(Gainclone Preamp) ACTIVE or PASSIVE ?

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Hello Guys ;) !!!

I built gainclone with two Mono LM4780.

I want the best sound quality as possible.

I don't know if I need buffered preamp or unbuffered preamp.

Why many people make gainclone with OPAMP buffer and why other use only volume attenuator ?

WHAT'S THE BEST ?!?

Thanks !!!

Nick TheVoice
 
Hi Nick

You're going to have a real hard time finding an answer to 'WHAT IS THE BEST?" because there probably isn't one.

There are lots of opinions though. Something that is important though, is the output impedance of your source, and how far it is from the amps. Is it a CD player, computer, or something analog? I suppose you need some sort of volume control? There are many options, and lots of the designs on this board are high quality. Look at the different options and their different strengths, and try and weigh your priorities
 
GAINCLONE BUFFERED or NOT ???

if I take a look at the integrated amp of audiosector unbuffered

and the original gaincard is unbuffered too !


but I don't know if the sound is great........... ;) I did not hear.

okay if I know the buffer serves to "balance input" & "gain boost" ?


P.s. The source is CD player.
 
What about noninverting GC?...

When I wrote that, I was only using IGC's, and unlike many who love to appear knowledgeable about everything, I prefer to limit my remarks to what I have actually tried myself. ;)

...Will it work better with a an active preamp or passive?

Is that a rhetorical question Peter? I can't believe you don't know the answer! :eek: The answer is of course system dependent but generally, now I have built a few NIGCs, I would say the addition of an active buffer/pre is a good thing.
 
I would try LME49710

If I want try Buffer in my gainclone. How plug it ?

Because in the diagram of national.com, I have many choice of diagram RIAA phono preamp, and other but the simple boost gain OP-AMP is not illustrated ?

I put the voltage +-15v and that's it ??? I need more parts ? resistor & capacitor, what's the value and quantity ?

P.s. I don't need phono input or other only 1 CD player input !

Thanks !

NicK
 
Hi there guys, sorry for letting you sweat this one on your own Nuuk.

I'm in Nuuks camp, IGC + active buffer brings the best out in these chips, in my opinion.

My buffer experiements included among others, a valve based cathode follower, Rod Elliots P88, and most of the buffers on Nuuks site, my favourite is the Pedja rogic jfet buffer... low parts cost and almost "blameless" sound, pure, clean and natural.

You can use the search function on the website and searh useing my nic and the search term Pedja Rogic Buffer, the thread is called pedja rogic buffer for dummies.

In there you will find an easy veroboard layout, wich has been tested and works perfectly, and is easily adjustable to cater for diffirent size caps...

It is the same schematic from Nuuk's site, just a "better" layout.

Guess you can buy all the components for the jfet buffer for less money than 2, or maybe even one opamps

It works well on a wide supply range... tested same board without modifications from 12V to 18V, and it kept on working just fine... I would say sound quality improved the higher the voltage went...

In my opinion you are going to have a hard time beating that circuit for a gainclone buffer with chips.

Like Nuuk I also preffer and limit myself to the inverted configuration, although I have tested non inverted...

Non-inverted seems to me, to give slightly better soundstage, but it doesn't have the nice "feel" to the sound that the inverted modules do. Every time I set out to build a NIGC, I went back and rebuild the thing cause I couldn't live with the sound..
 
Nordic, I hadn't seen your thread before so thanks for the heads up!

If that is a better layout, I may have to build another one for myself, although the one I am listening to right now is excellent! ;) It's one of those circuits that is so good, I will one day get round to making up a PCB for it!

Anyway, between us, we should have provided all the information needed to complete a Pedja buffer. I really think it is one of the things that is a 'must try' with a Gainclone (but I do qualify that by saying get the PSU right too)! :)
 
nickthevoice said:
I built gainclone with two Mono LM4780.

I want the best sound quality as possible.

I don't know if I need buffered preamp or unbuffered preamp.

Why many people make gainclone with OPAMP buffer and why other use only volume attenuator ?

WHAT'S THE BEST ?!?

Since he already built a GC, and I assume it is non inveritng, there is no point in discussing here the virtues of inverting topology.

If you want the best sound quality, don't use preamp.

If your source is not up to a task of driving the amp directly, install a buffer at the output of the source.
Somebody told me that simple Borberly buffer, (figure 15C) from the link: http://www.borbelyaudio.com/adobe/ae699bor.pdf works very well, better than more complicated designs, and that's what I would recommend for a start.

You will need volume control, and it's best to install it directly at the amp's input. I was running a similar setup for a while, but later switched to S&B TVC, and to me, this is the best sound so far from a GC, especially if the amp is driven in a balanced mode and TVC is inside the amp. The amp in the following link is way better than my original Inverting Amp circuit, I was beginning with.

http://www.diyaudio.com/forums/showthread.php?s=&threadid=76609&highlight=

So, getting back to to the issue of ACTIVE or PASSIVE, I would say, if everything is done right, with passive you have more chances to achieve purity of the sound, which not neccessarily means your best sound.;)
 
I also agree with Peter to some extent, on my DX HRII discrete amp, the buffer is second to just a pasive volume control....

With my myref_c I find with passive, I have better (more neutral) bass and midrange, but the higher frequency sounds just don't seem to be smooth. With a buffer it seems to smooth out the trebles a little but it is at the price of a less convinceing overall impression of realism.

So I am infact running a passive control at the moment... but, as you may know the myref is no gainclone... (SS amp being modified a the moment).

With plain gainclone configs I find the music tends to be lifeless and without impact without a buffer.

The cost of experimenting with some of the basic buffers like the rogic buffer and the one suggested by Peter is low enough to take it as a learning experience, and it may just fit your needs perfectly.
 
hi all,

I have yet to even realy start with this as a hobby.

Why does any body not ofer a kit for source switching, volume control, pree amp and buffer. if it is as simple as you are saying the kit could have more than one implementation varios stages alowing true amiters like me to build and find out what thay like or for that matter dont like.

the fact that there are kist avaloble for chip amps are what are inticing me in to this as a project and for me I would find a kit that offred this tipe of thing very useful.

blake
 
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