My "audiophile" LM3886 approach

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#1,902
A NE5532 will not work seeing that it is a dual opamp. A NE5534 will work and it does have the compensation/balance pins but the circuit is not optimised for it, I have used it without any ill effect, but the possibility for oscillation does exist
 
#1,903
Learned today that the little REV C doesn't like driving just any load... had a visit at one of our forum member's homes... wow never seen such thick speaker cables... anyhow we did some A/B comparisons using my REV C and his mix and match setup....with very nice DIY Seas drivers...about 6ohm impedance

The rev C lost by an emabrasing margin in musicality, bass drive and power. OK the other amp (hybrid valve-solidstate) had about 3 times the power, but even at lower volume levels, the REV C was like listening to the DIET version of the song... Coke Light!!!

The C didn't have anything rudely wrong with the sound, and does not get irritating, it just lacks musicality and bass.

And Wills' speakers can do 20 Hz, shakeing like mad, without you hearing anything.

I have yet to get Rudi out of holiday mode so I can do the X-cal, but I'm afraid my REV C simply can't be left this way, right now I am so desperate I am considering $30 beeswax input caps, or a blowtorch, whichever I can get my hands on first actualy.

If I didn't have much drive to improve on my setup, today was most educational, and most and encourageing.

Also the amp had quite a bit of distortion it doesn't normaly have at high volume...
 
#1,904
I used the REV_C on the Madisound Thor kit. It was NOT a good match.

I have used the REV_C on B&W remakes(Hi-Vi drivers), and Vifa 7" 2-way with 1" silk dome tweeters and that sounded VERY good.

I think the Rev_C just might not like the low impedance. Just a guess.

It is still currently my favorite amp though.
 
#1,906
Nordic, sounds like he has speakers which need much more power than MyRef can deliver. Without more details its hard to say what exactly was wrong with the combo, but does not sound like a situation where you would use an amp like MyRef (any revision). This is a limitation of the LM3886 and the circuit, it would not matter which PCB,rectifier,PS, etc.. you used.
 
#1,908
The RevC is very good but its still only a budget amp, its hardly fair to expect it to beat every other diy or commercial amp

I recently built up a pair of the Hypex UCD amps to add to my collection, comparing these against my RevC was interesting🙂
 
#1,910
Nordic said:
The question is, is it ultimatley posible to build such a beat all class amp from the National Overture series?
Click to expand...

Well I've built more than a few amps using this chipamp, some better than others
Regarding building something that could beat all other class amps ,If I'm totally honest and this is only MY opinion, I doubt it
They do offer excellent value for money though and most of my other none chip based amps cost more
It probably comes down to personnel taste too, thats the main reason I'll always build something before ever giving opinions on it
 
#1,912
Nordic said:
"thats the main reason I'll always build something before ever giving opinions on it" and even that sometimes doesn't work we have learned here....

Anyway thanks for the advice, I know Rudi always takes your opinion in high esteem.
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No probs and thanks!

There have been amps I have built in the past which I thought I wouldn't like but tried them anyway, its all part of the fun really and is the only way to know for sure🙂

I don't like to cause arguments, I can't see any point in it, the only thing that interests me is to get the best sound to my ears and something that does not cost a fortune to build
I did actually build the RevC using all the standard parts to start with, the sound was ok but the addition of the other changes components etc worked better for me
No doubt the standard RevC is more than good enough for others and thats all that matters😉
 
#1,913
T., Which PCB did you use? I was not aware if you built the monoblocs which I layed out. There are some significant differences between that and Rudi's. Not that either is better, but they may indeed sound different.

It can be confusing to those reading the posts if they do not know which amp you built.

One thing to note, quite a lot has happened off the forum, including a new My_Ref Rev. C version 1.1 based on new input from Mauro which has led to a few small tweaks for the PS (discrete rectifier diodes) and the input cap.

If there is interest I will share it.

Cheers and happy new year!
Russ
 
#1,914
Russ White said:
T., Which PCB did you use? I was not aware if you built the monoblocs which I layed out. There are some significant differences between that and Rudi's. Not that either is better, but they may indeed sound different.

It can be confusing to those reading the posts if they do not know which amp you built.

One thing to note, quite a lot has happened off the forum, including a new My_Ref Rev. C version 1.1 based on new input from Mauro which has led to a few small tweaks for the PS (discrete rectifier diodes) and the input cap.

If there is interest I will share it.

Cheers and happy new year!
Russ
Click to expand...

since I've built the REV A prototype and sounds great, I will make 3 more PCB's. I'm interested. If I will build more amps, the lastest version is what I want.

Thanks!!!!
Jorge.
 
#1,915
Russ White said:
T., Which PCB did you use? I was not aware if you built the monoblocs which I layed out. There are some significant differences between that and Rudi's. Not that either is better, but they may indeed sound different.

It can be confusing to those reading the posts if they do not know which amp you built.

One thing to note, quite a lot has happened off the forum, including a new My_Ref Rev. C version 1.1 based on new input from Mauro which has led to a few small tweaks for the PS (discrete rectifier diodes) and the input cap.

If there is interest I will share it.

Cheers and happy new year!
Russ
Click to expand...

Hi Russ,

I actually etched Rudi's mainly because of the dual rectifiers which would allow me to upgrade later although I first used standard parts as recommended on here, I also did not fit that resistor to the LM318 to start with so to keep everything as close to the original as I could, I then started to try different parts.
Your board may sound different to Rudi's but would there be such a big difference?
I've already tried a lot of mods,component changes etc including disconnecting all the psu and trying something else, I just stuck to what ever sounded best in my set up
No doubt all the parts I use would not suit everyone including the choice of rectifier diodes or coupling caps etc
I still have Rudi's new board to try too, I'm not sure how its going to compare against this RevC setup I have settled on but like everything else, I'll try it out because I promised a while ago I would
The RevC is still good but please do remember this is not the only amp I have built,infact I now have around several different diy amps to compare it against🙂
 
#1,916
V. 1.1

Monobloc MyRef Version 1.1 🙂 Still a work in progress, but coming along nicely.
 

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#1,919
t. said:


Hi Russ,

I actually etched Rudi's

Your board may sound different to Rudi's but would there be such a big difference?
Click to expand...

Absolutely there could be an appreciable difference, a layout indeed can make or break any circuit. In this case I seriously doubt the difference is huge, maybe not even detectable, but one would have to build both with the same parts and everything else being equal to know.

My only goal was to have people know which is which, since clearly the comparisons are not apples to apples.

Cheers!
Russ
 
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