Mauro Penasa MyRef vs simple LM3886 circuit - Page 3 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 16th May 2012, 04:14 PM   #21
Reality first!
diyAudio Member
 
ClaveFremen's Avatar
 
Join Date: May 2005
Location: Milan, Italy
Quote:
Originally Posted by AndrewT View Post
Clave,
thanks for that summary and the specific answers.
You're welcome Andrew.

Quote:
Originally Posted by AndrewT View Post
I found that summary quite revealing and not what I understood from reading all your Threads & posts on the various 3886 implementations.
I know that my enthusiasm on component selection, materials, and so on can sound silly/naive/irritating to more technically prepared people like you but, although in a different field (computer science), I'm a tech too with a technical diploma.

Maybe that enthusiasm can be, sometimes, misleading.
__________________
Dario
ClaveFremen "Bailando Salsa en el Sietch"
  Reply With Quote
Old 16th May 2012, 05:28 PM   #22
bcmbob is offline bcmbob  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Bay City, Michigan
Hi Andrew, as noted - Dario hit all the significant technical points. My purchase path/history matches the progression of the improvements due to revisions and developments for the LM3886 family.

Since the introduction of each concept/version/flavor, developers and experimenters have contributed upgrade paths that have proven to be quite useful and effective. The BrianGT stands somewhat separated, as it has no reference to anything "MyRef". I have made no changes to the original parts on the kit other than Uriah's Resistor Replacer. That device significantly cleans and warms the signal to the point I would recommend it as a "Must" for that amp. I also built two BPA-150s for use with 4 ohm speakers but that project is sitting on the shelf. Those and the BrianGTs could well be all that's desired for those wanting excellent sound and have not been sucked into the quest for "Audiophile Nirvana"

For the MyRef family there are a few universal items that produce dramatic improvements:

1. Mundorf AG caps for C3 & C8 - everything from the mids down gains power, depth, punch and control.
2. C9 - Black Gates I believe are the acknowledged best choice, but are difficult to find and the price can be dumb high. In any case that position is critical for clarity and stage.
3. C13 - same as above in importance but can be more easily chosen to match a user's preferences and system.

The singular standout for all MyRefs, up to the FE and even for stock builds, is Siva's LF01 module. When it is added a whole new amp appears - warm, clean, smooth and inviting.

Though I thought I might be spinning my wheels a bit, I purposely decided to build the Fremen Edition from the stock Mouser BOM Dario provided. In truth (a little confession is good for the soul) I held back in reporting how good the FE sounded because I didn't want to sound hyperbolic. It's ironic that you ask this question today - cause yesterday was the first time I chose to use the phrase that came to mind when I first powered up the amps on really good speakers - "a quantum step". I did, in fact use that phrase in a PM to Tom E. several months ago.

I never thought I would be doing things like using sockets for swapping resistors and caps, or going so far as reversing polarities for components - but as I follow the designer's lead, the benefits have been born out. I am confident that when a few more people build the FE and report what they hear, the idea of a big step forward in top end DIY audio will be confirmed.
__________________
Bob M.
"Arrange Whatever Pieces Come Your Way."

Last edited by bcmbob; 16th May 2012 at 05:39 PM.
  Reply With Quote
Old 16th May 2012, 06:29 PM   #23
bcmbob is offline bcmbob  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Bay City, Michigan
Sorry, I forgot to add the alternate compensation discussed on the "Audiophile Approach" thread. It should be number 4 on the universal list. It produces a very "Tube like" effect, meaning softer and smoother without diminishing the clarity, depth and sparkle.
__________________
Bob M.
"Arrange Whatever Pieces Come Your Way."

Last edited by bcmbob; 16th May 2012 at 06:32 PM.
  Reply With Quote
Old 16th May 2012, 07:12 PM   #24
Reality first!
diyAudio Member
 
ClaveFremen's Avatar
 
Join Date: May 2005
Location: Milan, Italy
Bob, you're embarassing...

I'm also enthusiast on the FE but I wouldn't use the sentence 'big step forward in top end DIY audio'... a bit hyperbolic
__________________
Dario
ClaveFremen "Bailando Salsa en el Sietch"
  Reply With Quote
Old 16th May 2012, 07:30 PM   #25
bcmbob is offline bcmbob  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Bay City, Michigan
I would, and I did - let's see what the coming reviews form future builders say
__________________
Bob M.
"Arrange Whatever Pieces Come Your Way."

Last edited by bcmbob; 16th May 2012 at 07:37 PM.
  Reply With Quote
Old 17th May 2012, 02:50 PM   #26
hurtz is offline hurtz  Germany
diyAudio Member
 
Join Date: Jun 2010
Were any measurements taken to see if the whole tightness and punching isn't just purely subjective?

cheers!
hurtz
  Reply With Quote
Old 17th May 2012, 03:06 PM   #27
Reality first!
diyAudio Member
 
ClaveFremen's Avatar
 
Join Date: May 2005
Location: Milan, Italy
Quote:
Originally Posted by hurtz View Post
Were any measurements taken to see if the whole tightness and punching isn't just purely subjective?
Hi Hurtz,

sadly no measures, I don't have the necessary equiment.

But subjectively the differenceis is obvious, we're not talking about nuances.
__________________
Dario
ClaveFremen "Bailando Salsa en el Sietch"
  Reply With Quote
Old 17th May 2012, 03:57 PM   #28
hurtz is offline hurtz  Germany
diyAudio Member
 
Join Date: Jun 2010
Hmm too bad, would really interest me.

Although I'm a little bit suprised that so few people have/use measurement equipment, considering the amount of interchangeable parts I wouldn't trust my judgement after the third "revision".

Could you just do some simple rmaa measurements? I'd really like to know how it compares to my lm3886 concerning IMD and noise.

cheers!
hurtz
  Reply With Quote
Old 17th May 2012, 04:01 PM   #29
bcmbob is offline bcmbob  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Bay City, Michigan
Same here hurtz,

All I own is a Radio Shack sound level meter that just gives general SPL readings. However, in the list of options I gave please not the indication of "dramatic" relating to those four. They are not just my opinions but reflect a compilation of reports/agreements across several LM3886/MyRef threads on the forum.

There are a number of things like wire composition, connector styles/brand, interconnect length and so forth that I would consider "tweaks". I tried to avoid those and give a summary of what are honestly considered to be upgrades.

If you can describe the measurements you are seeking, we might be able to point you to some relevant posts already on the threads.

I am actively searching for an affordable PC based diagnostics tool that will give usable information. If you you are aware of such please pass along the info. That would be both helpful and a lot of fun.
__________________
Bob M.
"Arrange Whatever Pieces Come Your Way."

Last edited by bcmbob; 17th May 2012 at 04:08 PM.
  Reply With Quote
Old 17th May 2012, 05:24 PM   #30
hurtz is offline hurtz  Germany
diyAudio Member
 
Join Date: Jun 2010
Hi bcmbob!

Since sound quality is so highly subjective I try to concentrate on a technically perfect build, whatever improvements in listening quality may come with it ;-)

So I am naturally keen on measuring those differences, to not at last, get a better price/value ratio.

I would think of rightmark audio analyser at first, http://audio.rightmark.org/ its a free tool to measure THD, noise, IMD, crosstalk and some more using a pc sound card. Some time ago I used an asus xonar d2x which has excellent noise and dynamics rating. It goes for around 130€.
A cheaper and most probably still sufficient alternative would be the asus xonar DX around 65€.
I also heard that the auzentech soundcards perform equally well and are a bit cheaper at that, but I never had one of those.

The method of testing is quite simple, rmaa will play a series of different test tones, record the resulting wave-file and afterward analyse it.
Now to measure you connect the line-out from the soundcard to the line-in of the amp, and the power-out via a voltage divider (or much better/safer opamp) to the line-in of the soundcard. Take good care when using a simple voltage divider and triple check that all cables are what they pretend to be... I killed one of my line-in channels of my d2x...

If you google "asus xonar d2x rmaa" the second link will give you a pdf with a good guide on how to do the loop-back test. For any further questions, don't hesitate to ask!

cheers,
hurtz!
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mauro Penasa MyRef RevC GainClone Mono Blocks apoopoo999 Swap Meet 6 29th July 2011 04:27 AM
my_ref revC group buy (Mauro Penasa LM3886 design) schro20 Group Buys 650 17th October 2010 11:42 PM
Evolution Amplifier by Mauro Penasa Panelhead Chip Amps 14 22nd July 2010 09:56 AM
WTB: Mauro Penasa Ref C marginwalker Swap Meet 0 13th October 2007 05:28 PM
MY_REF EVOLUTION by MAURO PENASA goldkenn Chip Amps 8 25th September 2007 04:50 PM


New To Site? Need Help?

All times are GMT. The time now is 07:25 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2