[guest1632]

Hi Hugh,

Had read on your site about the Lifeforce 55 with a 36 VDC output. ok, so if I were to build the Lifeforce 100W amp, what do I need as far as power supply? Do you supply the power supply boards too? And of course, no prices have been mentioned because you haven't thrown open the doors to the general DIYer yet for the Lifeforce amps. Thanks for your time.

Regards,
Ray Bronk

[AKSA]

Hi Ray,

Thanks for your post and your interest in the LF.

In fact, the Lifeforce is now available as a standalone purchase, no trade-in, and later today I shall post the prices on the website.  The idea was to give my AKSA customers first option, and a trade-in, both to establish a module assembly process in my business in limited numbers at first, then to get a few out there for people to listen to and report on.  This phase is now complete, so the LF is ready for general sale.

If you like high detail without fatigue, a sense of actually being at the recording, this is the amp for you!

Cheers,

Hugh

[PSP]

Hi Hugh,
Are your recommendations regarding speaker cable capacitance similar for the 55 N+ and 55LF?

Many thanks,
Peter

[guest1632]

Hi Ray,

Thanks for your post and your interest in the LF.

In fact, the Lifeforce is now available as a standalone purchase, no trade-in, and later today I shall post the prices on the website.  The idea was to give my AKSA customers first option, and a trade-in, both to establish a module assembly process in my business in limited numbers at first, then to get a few out there for people to listen to and report on.  This phase is now complete, so the LF is ready for general sale.

If you like high detail without fatigue, a sense of actually being at the recording, this is the amp for you!

Cheers,

Hugh

Hi Hugh,

So, what do I need to build this amp? I gathered the board and heatsink already come together, so besides the case and external stuff like power switch, RCA, speaker posts, what internals do I need? Or do I have to buy a completed unit? Give me some details. Thanks for your time.

Regards,
Ray

[AKSA]

Ray,

I will post more details on the website;  I don't want to repeat myself too much!

You will be able to buy the internals for some time, I assure you.....

Cheers,

Hugh

[guest1632]

Ray,

I will post more details on the website;  I don't want to repeat myself too much!

You will be able to buy the internals for some time, I assure you.....

Cheers,

Hugh

 

Hi Hugh,

 Well, just got through reading through the Aksa amp stuff on the  Aksa webpage. I'll just wait a few days til you get the website updated. I have been looking around as to which amp to build. So the reviews on the LF amps are remarkable. Your discussion on transformer sizes answered questions I have asked for years. In that discussion, you seemed to mention/lean more/towards  about the 55W than the 100W. So I wasn't sure what secondary voltages for the 100W transformer to look for. Anyway, do the same requirements apply to the LF?  That is all I was asking. Most likely, I'd be interested in both the LF board and the accompanying power supply. I can solder, and I can drill holes easy enough. Would just have to ask a person like my wife with a pair of eyes to tell me wihch connection is which.

One question I do have, and I hope I am not asking one you've repeated a dozen times. If memory serves me right, the LF will work down to about 3 ohms or so. If you have a tougher load than that, then what? Is there some protection built in, so as to not fry the output transistors?

Regards,
Ray Bronk

[AKSA]

Ray,

Yes, 33-0-33Vac trafos, two of them each rated at 300VA, 8% regulation or better.

The LF will go to 2.5 ohm loads.

Protection is not oriented towards protecting the output devices, which almost never fail in practice.  The idea is to protect the speaker which is far more expensive.  I use rail fuses, well specced.  Output stage is quite suitable for driving electrostatics, this is one robust, stable amp.

Cheers,

Hugh

[guest1632]

Ray,

Yes, 33-0-33Vac trafos, two of them each rated at 300VA, 8% regulation or better.

The LF will go to 2.5 ohm loads.

Protection is not oriented towards protecting the output devices, which almost never fail in practice.  The idea is to protect the speaker which is far more expensive.  I use rail fuses, well specced.  Output stage is quite suitable for driving electrostatics, this is one robust, stable amp.

Cheers,

Hugh

Hi Hugh,

Will now wait for the priceing and other such details. Thanks.

Ray

[guest1632]

Ray,

Yes, 33-0-33Vac trafos, two of them each rated at 300VA, 8% regulation or better.

The LF will go to 2.5 ohm loads.

Protection is not oriented towards protecting the output devices, which almost never fail in practice.  The idea is to protect the speaker which is far more expensive.  I use rail fuses, well specced.  Output stage is quite suitable for driving electrostatics, this is one robust, stable amp.

Cheers,

Hugh

Hi Hugh,

Ok, dumb question: 33V? It's easy to find a 30V or 35V with the primary at 110V or so.

You don't see to many of them any more, but there are still those hard loads down to 1 ohm. Anyway, looks like I should just use a 30V transformer?

 Now, you mentioned that a larger transformer could slow down transients. Understood. If you are using a larger transformer say 600VA for both channels, wouldn't the oversize take care of any possible current reserves needed? Or does this have to do with the type of core?

Regards,
Ray
Hi Hugh,

Will now wait for the priceing and other such details. Thanks.

Ray

[Freddy57]

Ray, I have just finished my LF100 (60 hour burn in) with Avel Lindberg 30-0-30, 330v and it sounds great.  It has plenty of punch. I am driving 86db/w 8ohm 2 ways and they are fine.   I believe I have lost nothing and maybe gained some reliability.  With occasional dirty mains (spikey) I think it was a safe way to go.  Use your own judgement of course.
   Cheers,VERN

[guest1632]

Ray, I have just finished my LF100 (60 hour burn in) with Avel Lindberg 30-0-30, 330v and it sounds great.  It has plenty of punch. I am driving 86db/w 8ohm 2 ways and they are fine.   I believe I have lost nothing and maybe gained some reliability.  With occasional dirty mains (spikey) I think it was a safe way to go.  Use your own judgement of course.
   Cheers,VERN

Hi, That sounds really good. Just now looking on the site to find out the details of price and such. So far, all I see is the LF modules are restricted to those who are trading in their Aksa modules.  Well, it sure looks like an amp to get.

Ray

[AKSA]

Ray,

Site now updated with all relevant Lifeforce details.

Dan,

Orion power supply modules are next!!

Please pardon my delays,

Cheers,

Hugh

[guest1632]

Ray,

Site now updated with all relevant Lifeforce details.

Dan,

Orion power supply modules are next!!

Please pardon my delays,

Cheers,

Hugh

Well, ask a busy man and it usually gets done. Thanks Hugh.

Ray

[guest1632]

Ray,

Site now updated with all relevant Lifeforce details.

Dan,

Orion power supply modules are next!!

Please pardon my delays,

Cheers,

Hugh

Hi Hugh,

A couple of questions which any one who has built this amp can also chime in. Is thee 5 inch side the side where the transistor and heatsink is attached. How long is the heatsink. Also, how big are the power supply boards? Just trying to get a handle on the size of the case needed, and possible layout. I figure the transformers about 7 inches in diameter, with maybe an inch or so between them. If you want to just PM me, that's ok. I certainly don't want to bore the rest of the people who might be reading this circle. Again, thanks for your time.

Regards,
Ray Bronk

Ray

[AKSA]

Hi Ray,

you wrote:

Hi Hugh,

A couple of questions which any one who has built this amp can also chime in. Is thee 5 inch side the side where the transistor and heatsink is attached. How long is the heatsink. Also, how big are the power supply boards? Just trying to get a handle on the size of the case needed, and possible layout. I figure the transformers about 7 inches in diameter, with maybe an inch or so between them. If you want to just PM me, that's ok. I certainly don't want to bore the rest of the people who might be reading this circle. Again, thanks for your time.

Regards,
Ray Bronk

Yes, the 100W module is 5" long along the heatsink;  the four output devices are spread along this dimension.  Heatsinks, two, one for each module, are each 300mm long and 75mm tall.

Power supply pcb is 5" x 4", incorporates all rectifiers, bleeder resistors, and eight large Nichicon power electrolytics.  Toroids are smaller than your figures;  a 300VA typically is 122mm diameter (4.8") by 53mm height (2.1").

A Par-metal racking case of standard 19" width and 14" depth is fine for the 100W AKSA Lifeforce.  These cases are around 3 1/2" tall.  Their site is www.par-metal.com.

Hope this helps,

Cheers,

Hugh

[guest1632]

Hi Ray,

you wrote:

Hi Hugh,

A couple of questions which any one who has built this amp can also chime in. Is thee 5 inch side the side where the transistor and heatsink is attached. How long is the heatsink. Also, how big are the power supply boards? Just trying to get a handle on the size of the case needed, and possible layout. I figure the transformers about 7 inches in diameter, with maybe an inch or so between them. If you want to just PM me, that's ok. I certainly don't want to bore the rest of the people who might be reading this circle. Again, thanks for your time.

Regards,
Ray Bronk

Yes, the 100W module is 5" long along the heatsink;  the four output devices are spread along this dimension.  Heatsinks, two, one for each module, are each 300mm long and 75mm tall.

Power supply pcb is 5" x 4", incorporates all rectifiers, bleeder resistors, and eight large Nichicon power electrolytics.  Toroids are smaller than your figures;  a 300VA typically is 122mm diameter (4.8") by 53mm height (2.1").

A Par-metal racking case of standard 19" width and 14" depth is fine for the 100W AKSA Lifeforce.  These cases are around 3 1/2" tall.  Their site is www.par-metal.com.

Hope this helps,

Cheers,

Hugh

Hi Hugh,

Thanks for the help. That does a lot of explaining. I presume in your guide that you have a suggested layout as to where the boards mount? You and I are roughly the same age, but I am a Yank, who doesn't really speak metrics much. lol. So those heatsinks are what size again?

Those cases, are they or do they have a predrilled config for the LF amp?

Since you mention several brands of transformers, do you have any particular favorite?

Ray

Ray

[andyr]

I am a Yank, who doesn't really speak metrics much. lol. So those heatsinks are what size again?

Ray

Ray,

You're letting your side down, mate.

I would've thought 1" = 25mm (well, actually 25.4mm but WGAF about the 0.4mm!  ) is something our kids learn in primary school here!

So ... 300mm = 12" = 1'; 450mm = 18"; 600mm = 24" = 2' etc.

Regards,

Andy

[guest1632]

Ray,

You're letting your side down, mate.

I would've thought 1" = 25mm (well, actually 25.4mm but WGAF about the 0.4mm!  ) is something our kids learn in primary school here!

So ... 300mm = 12" = 1'; 450mm = 18"; 600mm = 24" = 2' etc.

Regards,

Andy

Hey Andy,

Apreciate the education there. one meter is 39.34 inches. Originally, we weren't taught that Metric stuff in School til at least the 7th Grade, I think. And then it was a simple mention. We like our Inches and Feet lol.

Ray

[andyr]

Hey Andy,

Apreciate the education there. one meter is 39.34 inches. Originally, we weren't taught that Metric stuff in School til at least the 7th Grade, I think. And then it was a simple mention. We like our Inches and Feet lol.

Ray

Haha ... well if you've ever come across the old Aussie joke about 6", you'll realise we also talk imperial too, Ray!   

[Blonde to blonde talk: "Well, yes, my boyfriend's got 6" (holding her hands apart what she thinks is this distance ... trouble is ... it's more like 3"!!)    ]

Regards,

Andy

[AKSA]

Andy,

Why would you talk about a Sub-of-the-day in this way?

Ciao,

Hugh