LF100 US build q's

Berndt · « **on:** 9 Aug 2009, 06:30 am »

Hi gents, as soon as my old amps sell I am going to give the lifeforce a twirl.
I am listening to a comrades fully modded Hafler D200 (musical concepts dual mono driver boards, dual torroids, and everything else you can do via MC).
I like the transparency of this rig and it made a ss believer out of me.
I am curious as to what would constitute a blue chip build for the 100 module? (specific trannies and caps)
I'll be able to do the casework no problem just curious about proven component matching cap and tranny wise in the US?
I really want to build it with the designer suggested parameters, not just shoot from the hip.
The thing I miss with the hafler vs. my old amps is the bass drive. Not that the bass is soft, it is just that my old amps were exceptional in this regard.
Looking at the plitron trannies but could use a little handholding, forgive me if this is too rudimentary a request?
I'll be driving my Audio Kinesis Jazz Module speakers which are 92db efficient and have a rising impedence curve in the lower frequencies as they were designed for the 30w atmasphere OTL amp.
The amp will be driven by my diy ef806 preamp.
TIA,Bill

whubbard · « **Reply #1 on:** 9 Aug 2009, 11:07 pm »

Hi Bill,
First you understand that it comes built and attached to a heatsink. Many of us do 'after-market' mods to our LFs. I have Sonicap platinums as the input capacitors and will probably wind up tweaking a bit more later. Hugh feels that C9 and C10 on the LF100 also have a profound impact on the sound. For Trannies I used all Plitron, expensive, but they're very nice.

-West

Berndt · « **Reply #2 on:** 9 Aug 2009, 11:59 pm »

which plitron(pair) should I be looking at?
what cap values should I be looking for the ps?

AKSA · « **Reply #3 on:** 10 Aug 2009, 12:48 am »

Hi Berndt,

Thanks for visiting the Aspen forum, and for consdering the LF100. It is indeed an impressive amp, but I would urge you to own it first over a period of a month or two, and only then make changes.

This gives you a benchmark, which is very important.

Absolutely everything you change in the system has an effect, some more than others. West's suggestions about the sonicap are very good, but I would not change the power supply caps as they are Nichicon Golds, VERY good caps, premium quality, made to my order in Japan.

The Plitron to choose is their 33-0-33Vac model, rated to 300VA EACH. You need two! Visit the site and pick of the model number; I'm sorry I don't have it to hand.

Look forward to hearing from you!

Cheers,

Hugh

Berndt · « **Reply #4 on:** 10 Aug 2009, 02:31 am »

sooo, the ps caps come w/ the amp board?
I was under the impression that you needed to supply the ps parts. The only thing I need to buy besides the case and the sundry hookup jacks, binding posts and iec are the transformers?
Thanks,Bill

Berndt · « **Reply #5 on:** 10 Aug 2009, 02:47 am »

does this transformer look appropriate?
http://www.plitron.com/shopping/shopexd.asp?id=169
Thanks,Bill

AKSA · « **Reply #6 on:** 10 Aug 2009, 03:41 am »

Hi Bill (much easier to spell!),

Thanks for the reply. Yes, Product ID: 077019201 is the one, right on the money.

To confirm: all power supply parts, rectifiers, caps, custom pcb, bypasses, are supplied. You have only to supply trafos, IEC and speaker binding posts, and enclosure.

I hope to welcome you to the Aspen family soon!

Cheers,

Hugh

Berndt · « **Reply #7 on:** 10 Aug 2009, 02:15 pm »

thanks for the attention.
Everything is becoming clearer!
Keeping my fingers crossed on the amplifier sale

regards,Bill

andyr · « **Reply #8 on:** 12 Aug 2009, 09:35 am »

Quote from: Berndt on 9 Aug 2009, 06:30 am

Hi gents, as soon as my old amps sell I am going to give the Lifeforce a twirl.

I am listening to a comrade's fully modded Hafler D200 (musical concepts dual mono driver boards, dual torroids, and everything else you can do via MC).

I like the transparency of this rig and it made a ss believer out of me.

TIA,Bill

Hehe, Bill ... I'll put $10 on the table that the AKSA Lifeforce will blow the MC-tweaked Hafler D200 out of the water in both bass and treble ... and transparency/detail!

Quote from: Berndt on 9 Aug 2009, 06:30 am

The thing I miss with the hafler vs. my old amps is the bass drive. Not that the bass is soft, it is just that my old amps were exceptional in this regard.

You didn't specify your "old" amps but the bass on a LF IMO is very good. So I would expect you will not find it lacking.

Quote from: Berndt on 9 Aug 2009, 06:30 am

I'll be driving my Audio Kinesis Jazz Module speakers which are 92db efficient and have a rising impedence curve in the lower frequencies as they were designed for the 30w Atmasphere OTL amp.

So, if your speakers were designed with a 30w tube amp in mind - which LF are you considering? The 100 or the 55? I mean a 30w-into-Xohms tube amp probably sounds better when you're stressing it than a 55w ss amp ... but if your Audio Kinesis Jazz Module speakers dip down to 4ohms, a 55w LF ss amp will probably drive them better (it's 100w into 4ohms)?

So you may not need the 100w? Then again, the 100w amp has more power in reserve for transients ... which some people say requires instantaneous power delivery 100s of times the average power draw?

Maybe you should ask Hugh - or this Forum - for opinions as to which would be the better match for your speakers? In particular, I am not sure which delivers better bass?

Regards,

Andy

Berndt · « **Reply #9 on:** 12 Aug 2009, 01:26 pm »

andyr, remember you from the planar aylum, an old friend of peter gunns...
Anyways the speakers have a steady 8ohm impedance rising to 16 ohms in the lower frequencies to make them a stable load for otl tube amps.
My old amps (cross my fingers not sold yet) are jolida 211pp 200wpc triode amps.
The more I listen to this hafler the more I like it, it's become my datum. The LF55 would be just fine, just thinking of the added versatility of more power. All of the stuff I have read so far comparing the 55 to the 100 leads me to believe they are voiced similiarly, but I am more than willing to have anyone who is in the know to compare and contrast?
Are there qualities the lf55 has that the lf100 does not?

AKSA · « **Reply #10 on:** 13 Aug 2009, 04:07 am »

Hi Bill,

I agree with you that the LF55 will be best in this application; you do not need to spend the extra money for the 100W version as your speakers are easy, relatively efficient loads.

There are customers who think the LF55 has more resolution; I'm not so sure, the LF100 is outstanding in this connection too, but the difference is one of scale with large orchestras at high volume. I'd be quite happy with the LF55 in all situations in my listening room with my efficient VSonics, but as a general rule North Americans like a little more power than Aussies, so it is largely a preference.

I look forward to welcoming you to the Aspen family!

Cheers,

Hugh

VYnuhl.Addict · « **Reply #11 on:** 13 Aug 2009, 10:15 pm »

Hi Hugh, Berndt,

In some respects id agree that a 55w version would sound instantly slightly more resolving off hand, but have often found this has been at the expense of the final word in control of the Lowest End of Bass which seems to retain a slightly differenc ebalance when you weigh the two against eachother, the 100w seems more fleshed out overall..I have found massive differences between 55w and 100w even when powering drivers as small as 6.5" in control, but technically it makes much sense as when you start paralelling output devices you not only lower open loop output impedence before feedback, you also gain a signifigant increase in current linearity from already very linear devices on their own merit. The economist in me would say go for the 100w, which means even with a speaker change, upgrade, you will still have a good reserve of unfettered output drive, and with the bonus that it is more likely as the product line changes many future upgrades will be replaced with 100w modules as the low power end of things allowing easy upgrading along the way when the bug bites again

...

Hope this helps a little
Colin

RonR · « **Reply #12 on:** 14 Aug 2009, 11:54 am »

Guys,

We've seen in earlier posts that a 55W amp module can be used at lower rail voltages, mainly for tweeters in active configuration. This is reported to give a more 'refined' sound.

If parallel output devices give advantages in output impedance and linearity, but I only require 50W from the Amp, could I run the 100W amp modules at a lower voltage and still see the benefits?

Just a thought....

Ron.

andyr · « **Reply #13 on:** 15 Aug 2009, 08:45 am »

Quote from: Berndt on 12 Aug 2009, 01:26 pm

andyr, remember you from the planar aylum, an old friend of peter gunns...

The more I listen to this Hafler the more I like it, it's become my datum. The LF55 would be just fine, just thinking of the added versatility of more power. All of the stuff I have read so far comparing the 55 to the 100 leads me to believe they are voiced similiarly, but I am more than willing to have anyone who is in the know to compare and contrast?

Are there qualities the lf55 has that the lf100 does not?

Hi Bill,

Yes, I understand you "persuaded" PG to get into hardwood frame building!

As a result of his journey, I put my Maggies into hardwood frames last year!

I Googled the Hafler D200 but couldn't find its rated power? However, my understanding is ... Haflers were pretty powerful beasts? So maybe the LF100 is the one to go for? I suggest Colin's comments are on the money given your liking of your Jolida amp's bass competence. And are you going to have your 92dB-efficient speakers forever?

Regards,

Andy

lonewolfny42 · « **Reply #14 on:** 15 Aug 2009, 09:52 am »

Quote

I Googled the Hafler D200 but couldn't find its rated power?

"Hafler DH 200 amplifier. 100 watts per channel"...

Bill.... Go with the LF100...

AKSA · « **Reply #15 on:** 16 Aug 2009, 11:05 am »

Yes emphatically,

No problem at all, it's easy to configure the LF100 for lower voltage rails - easy as pie. This does indeed give impedance advantages, and in fact at least one Aspen user here has done it - PSP.

Cheers,

Hugh

Berndt · « **Reply #16 on:** 20 Aug 2009, 01:26 am »

how about this for a combination IEC/switch?
http://www.mouser.com/Search/ProductDetail.aspx?qs=1o9OSiPlHsiOOXnbybPMOA%3d%3d

RonR · « **Reply #17 on:** 20 Aug 2009, 08:24 am »

Hi Bill,

Be careful, the IEC/Switch you pointed out has internal filtering, which has a tendency to "sit on" the music somewhat when used in power amps. Better to have something unfiltered, then add something like a "Felix" if you need mains filtering later.

Cheers,

Ron.

AKSA · « **Reply #18 on:** 20 Aug 2009, 11:33 pm »

Bill,

Ron is absolutely correct. The usual inexpensive mains filters do not do that well on Class AB amps because of their very dynamic power demands. You really are better off going for a Felix, like Paul Kaplan's well explained design in the 'The Lab'.

I can vouch for Paul, too, he knows precisely what he is doing....... and I believe there was a group buy somewhere around here for pcbs for the Felix, too.

Hope this helps,

Hugh

Occam · « **Reply #19 on:** 22 Aug 2009, 01:13 am »

Hugh,

Thanks for the vote of confidence. I've had a Felix on my (your) amps ever since I got them, AKSA, Nirvana+, Lifeforce, and now the Soraya. I find them to make everything 'mo betta, and actaully increase dynamics.
Unfortuneately, the CMC I prefer on the amps is the JW Miller 8120-RC, available from Mouser, Newark, and Digikey, which is too large to fit on the group buy Felix board, but its quite easy to assemble on a perfboard.

FWIW,
Paul