Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Login


Options
View
Go to last post Go to first unread
nvrgdenuf  
#1 Posted : Monday, February 19, 2007 9:10:39 PM(UTC)
nvrgdenuf

Rank: Member

Groups: Member
Joined: 2/19/2007(UTC)
Posts: 1
Location: Arizona

Will the power supply that comes with the LM3886 kit be sufficient to
run 5 amps in the single ended mode? I want a 5 channel amp in one box.
If so, what toroidal should I use? Voltage? VA? 25+25 650va?
Brian I see you answered a post about the REV C having a better sound
quality than the LM3886, why is this? Would I be better off with 5 of
those? These are to run 98db efficient Hawthorne Audio 15" coaxial
speakers in an H/T environment, with a Creative Labs X-Fi platinum as
the preamp.They roll off quickly below 50hz so no low bass necessary. I want to order the rest and need some clarification.
thanks,
Russ White  
#2 Posted : Tuesday, February 20, 2007 6:02:04 AM(UTC)
Russ White

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN

Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
Hi,

I would not say either amp is "better" then the other. I think Brian was trying to convey that the RevC does have lower distortion and better phase coherence then a "plain" vanilla chip amp (which a standalone TPM would be). That said some may prefer the sound of the chip amp, and many chip amps have been built and highly rated. You have to look at your goals. You could fit more TPMs into a small space then you can RevCs if you share a power supply(or more then one).

Each TXPS is capable of delivering 10A or so. So you would need to figure out how much current your amplifiers will draw on average. It is likely you could indeed power 5 TPM modules from a single PS in your case.

Now back to comparisions:

1) Rev C is current pump in the feedback loop of a LM318, The LM318 dominates the sound character of the amp.
2) TPM-LM3886 alone is an ordinary non-inverting voltage feedback power opamp with optional servo(very handy) and feedback cap (some like this option) so it sound is characterized by the LM3886 itself, which is no slouch.
3) TXO-2/TXO-2 are fully symmetrical power amplifiers where a TXD(THS4131) is the "master" loop. The sound is characterized by that opamp. This amp is not even in the same league as either of the previous two. THD is dramatically lower (early tests indicate < .0005%) and damping factor is very high (better control over the speaker). Damping factor is one area where the RevC is actually not great, so it does not suit all speakers equally well.

So in short, each amp has features to recommend it.

Cheers!
Russ

Edited by user Tuesday, February 20, 2007 6:03:46 AM(UTC)  | Reason: Not specified

Russ White  
#3 Posted : Tuesday, February 20, 2007 6:10:07 AM(UTC)
Russ White

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN

Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
I forgot to mention that should you use TPMs one PS with a 650VA transformer is probably just fine. 800VA to 1KVA would give you a bit more headroom but then you may need to substitute some parts(not sure yet) to handle the higher current. I would check the current rating on the bridge for instance.

Cheers!
Russ
Rss Feed  Atom Feed
Users browsing this topic
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.