Amplifier Upgrade Musings

[Nude]

Hi Brumby,

I have a spare McCormack Powerdrive DNA1, see specs and links below (hope I did them right)

This is an amp that for those who know me, I adore as an absolute bang for your buck classic

If you pay for and organise the shipping, you can sit them in your system and play to your hearts content for a month or so with no obligation

If you likey, you pay

If you not likey, you send em back

Cheers

Nude

http://www.stereophile.com/solidpoweramps/520/

http://www.soundstage.com/wrk_dna1.htm

DNA 1 Technical Specifications

• Output Power at Clipping, both channels driven RMS Watts per channel: 185 Watts @ 8 ohms, 370 Watts @ 4 ohms, 600 Watts @ 2 ohms
  
• Output Current: 50 Amps peak, per channel
  
• Input Impedance: 100K ohms
  
• Input Sensitivity: 1 Vrms
  
• Frequency Response: -3db @ 0.5 Hz, 250 KHz
  
• Risetime: <2 micro seconds
  
• Slew Rate: 50V/micro second
  
• Signal-to-Noise: 88dB, "A" weighted
• Damping Factor (1 KHz, 8 ohm load): >100
  
• Output Impedance: <0.1 ohm
  
• DC Offset (Servo-controlled): <5mV
  
• Signal Polarity ("Absolute Phase"): Non-inverting
• Power Requirements: 100-117 VAC/60 Hz, 1.2 Amps/130 Watts @ idle, 3.5 Amps/400 Watts @ clipping
  
• Power Requirements: 220-240 VAC/50 Hz, .6 Amps/130 Watts @ idle, 1.8 Amps/400 Watts @ clipping
  
• Dimensions: 19" wide, 7" high, 15" deep
• Shipping weight: 55 lbs.
  

[Moondog]

Hi Brumby,

I have a spare McCormack Powerdrive DNA1, see specs and links below (hope I did them right)

This is an amp that for those who know me, I adore as an absolute bang for your buck classic

If you pay for and organise the shipping, you can sit them in your system and play to your hearts content for a month or so with no obligation

If you likey, you pay

If you not likey, you send em back

Cheers

Nude

http://www.stereophile.com/solidpoweramps/520/

http://www.soundstage.com/wrk_dna1.htm

DNA 1 Technical Specifications

• Output Power at Clipping, both channels driven RMS Watts per channel: 185 Watts @ 8 ohms, 370 Watts @ 4 ohms, 600 Watts @ 2 ohms
  
• Output Current: 50 Amps peak, per channel
  
• Input Impedance: 100K ohms
  
• Input Sensitivity: 1 Vrms
  
• Frequency Response: -3db @ 0.5 Hz, 250 KHz
  
• Risetime: <2 micro seconds
  
• Slew Rate: 50V/micro second
  
• Signal-to-Noise: 88dB, "A" weighted
• Damping Factor (1 KHz, 8 ohm load): >100
  
• Output Impedance: <0.1 ohm
  
• DC Offset (Servo-controlled): <5mV
  
• Signal Polarity ("Absolute Phase"): Non-inverting
• Power Requirements: 100-117 VAC/60 Hz, 1.2 Amps/130 Watts @ idle, 3.5 Amps/400 Watts @ clipping
  
• Power Requirements: 220-240 VAC/50 Hz, .6 Amps/130 Watts @ idle, 1.8 Amps/400 Watts @ clipping
  
• Dimensions: 19" wide, 7" high, 15" deep
• Shipping weight: 55 lbs.
  

[/b]

Nude , If its still in circulation after that , I would be interested in some of the same

[brumby]

Andrew and Nude. Thank you very much for your offers. Andrew, I'll be answering your PM tomorrow for sure. I am serious, I will be getting new amplification.

Nude, how much is the McCormack and how old is it? AFAIK, the DNA 1 has been around since the early '90s. And its reputation is stellar. I'm not saying that 50 wpc precludes it, but the Dyns do like some power behind them.

It is difficult up here. Supposedly, AV Domain in Brisbane now carries Xindak but I've seen nothing about them on their website. I know that whatsisname at Caxton Audio carries Conrad Johnston and McCormack. I believe McCormack was recently bought by CJ.

I think the Xindaks must be in the running. Any other remarks re these amplifiers would be appreciated. You Adelaide GTG lot all had a chance to hear them. The only possible caveat I might have is that they have, I believe, only three inputs. That's not much of an impediment, though. CD - DVD - Tuner is all I need now.

It's a fact of life that Brisbane is not the centre of the universe, let alone Australia, as far as two channel is concerned. I'd love to take part in some of the GTGs, but I'm a long way away from you lot.

Again, I'm most grateful for these offers and for all the information I've picked up and continue to pick up on this forum. It warms the heart of a bloke who's a long way from where the action is.

Edit: Nude, I'm a ****head. That's 50 AMPS per channel. 185 watts into 8 ohms and 370 into 4, right? Now THAT'S interesting.

[Aslan]

I think the Xindaks must be in the running. Any other remarks re these amplifiers would be appreciated. You Adelaide GTG lot all had a chance to hear them. The only possible caveat I might have is that they have, I believe, only three inputs. That's not much of an impediment, though. CD - DVD - Tuner is all I need now.[/b]

Hi Brumby, we actualy didn't run the Xindaks for very long in Adelaide. Tony M's cottage had a very iffy power supply (read ONE circuit feeding both the listening room and kitchen). With everything hooked up the circuit struggled with voltage drops, and started throwing the circuit breaker, so we removed the highest draw devices, i.e. the Xindaks.

Funnily enough, in my demo room they ran fine.............again, everything on the one circuit, BUT it is dedicated to the gear room only.

[brumby]

Hi Brumby, we actualy didn't run the Xindaks for very long in Adelaide. Tony M's cottage had a very iffy power supply (read ONE circuit feeding both the listening room and kitchen). With everything hooked up the circuit struggled with voltage drops, and started throwing the circuit breaker, so we removed the highest draw devices, i.e. the Xindaks.

Funnily enough, in my demo room they ran fine.............again, everything on the one circuit, BUT it is dedicated to the gear room only.[/b]

Hmmm. Perhaps I'd better get a sparky in to check out my curcuit, especially since the repairer swears up and down that my ME got hit by a power surge.

[seano]

Yours truly probably had the longest run at the Xindaks whilst they were in Adelaide...I was playing when we realised they were sucking way hard on the available power...even though the situation wasn't ideal must say I was impressed. Mainly in how much you can get these days for nowhere near as much as you would have had to pay a decade ago.

My lasting impression of them was that they were very capable but a bit 'cold'.......gee, that's helpful ain't it.

But I still like my little amp.....

[Nude]

Andrew and Nude. Thank you very much for your offers. Andrew, I'll be answering your PM tomorrow for sure. I am serious, I will be getting new amplification.

Nude, how much is the McCormack and how old is it? AFAIK, the DNA 1 has been around since the early '90s. And its reputation is stellar. I'm not saying that 50 wpc precludes it, but the Dyns do like some power behind them.

It is difficult up here. Supposedly, AV Domain in Brisbane now carries Xindak but I've seen nothing about them on their website. I know that whatsisname at Caxton Audio carries Conrad Johnston and McCormack. I believe McCormack was recently bought by CJ.[/b]

Brumby

You're correct, the amp is from the early to mid nineties, I am the second owner, having bought it around 1998 from a workmate at the time.

It is in fine condition, but I do not have the original packing

CJ bought McCormack from Steve some time ago now for reasons that sha'nt be posted on this site, although I'm sure that David from Caxton will regale you with story if you ask nicely

Asking price is $1800 plus any shipping

Nude , If its still in circulation after that , I would be interested in some of the same[/b]

Moondog,

You have second dibs.

Cheers

Nude

[brumby]

Yours truly probably had the longest run at the Xindaks whilst they were in Adelaide...I was playing when we realised they were sucking way hard on the available power...even though the situation wasn't ideal must say I was impressed. Mainly in how much you can get these days for nowhere near as much as you would have had to pay a decade ago.

My lasting impression of them was that they were very capable but a bit 'cold'.......gee, that's helpful ain't it.

But I still like my little amp.....[/b]

Hi Seano. That's interesting. Everything I've read on the Xindak - and I haven't been able to find much - commented on its "warmth".

You run an Aksa 55, don't you?

[SKA]

Hi Brumby,

Maybe you haven't heard of my SKA amplifiers. If you want something really transparent and involving for not a lot of $$, you won't beat the GB150D under $10K!

I'm the only designer in Australia whose amp designs have won TAS Golden Ear and has worked as a consultant designer in the US ( to Madrigal - makers of Mark Levinson amps).

The complete GB150D kit will be available in about 3 weeks, or built units for $1500.

Greg B.

[brumby]

Hi Brumby,

Maybe you haven't heard of my SKA amplifiers. If you want something really transparent and involving for not a lot of $, you won't beat the GB150D under $10K!

I'm the only designer in Australia whose amp designs have won TAS Golden Ear and has worked as a consultant designer in the US ( to Madrigal - makers of Mark Levinson amps).

The complete GB150D kit will be available in about 3 weeks, or built units for $1500.

Greg B.[/b]

Hi Greg,

Now that's confidence for you. Peter Stein only claims his are the best under $5k :wink:

Latest in the saga. Been in touch with Peter. He is adamant that the ME was the victim of a power surge/lightning strike. This is quite feasible. I am usually good about unplugging equipment when storms threatened but I must admit that I sometimes miss the amp, which is plugged into its own source.

Anyway, my insurance will cover the repair so I won't be out of pocket much. Peter will do the rebuild and give the amp a good "soak" test. I'm going to check out the result before making any final decisions, and that's probably gonna take a week, more likely two. I still may well decide to sell the ME combo. If I do, somebody will get a completely overhauled amp tested by the original maker.

If the moderators wanted to turf me off this site for terminal procrastination, I would certainly understand. :blush: :angry:

Nude, please elevate Moondog to "first dibs" on your McCormack.

[Mr_Gadget]

How about the new Cambridge Audio 840W power amp? Not sure if it is on sale yet but I think it is $3K. The pre-amp should be good too (if the volume clicking noise doesn't bother you)

[seano]

Hi Seano. That's interesting. Everything I've read on the Xindak - and I haven't been able to find much - commented on its "warmth".

You run an Aksa 55, don't you?[/b]

......which is where one man's tea can easily be another's horse manure.

To be fair and honest, the Xindak's never really got warmed up....sure they played Kasey Chambers for most of an album but not that loud and when I touched the heatsinks there was little thermal evidence of all that Class A goodness. And when I sank the slipper in......we ran out of juice.

Not quite.....I use an AKSA 100 with the N+ upgrade......for a little bit more welly in the bass department.

Glad to hear the ME's will live to see the light of day......it'd be sad to see a classic die.....unless it went down in flames whilst trying to reproduce musical goodness.

[Nude]

Nude, please elevate Moondog to "first dibs" on your McCormack.[/b]

Moondog,

Still interested?

Nude

[SKA]

Hi brumby,

Now that's confidence for you. Peter Stein only claims his are the best under $5k[/b]

Heheh. My DIY customers in 28 countries say so. Even north of the Arctic Circle. :angry:

The SKA is revolutionary.

Visit My Website ( and attached Forum for more..)

Greg

[2sheds]

Hi brumby,

Heheh. My DIY customers in 28 countries say so. Even north of the Arctic Circle. :angry:

The SKA is revolutionary.

Visit My Website ( and attached Forum for more..)

Greg[/b]

Greg,

I notice in your specs you quote figures for damping factor. Back in the 70s and 80s it was common to do so. I found it helpful, as I invariably seemed to favour amps with good damping factory presumably because of the good control it had over the speakers (amongst other things).

Is there some reason why other manufacturers would want to downplay damping factor? and is it as important as I seem to think?

Excellent site, by the way - very clear and informative layout. And some very tempting gear.. :biggrin:

cheers

2sheds

[SKA]

Thanks 2sheds.

Damping factor is simply 8 ohms / Z out. There are a few ways to achieve high damping factor or low output impedance for an amplifier. One is high feedback at low frequencies, another is to use deep darlington driver and output stages. Generally damping factor is assumed to be OK if it's 10+ so the speaker is voltage driven. Much beyond that is considered a meaningless numbers race, largely swamped by speaker cable impedance.

I think there are other issues with amplifiers that 'the market' has moved into the frame.

Supply rejection is one I labour as it is largely ignored by less technical producers, but has an enormous reward in 'micro-detail' and 'involvement' once mastered. This was/is one of the primary design objectives of the unique SKA topology.

You know, more than 90% of my kits go overseas. :angry:

Greg

[56oval]

Thanks 2sheds.

You know, more than 90% of my kits go overseas. :angry:

Greg[/b]

Like most well designed Aussie audio gear .Some people think the grass is greener over the other side.

Before the mods ask put your company name in your sig

Cheers .

[Moondog]

Moondog,

Still interested?

Nude[/b]

Yes , Though not for a few weeks , My SE amps are in dry dock undergoing a refit , Tentlabs Regulators are going on the 300b an 805 tubes heaters

New power supply caps etc , If you get the opportunity to sell it then go for it .

Moondog

[Phil G]

Hi amplifierguru. Good to see you posting, as you have been a member for quite a while. As you have a business interest related to our hobby, could you please disclose your business in your signature, as 56 has rightly alluded to.

You cannot add a link to your website in your signature though, in-line with this forum's guidelines. That right is reserved for our sponsors.

Thanks.

[SKA]

Hi again brumby,

As my kids are both playing regional sunshine coast soccer this year I should be all over the sunshine coast over the next 20 Saturdays so could easily drop by and give you an audition of the new SKA amp!

Then again it's not that far from Bribie to ??

If you want to hear REAL transparency and dynamics?

Greg B.

[skood]

Hey Brumby , I feel compelled to recommend Gregs amps, I've heard all the ME range 240, 550, 840 with various speakers, Ambience, B&W ,Equinox, I've also heard a lot of amps from 1-10k and can say if you're after a transparent window the GB's provide it - transparency, dynamics and balance are words that come to mind...,.. they are phenomenal amps.

[brumby]

Hey Brumby , I feel compelled to recommend Gregs amps, I've heard all the ME range 240, 550, 840 with various speakers, Ambience, B&W ,Equinox, I've also heard a lot of amps from 1-10k and can say if you're after a transparent window the GB's provide it - transparency, dynamics and balance are words that come to mind...,.. they are phenomenal amps.

Hi Skood. I'm sure Greg's amps are fine, but I'm an ME user from WAY back. I'm gonna listen to what I've got for a while longer before I make any decisions. Upgrading is something I do pretty rarely.

I almost bought a Supratek pre, but that fell through. Now, I'm just happy to have my amp back and am gonna overdose for a few days. After that, truth be known, the source is probably what I'll look into.

Add in the fact that money is running through our fingers like water ATM as we are getting both our bathrooms totally redone - one down and the ensuite to go.

I'm interested in the Raysonics and the Melody CD players and I'm also curious about the Cambridge Azur 840C. But I'm not like many here. I've been known to keep a component for a decade or more. I've never been susceptible to upgradeitus.

[skood]

I've been known to keep a component for a decade or more. I've never been susceptible to upgradeitus.

You are blessed;.. I'm getting there, amps are a long term stayer and speakers...I think;

[Catostylus]

Well, since I'm denied the chance of getting the MEs I'd always wanted, I'll look into the SKAs.

Are they only available as kits or can you get them built?

[skood]

Greg can build them for you; which isn't a bad idea unless you have a reasonable understanding of electronics..