Arcam Class G amps ...
- Thread starter beammeup
- Start date
Arkless Electronics
Trade: Amp design and repairs.
For 405 IIRC I calculated it at 18mW so probably in the same ball park... 15 -30 ish prob.
I have a mate with a great pile of Carver amps, some of which he rates as the best he's had. He has I think the full set of Phase Linear (Flame Linear) amps that spend about as much time at the repairers as my car does in the garage. One day (Rodney) he is going to put them all together and build a huge cinema system, it's going to be 7.1, 9.2, or 11.2 depending on his mood, with piles of huge amplifiers. It may one day happen but I doubt it, I suspect that none of us ever really want to meet our heroes.
linnfomaniac83
I bet you can’t wheelie a unicycle!
Well at least if he does, the explosions will be real!
RE, multi channel home theatre, I think it’s mostly had it’s day. I’ve had various setups over the years and invariably, I’ve gotten fed up with it after the honeymoon wears off, I can’t be doing with that many speakers in a room. I still have some Meridian kit but I think I’m going to give it to my cousin, I set it all up last year and then packed it away again a month later.
Arkless Electronics
Trade: Amp design and repairs.
Erm.. yes, BUT load impedance is just as important. For a given amount of class A power you need a specific quiescent current for the intended load. The supply rails then must be high enough to support driving this current into that load impedance (plus a bit to allow for losses etc) but for best efficiency whilst staying in class A no higher than that.
A 4R speaker needs twice as much quiescent current as an 8R speaker for the same amount of class A power but can manage with lower voltage supply rails.
An amp that can give the first 10W in class A but then continue on to give 100W in class A/B will be quite a beast of a hot running thing as the current needed for 10W class A is supported by enough voltage to give 100W... it will be as hot, heavy and expensive as lets say a 30W "pure" class A amp that clips at 30W... (the class A up to 10W in the first version is just as "pure" up to it's class A limit as the latter version).
This is where the efficiency advantage of class G and H comes in. It gets around all that but at the expense of greater complexity and there being a switching between the two modes. Hopefully this switching is carried out fast enough to be inaudible.
So, a "pure" class A amp, push pull, of 10WPC into 8R will deliver (theoretically) 20W into 4R BUT only the first 5W would now be in class A.
I think he wants to do it so that he can tell people he has a 1kW per channel home cinema. He's still 3 months away from being able to get in that room, it's not going to happen anytime soon.
beammeup
pfm Member
Maybe you should also compare your current a75 with a Class G design before jumping on the hybrid valve amp wagon (however I'm loving the Croft so who am I to speak - the A29 though has its strengths which you may personally like very much). The Class G SA30 looks interesting - it's endowed with dirac room control and comes with streaming capabilities - it could be the only one box system you would ever need.
After the current positive experience I am getting with the A29 I'm considering the SA30 with a pair of new Magnepan LRS speakers in the den.
hifinutt
hifinutt
yes you may be right there re class G comparisons . actually had some lovely valve hybrids made by the illustriuos firebottle , marvellous amps with tremendous power . very very similar to supernait 2 in nuetrality and power etc . However the Arcam has a certain warmth and tone controls . I also have an a85 which was not as good as the a75 with the taus
Dirac may be great for technically minded but not for me ... too complex .
I am only trying out the hybrid valve , its made by company owned by a Korean billionaire . they were one of the highlights of the munich show but as you know thats been cancelled . should be fun to try it
this is the guy i think
Dirac may be great for technically minded but not for me ... too complex .
I am only trying out the hybrid valve , its made by company owned by a Korean billionaire . they were one of the highlights of the munich show but as you know thats been cancelled . should be fun to try it
this is the guy i think
Arkless Electronics
Trade: Amp design and repairs.
It should maybe be said that there is nothing about class G that would give "a class G sound"!
beammeup
pfm Member
OK I've been really impressed by the big boned yet smooth presentation of the A29 - but alas something has to give, I can't keep everything I like (I can't afford to) so I have decided to put back the Croft - she's going on eBay tomorrow unless someone here is interested first.
I have the original box, manual, leads, I didn't even use the power leads that came in the box, plus the remote. I know this isn't the classified section but I want no less than £365 plus delivery.
I have the original box, manual, leads, I didn't even use the power leads that came in the box, plus the remote. I know this isn't the classified section but I want no less than £365 plus delivery.
beammeup
pfm Member
Ha! I recall selling a rare classical record to him about 3 years ago.
beammeup
pfm Member
OK I've had a long listen to the MS3si knowing how the Arcam A29 sounds (obviously you have experience too) - and in my mind the A29 is far better (again subjective perhaps) - far less fatiguing, great at low volume and high volumes, sweet detail - the MF was far more in your face. Either way - I've sold the MF on the bay (didn't take long), and don't regret that decision knowing that the A29 is better.
So, that's one gone - Yamaha AS-801 next. I'm still selling the A29, but may put the funds toward the multi-functional integrated Class G SA30.
Craig B
Re:trophile
Zoom, those months went by fast; seems like it was only last Thursday.
beammeup
pfm Member
Zoom, those months went by fast; seems like it was only last Thursday.
I know! A far quicker turnaround with the MF than I thought. I gave the MF a fair run over about three days and swapped out different DACs in the process - it was very obvious to me that the MF did not compare with the Arcam so was an easy decision to make.
Perhaps I should have sat it in the rack for 2 or so weeks - but I didn't think it was necessary.
Arkless Electronics
Trade: Amp design and repairs.
There is no class G sound!! It is also VERY unlikely that this has much class A operation. As it seemed doubtful I googled the unit and neither Arcams brochure nor a What Hi Fi? review even mention it. The heatsink looks to small in photos as well.
beammeup
pfm Member
Sorry yes of course - it's not a Class G sound, it's either a Class A sound or Class AB sound - depending on the power rail it jumps on to.
Interesting that you don't think is does much class A operation because of your assessment there isn't enough heat sinking in there - Arcam replied it runs in pure class A (yes that's 'pure' class A) up to about 20 - 25 Watts. I'm not sure how all this work - when transients require more than 25 watts in music - does the Arcam briefly jump rails then jump back again trying to keep it running in Class A as much as possible?
Arkless Electronics
Trade: Amp design and repairs.
If there was much class A power available they would surely make a big thing of it in their marketing blurb etc... especially as 25W class A (no real such thing as pure or not class A. Either it runs in class A or it doesn't) would probably triple the cost and weight of the unit. I would assume only a W or so class A.