My "audiophile" LM3886 approach - Page 118 - 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 21st October 2005, 05:09 PM   #1171
Nordic is offline Nordic  South Africa
diyAudio Member
 
Nordic's Avatar
 
Join Date: Sep 2005
OK I'm convinced, payment done.
  Reply With Quote
Old 21st October 2005, 05:38 PM   #1172
...truth seeker...
diyAudio Member
 
Ed LaFontaine's Avatar
 
Join Date: Feb 2004
Location: where the Appalachians rise from the Blue Grass
Default hmmmmm...

Quote:
My wife listened with me. She quit doing that 10 yrs ago. I asked why she was "here", and she said she was listening. I discreetly said "WHAT!". And she replied "this sounds nice".
Maybe this work for Mongo...need spend more time with woman...better get off rear end and finish RevC...
  Reply With Quote
Old 21st October 2005, 05:49 PM   #1173
diyAudio Member
 
tommytube's Avatar
 
Join Date: Sep 2004
Location: Eastern Oregon
Default Pictures of MyRef Rev. A

http://tommytube.com.moranplanet.com/MyRef/

I've finally got my amp up and running and placed in my big rig. It's about 95% completed. You can see some pix at the above URL. It's working well and doesn't have any hum at all. Rev. A components.

My issue from a week again was a dodgy solder joint which was causing the left channel to heat up and oscillate. Finally found that and it's working fine now.

My last bit of problem was my power switch had a broken pin so I'm awaiting a new one. That's why the power is wire nutted. I also haven't punched a hole for a fuse yet...which I probably will add in so it's externally accessible.

I pretty much used the values stated on the BOM, but choose different parts since that's something I really enjoy doing. I used 15,000uF electrolytics on the power side. These are bigger than the normal 10,000 cans. To make them fit all I had to do was rotate the outside cap 180 degrees and run a jumper from the inner node to the outside pin on the cap. The advantage of this is it leaves room to run a screwdriver in to tighten/loosen the screws on the LM3886/heatsink.

The heatsink was the hardest part of the kit. Getting it tapped and placed was a challenge. I originally started using a smaller heatsink, but switched it out when they started getting really hot. I like to crank it up and wanted to have plenty of sinking for the heat.

The external cap board is for the input capacitors. I used a Rel Multicap MKP 1.0uF in parallel with a Russian teflon .1uF cap. I have tons of nice weird caps on hand, so I look for special opportunities to use them whenever I can.

I used 160VA toroids from Plitron. All wiring is cryo'ed from Cryo-parts.com...which is my favorite place for tweaky stuff. The case is a Parmetal case off Ebay painted Hammertone light green. I've installed a cryo'ed IEC connector and am using a well burned in VHAudio Flavor 4 power cord (which usually gives great low end and imagining).

If you look at the main picture of the amp, you will see three other tube amps that I frequently use....a VAC, a Mac MC240 and a ST35 dynaclone with EL84 tubes. I also have a TEAC tripath amp and a 41Hz Amp3 tripath. So my sound impressions are based on comparisons to mainly tripath SS and tube sound.

The MyRef is very clean and detailed sounding. Very punchy sound with plenty of volume. The midrange is well fleshed out with a bit of a rising top end on certain material. The bass is decent and has a bit of slam, but I'm hoping it'll develop a bit more as it settles in. It's a more up front sound than the Tripath amps I've used. The Tripath stuff is a bit more laid back and softer sounding. The MyRef is almost front hall in it's perspective. While it certainly doesn't have the warmth of an EL84, it does have a slightly warm sound and isn't sterile by any standard. Just very accurate and laid bare. Very clear window into the performance....it's accuracy is startling on certain material.

These are initial impressions and since I am a firm believer in burn in, I am expecting to get improvements over the next 100 to 200 hours. Typically I find bass to strengthen and tighten up and any rising top end/harshness to eventually even out and subside. I am very happy with this amp and am looking forward to playing the sh*t out of it all this weekend. Quite a fun project and Mauro should be commended for turning us onto his design. Also Russ thanks for doing the PCB.

I'm still undecided whether I should add in a Kookaburra pre since my VAC preamp is so fun to use.
  Reply With Quote
Old 21st October 2005, 07:40 PM   #1174
Banned
 
Join Date: Mar 2003
Location: Lisbon, Portugal
Quote:
Originally posted by Russ White
The reason is, it is easy to fool yourself with euphonics simply because you expect a change to occur. It is pure psychology.
Yeah, I'm a psycho.
Russ, you tend to treat everyone as kids, that's a very beginner mistake to make, to fool yourself because you expect a change.

Quote:
Originally posted by Russ White
If the snubbers really had any positive effect in this circuit, they would be on the PCB, at least mine.
With my permission you could use them, you didn't ask.
Not that I own anything, it's just a question of principles.
My schematics are clear, and we are just talking about this because I shared it.
You didn't build any of my last PSUs, regulated and/or unregulated, so you can't comment on that.

Just let people try it, ok?
Maybe you like a certain kind of sound, or your amp just sounds better to you that way with your source and/or speakers.
Certainly for me a 'smoother' sound than a Yamaha amp is way out of question.
  Reply With Quote
Old 21st October 2005, 07:56 PM   #1175
diyAudio Member
 
Russ White's Avatar
 
Join Date: Jan 2005
Location: Nashville, TN, USA
Send a message via Yahoo to Russ White
Hi Carlos,
Quote:
Originally posted by carlosfm

that's a very beginner mistake to make, to fool yourself because you expect a change.
It's a mistake people make all the time Carlos. Any honest person would admit that, especially when tests aren't done blind.

Quote:
Originally posted by carlosfm
tWith my permission you could use them, you didn't ask.
Not that I own anything, it's just a question of principles.
Ok that is absurd... why on earth would someone ask your permission to implement an idea that is not yours?
Quote:
Originally posted by carlosfm
You didn't build any of my last PSUs, regulated and/or unregulated, so you can't comment on that.
That is not even close to true, I very certainly have built them and even have a test rig just for that, just in case some miracle should actually happen. , and how would you assume to know what I have or have not built anyway? That is once again absurd.
Quote:
Originally posted by carlosfm
Just let people try it, ok?
I stated right off that bat that people should try whatever they like, and still hold to that. People should try whatever they like.

There is one clear problem though... You have not even tried this amp, yet you claim to know what impact your PS mods will have on it... once again absurd.

And BTW, I think most people would not think this amp is overly warm at all. Just ask Troy, Brian, Ed.., George.. Etc... Etc... Etc..

Good day to you.
__________________
Less pulp more juice Twisted Pear Audio.
  Reply With Quote
Old 21st October 2005, 08:24 PM   #1176
Banned
 
Join Date: Mar 2003
Location: Lisbon, Portugal
Quote:
Originally posted by Russ White
Hi Carlos,
It's a mistake people make all the time Carlos. Any honest person would admit that, especially when tests aren't done blind.
Blind tests, sure. That would give another debate, and I'm not in the mood.
One thing you can't accuse me is not being honest.
Unless you have something to point me.
I'm doing blind tests for more years than you know what's hi-fi.

Quote:
Originally posted by Russ White
Ok that is absurd... why on earth would someone ask your permission to implement an idea that is not yours?
Well, that clearly makes the point, who's honest.
Instead of discussing, you should accept it.
I never asked money to anyone for using my public schematics, for personal or even commercial use.
But for commercial use I like to be contacted, and I like to be given credit for my schematics.
Brian (GT) contacted me to make the snubberized PSU boards. He used a schematic of mine, and I even helped him with the PCB layout.
Money? Me? No.
Of course this is out of the question for you, because you don't understand these principles.
Mauro also didn't invent anything, so I suppose it would be ok for anyone to copy his schematics and boards and sell them, without giving any credit for him, right?

PS: some time ago you posted the values of the snubbers you tried. Now you say you tried everything.
Hey, I'm a serious man. I don't lie and I have no patience for these discussions, when they are not serious.
  Reply With Quote
Old 21st October 2005, 08:49 PM   #1177
diyAudio Member
 
BrianDonegan's Avatar
 
Join Date: Dec 2004
Location: TPA HQ (The Basement)
I'd like to sidestep the whole snubber discussion, but would like to point out to everyone that Russ and I are not doing this to make any money. Both of use are, in fact, currently carrying quite a bit of debt for the efforts.

The goal of selling stuff through the web site is to avoid the whole Group Buy affair, which is hard to manage, and leaves a lot of people out, mostly because of simple timing. We want to make the stuff we offer available on a continuing basis, so everyone can get one. (Look around the forum and see how many times you see this: "Hey, am I too late to get in on this group buy?") Half the question we field through the web site ask just that.

The downside of doing it this way is that we have to pay for lots of stuff ahead of time, and hope people buy it. There is a tiny bit of profit, maybe a couple of dollars per kit, but that is more than erased by the credit card interest and many many hours that go in to getting everything ordered, packaged, discribed, shipped, supported, etc. I think the yearly fee for the web site alone probably erases any profit. Total up the parts in the kits and compare to how much they cost if you were to buy them. Not much difference, if any. I work a after hours contract job to get the money to front for all the parts.

Don't get me wrong, I am doing this because I enjoy it, but it's a mountain of work. The more popular it is, the more work.

The good part? Why are we doing it? Well, we get to design stuff, play with it, and share it. We have a great amp, a great preamp, and soon a great source selector. you can make your own boards, or get ours, buy your own parts, or get ours (well, the source selector pretty much has to be a double-sided board, unless it's really big, so that might be tougher, but we will share the schematic for it).

Sorry for the rant, just wanted to chime in about the "commercial profit" stuff.
__________________
Twisted Pear Audio
  Reply With Quote
Old 21st October 2005, 08:56 PM   #1178
Banned
 
Join Date: Mar 2003
Location: Lisbon, Portugal
Quote:
Originally posted by BrianDonegan
I'd like to sidestep the whole snubber discussion
I agree, just forget about the snubber, move on.
I suggest the unfortunate member that used 15,000uf caps and reported his honest results (what proves that he's not biased with the new amp just because he's changing something on his system) to contact me personally and I'll try to help.
Also the LM318 op-amp PSU bypass, etc.
  Reply With Quote
Old 21st October 2005, 09:03 PM   #1179
Nordic is offline Nordic  South Africa
diyAudio Member
 
Nordic's Avatar
 
Join Date: Sep 2005
Well I think everyone should be thanked for their contributions, I have ordered my Rev C boards, but I also went to go and buy components to try the Carlos version for educational value, and so that I don't have to rely on theory and say so, but rather practical experience. Unfortunately I got some new games today so soldering is out of the question.....maybe tommorrow
  Reply With Quote
Old 21st October 2005, 09:05 PM   #1180
diyAudio Member
 
BrianDonegan's Avatar
 
Join Date: Dec 2004
Location: TPA HQ (The Basement)
Sorry, when I said I want to sidestep it, I just meant I have no comment.
__________________
Twisted Pear Audio
  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



New To Site? Need Help?

All times are GMT. The time now is 06:03 AM.


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