

[Ali Tait]

I wouldnt leave it on when not in use. its class a, i think and if the energy is not going out the speakers it will get pretty hot. an idle temp of 5p/60 degrees is normal ....

Will be at the same temp whether music is going through it or not. I measured the temp at 56 degrees. Agree switch off after use.

[DSJR]

Just to add that the whole amp range they made is quirky, in sound and looks ;)

Electrolytic capacitors CAN last for thousand and thousands of hours as long as they're not thermally stressed near their temperature or voltage limits. A case running at 50 to 60 degrees will not do them any favours long term IMO. I'm told that there's no need for Class A these days anyway, as output transistors developed over the last thirty plus years have apparently far better tolerances than before and AB use is fine - apparently..

[struth]

true they run hot no matter but when you turn the vol up some of the energy is not turned to heat so will run a little cooler. class a will produce twice the wattage of the amps output which if not being used is converted solely to heat.

[Ali Tait]

Just to add that the whole amp range they made is quirky, in sound and looks ;)

Electrolytic capacitors CAN last for thousand and thousands of hours as long as they're not thermally stressed near their temperature or voltage limits. A case running at 50 to 60 degrees will not do them any favours long term IMO. I'm told that there's no need for Class A these days anyway, as output transistors developed over the last thirty plus years have apparently far better tolerances than before and AB use is fine - apparently..

The caps in this were only rated 5v higher than the rail voltage, so I thought it was sensible to replace them, given the amp is 25 years old or thereabouts.

AB is fine. I prefer the sound of Class A however. Yet to hear an AB amp that sounds better than a good Class A amp to my ears.

[DSJR]

You did the right thing Ali. We found Alchemist difficult to sell because it looked different (I think the market was starting to change sadly, around twenty years ago and looks were getting more 'safe' and bland), but they could sound very nice indeed I remember.

I remember being pleasantly shocked by the (now cheap on the used market) Quad 77 integrated. Forget the ergonomic limitations for a minute, this amp sounded so sweet and atmospheric and for me anyway, reminiscent of the II valve amps - yes, really, it was that good when launched IMO. Other Quads can do this, but the 77 (more modern? class AB) showed me at any rate that you don't need fancy topologies these days for a good, basically sweet and grain-free sound..

[Ali Tait]

Well isn't that the point of Class A - it's simpler.. :-)

[Arkless Electronics]

Don't leave it turned on! This is my advice for ALL equipment BTW but is especially important for units that get hot as the Kraken does. I was Chief Engineer with Alchemist BTW but not the designer of this model which was designed by Glen Gayle (as were most of the range). It's only class A up to approx 4 Watts.
I guess it's looks are a Marmite thing.... many (most?) owners bought them and love them because of the looks!. I still get a steady stream of these in for repair and/or rebuild and upgrades.

[Arkless Electronics]

Well isn't that the point of Class A - it's simpler.. :-)

Not necessarily..... That's usually only the case for single ended class A and even then not always. Complexity of the power supply can outweigh any simplicity in some single ended class A amps though.

[Ali Tait]

Can't disagree, but then from the stuff I've heard, power supply is everything when it comes to SQ.

For SS stuff, the Pass designs I've heard sound great. No feedback..

[Arkless Electronics]

Can't disagree, but then from the stuff I've heard, power supply is everything when it comes to SQ.

For SS stuff, the Pass designs I've heard sound great. No feedback..

It's very important yes but is hugely over rated by audiophiles in general.... as with many other aspects of good sound! People read things in magazines or forums which are often simply wrong in the first place (or right only under specific circumstances) and then a process of "Chinese whispers" and expectation bias can sometimes lead to certain ideas becoming "accepted truth" even though they are 100% incorrect.... In the case of power supplies the important thing is that the circuitry being powered can have good or bad PSRR (power supply rejection ratio). With exceptional PSRR just about any old power supply will do fine and improving it will result in minimal SQ improvement.
With very poor or non existent PSRR, common in VERY simple circuitry, then the power supply itself is indeed hugely responsible for the SQ obtained.... but no more so than the design of the amplifier circuitry itself! It is also often not appreciated that the internal grounding regime used is every bit as important as the power supply itself and has exactly the same effects as the power supply itself....

[Ali Tait]

Well I'm mostly talking about valve designs, but I'm talking from what I've actually heard, not just read. Yes agree grounding is very important too.

[Arkless Electronics]

Well I'm mostly talking about valve designs, but I'm talking from what I've actually heard, not just read. Yes agree grounding is very important too.

I can assure my knowledge, gained over decades as a professional, goes much further than just having read something somewhere!!
Much of what is said about hifi, technically, is simply wrong and has it's roots in marketing combined with "a little bit of knowledge is a dangerous thing"....

[southall-1998]

I couldn't give a shit if the Kraken is class A (Or AB). This is indeed a nice sounding amp in its own right.

S.

[Ali Tait]

Yep agree, it's a good amp.

[Marco]

Heard yours at NEBO and liked it :)

Marco.

[southall-1998]

What speakers was my Kraken driving?

S.

[struth]

If its the one Ali had, then Ive heard it running the edlindales and it sounded superb.

[southall-1998]

If its the one Ali had, then Ive heard it running the edlindales and it sounded superb.


Ah yes, those chunky looking floor-standers.

S.

[Arkless Electronics]

I'm not overly keen on them myself... a bit too soft and warm sounding.

[southall-1998]

I'm not overly keen on them myself... a bit too soft and warm sounding.


Does the Kraken sound slightly similar to the Quad II?

s.

[Arkless Electronics]

Does the Kraken sound slightly similar to the Quad II?

s.

Not quite that bad! :eyebrows:

[southall-1998]

Jez, is Glen Gayle still operating these days?

S.

[Arkless Electronics]

Jez, is Glen Gayle still operating these days?

S.

No. Last I heard he had jacked in electronics altogether to become a children's social worker...

[Rush2112]

Great amp, I bought one for my Dad the dual mono version with separate dedicated power supply, it's still providing Stirling service. Switched off when not in use and yes I guess the green crackle finish is not everyone !