Revival of incredible LM3886 design

[udailey]

Dario,
Added yours to the list on the other GB thread.
Uriah

[vonfilm]

How much are the extra PCB's for those in the group buy?

[udailey]

Hi Vonfilm
Looks like, if I go with the pcb house I am considering, that the price will be about $8 each.
Uriah

[aquaman8]

Hi,

Great initiative! Well done!

Put my name in for the group buy and was wondering where the definitive list lives?

Mitch

[udailey]

Hi Mitch.
I update the list on this thread
my_ref revC group buy (Mauro Penasa LM3886 design)
Try the last page any day and usually there is an update. WE have no closed the buy but those who have ordered kits can still order extra pcbs for maybe a week or so.
Uriah

[Tony X]

"Yes I would recommend it for your system. HOWEVER if you want more bass you have to attenuate it or get a subwoofer. Meaning a preamp with controls or a powered sub. This chip is amplifying what is sent to it. So if you dont send it bass its not going to make any and if the bass on the CD isnt enough you have to have some preamp asking the amp for more bass."

Hi Uriah,

In anticipation of receiving the kit, I'll start looking for a local supplier of suitable toroids and pots. This is not so easy in France as the well known parts suppliers have prohibitive minimum order policies.

I am fairly new to the subject and have a lot to learn. I get the impression that most of the members confirming interest in this amp are going the dual mono route. Before I make my final choice:
1) can you point me to a good discussion on the relative merits of stereo vs. dual mono?
2) Is there any physical difference between the two kits?

After having read your comments on my setup (post 29 to this thread), my plan is to build and install this amp to replace the T-amp then, if necessary, look at further improvements in the following order:
a) preamp
b) woofer
c) change cd player (I yearn after a Shanling T100).

Cheers

[udailey]

Hi Tony,
Good questions to ask.
Is dual mono or stereo better? Probably that really depends on the way the music was recorded. If you google 'dual mono vs stereo' you will get thousands of answers and the first ten or so should give you a great idea as to what this really means. In the case of the group buy EVERYONE is getting dual mono. There really is no stereo. And in both scenarios for the GB dual mono vs stereo has not much to do with what we send you but more with how you package it once you get it and what you feed it as far as your source.
What I mean is that I am going to send you two boards. You can feed them each the same signal (dual mono) or you can feed them each a different signal (stereo). Your CDP is going to send stereo so you are going to have stereo.
When people talk about dual mono vs stereo on this thread really what they mean is are you going to stick two boards in one housing/chassis and power them with one single toroid, or, are you going to power them each individually and put them in separate housing/chassis. This separate housing/chassis would make them Monoblocks and thats kind of what the definition of mono is in this GB. Sorry, it gets a bit confusing since people are using it as slang.
Are there benefits to powering separately? My opinion is no but you will get other opinions. If you buy a big enough toroid it wont matter at all. But what if you buy two smaller toroids? What if you are driving the amp hard and it uses up your small toroids power supplying capabilities? What if you had a huge toroid supplying both boards and one board needed huge power while the other didnt?
So, if you can think through those questions you might come to the conclusion that they both have their merits but that in the end if you get one large transformer you will not leave either board lacking in power ever.
OH, some people will use monoblocks to remove chances of cross talk between the channels. This makes good sense and if you find a good deal on dual toroids it is a good reason to do so. However, if cost is a big deal to you, as it is for me, you might want to only have to buy one chassis and one toroid.
Some people like to build monoblock so that they can stick one amp right next to each speaker. This shortens the length of speaker wire. Therein lies another huge audiophile debate. Many people never consider that the amplified audio signal travels through hundreds of feet of speaker coil wire. Hmm.
Lots to think about. Frankly it comes down to audiophile philosophy and I would not let it worry you. Price and asthetics are my driving factors in making this choice.
NOW, There is only one kit but each kit is one channel. So for two speakers you need two kits. Two kits should be $65.
You may want to look at the specs of your subwoofer driver. What are the ohms and what is the db/spl rating. If it is 4-8ohms with a db/spl rating around 82 or more then driving it with this amp is a good idea. You could even use a lower efficiency driver but the decibels coming from it are going to be very low. 82db/spl is going to give you about a max of 100db from the driver and it wont sound good at that point. Remember for each 3db increase you double the watts needed. So on an 82db/spl driver you need 1 watt to get 82db at one meter but you need 64watts for 100db. I love efficient speakers. So, maybe you will prefer 3 kits. One to drive the sub.
If you have the ability to change tone on your preamp then you will be able to get more bass than the signal from your cd player is asking for. If you have a dedicated subwoofer output from your preamp or receiver then this will be nice for you. Otherwise you may need to build some sort of filter for the sub so that its not trying to reproduce high frequencies.
If you are adventurous and have no shame then you might want to try the very fist PS1 ever made. In the US it is model number sp1001 and it sounds wonderful as a cd player. No kidding. Seriously. It cost me 20 dollars and looks like junk but sounds like heaven.
We can go over more questions for you and sorry if I was way to long in my response.
Uriah

[carcass]

Can I stil get in??

if so, 2 Mono B's please!!!

kind regards

[udailey]

Sorry, GB is closed. Please watch the thread in case some members end up not paying.
Uriah

[carcass]

ok, will do , thanks